HĂŠctor H. Cubides Z. Internal Medicine
BIOFILM
INTRODUCTION BIOFILM (Pathophysiological) : • Microorganisms attach synthetic surfaces • Microorganisms multiply • Extracellular polymeric substance (Matrix) BIOFILM (Problem) • Associated device-related infections • Bacterial antibiotic resistance
INTRODUCTION ENDOTRAQUEAL TUBE (ETT): Impairs mucocilliary clearance Disrupts cough reflex Inoculate bacteria low airway Produce injury airway PROMOTE
BIOFILM VAP VAP
INTRODUCTION • Biofilm be universally on surface ETT • High concordance between microorganisms: – Colonization oropharyngeal-ETT (biofilm)-VAP
• ETT biofilm promote survival bacterial • Microbial persistence airways implicated: – Lack response A/B (RESISTANCE-FAILURE TTO) – Relapse VAP
OBJETIVE INVESTIGATE THE ROLE OF ETT BIOFILM IN VAP PATHOGENESIS, RESPONSE TO TREATMENT AND RELAPSE
MATERIALS AND METHODS • Prospective observational study single center • Follow-up period 7 month • Protocol reviewed, approved X Institutional Review Board
• Patients (relatives) provided informed consent • Inclusion criteria: – All patients required MV for at least 24 hours
MATERIALS AND METHODS STATISTICAL ANALYZES (SPSS 16.0): • Results continuous variables expressed: – Mean/Median (Interquartile range) for and the
• Results dichotomous variables expressed: – # (Percentage)
• Risk factors analyzed by univariate analysis – chi-square test/ANOVA (Dichotomous variables) – Mann-Whitney U test (Continuous variables)
• P <0.05
MATERIALS AND METHODS DATA RECORDED: • Age - Sex • APACHE II Score • Cause and duration mechanical ventilation • Maneuvers to prevent VAP • Occurrence or not of nosocomial pneumonia • Pathogen isolated (respiratory samples ETT biofilm)
• Antibiotic therapy and sensitivity patterns
MATERIALS AND METHODS RESPIRATORY SAMPLES surveillance sampling TIME TIMEINTUBATION INTUBATION
(analysis (analysismicrobiology microbiologylaboratory) laboratory)
TWICE TWICEXXWEEK WEEK
(analysis (analysismicrobiology microbiologylaboratory) laboratory)
BAL BALBEFORE BEFORETO TOSTART STARTA/B A/B (Suspected (SuspectedVAP) VAP)
MATERIALS AND METHODS PROCESSING ETT AFTER EXTUBATION ETT (1CM) WAS COLLECTED ELECTRON ELECTRONMICROSCOPY MICROSCOPY
QUANTIFY QUANTIFY BIOFILM BIOFILM
IDENTIFY IDENTIFY MICROORGANISMS MICROORGANISMS
BACTERIAL BACTERIALCULTURES CULTURES
OPERATIONAL DEFINITIONS VAP: – New infiltrates > 48 hours after intubation – 2 or more: Fever, / WBC, Purulent secretions – Microbiological confirmation by BAL (> 1.000 UFC/ml)
– Management based ATS/IDSA guidelines
VAP-EARLY: – Pneumonia initiated 4 days/less intubation
OPERATIONAL DEFINITIONS MICROBIAL PERSISTENCE: • Persistence causative microorganism VAP least 2 successive respiratory samples, despite 72 H A/B
VAP RELAPSE: • • • • •
New clinical at least 72 H after clinical resolution Culture (+) for previously isolated strain New infiltrate on the chest X-ray IRSS Absence extrapulmonary source of infection
OPERATIONAL DEFINITIONS TREATMENT FAILURE: Least one, 72 H after initiation A/B – Failure to improve PaO2/FiO2 – Fever/hypothermia + purulent secretions – Worsening pulmonary infiltrates (> 50%) – Septic shock/Multiple organ dysfunction not present at the onset of pneumonia
RESULTS 81 PATIENTS THAT REQUIRED IMV 2:2:LOSS LOSSOF OFETT ETTAFTER AFTEREXTUBATION EXTUBATION 4:4:INAPPROPRIATE INAPPROPRIATEFIXATION FIXATIONTECHNIQUE TECHNIQUE
75 PATIENTS INCLUDED ANALYSIS ALL ALLMULTIDRUGMULTIDRUGRESISTANT RESISTANT
RESULTS
RESULTS - SURVEILLANCE CULTURES • Bacterial growth cultures (+) 65 patients (87%) • ETA sampled, 252/151 (60%) grew (+) microorganisms • Latency time 2.1 ± 0.4 days
ALL ALLMULTIDRUG-RESISTANT MULTIDRUG-RESISTANT
RESULTS - BIOFILM FORMATION • Biofilm was present 71 (95%) ETTs: – Scarce biofilm (18%) – Dispersed clusters biofilm (37%) – Confluent abundant biofilm (41%)
• Biofilm formation was not associated: – Duration stay ETT – Selective digestive decontamination – Systemic antibiotics – Grade immunosuppression
RESULTS - VAP
EARLY EARLYONSET ONSET
RESULTS - VAP Days intubation Previous airway colonization Associated Associated(+) (+)
LATE-ONSET VAP
P. Aeurginosa (OR) 10.2; 95% CI, 2.11- 49.3; P = 0.005
A. Baumannii (OR) 4.9, 1.18-20.3; P = 0.03
RESULTS - VAP Age - Gender APACHE II Grade Immunosuppression Diabetes Cause of ICU admission Cause of intubation A/B previo to intubation Biofilm extension Not NotAssociated Associated
DEVELOPMENT VAP
CONCLUSIONS • A. baumannii-P. aeruginosa most frequently implicated microbial persistence • Bacterial survival on biofilm was associated to microbial persistence (100% vs 29%; P = 0.021) • All TTO failure/relapse related A. baumannii - P. aeruginosa
BACTERIAL BACTERIAL SURVIVAL SURVIVAL
BACTERIAL SURVIVAL SURVIVAL BACTERIAL
CONCLUSIONS
CONCLUSIONS TENDENCY (57% vs 14%; P = 0.133): TTO failure was more frequent when causal bacteria remained biofilm despite appropriate TTO
Biofilm formation and airway colonization were necessary but not sufficient for VAP development