Pulmonary and Critical Care Medicine pulmonary and critical care medicine
The Best Review and Test Questions in Medicine:
• Pulmonary Diagnostic Tests
• Asthma • Chronic Obstructive Pulmonary Disease • Diffuse Parenchymal Lung Disease • Occupational Lung Disease • Pleural Disease • Pulmonary Vascular Disease • Lung Tumors • Sleep Medicine • High-Altitude–Related Illnesses • Critical Care
Plus much more . . .
ISBN 978-1-938245-11-4
9 781938 245114
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Medical Knowledge Self-Assessment Program
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Pulmonary and Critical Care Medicine All New Content, Including 108 Multiple-Choice Questions
C u m u l at i v e
INDEX
16 AMA PRA Category 1 Credits™ available until Dec. 31, 2015.
9/27/12 2:00 PM
Table of Contents
Pulmonary Diagnostic Tests Pulmonary Function Testing . . . . . . . . . . . . . . . . . . . . . . . 1 Spirometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Bronchial Challenge Testing . . . . . . . . . . . . . . . . . . . . 1 Lung Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Diffusing Capacity for Carbon Monoxide . . . . . . . . . . 3 6-Minute Walk Test . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pulse Oximetry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Imaging and Bronchoscopy . . . . . . . . . . . . . . . . . . . . . . . . 3 Chest Radiography . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Computed Tomography . . . . . . . . . . . . . . . . . . . . . . . 4 Positron Emission Tomography . . . . . . . . . . . . . . . . . 4 Bronchoscopy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Asthma Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Epidemiology and Natural History . . . . . . . . . . . . . . . . . . 7 Pathogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Clinical Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Asthma Syndromes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Occupational Asthma . . . . . . . . . . . . . . . . . . . . . . . . . 8 Reactive Airways Dysfunction Syndrome. . . . . . . . . . . 9 Virus-Induced Asthma . . . . . . . . . . . . . . . . . . . . . . . . 9 Cough-Variant Asthma . . . . . . . . . . . . . . . . . . . . . . . . 9 Gastroesophageal Reflux Disease and Asthma . . . . . . 10 Allergic Bronchopulmonary Aspergillosis . . . . . . . . . 10 Exercise-Induced Bronchospasm. . . . . . . . . . . . . . . . 10 Vocal Cord Dysfunction . . . . . . . . . . . . . . . . . . . . . . 10 Aspirin-Sensitive Asthma. . . . . . . . . . . . . . . . . . . . . . 10 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Pharmacotherapy . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Allergen Immunotherapy and Allergen Avoidance. . . 15 Alternative and Complementary Therapies . . . . . . . . 15 Management of Asthma Exacerbations . . . . . . . . . . . 15 Difficult-to-Manage Asthma . . . . . . . . . . . . . . . . . . . 15 Asthma and Pregnancy. . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Chronic Obstructive Pulmonary Disease Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Extrapulmonary Effects and Comorbid Conditions . . . . . 18
Assessment and Monitoring of Disease Progression . . . . . 19 Assessment and Classification . . . . . . . . . . . . . . . . . . 19 Ongoing Monitoring . . . . . . . . . . . . . . . . . . . . . . . . 20 Referral. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Pharmacologic Therapy . . . . . . . . . . . . . . . . . . . . . . 21 Nonpharmacologic Therapy . . . . . . . . . . . . . . . . . . . 26 Managing Exacerbations of COPD . . . . . . . . . . . . . . . . . 28 Home Management . . . . . . . . . . . . . . . . . . . . . . . . . 29 Hospital Management . . . . . . . . . . . . . . . . . . . . . . . 29 Hospital Discharge and Follow-up . . . . . . . . . . . . . . 29
Diffuse Parenchymal Lung Disease Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Classification and Epidemiology. . . . . . . . . . . . . . . . . . . . 30 Diagnostic Approach and Evaluation . . . . . . . . . . . . . . . . 30 History and Examination Features . . . . . . . . . . . . . . 30 High-Resolution CT. . . . . . . . . . . . . . . . . . . . . . . . . 31 Surgical Lung Biopsy . . . . . . . . . . . . . . . . . . . . . . . . 32 Idiopathic Interstitial Pneumonias . . . . . . . . . . . . . . . . . . 32 Idiopathic Pulmonary Fibrosis . . . . . . . . . . . . . . . . . 32 Nonspecific Interstitial Pneumonia . . . . . . . . . . . . . . 34 Cryptogenic Organizing Pneumonia. . . . . . . . . . . . . 34 Acute Interstitial Pneumonia. . . . . . . . . . . . . . . . . . . 34 Diffuse Parenchymal Lung Disease of Known Cause . . . . 35 Smoking-Related Parenchymal Lung Disease . . . . . . 35 Connective Tissue Disease . . . . . . . . . . . . . . . . . . . . 35 Hypersensitivity Pneumonitis . . . . . . . . . . . . . . . . . . 35 Drug-Induced and Radiation-Induced Parenchymal Lung Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Miscellaneous Diffuse Parenchymal Lung Diseases. . . . . . 38 Sarcoidosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Lymphangioleiomyomatosis . . . . . . . . . . . . . . . . . . . 38
