Feline emergency & critical care medicine by Grupo Asís

Christopher G. Byers Massimo Giunti

FELINE EMERGENCY & CRITICAL CARE MEDICINE

Christopher G. Byers Massimo Giunti

FELINE EMERGENCY & CRITICAL CARE MEDICINE

Book Publishing Manager: Costanza Smeraldi Paper, Printing and Binding Manager: Paolo Ficicchia Cover and Layout: T&T Studio, Milano, Italy Copyediting: Mercedes González Fernández de Castro – Science & Health Publications Scientific consultant: Enrico Febbo

The rights of translation, electronic storage, reproduction or total or partial adaptation by any means (including microfilms and photostatic copies), are reserved for all countries. Photocopies for personal use of the reader can be made within the limits of 15% of each volume upon payment to the SIAE of the compensation provided by the art. 68, paragraphs 4 and 5, of the law of 22 April 1941 n. 633. Photocopies made for professional, economic or commercial purposes or for any use other than personal use can be made following a specific authorization issued by CLEARedi, Licensing and Authorization Center for Editorial Reproductions, Corso di Porta Romana 108, 20122 Milan, e-mail permissions@clearedi.org and website www.clearedi.org. Knowledge and best practice in this field are constantly changing: As new research and experience broaden our knowledge, changes in practice, treatment, and drug therapy may become necessary or appropriate. Readers are advised to check the most current information provided (i) or procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of the practitioners, relying on their own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the Editors assume any liability for any injury and/ or damage to persons or property arising out of or related to any use of the material contained in this book. This publication contains the author’s opinions and is intended to provide precise and accurate information. The processing of the texts, even if taken care of with scrupulous attention, cannot entail specific responsibilities for the author and / or the publisher for any errors or inaccuracies. The Publisher has made every effort to obtain and cite the exact sources of the illustrations. If in some cases he has not been able to find the right holders, he is available to remedy any inadvertent omissions or errors in the references cited. All registered trademarks mentioned belong to their legitimate owners.

Edra S.p.A. Via G. Spadolini 7, 20141 Milano (Italy) Tel. 02 881841 www.edizioniedra.it Printed by “Printer Trento” S.r.l., Trento (Italy), September 2021

(*) Edra S.p.A. is a part of

Editors Dr. Christopher G. Byers DVM, Dipl. ACVECC, Dipl. ACVIM (SAIM), CVJ He is a practicing board-certified veterinary emergency & critical care and small animal internal medicine specialist, as well as a certified veterinary journalist, based in Omaha, Nebraska. He received his Bachelor of Science degree as University Honors Scholar in Animal Sciences from Colorado State University and his Doctor of Veterinary Medicine from Cornell University. Dr. Byers’ professional passions are mentoring and coaching veterinary students and colleagues in the areas of emergency & critical care, internal medicine, and communication skills. He is the Co-Editor of the textbook, Feline Emergency & Critical Care Medicine, and has published chapters and articles in numerous textbooks and peer-reviewed medical journals. Dr. Byers also publishes a weekly blog called CriticalCareDVM.com with goals to educate pet owners and promote the triad of care.

Dr. Massimo Giunti DVM, PhD, Dipl. ECVECC

He is a practicing board-certified and European Veterinary Specialist™ in Emergency and Critical Care. He is associate professor and Head of the small animal emergency and critical care unit of the veterinary university hospital of the Alma Mater Studiorum - University of Bologna (Italy). He received both his degree in veterinary medicine and his Ph.D. degree in veterinary science from the same university. His main research activity focuses on biomarkers of critical illness in small animals. He is the Co-Editor of the textbook, Feline Emergency & Critical Care Medicine, and author and co-author of several papers in the field of veterinary emergency and critical care medicine in peer-reviewed journals.

VII

Section Editors Stefano Cortellini

DMV, MVetMed, Dipl. ACVECC, Dipl. ECVECC Clinical Science and Services Department The Royal Veterinary College Hatfield, United Kingdom

Gualtiero Gandini DVM, PhD, Dipl. ECVN

Department of Veterinary Medical Sciences Alma Mater Studiorum University of Bologna Ozzano Emilia (BO), Italy

Kris Gommeren

DVM, MSc, PhD, Dipl. ECVIM-CA (Internal Medicine), Dipl. ECVECC Department of Companion Animal Clinical Sciences University of Liège – Liège, Belgium

Kelly E. Hall

DVM, MS, Dipl. ACVECC Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Sabrina N. Hoehne

Dr. med. vet., Dipl. ACVECC, Dipl. ECVECC Department of Veterinary Clinical Sciences, Division of Small Animal Emergency and Critical Care Washington State University Pullman, Washington (USA)

Patty A. Lathan

MS, VMD, Dipl. ACVIM (SAIM) College of Veterinary Medicine, Department of Clinical Sciences Mississippi State University Starkville, Mississippi (USA)

Céline Pouzot-Nevoret DVM, PhD, Dipl. ECVECC

Intensive Care Unit – SIAMU VetAgro Sup Campus Vétérinaire de Lyon Marcy l’Etoile, France

Lisa L. Powell

DVM, Dipl. ACVECC BluePearl Veterinary Partners Eden Prairie, Minnesota (USA)

Contributors Sophie Adamantos, BVSc, CertVA, Dipl. ACVECC, Dipl. ECVECC, MRCVS, FHEA

Paragon Veterinary Referrals Wakefield, United Kingdom

Ashley P. Anderson, DVM College of Veterinary Medicine University of Missouri Columbia, Missouri (USA)

Lillian R Aronson, VMD, Dipl. ACVS Department of Clinical Sciences and Advanced Medicine – University of Pennsylvania Philadelphia, Pennsylvania (USA)

Andrea Balboni, DVM, PhD Department of Veterinary Medical Sciences Alma Mater Studiorum - University of Bologna Ozzano Emilia (BO), Italy

Anthony Barthélemy, DMV, MS, PhD Emergency and Intensive Care Unit Centre Hospitalier Vétérinaire HOPia Guyancourt, France

Mara Battilani, DVM, PhD Department of Veterinary Medical Sciences Alma Mater Studiorum - University of Bologna Ozzano Emilia (BO), Italy

Ludivine Boiron, DVM, Dipl. ACVECC, MRCVS Centre Hospitalier Languedocia Montpellier, France

Luis Bosch, LV, MSc, Dipl. ACVECC, Dipl. ECVECC Fundació Hospital Clinic Veterinari Universitat Autònoma de Barcelona Barcelona, Spain

Juliette Bouillon, DMV, MVSc, Dipl. ACVIM School of Veterinary Medicine Ross University Basseterre, St. Kitts, West Indies

Tomas Boullhesen Williams, DVM College of Veterinary Medicine Cornell University Ithaca, New York (USA)

Christina Bové, DVM, MS, Dipl. ACVIM (Cardiology) Four Seasons Veterinary Specialists Loveland, Colorado (USA)

Søren Boysen, DVM, Dipl. ACVECC Department of Veterinary Clinical and Diagnostic Sciences University of Calgary Calgary, Alberta (Canada)

Angela Briganti, DVM, PhD Department of Veterinary Sciences University of Pisa Pisa, Italy

Yaron Bruchim, DVM, Dipl. ECVECC, Dipl. ACVECC Koret School of Veterinary Medicine Hebrew University of Jerusalem Rehovot, Israel

Maxime Cambournac, DVM, Dipl. ECVECC Service d’Urgence, Réanimation et Soins-Intensifs Centre Hospitalier Vétérinaire Fregis, Arcueil, France

Amanda A. Cavanagh, DVM, Dipl. ACVECC Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Nolan V. Chalifoux, DVM Department of Clinical Sciences and Advanced Medicine University of Pennsylvania Philadelphia, Pennsylvania (USA)

Leah A. Cohn, DVM, PhD, Dipl. ACVIM (SAIM) Department of Veterinary Medicine and Surgery University of Missouri Columbia, Missouri (USA)

Laura Cole, MA VetMB, MVetMed, CertVPS, CertAVP (ECC), Dipl. ACVECC, Dipl. ECVECC

Clinical Science and Services Department The Royal Veterinary College Hatfield, United Kingdom

Julie Combet-Curt, DMV, MSc Intensive Care Unit – SIAMU VetAgro Sup Campus Vétérinaire de Lyon Marcy l’Etoile, France

Crystal M. Cooley, DVM, MS, Residency Trained in Small Animal Internal Medicine

VCA Midwest Veterinary Referral and Emergency Center Omaha, Nebraska (USA)

XII Contributors

Amy E. DeClue, DVM, MS, Dipl. ACVIM (SAIM) College of Veterinary Medicine University of Missouri Columbia, Missouri (USA)

Armelle deLaforcade, DVM, Dipl. ACVECC Cummings School of Veterinary Medicine Tufts University North Grafton, Massachusetts (USA)

Nausikaa Devriendt, DVM, Dipl. EVCS Faculty of Veterinary Medicine, Small Animal Department Ghent University Merelbeke, Belgium

Elizabeth B. Davidow, DVM, Dipl. ACVECC Department of Veterinary Clinical Sciences Washington State University Pullman, Washington (USA)

