Introduction: Ventilator-associated pneumonia (VAP) secondary to Acinetobacter spp.in critically-ill trauma patients has increased. More importantly, the incidence of multi-drug resistant (MDR) Acinetobacter VAP has also increased. Still, the risk factors associated with this increased resistance have yet to be elucidated. The purpose of this study was to evaluate the change in Acinetobacter sensitivity over time and determine which risk factors predict resistance in trauma patients.

Methods: Patients (surviving >5 days post-injury) with Acinetobacter VAP (?105 CFU/mL in BAL) over 5 years were divided based on pathogen sensitivity (sensitive [SEN] vs MDR) and stratified by age, severity of shock (BE, blood transfusions), injury severity (ISS, admission GCS, chest and extremity AIS) and year. Empiric (E), prophylactic (P), E+P and total antibiotic days, ventilator days and mortality were compared. Multivariable logistic regression (MLR) was performed to determine which risk factors were independent predictors of resistance.

Results: 96 patients (81% men) were identified: 62 SEN and 34 MDR. Groups were clinically similar in terms of age, shock and injury severity with the exception of ext AIS (Table). Antibiotic exposure was also increased in the MDR group (Table). The incidence of MDR Acinetobacter VAP increased from 0 to 66% (p<.0001) over the study.

	E	P	Total	Ext AIS
SEN	2.5	1.7	15	1.4
MDR	1.8	6.9	26	2.2
p	.052	<.0001	.0001	.01

MLR identified P antibiotic days as an independent predictor of MDR in patients with Acinetobacter VAP after adjusting for age, chest AIS and year (OR=1.94, p<.0001).

Conclusion: The incidence of MDR Acinetobacter VAP has increased over time. Increased extremity AIS may have contributed to unnecessary prolonged antibiotic exposure in those patients with MDR Acinetobacter VAP. In fact, MLR identified prophylactic antibiotic days as an independent risk factor for MDR Acinetobacter VAP in trauma patients.