Impact of Critical Care Air Transport Team (CCATT) ventilator management on combat mortality

BACKGROUND Aeromedical evacuation platforms such as Critical Care Air Transport Teams (CCATTs) play a vital role in the transport and care of critically injured and ill patients in the combat theater. Mechanical ventilation is used to support patients with failing respiratory function and patients requiring high levels of sedation. Mechanical ventilation, if not managed appropriately, can worsen or cause lung injury and contribute to increased morbidity. The purpose of this study was to evaluate the impact of ARDSNet protocol compliance during aeromedical evacuation of ventilated combat injured patients. METHODS We performed a retrospective chart review of combat injured patients transported by CCATTs from Afghanistan to Landstuhl Regional Medical Center (LRMC) in Germany between January 2007 and January 2012. After univariate analyses, we performed regression analyses to assess compliance and post-flight outcomes. Cox proportional hazard models were used to evaluate associations between the risk factor of non-compliance with increased number of ventilator, ICU, or hospital days. Nominal logistic regression models were performed to evaluate the association between non-compliance and mortality. RESULTS Sixty-two percent (n = 669) of 1,086 patients required mechanical ventilation during transport. A total of 650 patients required volume-controlled mechanical ventilation and were included in the analysis. Of the 650 subjects, 62% (n = 400) were non-compliant per tidal volume and ARDSNet table recommendations. The groups were similar in all demographic variables, except the Non-compliant group had a higher Injury Severity Score compared to the Compliant group. Subjects in the Compliant group were less likely to have an incidence of acute respiratory distress, acute respiratory failure, and ventilator-associated pneumonia when combing the variables (2% vs. 7%, p < 0.0069). The Non-compliant group had an increased incidence of in-flight respiratory events, required more days on the ventilator and in the ICU, and had a higher mortality rate. CONCLUSIONS Compliance with the ARDSNet guidelines was associated with a decrease in ventilator days, ICU days, and 30-day mortality. LEVEL OF EVIDENCE Therapeutic/care management, level IV.