Occupational Lung Disease Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 When to Suspect an Occupational Lung Disease . . . . . . . 39 Key Elements of the Exposure History. . . . . . . . . . . . . . . 39 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Surveillance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Asbestos-Related Lung Diseases. . . . . . . . . . . . . . . . . . . . 40 Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
ix
Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Pleural Diseases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Silicosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Pleural Disease Pleural Effusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 History and Physical Examination. . . . . . . . . . . . . . . 42 Pleural Fluid Analysis . . . . . . . . . . . . . . . . . . . . . . . . 43 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Pneumothorax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Pulmonary Vascular Disease Acute Pulmonary Thromboembolism . . . . . . . . . . . . . . . 46 Pathophysiology and Epidemiology . . . . . . . . . . . . . 46 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Acute Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Ongoing Management and Prevention of Recurrent Pulmonary Embolism . . . . . . . . . . . . . . . . . . . . . . . . 51 Pulmonary Hypertension. . . . . . . . . . . . . . . . . . . . . . . . . 52 Pathophysiology and Epidemiology . . . . . . . . . . . . . 52 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Chronic Thromboembolic Pulmonary Hypertension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Pulmonary Arterial Hypertension . . . . . . . . . . . . . . . 54
Lung Tumors Pulmonary Nodule Evaluation. . . . . . . . . . . . . . . . . . . . . 55 Assessment of Risk for Malignancy . . . . . . . . . . . . . . 55 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Lung Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Screening and Primary Prevention . . . . . . . . . . . . . . 58 Diagnosis and Evaluation . . . . . . . . . . . . . . . . . . . . . 58 Staging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Prognosis and Follow-up . . . . . . . . . . . . . . . . . . . . . 61 Other Pulmonary Neoplasia. . . . . . . . . . . . . . . . . . . . . . . 62 Carcinoid Tumors. . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Mesothelioma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Neoplasms Metastatic to the Lung . . . . . . . . . . . . . . 63 Mediastinal Masses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Anterior Mediastinal Masses . . . . . . . . . . . . . . . . . . . 63 Middle Mediastinal Masses . . . . . . . . . . . . . . . . . . . . 63 Posterior Mediastinal Masses. . . . . . . . . . . . . . . . . . . 63
Sleep Medicine Excessive Daytime Sleepiness . . . . . . . . . . . . . . . . . . . . . . 64 x
Common Conditions that Disrupt Circadian Rhythm . . . 64 Jet Lag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Shift Work Sleep Disorder. . . . . . . . . . . . . . . . . . . . . 64 Obstructive Sleep Apnea . . . . . . . . . . . . . . . . . . . . . . . . . 65 Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Clinical Features and Diagnosis. . . . . . . . . . . . . . . . . 65 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Central Sleep Apnea Syndromes. . . . . . . . . . . . . . . . . . . . 67 Classification and Pathophysiology . . . . . . . . . . . . . . 67 Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Symptoms and Diagnosis . . . . . . . . . . . . . . . . . . . . . 67 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Sleep-Related Hypoventilation Syndromes . . . . . . . . . . . . 68 Chronic Obstructive Pulmonary Disease. . . . . . . . . . 68 Obesity Hypoventilation Syndrome . . . . . . . . . . . . . 68 Neuromuscular Diseases . . . . . . . . . . . . . . . . . . . . . . 68
High-Altitude–Related Illnesses Sleep Disturbances and Periodic Breathing. . . . . . . . . . . . 69 Acute Mountain Sickness and High-Altitude Cerebral Edema . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 High-Altitude Pulmonary Edema . . . . . . . . . . . . . . . . . . 69 Air Travel in Pulmonary Disease . . . . . . . . . . . . . . . . . . . 69