Lindsey Dodd, BSc (Hons), VPAC, VTS (ECC), HE FHEA RVN Lumbry Park Veterinary Specialists Alton, Hampshire, United Kingdom

Francesco Dondi, DVM, PhD Department of Veterinary Medical Sciences Alma Mater Studiorum - University of Bologna Ozzano Emilia (BO), Italy

Christiana Fischer, VMD School of Veterinary Medicine University of Pennsylvania Philadelphia, Pennsylvania (USA)

Jessica A. Florey, BVM&S, MVetMed, Dipl. ACVIM (SAIM), Dipl. ECVIM-CA (Internal Medicine), MRCVS Dick White Referrals Six Mile Bottom, Cambridge, UK

Thierry Francey, DMV, DACVIM (SAIM), DECVIM-CA

(Internal Medicine)

Department of Clinical Veterinary Medicine University of Bern Bern, Switzerland

Teresa Gagliardo, DVM, PhD Diagnostic Veterinary Center PalermoVet Palermo, Italy

Sara Galac, DVM, PhD Faculty of Veterinary Medicine, Department of Clinical Sciences Utrecht University Utrecht, The Netherlands

Antonella Gallucci, DVM, PhD, Dipl. ECVN La Fenice Veterinary Center Neurology Service Cagliari, Italy

Katherine K. Gerken, DVM, MS, Dipl. ACVECC College of Veterinary Medicine, Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Suzanne Gray, BSc(Hons), BVetMed(Hons), MFA, Dipl. ACVIM (SAIM)

San Diego, California (USA)

Julien Guillaumin, Docteur Veterinaire, Dipl. ACVECC, Dipl. ECVECC

Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Simon P. Hagley, BVSc, Dipl. ACVECC Vets Now Referrals, Manchester Hospital Department of Small Animal Emergency and Critical Care Manchester, United Kingdom

Andrew S. Hanzlicek, DVM, MS, Dipl. ACVIM (SAIM) MiraVista Diagnostics Indianapolis, Indiana (USA)

Stephanie A. Harris, DVM College of Veterinary Medicine, Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Andrea Henriksson, DVM Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Guillaume L. Hoareau, Dr. Vét., PhD, Dipl. ACVECC, Dipl. ECVECC

Department of Surgery, Division of Emergency Medicine University of Utah Salt Lake City, Utah (USA)

Karen Humm, MA, VetMB, Msc, CertVA, DACVECC, DECVECC, FHEA, MRCVS Clinical Science and Services Department The Royal Veterinary College Hatfield, United Kingdom

Danielle M. Hundley, DVM, MS, Dipl. ACVECC VCA Midwest Veterinary Referral & Emergency Center Omaha, Nebraska (USA)

Aime K. Johnson, DVM, DACT Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Marta E. Kantyka, Dr. med. vet., DVM, ECVAA

residency trained

Department of Clinical Veterinary Medicine, Division of Anesthesiology and Pain Therapy University of Bern Bern, Switzerland

Christopher R. Kennedy, DVM, Dipl. ACVECC Department of Companion Animal Clinical Sciences University of Liège – Liège, Belgium

Mark W. Kim BVSc MVSc Dipl. ACVECC Intensive Care Unit – SIAMU VetAgro Sup Campus Vétérinaire de Lyon Marcy l’Etoile, France

Contributors XIII

Barbara E. Kitchell, DVM, PhD, Dipl. ACVIM (SAIM, Oncology)

VCA Veterinary Referral Center Albuquerque, New Mexico (USA)

Hans S. Kooistra, DVM, PhD, Dipl. ECVIM-CA (Internal Medicine)

Faculty of Veterinary Medicine, Department of Clinical Sciences Utrecht University Utrecht, The Netherlands

Kendon W. Kuo, DVM, MS, Dipl. ACVECC College of Veterinary Medicine, Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Dana N. LeVine, DVM, PhD, Dipl. ACVIM (SAIM) Department of Veterinary Clinical Sciences Iowa State University Ames, Iowa (USA)

Jennifer Loewen, DVM, Dipl. ACVECC Western College of Veterinary Medicine, Department of Small Animal Clinical Sciences University of Saskatchewan Saskatoon, Saskatchewan (Canada)

Whitney M. Long, DVM, Dipl. ACVECC Nashville Veterinary Specialists Nashville, Tennessee (USA)

Catriona M. MacPhail, DVM, PhD, Dipl. ACVS Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Sarah J. Marvel, DVM, MS, Dipl. ACVS-SA Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Anna M Massie, DVM, Dipl. ACVS-SA Department of Clinical Sciences and Advanced Medicine University of Pennsylvania Philadelphia, Pennsylvania (USA)

Allison Mazepa DVM, Dipl. ACVIM (SAIM) BluePearl Veterinary Partners Eden Prairie, Minnesota (USA)

Maureen A. McMichael, DVM, M.Ed., Dipl. ACVECC Department of Clinical Sciences Auburn University Auburn, Alabama (USA)

Julie Menard, DVM, Dipl. ACVECC Department of Veterinary Clinical and Diagnostic Sciences University of Calgary Calgary, Alberta (Canada)

Carla Molina, DVM, ECVECC Resident Fundació Hospital Clinic Veterinari Universitat Autònoma de Barcelona Barcelona, Spain

Joanna E. Murdoch, DVM Department of Small Animal Medicine and Surgery University of Georgia Athens, Georgia (USA)

Alexandra Nectoux, DVM, MSc Intensive Care Unit – SIAMU VetAgro Sup Campus Vétérinaire de Lyon Marcy l’Etoile, France

Ran Nivy, DVM, Dipl. ECVIM-CA (Internal Medicine) Koret School of Veterinary Medicine Hebrew University of Jerusalem Rehovot, Israel

Stéphanie M.P. Noël, DVM, PhD, Dipl. ECVS Clinique Vétérinaire Universitaire University of Liège Liège, Belgium

Mariana A. Pardo, BVSc, MV, Dipl. ACVECC Veterinary Medical Center of Long Island West Islip, New York (USA)

Rodrigo Pinheiro de Lacerda, DVM, Dipl. ECVO, MRCVS Willows Veterinary Centre & Referral Service West Midlands, United Kingdom

Carlos Pizarro, LV, MSc, Resident ECVECC Fundació Hospital Clinic Veterinari Universitat Autònoma de Barcelona Barcelona, Spain

Erica L. Reineke, VMD, Dipl. ACVECC Department of Clinical Sciences and Advanced Medicine University of Pennsylvania Philadelphia, Pennsylvania (USA)

Joris H. Robben, PhD, Dipl. ECVECC, Dipl. ECVIM-CA (Internal Medicine)

Department Clinical Sciences Section of Emergency and Intensive Care Utrecht University Utrecht, The Netherlands

Elizabeth A. Rozanski, DVM, Dipl. ACVIM (SAIM), Dipl. ACVECC

Cummings School of Veterinary Medicine Tufts University North Grafton, Massachusetts (USA)

Renee Rucinsky, DVM, Dipl. ABVP (Feline) Mid Atlantic Cat Hospital Mid Atlantic Feline Thyroid Center Queenstown, Maryland (USA)

Laurence M. Saint-Pierre, Dr. Vét Emergency and Critical Care Department University of California Davis Davis, California (USA)

Ariane Schweighauser, DVM, Dipl. ACVIM (SAIM), Dipl. ECVIM-CA (Internal Medicine) Department of Clinical Veterinary Medicine University of Bern Bern, Switzerland

XIV Contributors

Claire R. Sharp, BSc, BVMS(Hons), MS, Dipl. ACVECC School of Veterinary Medicine Murdoch University Murdoch, Australia

Emily K. Thomas, BA VetMB, Dipl. ACVECC, Dipl. ECVECC, FHEA, MRCVS

Dick White Referrals Cambridgeshire, United Kingdom

Michael Tivers, BVSc, PhD, CertSAS, MRCVS, Dipl. ECVS

Paragon Veterinary Referrals Wakefield, United Kingdom

Roberta Troìa, DVM, PhD, Dipl. ECVECC Department of Veterinary Medical Sciences Alma Mater Studiorum - University of Bologna Ozzano Emilia (BO), Italy

Julie E. Trzil, DVM, MS, Dipl. ACVIM (SAIM) Nashville Veterinary Specialists Nashville, Tennessee (USA)

Theo van den Herik, VTS (ECC) Evidensia Dierenziekenhuis Nieuwegein, The Netherlands

Iris Van Soens, DVM, PhD, Dipl. ECVN Clinique Vétérinaire Universitaire University of Liège – Liège, Belgium Evidensia dierenziekenhuis Hart van Brabant Waalwijk, The Netherlands

Lori S. Waddell, DVM, Dipl. ACVECC School of Veterinary Medicine University of Pennsylvania Philadelphia, Pennsylvania (USA)

Cynthia R. Ward, VMD, PhD, Dipl. ACVIM (SAIM) Department of Small Animal Medicine and Surgery University of Georgia Athens, Georgia (USA)

