Infections Complicating the Care of Combat Casualties During Operations Iraqi Freedom and Enduring Freedom

BACKGROUND: Continued assessment of casualty complications, such as infections, enables the development of evidence-based guidelines to mitigate excess morbidity and mortality. We examine the Joint Theater Trauma Registry (JTTR) for infections and potential risk factors, such as transfusions, among Iraq and Afghanistan trauma patients. METHODS: JTTR entries from deployment-related injuries with completed records between March 19, 2003, and April 13, 2009, were evaluated using International Classification of Diseases-9 codes for infections defined by anatomic/clinical syndromes and/or type of infecting organisms. Risk factors included mechanisms of injury, patient demographics, Injury Severity Score (ISS), and transfusion, including massive transfusions (≥ 10 units of packed red blood cells). RESULTS: We reviewed 16,742 patients entries (15,021 from Operation Iraqi Freedom (9,883 battle injuries BI) and 1,721 from Operation Enduring Freedom (1,090 BI). A total of 96.6% were men and 77.6% were Army personnel. The majority of BI were due to explosive devices (36.3%). There were 921 patients (5.5%) who had one or more infection codes with only 111 (0.6%) recorded deaths (16 with infections). Infections were commonly gram-negative bacteria (47.6%) involving skin/wound infections (26.7%), and lung infections (14.6%). Risk factors or associations that were most notable in univariate and multivariate analysis were calendar year of trauma, ISS, and pattern of injury. CONCLUSION: The 5.5% infection rate is consistent with previous military and civilian trauma literature; however, with the limitations of the JTTR, the infection rate is likely an underrepresentation due to inadequate level V and long-term infectious complications data. Combat operational trauma is primarily associated with gram-negative bacteria typically involving infections of wounds or other skin structures and lung infections such as pneumonia. They are commonly linked with higher ISS and injuries to the head, neck, and face.