Critical Care Recognizing the Critically Ill Patient . . . . . . . . . . . . . . . . 70 Respiratory Failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Hypoxemic Respiratory Failure. . . . . . . . . . . . . . . . . 70 Ventilatory (Hypercapnic) Respiratory Failure. . . . . . 72 Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Noninvasive Mechanical Ventilation . . . . . . . . . . . . . . . . . 78 Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Patient Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Invasive Mechanical Ventilation . . . . . . . . . . . . . . . . . . . . 80 Acute Respiratory Distress Syndrome . . . . . . . . . . . . 80 Obstructive Lung Disease . . . . . . . . . . . . . . . . . . . . . 81 Weaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Ventilator-Associated Pneumonia . . . . . . . . . . . . . . . 81 Sepsis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Classification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Emergent Disorders in Critical Care. . . . . . . . . . . . . . . . . 84 Acute Inhalational Injuries . . . . . . . . . . . . . . . . . . . . 84 Anaphylaxis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Hypertensive Emergencies . . . . . . . . . . . . . . . . . . . . 85 Hyperthermic Emergencies. . . . . . . . . . . . . . . . . . . . 86
Hypothermic Emergencies . . . . . . . . . . . . . . . . . . . . 87 Toxicology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Acute Abdominal Surgical Emergencies . . . . . . . . . . 90 Supportive Care in Critical Illness . . . . . . . . . . . . . . . . . . 92 Intensive Care Unit–Acquired Weakness . . . . . . . . . . 93 Persistent Neuropsychiatric Disorders After Critical Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Nutrition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Approaches to Providing Best Practice . . . . . . . . . . . . . . . 94 Structural Measures . . . . . . . . . . . . . . . . . . . . . . . . . 94
Process Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Rapid Response Team. . . . . . . . . . . . . . . . . . . . . . . . 94 Intensive Care Unit Prognosis . . . . . . . . . . . . . . . . . . . . . 94
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Self-Assessment Test . . . . . . . . . . . . . . . . . . . . . . . . . 99 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
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Pulmonary and Critical Care Medicine
Pulmonary Diagnostic Tests Pulmonary Function Testing Pulmonary function tests are used to evaluate patients with pulmonary symptoms (most frequently dyspnea). They provide information on the degree of impairment and potential causes. These tests are typically obtained in patients with known lung disease or unexplained pulmonary symptoms; they are also used to establish a baseline in patients who are starting a job or a treatment that may cause lung dysfunction. They should be performed during preoperative evaluation, especially in patients undergoing thoracic surgery (particularly lung resection). Pulmonary function tests are essential in these patients to assess the feasibility of lung resection and calculate predicted lung function after resection.
Spirometry Spirometry is the most widely used pulmonary function test. It can be performed in the outpatient setting with relative simplicity using small, hand-held devices that can be connected to a personal computer for immediate display and storage of test results. Spirometry is obtained by measurement of forced expiratory volume over time after the patient has taken a deep inspiration (Table 1). Coaching the patient throughout the
TABLE 1. Guidelines for Performance of Office Spirometry
Spirometry should be performed by a trained medical technician using an approved spirometer that is calibrated regularly The patient is seated comfortably and is asked to: inhale completely position the mouthpiece in the mouth and close lips around it exhale with maximal force Coach the patient to perform the expiratory volumes tracing for 6-12 seconds Three technically adequate curves should be obtained The FVC and FEV1 values in at least two of these curves should not vary by more than 5% (reproducible curve) The highest FEV1 and FVC from any of the reproducible curves can be used Compare the results to predicted values based on age, height, gender, and race Data from: Standardization of Spirometry, 1994 Update. American Thoracic Society. Am J Respir Crit Care Med. 1995;152(3):1107-1136. [PMID: 7663792]
maneuver is critical to obtaining an optimal result. The patient may have to repeat the maneuver up to eight times to generate a reproducible and maximum effort. The maximum volume exhaled in this maneuver is referred to as the forced vital capacity (FVC); the maneuver should last 6 to 12 seconds to obtain an accurate measurement. The forced expiratory volume exhaled in the first second is called the FEV1. An FEV1/FVC ratio of less than 70% indicates airway obstruction. Spirometry can be repeated after giving an inhaled bronchodilator to assess reversibility, which is defined as an improvement in FEV1 of 12% or greater compared with baseline (provided the increase in FEV1 is actually greater than 200 mL). An important aspect of examining spirometry is reviewing the flow-volume curve for evidence of hesitation, cough, or a slow start, all of which could influence the accuracy of the results. A flow-volume loop can help determine the cause of airway obstruction (Figure 1).