Janelle R. Wierenga, DVM, MPH, Dipl. ACVECC Ta-wharau Ora – School of Veterinary Science Massey University Palmerston North, New Zealand

Christine I. Wong, DVM, Dipl. ACVECC Sage Veterinary Centers Campbell, California (USA)

Megan Work, BVMS, MRCVS Willows Veterinary Centre and Referral Service Shirley, United Kingdom

Ivayla D. Yozova, MVM, Dr.med.vet., AFHEA, Dipl. ACVECC, Dipl. ECVECC

Ta-wharau Ora – School of Veterinary Science Massey University Palmerston North, New Zealand

Kristin M. Zersen, DVM, Dipl. ACVECC Clinical Sciences Department Colorado State University Fort Collins, Colorado (USA)

Preface The goal of this textbook is to provide veterinarians, veterinary technicians/nurses, and other readers a comprehensive resource on feline emergency and critical care medicine. Successfully managing emergency patients and those with critical illness requires knowledge and skills often not adequately covered in veterinary school and veterinary technician/nurse training programs. Through this book, we’ve created a comprehensive resource for primary care veterinarians, veterinary students, interns, residents, veterinary technicians/nurses, and board-certified veterinary specialists to use to grasp the issues and scope of problems they will inevitably encounter in clinical practice. The book’s format is designed to allow readers to digest the broad range of topics inherent to feline emergency and critical care medicine. Each chapter begins with a Summary Section that details practical points about pathophysiology, clinical signs, diagnosis, and treatment, including algorithms that attempt to simplify a problem and point the reader in the right direction. Each chapter also has a Comprehensive Section that dives deeper into the topic at hand to satisfy those who appreciate detailed discussions about pathophysiology, diagnostic investigations, and evidence-based therapies. The book has 10 sections and 100 chapters with accompanying images and videos. The authors are all practicing board-certified veterinary specialists and resident clinicians from around the globe. We believe this text is the perfect book for primary care veterinarians, veterinary students, veterinary technicians/nurses, and interns with an interest in feline emergency and critical care medicine. We believe it is also well-suited for veterinary residents and veterinary technician/nurse specialist (VTS/VNS) candidates preparing for certification examinations.

Christopher G. Byers

DVM, Dipl. ACVECC, Dipl. ACVIM (SAIM), CVJ

Massimo Giunti

DVM, PhD, Dipl. ECVECC

Table of contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XV Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XVII

section I APPROACH TO THE CRITICAL PATIENT Sabrina N. Hoehne chapter

1 Triage of the critical cat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sabrina N. Hoehne chapter

2 Cardiopulmonary resuscitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sabrina N. Hoehne chapter

3 Shock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Christine I. Wong chapter

4 Fluid therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Christine I. Wong chapter

5 Hypoxemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Guillaume L. Hoareau chapter

6 Hypercapnia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Guillaume L. Hoareau chapter

7 Basics of mechanical ventilation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Guillaume L. Hoareau chapter

8 Sedation and anesthesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Marta E. Kantyka and Sabrina N. Hoehne chapter

9 Analgesia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Marta E. Kantyka and Sabrina N. Hoehne chapter

10 ICU care and monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Simon P. Hagley

XXI

XXII Table of contents

s e c t i o n II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CARDIORESPIRATORY

Lisa L. Powell chapter

11 Approach to dyspnea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lisa L. Powell chapter

12 Upper airway obstruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Catriona M. MacPhail chapter

13 Feline asthma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Elizabeth Rozanski chapter

14 Parenchymal disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Claire R. Sharp chapter

15 Acute lung injury and acute respiratory distress syndrome. . . . . . . .

Ashley P. Anderson and Amy E. DeClue chapter

16 Pyothorax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Christiana Fischer and Lori S. Waddell chapter

17 Cardiomyopathies and heart failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Christina Bové chapter

18 Endocarditis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105

Christina Bové chapter

19 Feline aortic thromboembolism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

109

Armelle deLaforcade chapter

20 Hypertension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

114

Allison Mazepa

s e c t i o n III TRAUMA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

119

21 Approach to polytrauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

119

Kelly E. Hall chapter

22 Trauma-induced coagulopathy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

125

Kelly E. Hall and Julien Guillaumin chapter

23 Head trauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

129

Sophie Adamantos chapter

24 Spinal trauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

135

Kristin M. Zersen chapter

25 Thoracic trauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Michael S. Tivers and Sophie Adamantos

141

Table of contents XXIII

chapter

26 Diaphragmatic herniation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

147

Catriona M. MacPhail and Sarah J. Marvel chapter

27 Abdominal and pelvic trauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

151

Amanda A. Cavanagh chapter

28 Urinary tract trauma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

158

Julien Guillaumin chapter

29 Bite wounds and crush injuries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

164

Nolan V. Chalifoux and Erica L. Reineke chapter

30 Wound management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

169

Sarah J. Marvel and Catriona M. MacPhail chapter

31 Open fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

176

Anna M. Massie

s e c t i o n IV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INFECTIOUS & SEPSIS

181

Massimo Giunti chapter

32 Sepsis and septic shock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

181

Roberta Troìa chapter

33 Bacterial infections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

187

Julie Menard chapter

34 Mycoplasma, Nocardia, and Actinomyces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

195

Crystal M. Cooley and Christopher G. Byers chapter

35 Fungal infections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

201

Andrew S. Hanzlicek chapter

36 Vector borne diseases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

207

Leah A. Cohn chapter

37 Feline infectious peritonitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

214

Francesco Dondi chapter

38 Respiratory viral disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

218

Jessica A. Florey chapter

39 Feline panleukopenia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

222

Massimo Giunti chapter

40 Feline leukemia virus infection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

227

Mara Battilani chapter

41 Feline immunodeficiency virus infection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

231

Massimo Giunti and Andrea Balboni chapter

42 Tetanus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Teresa Gagliardo and Gualtiero Gandini

236

XXIV Table of contents

s e c t i o n V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRONMENTAL AND TOXICOLOGY

241

Céline Pouzot-Nevoret chapter

43 Triage of the poisoned patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

241

Megan Work and Ludivine Boiron chapter

44 Intravenous lipid emulsion therapy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

247

Joris H. Robben chapter

45 Ethylene glycol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

251

Anthony Barthélemy chapter

46 Acetaminophen intoxication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

255

Alexandra Nectoux and Céline Pouzot-Nevoret chapter

47 Rodenticides. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

259

Anthony Barthélemy chapter

48 Carbon monoxide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

263

Laurence M. Saint-Pierre and Guillaume L. Hoareau chapter

49 Methemoglobinemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

267

Julie Combet-Curt and Céline Pouzot-Nevoret chapter

50 Serotonin syndrome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271

Mariana A. Pardo chapter

51 Methylxanthine intoxication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

277

Mariana A. Pardo chapter

52 Lilies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

282

Maxime Cambournac chapter

53 Grapes and raisins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

286

Maxime Cambournac chapter

54 Pyrethrins and pyrethroids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

289

Ivayla D. Yozova and Janelle R. Wierenga chapter

55 Organophosphates and carbamates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

295

Janelle R. Wierenga and Ivayla D. Yozova chapter

56 Calcium channel blocker intoxication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

301

Carlos Pizarro and Luis Bosch chapter

57 Nonsteroidal anti-inflammatory drugs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

306

Mark W. Kim chapter

58 Smoke inhalation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

311

Ran Nivy and Yaron Bruchim chapter

59 Lightning and electrocution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ludivine Boiron

316

Table of contents XXV

chapter

60 Thermal injury. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

321

Guillaume L. Hoareau and Laurence M. Saint-Pierre chapter

61 Hyperthermia and heatstroke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

327

Yaron Bruchim and Ran Nivy

s e c t i o n VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HEMATOLOGY, ONCOLOGY & TRANSFUSION MEDICINE

333

Christopher G. Byers chapter

62 Approach to the bleeding cat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

333

Danielle M. Hundley chapter

63 Hemolytic anemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

338

Christopher G. Byers chapter

64 Thrombocytopenia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

344

Dana N. LeVine chapter

65 Coagulation disorders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

350

Elizabeth B. Davidow chapter

66 Basic principles of transfusion medicine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

357

Elizabeth B. Davidow chapter

67 Oncologic emergencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

362

Barbara E. Kitchell

s e c t i o n VII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . URINARY, REPRODUCTIVE & PEDIATRIC EMERGENCIES

367

Stefano Cortellini chapter

68 Acute kidney injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

367

Stefano Cortellini and Laura Cole chapter

69 Urologic emergencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

373

Emily K. Thomas chapter

70 Peritoneal dialysis and extracorporeal therapies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

378

Thierry Francey and Ariane Schweighauser chapter

71 Renal transplantation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

384

Lillian R. Aronson chapter

72 Pyometra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

389

Karen Humm chapter

73 Dystocia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

393

Aime K. Johnson chapter

74 Neonatal and pediatric emergencies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maureen A. McMichael and Andrea Henriksson

397

XXVI Table of contents

s e c t i o n V III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NEUROLOGIC & OPHTHALMIC

403

Gualtiero Gandini chapter

75 Status epilepticus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

403

Antonella Gallucci and Gualtiero Gandini chapter

76 Vestibular diseases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

410

Teresa Gagliardo and Gualtiero Gandini chapter

77 Ocular emergencies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

415

Rodrigo Pinheiro de Lacerda

s e c t i o n IX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GASTROINTESTINAL, HEPATIC, & ENDOCRINE

421

Patty A. Lathan chapter

78 Diabetic ketoacidosis and hyperglycemic

hyperosmolar syndrome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

421

Stephanie A. Harris and Katherine K. Gerken chapter

79 Thyrotoxicosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

428

Joanna E. Murdoch and Cynthia R. Ward chapter

80 Hypoglycemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

434

Renee Rucinsky chapter

81 Primary hyperaldosteronism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

438

Hans S. Kooistra and Sara Galac chapter

82 Acute vomiting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

443

Kendon W. Kuo and Katherine K. Gerken chapter

83 General approach to the acute abdomen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

449

Katherine K. Gerken chapter

84 Peritonitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

457

Katherine K. Gerken chapter

85 Acute pancreatitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

464

Juliette Bouillon and Jennifer Loewen chapter

86 Acute hepatopathies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

471

Julie E. Trzil and Whitney M. Long chapter

87 Hepatic lipidosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

479

Crystal M. Cooley and Christopher G. Byers chapter

88 Acute liver failure and hepatic encephalopathy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Suzanne Gray

484

Table of contents XXVII

s e c t i o n X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PROCEDURES IN EMERGENCY AND CRITICAL CARE MEDICINE

493

Kris Gommeren chapter

89 Point-of-Care Ultrasonography (POCUS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

495

Søren Boysen chapter

90 Arterial catheterization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

495

Theo van den Herik and Kris Gommeren chapter

91 Central venous catheterization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

496

Theo van den Herik and Kris Gommeren chapter

92 Intraosseous catheterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

496

Christopher R. Kennedy chapter

93 Feeding tubes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

496

Lindsey Dodd chapter

94 Temporary tracheostomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

497

Stéphanie M.P. Noël chapter

95 Thoracocentesis and thoracostomy tube placement. . . . . . . . . . . . . . . . . . . . .

498

Julie Menard and Tomas Boullhesen Williams chapter

96 Cardioversion and defibrillation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

498

Christopher R. Kennedy chapter

97 Cerebrospinal fluid sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

499

Iris Van Soens chapter

98 Locoregional analgesia techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

499

Angela Briganti chapter

99 Urinary stents, tubes, and bypass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

500

Nausikaa Devriendt chapter

100 Oxygen therapy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

500

Carla Molina and Luís Bosch

Subject index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501

chapter

Feline aortic thromboembolism Armelle deLaforcade

SUM M A RY SE C T I ON Pathophysiology

Feline arterial thromboembolism (FATE) is a common and devastating complication of feline cardiomyopathy where blood flow to the limbs is acutely restricted due to thromboembolism, resulting in severe pain and paresis. Both pelvic limbs are most commonly affected though single limb involvement may also occur. A combination of left atrial enlargement and reduced left atrial and left atrial appendage flow create an environment of blood stasis, which combined with underlying hypercoagulabilty and platelet endothelial interactions, results in intracardiac thrombus formation. Thrombus dislodgement leads to peripheral vascular occlusion and tissue ischemia causing loss of ambulation, pain, and distress.

Clinical signs

Classic signs of FATE consist of acute partial or complete loss of motor function to affected limbs, vocalization, and extreme discomfort or distress. Tachypnea or dyspnea is present in nearly all cases and results from pain, anxiety, and/or congestive heart failure (CHF). Hypothermia is common and independently associated with a negative outcome. Cats may or may not experience concurrent congestive heart failure. Affected limbs are discolored and cool to the touch.

Diagnosis

A cursory examination of the affected limb often reveals the five Ps of FATE: paresis or paralysis, pain, pulselessness, footpad pallor, and polar (cold to the touch). Comparison of blood glucose concentration between affected and unaffected limbs can lend further support to a diagnosis of FATE with significantly lower glucose concentration noted in the affected limbs. Echocardiography commonly identifies underlying cardiac disease, though in some cases structural cardiac abnormalities are not noted (fig. 19.1).

Therapy

Analgesia is the first priority in treatment of cats with ATE. Full μ opioid agonists, such as methadone or hydromorphone, are preferred due to the severity of pain and their superior analgesic effect. Butorphanol or buprenorphine have lesser analgesic effect. Antithrombotic therapy consisting of unfractionated heparin, low molecular weight heparin, or a factor X inhibitor is recommended along with clopidogrel as a platelet inhibitor. Treatment for congestive heart failure can be initiated based on findings of B-lines on thoracic Point-of-Care ultrasonography (POCUS) but should be continued only in cats with radiographic evidence of pulmonary infiltrates.

109

110

Section II CARDIORESPIRATORY

5 Ps

Analgesia

> Methadone (0.3-0.5 mg/kg IM or IV) > Hydromorphone (0.1 mg/kg IM or IV) > Fentanyl (2-5 μg/kg/h IV) If none available, > Buprenorphine (0.01 mg/kg IM or IV)

> Paresis or paralysis > Pulselessness > Pain > Pallor > Poikilothermia

Anticoagulation

> Enoxaparin 1 mg/kg SC q8-12h > Rivaroxaban 0.5 mg/kg PO q24h Second agent > Clopidogrel 18.75 mg PO q24h

Management of CHF

> Oxygen supplementation > Furosemide 2 mg/kg IM or IV

> Fig. 19.1 Presenting examination findings and treatment options for feline aortic thromboembolism. CHF, congestive heart failure.

COMPR E H ENSIV E SE C T I ON Feline arterial thromboembolism (FATE) is a common and devastating complication of feline cardiac disease. Characterized by acute limb paralysis and extreme pain, FATE occurs most commonly as a complication of hypertrophic cardiomyopathy (HCM), although other forms of cardiomyopathy including unclassified (UCM), restrictive (RCM), dilated (DCM), hypertrophic obstructive (HOCM), and intermediate cardiomyopathy (ICM) are also frequently diagnosed. Non-cardiac conditions associated with FATE are uncommon but may include hyperthyroidism and neoplasia.1-3 The reported prevalence of FATE is 0.6% (1 in 175) of cats presented to an academic teaching hospital and 0.3% of cats in primary care practice.2,4 Males are reportedly more commonly affected, although this is thought to reflect the greater incidence of HCM among male cats rather than a specific predisposition to thromboembolism.2,5 One study identified peak prevalence during springtime (March-May), possibly related to a greater likelihood of interaction among cats and decompensation of underlying cardiac disease.5

Pathogenesis The pathogenesis of FATE is likely multifactorial. Reduced left atrial and left atrial appendage blood flow

velocity with cardiac chamber enlargement promotes aggregation of red blood cells, resulting in echogenic particles during cardiac imaging referred to as spontaneous echocardiographic contrast or SEC. Spontaneous echocardiographic contrast is indicative of blood stasis and is a known risk factor for arterial thromboembolism in people.6 SEC has been associated with feline cardiomyopathy and an increased risk of death in cats and thus is considered a likely risk factor for arterial thromboembolism in cats.7,8 While changes in blood flow alone may affect the clearance of activated coagulation factors, a systemic hypercoagulability has also been documented in cats with cardiomyopathy and may further enhance the risk of thrombus formation. One study identified hypercoagulability in 56% of cats with ATE with specific changes including elevated fibrinogen and factor VIII concentrations, von Willebrand factor (vWF) activity (a marker of endothelial injury), and thrombin antithrombin complex formation. Fifty percent of cats with left atrial enlargement and SEC were also identified as hypercoagulable, although this was not true of cats with left atrial enlargement alone. Interestingly, cats that met the criteria for hypercoagulability were not

Chapter 19 Feline aortic thromboembolism

more likely to have congestive heart failure or left atrial enlargement.9 Finally, enhanced platelet activation and increased platelet-endothelium interactions could promote intracardiac thrombus formation.10 Overall, 12-21% of cats with HCM develop FATE.11,12 Despite a lack of correlation between increasing left atrial size and risk of FATE, a large retrospective study of cats with HCM suggested those experiencing a thromboembolic event had greater left atrial measurements compared to cats with congestive heart failure or preclinical disease.13 Current consensus guidelines, therefore, recommend thrombophylaxis when risk factors, including moderate to severe left atrial enlargement (stage B2 cardiomyopathy), spontaneous echocardiographic contrast, or decreased left atrial appendage flow velocity, are present.7,12,14 Prophylactic antithrombotic therapy consists of platelet inhibition at minimum. Studies specifically comparing anticoagulation strategies are lacking. Aspirin exerts antiplatelet effect through cyclooxygenase inhibition and has traditionally been the most commonly used antithrombotic in cats. However, a large double-blinded randomized clinical trial established superior efficacy of clopidogrel, an ADP P2Y12 receptor antagonist, in preventing recurrence of ATE in cats compared to aspirin.15 A second antithrombotic medication is often added in cats with increased risk of thromboembolism. Low molecular weight heparins, such as enoxaparin (1 mg/kg SC q12h) or the factor X inhibitor rivaroxaban (0.5-1 mg/kg PO q24h) are acceptable options; greater long-term compliance maybe achieved using oral medications. Although cardiac disease is the leading comorbidity associated with FATE, the acute thromboembolic event is the first indication of any underlying disease in as many as 76-88% of cases described.2,9 Remaining cats either have previously documented cardiomyopathy at the time of presentation or are suspected to have underlying cardiomyopathy based on cardiac murmur or gallop but where no further diagnostics are performed.1,2,16,17 In 2565% of cases, radiographic evidence of congestive heart failure is present regardless of any known underlying cardiac disease.2,5,9,11,16,18