Bronchial Challenge Testing Bronchial challenge testing is performed to assess airway hyperresponsiveness. This test is very sensitive for asthma, but it is not very specific. Many conditions, including viral infections, allergy, smoking, bronchitis, and cystic fibrosis, can increase airway responsiveness. Bronchial challenge testing requires the support of a skilled technician to obtain serial spirometry measurements while administering increasing concentrations of an inhaled medication that promotes bronchoconstriction. Because the test may trigger significant bronchospasm, it should be performed in a controlled setting with personnel trained to manage provoked airway obstruction. A test is diagnostically positive if the FEV1 falls 20% from baseline. It is important to understand that this degree of bronchospasm seen on a challenge test is not diagnostic of asthma, given the many potential causes of a positive test. Patients with asthma may have a false-negative test if they have recently used their bronchodilator, if the test is not performed appropriately, or if the patient has seasonal or occupational asthma without recent exposures. The most appropriate use of this test is to exclude asthma in patients with normal spirometry and symptoms consistent with, but not typical of, asthma. The direct airway stimulants methacholine and histamine are the most commonly used agents for bronchial challenge testing. The FDA recently approved the use of inhaled mannitol to evaluate airway responsiveness. Mannitol is regarded as an indirect challenge that leads to release of endogenous mediators when inhaled, which in turn causes airway smooth
1
Pulmonary Diagnostic Tests
Expiratory Flow
Expiratory Flow
Inspiratory Flow
Inspiratory Flow
Volume
Volume
- - - - - = After bronchodilator
- - - - - = After bronchodilator
Expiratory Flow
Expiratory Flow
Inspiratory Flow
Inspiratory Flow Volume
Volume
- - - - - = After bronchodilator F I G U R E 1 . Top left panel: Flow-volume loop demonstrating normal spirometry, with similar maximum inspiratory and expiratory flows; no significant change is seen after bronchodilator administration. Top right panel: Flow-volume loop demonstrating asthma, with a reduction in peak expiratory flow and concave curvature for the expiratory limb while the inspiratory limb remains normal; improvement is seen in expiratory flows (particularly the increase in peak flow) after bronchodilator administration. Bottom left panel: Flow-volume loop demonstrating COPD, with a significant reduction in peak expiratory flow and concave appearance of the expiratory limb; no significant change is seen after bronchodilator administration. Bottom right panel: Flow-volume loop demonstrating fixed obstruction/tracheal stenosis, with flattening of the peak inspiratory and expiratory flows.
2
This self-assessment test contains one-best-answer multiple-choice questions. Please read these directions carefully before answering the questions. Answers, critiques, and bibliographies immediately follow these multiple-choice questions. The American College of Physicians is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. The American College of Physicians designates MKSAP 16 Pulmonary and Critical Care Medicine for a maximum of 16 AMA PRA Category 1 CreditsTM. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Earn “Same-Day” CME Credits Online For the first time, print subscribers can enter their answers online to earn CME credits in 24 hours or less. You can submit your answers using online answer sheets that are provided at mksap.acponline.org, where a record of your MKSAP 16 credits will be available. To earn CME credits, you need to answer all of the questions in a test and earn a score of at least 50% correct (number of correct answers divided by the total number of questions). Take any of the following approaches: ‚ Use the printed answer sheet at the back of this book to record your answers. Go to mksap.acponline.org, access the appropriate online answer sheet, transcribe your answers, and submit your test for same-day CME credits. There is no additional fee for this service. ‚ Go to mksap.acponline.org, access the appropriate online answer sheet, directly enter your answers, and submit your test for same-day CME credits. There is no additional fee for this service. ‚ Pay a $10 processing fee per answer sheet and submit the printed answer sheet at the back of this book by mail or fax, as instructed on the answer sheet. Make sure you calculate your score and fax the answer sheet to 215-351-2799 or mail the answer sheet to Member and Customer Service, American College of Physicians, 190 N. Independence Mall West, Philadelphia, PA 19106-1572, using the courtesy envelope provided in your MKSAP 16 slipcase. You will need your 10-digit order number and 8-digit ACP ID number, which are printed on your packing slip. Please allow 4 to 6 weeks for your score report to be emailed back to you. Be sure to include your email address for a response. If you do not have a 10-digit order number and 8-digit ACP ID number or if you need help creating a username and password to access the MKSAP 16 online answer sheets, go to mksap.acponline.org or email custserv@acponline.org. CME credit is available from the publication date of December 31, 2012, until December 31, 2015. You may submit your answer sheets at any time during this period.