Clinical presentation Due to the severity of signs, cats are often presented within 1-8 hours of the embolic event. A presumptive diagnosis of FATE can be made based on documentation of characteristic acute loss of motor function to affected limbs, vocalization, and extreme discomfort or distress. A cursory examination of the affected limb often reveals the 5 Ps of FATE: paresis or paralysis, pain, pulselessness, footpad pallor, and polar (cold to the touch). The majority of cats are presented with tachypnea or dysp-

111

nea secondary to pain, distress, and/or concurrent congestive heart failure. It should be noted in most studies the incidence of tachypnea exceeded that of congestive heart failure, making pain and distress significant contributors to respiratory changes noted at presentation.2 Hypothermia secondary to reduced systemic perfusion is a common finding, affecting 50-75% of cats regardless of thoracic or pelvic limb involvement. Despite the frequency of underlying cardiac disease, only roughly half of cats with FATE have a cardiac murmur, gallop, arrhythmia, or a combination of these documented on physical examination.2,16 The pelvic limbs are affected in more than 70% of cats, and paralysis is common; however, some motor function is retained in roughly 25% of cats, more frequently in cats with thoracic limb or unilateral pelvic limb involvement.2 In cats with thoracic limb involvement, the right thoracic limb is thought to be at greater risk of thromboembolism due to the anatomy of the blood supply. However, increased involvement of one thoracic limb over the other is not consistently reported across studies. Alternate sites of thromboembolism include the brachial, visceral, and cerebral arteries.1,2 In the rare cases where the limbs are not affected, presenting complaints are reflective of organs affected and include vomiting and acute abdominal pain (mesenteric thrombosis) or acute neurologic changes such as circling and nystagmus (cerebral thrombosis).2

Diagnostic testing In most cases, clinical presentation and physical examination changes are sufficient to initiate therapy for FATE. Comparison of blood glucose concentration between affected and unaffected limbs can lend further support to a diagnosis of ATE with significantly lower glucose concentration noted in the affected limbs. In one study, a difference in glucose concentration (delta glucose) of 30 mg/dL (1.7 mmol/L) had 100% sensitivity and 90% specificity for predicting ATE in cats.19 Differences in temperature between affected and non-affected limbs using thermography have been described to confirm a diagnosis of ATE.20 In addition to peripheral vascular occlusion secondary to a dislodged thrombus, profound vasoconstriction occludes collateral circulation and worsens limb ischemia. Consequently, biochemistry testing frequently identifies stress hyperglycemia and elevations in muscle enzyme activity (alanine aminotransferase/ALT, aspartase transaminase/AST, creatine kinase/CK). Azotemia due to reduced systemic perfusion may be identified at presentation or develop during treatment; while uncommon, occlusion of the renal artery is possible. Electrolyte disturbances are noted in approximately

112

Section II CARDIORESPIRATORY

10% of cases at presentation and include hyperkalemia, hyperphosphatemia, and hypocalcemia. Hyperkalemia in particular is more likely to develop during treatment as reperfusion occurs and must be closely monitored due to its cardiotoxic effect. Left atrial enlargement is the most common change noted on echocardiography and is present in 93% of cats with FATE. The presence of an intracardiac thrombus, as well as structural changes associated with underlying cardiomyopathy, may be identified. Radiographic evidence of pulmonary edema or pleural effusion confirms concurrent congestive heart failure with cardiomegaly evident in some cases. A range of arrhythmias may be noted via electrocardiography, including ventricular or atrial premature contractions, atrial fibrillation, and sinus bradycardia or tachycardia.2

Therapy Due to extreme discomfort and anxiety, analgesia should be prioritized as a therapeutic intervention for cats suspected of experiencing FATE. Full μ opioid agonists such as methadone (0.3-0.5 mg/kg IM or IV) or hydromorphone (0.1 mg/kg IM or IV) are preferred due to the severity of pain and their superior analgesic effect. Once hospitalized, an intravenous continuous rate infusion of fentanyl (2-5 μg/kg/h IV CRI) is highly effective and easily titratable for patient comfort. Partial agonists such as butorphanol, (0.1-0.4 mg/kg IM or IV) or buprenorphine (0.01 mg/kg IM or IV) are acceptable but are unlikely to provide sufficient pain control. Thoracic Point-of-Care ultrasonography (POCUS) may be performed depending on the degree of respiratory compromise prior to transfer into an oxygen-rich environment. Pulmonary crackles or ultrasonographic evidence of B lines (indicative of “wet lungs”) supports the administration of furosemide (2 mg/kg IM or IV if venous access is present) as treatment for presumptive congestive heart failure. Furosemide in the absence of supportive evidence for pulmonary infiltrates should be avoided as it may worsen azotemia and systemic hypoperfusion. Thoracic radiography and echocardiography are indicated but should be delayed until pain control is achieved, and the patient is stable outside an oxygen-rich environment. Anticoagulation remains the mainstay of therapy for FATE. Platelet inhibition alone does not appear sufficient to prevent recurrence with 49% of cats receiving clopidogrel and 75% of cats receiving aspirin experiencing recurrent ATE.15 By comparison, studies describing cats treated with heparin products report recurrence in 18-25%.2,21 The use of enoxaparin in a feline venous stasis model supports its antithrombotic effect with reduced thrombus formation using a dose of 1 mg/kg

SC q12h.22 Low molecular weight heparin injections are easily administered by pet owners and are well-tolerated by cats,21 but greater long-term compliance may be achieved with oral antithrombotics. Oral rivaroxaban, the currently available factor X inhibitor, seems also well tolerated in cats and has predictable anticoagulant effect.23 A randomized double-blinded study evaluating the efficacy of rivaroxaban compared to clopidogrel in preventing recurrence of FATE is ongoing (the SUPER-CAT study). Currently, both consensus guidelines for the rational use of antithrombotics (CURATIVE) and consensus guidelines for the treatment of cats with cardiomyopathy recommend the use of low molecular weight heparins, unfractionated heparin, or factor X inhibitors in cats to prevent recurrence of ATE.12,24 Clopidogrel can be added using loading dose of 75 mg followed by 18.75 mg PO q24h. Thrombolytic therapy is not currently recommended for the treatment of FATE. While tissue plasminogen activator, streptokinase, and urokinase are used to re-establish blood flow in embolized vessels in people, several studies evaluating their use in cats with FATE have failed to document a survival benefit despite encouraging signs, including restoration of femoral pulses and return of motor function. Significant and life-threatening adverse events were common, leading to early termination of one study using tissue plasminogen activator. Adverse events included life-threatening hyperkalemia, clinical bleeding, arrhythmias, neurologic events, and azotemia.16-18 One case report described successful treatment of one cat following local intraarterial infusion of urokinase.25 Surgical embolectomy is possible but infrequently performed given the surgical risk and high mortality associated with ATE.12,26 Additional treatment is generally supportive and includes treatment for underlying cardiac or endocrine disease. Complications of FATE include life-threatening hyperkalemia secondary to reperfusion, and ischemia-induced tissue necrosis. Wound management may be required; in severe cases, limb amputation is indicated.