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Self-Assessment Test
Pulmonary and Critical Care Medicine Self-Assessment Test
Each of the numbered items is followed by lettered answers. Select the ONE lettered answer that is BEST in each case.
Item 1
Item 3
A 48-year-old man is evaluated for a 1-year history of cough. He has not had dyspnea, abdominal pain, heartburn, or change in appetite or weight. He has a 30-packyear history of smoking. He does not have seasonal allergies. His medical history is significant for hypertension that is treated with losartan. On physical examination, vital signs are normal. Pulmonary examination discloses normal breath sounds that are equal bilaterally with no wheezing. No nasal polyps are noted. Abdominal examination is unremarkable. There is no cyanosis, clubbing, or edema. Pulmonary function tests disclose an FEV1 of 75% of predicted and an FEV1/FVC ratio of 63%. Following administration of a bronchodilator, there is no significant change in the FEV1/FVC ratio, and the FEV1 is 83% of predicted. Chest radiograph shows no masses and normal lung markings.
A 78-year-old man is evaluated during a routine physical examination. One year ago, he was treated in the intensive care unit (ICU) for severe sepsis and respiratory failure due to community-acquired pneumonia. He was intubated for 9 days during the ICU stay and required treatment with corticosteroids, ceftriaxone, levofloxacin, lorazepam, vecuronium, and norepinephrine. A family member reports concern that the patient has not regained his ability to function independently since the illness. He is forgetful, has occasional difficulty finding words, gets lost easily in familiar places, and cannot seem to make decisions. The patient has successfully completed a physical therapy rehabilitation program and has regained his former muscle strength. There is no history of chronic illness such as coronary artery disease, diabetes mellitus, or hypertension, and he takes no medications. On physical examination, vital signs are normal. He is alert but slow to answer questions. The cardiopulmonary examination is normal. The Mini–Mental State Examination score is 25/30. There are no focal neurologic deficits.
Which of the following is the most likely cause of this patient’s cough? (A) (B) (C) (D)
Asthma COPD Gastroesophageal reflux disease Losartan
Item 2 A 66-year-old man is evaluated in the intensive care unit for possible extubation. He was admitted for a severe COPD exacerbation 3 days ago. His carbon dioxide remained markedly elevated despite a trial of noninvasive ventilation, and he was therefore intubated and placed on invasive mechanical ventilation. He has improved with treatment of his COPD. His medications are methylprednisolone, albuterol, ipratropium, propofol, and levofloxacin. On physical examination, he is awake and responsive. Temperature is 37.0 °C (98.6 °F), blood pressure is 138/82 mm Hg, pulse rate is 96/min, and respiration rate is 20/min. Pulmonary examination reveals decreased breath sounds bilaterally with no wheezing. Accessory muscle use is noted. A small amount of thin secretions is noted with endotracheal suctioning. Arterial blood gas levels have returned to baseline, with a pH of 7.36, a PCO2 of 55 mm Hg (7.3 kPa), and a PO2 of 70 mm Hg (9.3 kPa) on an FIO2 of 0.35. He tolerates a weaning trial well and the decision is made to extubate. Which of the following interventions will decrease this patient’s risk for reintubation? (A) (B) (C) (D)
Incentive spirometry every 2 hours Inhaled helium-oxygen mixture Nebulized N-acetylcysteine Noninvasive positive pressure ventilation
Which of the following factors associated with this patient’s critical illness is the most likely cause of his clinical findings? (A) (B) (C) (D)
Chronic disseminated intravascular coagulation Critical illness polyneuropathy Post-ICU neuropsychiatric impairment Prolonged neuromuscular blockade
Item 4 A 67-year-old man is evaluated for a 3-month history of pauses in breathing during sleep that have been witnessed by his wife. He has minimal snoring but occasional paroxysmal nocturnal dyspnea. His normal sleep schedule is 10:30 PM to 6:00 AM. He does not have insomnia or daytime sleepiness. He was recently diagnosed with heart failure. His current medications are aspirin, lisinopril, atorvastatin, and metoprolol. On physical examination, temperature is 36.6 °C (97.9 °F), blood pressure is 128/78 mm Hg, pulse rate is 88/min, and respiration rate is 16/min; BMI is 24. Cardiac examination discloses an S3 but no murmurs. Pulmonary examination shows a widely patent oropharyngeal airway and a few bibasilar crackles. There is trace bilateral lower extremity edema. Polysomnography discloses classic Cheyne-Stokes breathing. Oxygen saturation throughout the study is greater than 88%. Which of the following is the most appropriate next step in treatment? (A) (B) (C) (D) (E)
Adaptive servoventilation Continuous positive airway pressure Diuresis Nocturnal oxygen Oral appliance 101
Self-Assessment Test
Directions
Answers and Critiques Answer:
B
Educational Objective: Diagnose COPD. The most likely cause of this patient’s cough is COPD. His postbronchodilator FEV1/FVC ratio less than 70% confirms airflow limitation and a diagnosis of obstructive lung disease; his relatively preserved FEV1 suggests that his COPD is mild. COPD should be considered in any patient older than 40 years who has dyspnea, chronic cough or sputum production, and/or a history of risk factors (such as exposure to tobacco smoke, dust, chemicals, outdoor air pollution, or biomass smoke). Spirometry is the gold standard for diagnosing COPD and monitoring its progress; it should be done to confirm the diagnosis and to exclude other diseases. The American College of Physicians and Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines require an FEV1/FVC ratio of less than 70% of predicted to establish the diagnosis of COPD. The GOLD guidelines use the degree of airflow obstruction as measured by the FEV1 to further describe the level of disease. Level 1 (mild) COPD is characterized by an FEV1 of 80% of predicted or greater; level 2 (moderate) COPD is characterized by an FEV1 of 50% to 79% of predicted; level 3 (severe) COPD is characterized by an FEV1 of 30% to 49% of predicted; and level 4 (very severe) COPD is characterized by an FEV1 less than 30% of predicted. Although asthma may present with cough, it is unlikely in this patient owing to the lack of atopy and history of respiratory symptoms as a child or any other clinical findings consistent with bronchospasm. Gastroesophageal reflux disease may cause cough; however, COPD is the more likely cause of cough in this patient who does not have heartburn symptoms, has a history of smoking, and demonstrates airflow obstruction on pulmonary function testing. ACE inhibitors may be associated with cough, but angiotensin receptor blockers (such as losartan) have a significantly lower rate of cough as a side effect and would not be a likely cause of this patient’s cough given his other clinical parameters. KEY POINT
• Spirometry is essential for the diagnosis of COPD and assessing its degree of severity; a postbronchodilator FEV1/FVC ratio less than 70% confirms airflow limitation.
Item 2
Answer:
D
Educational Objective: Manage weaning from invasive ventilation with noninvasive positive pressure ventilation. The most appropriate intervention at the time of extubation is noninvasive positive pressure ventilation (NPPV). Application of NPPV shortly after extubation for a 24-hour period reduced the need for reintubation in previous trials of intubated patients with chronic lung disease and hypercapnia after a successful weaning trial. This population also appears to benefit from NPPV even if it is not applied until after the patient has developed respiratory failure following extubation. However, studies enrolling unselected patients with postextubation respiratory failure indicate that the use of NPPV may actually increase mortality. The use of incentive spirometry reduces the risk of postoperative pulmonary complications but does not have a role in the routine management of nonsurgical patients following extubation. The reduced gas density of helium-oxygen mixtures (heliox) reduces resistance to airflow, and thereby the work of breathing, in patients with obstructive lung disease. However, there is insufficient evidence to support the routine use of heliox in the management of COPD exacerbations. N-acetylcysteine is a mucolytic agent that has been used to thin secretions in patients with excess mucus production. However, N-acetylcysteine is less likely to benefit this patient because he had minimal secretions prior to extubation. Furthermore, nebulized N-acetylcysteine may trigger bronchospasm. KEY POINT
• Application of noninvasive positive pressure ventilation shortly after extubation for a 24-hour period reduced the need for reintubation in trials of intubated patients with chronic lung disease and hypercapnia after a successful weaning trial. Bibliography Ferrer M, Sellarés J, Valencia M, et al. Non-invasive ventilation after extubation in hypercapnic patients with chronic respiratory disorders: randomised controlled trial. Lancet. 2009;374(9695):10821088. [PMID: 19682735]
Item 3
Answer:
C
Bibliography
Educational Objective: Diagnose neuropsychiatric impairment as a common complication after critical illness.
Global Strategy for Diagnosis, Management, and Prevention of COPD. December 2011. Available at: www.goldcopd.org. Accessed July 27, 2012.
The most likely long-term complication of critical illness is persistent neuropsychiatric impairment, which can affect up 129
Answers and Critiques
Item 1