Outcome Due to the severity of clinical signs and generally poor prognosis, approximately 33-35% of cats presenting with ATE are euthanized without further diagnostics or therapy. An additional 25-28% of cats die early in the course of hospitalization, leaving 35-39% of cats surviving to hospital discharge. Of all abnormalities described among cats with ATE, hypothermia is consistently associated with a negative outcome. Single limb involvement and the presence of motor function are more frequent among survivors.1,2,5 Euthanasia rates at presentation were significantly higher (61.2%) in a

Chapter 19 Feline aortic thromboembolism

large retrospective study of 250 cats with ATE evaluated specifically in primary care practice. In this study, cats were more likely to be euthanized if they were presented off hours, if ≥2 limbs were affected, or if they presented with concurrent congestive heart failure.4 Recurrence is likely in 18-25% of cats receiving antithrombotic therapy, and euthanasia is common following recur-

113

rence. Cats that are successfully discharged should be re-evaluated within seven days for assessment of electrolytes, tissue necrosis, neuromuscular function, and compliance with administration of medications. Owners should be warned neuromuscular function may take weeks to resolve, and lifelong medication and anticoagulation are required.27

REFERENCES 1. Laste NJ, Harpster NK. A retrospective study of 100 cases of feline distal aortic thromboembolism: 1977-1993. J Am Anim Hosp Assoc 31:492, 1995. 2. Smith, SA, Tobias AH, Jacob KA, Fine DM, Grumbles PL. Arterial thromboembolism in cats: Acute crisis in 127 cases (1992-2001) and long-term management with low-dose aspirin in 24 cases. J Vet Intern Med 17:73, 2003. 3. Hogan DF, Dhaliwal RS, Sisson DD, Kitchell BE. Paraneoplastic thrombocytosis-induced systemic thromboembolism in a cat. J Am Anim Hosp Assoc 6:483, 1999. 4. Wright J, Garrod O, Payne JR, Fuentes VL. Arterial thromboembolism in 250 cats in general practice: 2004-2012. J Vet Intern Med 28:102, 2014. 5. Schoeman JP. Feline distal aortic thromboembolism: A review of 44 cases (1990-1998). J Fel Med Surg 1:221, 1999. 6. Kelly RP, Feneley MP. Relations between left atrial appendage flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. J Am Coll Cardiol 23:961, 1994. 7. Schober KE, Maerz I. Assessment of left atrial appendage flow velocity and its relation to spontaneous echocardiographic contrast in 89 cats with myocardial disease. J Vet Intern Med 20:120, 2006. 8. Peck CM, Nielsen LK, Quinn RL, Laste NJ, Price LL. Retrospective evaluation of the incidence and prognostic significance of spontaneous echocardiographic contrast in relation to cardiac disease and congestive heart failure in cats: 725 cases (2006-2011). J Vet Emerg Crit Care 26:704, 2016. 9. Stokol T, Brooks M, Rush JE, Rishniw M, Erb H, Rozanski E, Kraus MS, Gelzer AR. Hypercoagulability in cats with cardiomyopathy. J Vet Intern Med 22:546, 2008. 10. Helenski CA, Ross JN. Platelet aggregation in feline cardiomyopathy. J Vet Intern Med 1:24, 1987. 11. Fox PR, Keene BW, Lamb K, Schobe KA, et al. International collaborative study to assess cardiovascular risk and evaluate long-term health in cats with preclinical hypertrophic cardiomyopathy and apparently healthy cats: the REVEAL study. J Vet Intern Med 32:930, 2018. 12. Fuentes VL, Abbott J, Chetboul V, Côté E, et al. ACVIM consensus statement guidelines for the classification, diagnosis, and management of cardiomyopathies in cats. J Vet Intern Med 34:1062, 2020. 13. Rush JE, Freeman LM, Fenollosa NK, Brown DJ. Population and survival characteristics of cats with hypertrophic cardiomyopathy: 260 cases (1990-1999). J Am Vet Med Assoc 2:202, 2002. 14. Payne JR, Borgeat K, Connolly DJ, Boswood A, et al. Prognostic indicators in cats with hypertrophic cardiomyopathy. J Vet Intern Med 27:1427, 2013.

15. Hogan DF, Fox PR, Jacob K, Keene B, et al. Secondary prevention of cardiogenic arterial thromboembolism in the cat: the double blind, randomized, positive-controlled feline arterial thromboembolism; clopidogrel vs. aspirin trial (FAT CAT). J Vet Cardiol 17:S306, 2015. 16. Moore KE, Morris N, Dhupa N, Murtaugh RJ, et al. Retrospective study of streptokinase administration in 46 cats with arterial thromboembolism. J Vet Emerg Crit Care 10:245, 2007. 17. Welch KM, Rozanski EA, Freeman LM, Rush JE. Prospective evaluation of tissue plasminogen activator in 11 cats with arterial thromboembolism. J Fel Med Surg 12:122, 2010. 18. Guillaumin J, Gibson RM, Goy-Thollot I, Bonagura JD. Thrombolysis with tissue plasminogen activator (TPA) in feline acute aortic thromboembolism: A retrospective study of 16 cases. J Fel Med Surg 21:340, 2019. 19. Klainbart S, Kelmer E, Vidmayer B, Bdolah-Abram T, Segev G, Aroch I. Peripheral land central venous blood glucose concentrations in dogs and cats with acute arterial thromboembolism. J Vet Intern Med 28:1513, 2014. 20. Pouzot-Nevoret C, Barthélemy A, Goy-Thollot I, Boselli E, et al. Infrared thermography: A rapid and accurate technique to detect feline aortic thromboembolism. J Fel Med Surg 20:780, 2018. 21. Smith CE, Rozanski EA, Freeman LM, Brown DJ, et al. Use of low molecular weight heparin in cats: 57 cases (1999-2003). J Am Vet Med Assoc 225:1237, 2004. 22. Van De Wiele CM, Hogan DF, Green HW, Sederquist KD. Antithrombotic effect of enoxaparin in clinically healthy cats: A venous stasis model. J Vet Intern Med 24:185, 2010. 23. Dixon-Jimenez AC, Brainard BM, Brooks MB, Nie B, et al. Pharmacokinetic and pharmacodynamic evaluation of oral rivaroxaban in healthy adult cats. J Vet Emerg Crit Care 26:619, 2016. 24. Goggs R, Bacek L, Bianco D, Koenigshof A, Li RHL. Consensus on the rational use of antithrombotics in veterinary critical care (CURATIVE): Domain 2 – Defining rational therapeutic usage. J Vet Emerg Crit Care 29:49, 2019. 25. Koyama H, Matsumoto H, Fukushima R, Hirose H. Local intra-arterial administration of urokinase in the treatment of feline distal aortic thromboembolism. J Vet Med Sci 72:1209, 2010. 26. Vezzosi T, Buralli C, Briganti A, Vannozzi I, et al. Surgical embolectomy in a cat with cardiogenic aortic thromboembolism. J Vet Cardiol 28:48, 2020. 27. Fuentes LV. Arterial thromboembolism: risks, realities, and a rational first-line approach. J Fel Med Surg 14:459, 2012.

section

III

chapter

TRAUMA

Approach to polytrauma Kelly E. Hall

SUM M A RY SE C T I ON Pathophysiology

Polytrauma can result in the combination of severe tissue injury and hemorrhage. Acute life-threatening injuries are due to failures of the respiratory system, circulatory malfunction (hemorrhage), and severe brain injury. While they may not be immediately life-threatening, swelling, inflammation, physical damage, and hemorrhage associated with other systems can lead to additional comorbidities and delayed healing.

Clinical signs

Clinicals signs are due to the variety of both blunt and penetrating mechanisms of injury, as well as a large breadth of degree of injury (as assessed by the Animal Trauma Triage score and modified Glasgow coma scale score), cats may be presented with little-to-no signs of injury or clear evidence of complex tissue injury. For this reason, a systematic approach to patient assessment is recommended.

Diagnosis

Utilization of a systematic approach to include a primary survey (identify and address life-threatening injuries) and secondary survey (assess all injuries) can guide the clinician in what can be a complex situation. One approach includes a rapid primary survey to identify injuries associated with catastrophic exsanguination and those associated with airway, breathing, circulation, disability, and environment (XABCDE) followed by a head to limb secondary survey.

Therapy

Immediate interventions are targeted to address primary survey abnormalities, including tempering catastrophic bleeding (e.g., occlusion of femoral artery or jugular vein injury), obtaining a patent airway (removal of blockage/obstruction, tracheostomy), ensuring adequate breathing (intubation and ventilation, addressing hemo- or pneumothorax), ensuring appropriate circulation (fluids to address blood loss and coagulopathy), preventing further disabilities (minimizing secondary neurologic injury, addressing pain), and addressing environmental considerations (covering open wounds, minimizing loss of heat and patient distress) (table 21.1).

Prognosis

The overall survival to discharge for cats sustaining traumatic injury is greater than 80% with ~15% being euthanized. These statistics are contrasted to ~5% of dogs being euthanized despite having an overall similar proportion that died naturally. This makes it hard to delineate cats that die from euthanasia that could otherwise survive their traumatic injuries from those that have traumatic injury beyond repair. Resources available to the injured cat (medical and financial) are clearly a large contributing factor to outcome.

119

120

Section III TRAUMA

> Table 21.1 Primary survey. Acronym Meaning

Evaluating

Possible interventions

Obvious catastrophic limb or body cavity hemorrhage? Open and adequate path for air to get to alveoli?

> Compression/packing

Catastrophic exsanguination Airway

Breathing

Adequate ability to move air (rate/depth)?

Circulation

Adequate perfusion?

Disability

Evidence of head or spinal injury?

Exposure Environment

Awareness of environmental factors

> Oxygen > Tracheostomy > Thoracocentesis > Sedate, intubate, ventilate > CPR > IV catheter > Fluids (see text)

> Pain relief > Backboard > Cover open wounds > Minimize patient distress and heat loss

Adjuncts to assessment

> SpO2 > Auscultation > Thoracic POCUS > PCV/TS or Hgb > Lactate > Blood gas > POCUS (identify sources of bleeding) > Blood pressure > mGCS score

CPR , cardiopulmonary resuscitation; Hgb, hemoglobin; IV, intravenous; mGCS , modified Glasgow coma scale score; PCV, packed cell volume; POCUS , Point-of-Care ultrasound; SpO2, peripheral capillary oxygen saturation; TS , total solids. Modified from Trauma Stabilization Course Module 1 working group.

COMPR E H ENSIV E SE C T I ON Trauma in cats is common. Despite an overall good survival to discharge, it is a leading cause of death.1,2 In the ACVECC-VetCOT trauma registry, fall from height, struck by vehicle, and unknown cause of injury (i.e., the cat shows up injured after missing) are the top three causes of blunt injury in cats while bite wound and unknown penetrating injury top the list of penetrating causes (unpublished data, 2017-2019 VetCOT registry). The top five causes for mortality in cats (reflecting complex injury) include struck by vehicle, ejected from vehicle, non-penetrating bite wound (crushing injury), ballistic injury, and choking/pulling injury. Factors that impact outcome include degree of injury and resources available (medical and financial) to identify and address injuries.3 For these reasons, a systematic approach to what can be a complex and dynamic situation is recommended.4,5 A primary survey completed rapidly followed by a secondary survey allows for the identification of injuries, determination of interventions, and assessment of whether definitive care can be achieved with local resources versus the need for referral to a vet-

erinary hospital with additional resources (e.g., blood products, advanced imaging, specialist care).

Primary survey The goal of the primary survey is to rapidly identify and address immediately life-threatening conditions in the order that pose the greatest threat to life. The primary survey is revisited and re-executed each time the patient’s status changes. A key point in a patient with mild injury is the primary survey can be done in less than 30 seconds by visual and brief physical exam, noting respiratory rate and effort, palpating pulse, and interacting with the patient (responsiveness). In the subset of patients with severe injury, intervention may be necessary during the primary survey, lengthening the time it takes to complete. The primary survey should be completed prior to moving to the secondary survey.

Catastrophic exsanguination This first step has recently been incorporated into the human medical field’s primary survey to address limb

Chapter 21 Approach to polytrauma

or core catastrophic bleeding imminently leading to arrest (e.g., major vessel injury).6,7 Anecdotal evidence in veterinary medicine suggests feline patients with these types of injuries rarely make it to a veterinary practitioner. In the event a feline patient arrives with this condition, the recommendation is to have one staff member compress or pack to stop or temper the bleeding while other team members proceed with the rest of the primary survey.

Airway Facial injuries associated with falls and cervical injuries associated with bite wounds are examples that may lead to compromise of the upper airway. 8,9 If the patient is struggling to move air through the airway, immediate sedation with intubation or temporary tracheostomy placement may be necessary. Ideally, patients should be provided supplemental oxygen (flow by, mask) as mild airway injuries may respond, and improving oxygen diffusion may have systemic benefits. Pulse oximetry can be a useful adjunct as long as continuation of primary survey is not delayed and is tolerated by the patient.

Breathing Both blunt and penetrating mechanisms can result in injuries that impact breathing rate, depth and effort, including hemothorax, pneumothorax, diaphragmatic hernia, and pulmonary contusions (see chapter 25). Assessment of breathing can be confounded by patient pain and distress. In addition to supplementing oxygen (as above), thoracic auscultation or assessment using Point-of-Care ultrasonography (POCUS) can help guide need for thoracocentesis or need for rapid sedation, intubation, and ventilation. Utilization of POCUS during the primary survey should be limited to identification of fluid or air for thoracocentesis; comprehensive POCUS evaluation is reserved for secondary survey. If pleural air or fluid is suspected, thoracocentesis without POCUS guidance can absolutely be performed. If a patient is not breathing, cardiopulmonary resuscitation should be initiated immediately (see chapter 2).

Circulation Hypovolemic shock (e.g., hemorrhage) can be a result of blunt or penetrating traumatic injury. Quantification of blood lost is challenging due to external blood loss en route and difficulties quantifying volume lost into cavities (e.g., thoracic, abdominal, retroperitoneal, gastrointestinal) and solid organs (e.g., contusions, muscle compartments). As a result, physical exam parameters are utilized initially to as-

121

sess circulatory ability: mucous membrane color and capillary refill time, pulse rate and quality, mentation, extremity temperature. Initiation of an intravenous (IV) bolus (5-10 mL/kg over 10-20 minutes) of a balanced isotonic crystalloid is recommended if shock is suspected based on primary survey exam findings. The goal with fluid resuscitation is to ensure perfusion and oxygen carrying capacity to tissues while minimizing potential negatives effects of volume overload, organ edema, dilution of clotting factors, and damage to the endothelium. See chapters 3, 4 and 22 for additional information on fluid resuscitation. In short, an initial crystalloid bolus and control of ongoing bleeding with early consideration for blood product administration in a severely hemorrhaging traumatized patient not responding to crystalloids are current recommendations. Minimally measuring packed cell volume and total solids (PCV/TS) from the catheter hub during IV catheter placement for fluid resuscitation is ideal with lactate, blood gas (to include base excess/BE), electrolyte, and glucose values strongly recommended during primary survey (and require only a small blood volume for many diagnostic instruments). If there is no delay in the primary survey, obtaining samples for a complete blood count, biochemical profile, blood type, and coagulation testing can help inform care. If the patient is severely compromised, determination regarding bleeding into major cavities needs to be identified and addressed. The use of POCUS to identify pleural, pulmonary, pericardial, peritoneal, and/or retroperitoneal fluid can be used as an adjunct in patients that are severely compromised during the primary survey; otherwise, comprehensive POCUS is completed during secondary survey. In dogs, an abdominal fluid score (AFS) of three or four (when evaluating for evidence of fluid in four abdominal quadrants) was associated with need for transfusion.10 Other values associated with blood transfusion in traumatically injured dogs include BE <−6.6 mmol/L and ionized calcium iCa <1.24 mmol/L (< 2.50 mEq/L).11,12 While these values have not been established in cats, consideration for performing blood type and crossmatch, assessing blood product readiness and availability, and estimating owner for blood transfusion should be considered with this combination of findings.

Disability In the 2013-2017 VetCOT Registry report of more than 3,400 cats with traumatic injury, 16.5% had evidence of head injury, and 8.7% had evidence of spinal trauma.2 During primary survey, the modified Glasgow coma scale (mGCS) score should be determined to assess for brain injury (see chapter 23), and palpa-

122

Section III TRAUMA

tion of the spinal column and rapid assessment of limb function should be performed and determined, respectively (see chapter 24). In addition to ensuring oxygen supplementation (as above), additional considerations for fluid therapy are important in patients with evidence of traumatic brain injury (TBI) in an effort to ensure perfusion and minimize secondary brain injury. Patients with evidence of spinal injury should be immobilized to prevent further damage pending secondary survey and advanced imaging. Once preliminary neurologic assessment is determined, appropriate analgesia should be administered (see chapter 9).

Exposure/environment Steps must be taken to ensure open wounds are covered until they can be addressed definitively after the secondary survey. Furthermore, steps to reduce heat loss are indicated when those without elevated body temperature. Medical teams must be conscientious of exacerbating patient distress. Possible interventions include temporary sterile bandaging to cover open wounds, passive and active rewarming interventions (e.g., placement of a blanket or towel between the patient and metal table, warmed fluids), and Fear-Free® handling techniques.

Secondary survey

The secondary survey (table 21.2) should be started only after the primary survey has been completed, and the patient has either been assessed as stable or life-threatening abnormalities are actively being addressed and improving. If a patient’s status worsens at any point, revisiting the primary survey in a systematic way is recommended. Table 21.2 represents a “head to limb” approach to the secondary survey, including common findings in feline trauma patients and adjunct tools that may be necessary to complete the assessment. The goal of the secondary survey is to ensure all pertinent information regarding the patient’s injuries is determined in a timely way in order to create a plan, determine resources needed, and communicate with the owner regarding current status and next steps. With advancement and availability of many bedside tools, a majority of patient assessment can be performed bedside. That being said, diagnostic imaging (e.g., radiographs, computed tomography) may need to be performed to fully identify the extent of injuries and resources necessary for repair (e.g., fractures, surgical procedures, etc.). Recognizing there is additional cost and potentially anesthesia associated with the imaging component of a secondary survey, the findings identified bedside are even more important in veterinary

> Table 21.2 Secondary survey. Common/possible findings and injuries

Adjuncts to assessment

Head (chapter 34)

Laceration, bleeding, proptosis, corneal defect, dental/maxillofacial injuries or fractures, aural hemorrhage

> Laryngoscope > Otoscope > Ophthalmoscope > Radiographs/CT

Thorax and cervical region

Punctures, laceration, rib fractures, flail chest, pneumothorax, hemothorax, pulmonary contusions, diaphragmatic hernia

> POCUS > Pulse oximetry/blood gas > Thoracocentesis > Radiographs/CT

Abdomen

Hemoabdomen, uroabdomen, evisceration, gastrointestinal penetrating injury, other solid organ bleeding or crushing injury, abdominal wall defect, prepubic tendon tear

> POCUS > Abdominocentesis > Radiographs/CT

Pelvis and perineum

Pelvic fracture(s), bleeding, lacerations, rectal/urethral damage

> Rectal exam > Radiographs/CT

Neurologic system

Traumatic brain injury, spinal cord injury, peripheral nerve damage

> mGCS score > Complete neurologic exam

Limbs

Long bone fractures, bleeding, lacerations, crushing injury, dislocation, abrasions (superficial to deep)

> Radiographs

(chapters 25 and 26)

(chapters 27 and 28)

(chapter 27) (chapter 24) (chapter 31)

CT, computed tomography; mGCS , modified Glasgow coma scale; POCUS , Point-of-Care ultrasound. Modified from Trauma Stabilization Course Module 1 working group.

Chapter 21 Approach to polytrauma

123

> Table 21.3 Animal Trauma Triage (ATT) score.13 Perfusion

Cardiac

Respiratory

Eye/muscle/ integument

Skeletal

Neurological

> HR : 120-200 > Normal sinus rhythm

> Regular respiratory rate with no stridor > No abdominal component to resp

> Abrasion, laceration: > Weight bearing none or partial in three or four thickness limbs, no palpable fracture or joint > Eye: no fluorescein laxity uptake

> HR : 200-260 > Normal sinus rhythm or VPCs <20/min

> Mildly ↑ resp rate and effort ± some abdominal component > Mildly ↑ upper airway sounds

> Abrasion, laceration: > Closed appendi> Central: conscious cular/rib fx or any full thickness, but dull, depressed, mandibular fx no deep tissue withdrawn involvement > Single joint laxity/ > Peripheral : luxation incl. > Eye: corneal abnormal spinal sacroiliac joint laceration/ulcer, not reflexes with perforated purposeful > Pelvic fx with movement and unilateral intact nociception intact SI-ilium-acetab in all four limbs > Single limb open/ closed fx at or below carpus/tarsus

> HR : >260 > Consistent arrhythmia

> Moderately ↑ resp effort with abdominal component, elbow abduction > Moderately ↑ upper airway sounds

> Abrasion, laceration: > Multiple grade > Central: full thickness, deep unconscious but 1 conditions tissue involvement, responds to noxious (see above) and arteries, nerves, > Single long bone stimuli muscles intact > Peripheral: absent open fracture > Eye: corneal above carpus/tarsus purposeful with cortical bone movement with perforation, preserved intact nociception punctured globe or proptosis in two or more > Non-mandibular limbs or nociception skull fracture absent only in one limb > ↓ anal and/or tail tone

> HR : ≤120 > Erratic arrhythmia

> Marked respiratory effort or gasping/agonal respiration or irregularly timed effort > Little or no detectable air passage

> Central: > Penetration to > Vertebral body thoracic/abdominal fracture/luxation nonresponsive cavity (except coccygeal) to all stimuli; refractory seizures > Abrasion, laceration: > Multiple long bone open fracture above > Peripheral: absent full thickness, deep tarsus/carpus tissue involvement, nociception in and artery, two or more limbs; > Single long bone nerve, or muscle absent tail or open fracture above compromised perianal nociception tarsus/carpus with loss of cortical bone

Grade 0 > MM pink and moist > CRT <2 s > Rectal temp ≥37.8° C (100° F) > Femoral pulses strong or bounding

> Central : conscious, alert slightly dull; interest in surroundings > Peripheral : normal spinal reflexes; purposeful movement and nociception in all limbs

Grade 1 > MM hyperemic or pale pink; MM tacky > CRT 0-2 s > Rectal temp ≥37.8° C (100° F) > Femoral pulses fair

Grade 2 > MM very pale pink & very tacky > CRT 2-3 s > Rectal temp <37.8° C (100° F) > Detectable but poor femoral pulses

Grade 3 > MM gray, blue, or white > CRT >3 s > Rectal temp <37.8° C (100° F) > Femoral pulse not detected

CRT, capillary refill time; fx, fracture; HR , heart rate; MM, mucosal membranes; VPC, ventricular premature complexes.

124

Section III TRAUMA

medicine in order to inform recommendations for next diagnostic and therapeutic steps. While the clinician performs the secondary survey, it is recommended if staff resources allow an abbreviated history is obtained from the owner. Brief history questions including how the injury occurred, patient status between injury and clinic arrival (ability to breathe, walk, interact), any allergies, current medications, and recent illnesses or diagnoses are recommended. If available, an additional teammate can (re)obtain and document patient vitals (temperature, pulse rate and quality, respiratory rate, body weight) and the Animal Trauma Triage score (table 21.3) that has been validated as a “degree of injury” score in feline patients.3,13

Preparation, communication and team work While a majority of feline patients with trauma have relatively minor injuries and primary and secondary surveys can be completed rapidly by 1-2 team members, thoughtful preparation and readiness by a team is important for situations when more severely injured feline patients arrive potentially disrupting the daily clinical flow. Established readiness protocols and/or checklists can have a positive impact on patient outcome and team confidence.5,7

For consideration: > Designated crash cart with supplies necessary for trauma resuscitation (primary survey) or CPR. > Established consent form and stabilization estimate for clients that includes fees associated with primary and secondary survey (e.g., exam fee, oxygen supplementation, IV catheter, initial fluids, minimum database, POCUS, pain relief). > Trained “front of the house”/front desk staff able to obtain informed consent from owners in emergent situation ± obtain pertinent historic information for secondary survey. > Relationship with other facilities and transport protocol for patients that need additional medical resources for definitive care (e.g., blood product, 24-hour monitoring, specialty interventions). > Team able to readily flex into roles for high acuity cases (1 person may need to fulfill multiple roles): – Leader (perform primary and secondary surveys). – IV catheter placement. – Placement of monitoring equipment and run bedside blood tests. – Get medications and fluid ready for administration. – Record findings and interventions. – Communicate with owner.

R E FE R EN C E S 1. O’Neill DG CD, McGreevy PD, Thomson PC, Brodbelt DC. Longevity and mortality of cats in England. Available from: https://www.rvc.ac.uk/Media/Default/VetCompass/ Documents/VetCompass%20Longevity%20and%20Mortality%20of%20Cats%20in%20England.pdf 2. Hall KE, Boller M, Hoffberg J, McMichael M, Raffe MR, Sharp CR. ACVECC-Veterinary Committee on Trauma Registry Report 2013-2017. J Vet Emerg Crit Care (San Antonio) 28:497-502, 2018. 3. Ash K, Hayes GM, Goggs R, Sumner JP. Performance evaluation and validation of the animal trauma triage score and modified Glasgow Coma Scale with suggested category adjustment in dogs: A VetCOT registry study. J Vet Emerg Crit Care (San Antonio) 28:192-200, 2018. 4. Haynes AB, Weiser TG, Berry WR, Lipsitz SR, Breizat AH, Dellinger EP, et al. A surgical safety checklist to reduce morbidity and mortality in a global population. N Engl J Med 360:491-499, 2009. 5. Kelleher DC, Carter EA, Waterhouse LJ, Parsons SE, Fritzeen JL, Burd RS. Effect of a checklist on advanced trauma life support task performance during pediatric trauma resuscitation. Acad Emerg Med 21:1129-1134, 2014. 6. Hodgetts TJ, Mahoney PF, Russell MQ, Byers M. ABC to <C>ABC: redefining the military trauma paradigm. Emerg Med J 23:745-746, 2006. 7. Spahn DR, Bouillon B, Cerny V, Duranteau J, Filipescu D, Hunt BJ, et al. The European guideline on management of

major bleeding and coagulopathy following trauma: 5th edition. Critical Care 23, 2019. 8. Mulherin BL, Snyder CJ, Soukup JW, Hetzel S. Retrospective evaluation of canine and feline maxillomandibular trauma cases. A comparison of signalment with non-maxillomandibular traumatic injuries (2003-2012). Vet Comp Orthop Traumatol 27:192-197, 2014. 9. Lyons BM, Ateca LB, Otto CM. Clinicopathologic abnormalities associated with increased animal triage trauma score in cats with bite wound injuries: 43 cases (1998-2009). J Vet Emerg Crit Care (San Antonio) 29:296-300, 2019. 10. Lisciandro GR, Lagutchik MS, Mann KA, Fosgate GT, Tiller EG, Cabano NR, et al. Evaluation of an abdominal fluid scoring system determined using abdominal focused assessment with sonography for trauma in 101 dogs with motor vehicle trauma. J Vet Emerg Crit Care (San Antonio) 19:426-437, 2009. 11. Stillion JR, Fletcher DJ. Admission base excess as a predictor of transfusion requirement and mortality in dogs with blunt trauma: 52 cases (2007-2009). J Vet Emerg Crit Care (San Antonio) 22:588-594, 2012. 12. Holowaychuk MK, Monteith G. Ionized hypocalcemia as a prognostic indicator in dogs following trauma. J Vet Emerg Crit Care (San Antonio) 21:521-530, 2011. 13. Rockar RA DK, Shofer FS. Development of a scoring system for the veterinary trauma patient. J Vet Emerg Crit Care (San Antonio) 4:77-83, 1994.