Risk Factors Associated with Invasive Fungal Infections in Combat Trauma

Abstract

Background: In recent years, invasive fungal infections (IFI) have complicated the clinical course of patients with combat-related injuries. Commonalities in injury patterns and characteristics among patients with IFI led to the development of a Joint Trauma System ( JTS) clinical practice guideline (CPG) for IFI management. We performed a case-control study to confirm and further delineate risk factors associated with IFI development in combat casualties with the objective of generating data to refine the CPG and promote timelier initiation of treatment. Methods: Data were collected retrospectively for United States (U.S.) military personnel injured during deployment in Afghanistan from June 2009 through August 2011. Cases were identified as IFI based upon wound cultures with fungal growth and/or fungal elements seen on histology, in addition to the presence of recurrent wound necrosis. Controls were matched using date of injury ( -3 mo) and injury severity score ( -10). Risk factor parameters analyzed included injury circumstances, blood transfusion requirements, amputations after first operative intervention, and associated injuries. Data are expressed as multivariate odds ratios (OR; 95% confidence interval [CI]). Results: Seventy-six IFI cases were identified from 1,133 U.S. military personnel wounded in Afghanistan and matched to 150 controls. Parameters associated significantly with the development of IFI multivariate analysis were blast injuries (OR: 5.7; CI: 1.1-29.6), dismounted at time of injury (OR: 8.5; CI: 1.2-59.8); above the knee amputations (OR: 4.1; CI: 1.3-12.7), and large-volume packed red blood cell (PRBC; > 20 U) transfusions within first 24 h (OR: 7.0; CI: 2.5-19.7). Conclusions: Our analysis indicates that dismounted blast injuries, resulting in above the knee amputations, and requirement of large volume PRBC transfusions are independent predictors of IFI development. These data confirm all the preliminary risk factors, except for genitalia/perineal injuries, utilized by JTS in their IFI CPG. Model validation is necessary for further risk factor specification.

Impact of Mucorales and Other Invasive Molds on Clinical Outcomes of Polymicrobial Traumatic Wound Infections

“…Specifically, times to wound closure for IFI wounds were significantly longer than those for wounds with SSTIs but lacking fungal infection. This complexity is likely due to the magnitude of tissue loss and severity of the blast injury, along with virulence and tissue destruction due to mold infection (11). While this finding highlights the morbidity of molds in trauma wounds in general, the longer times to wound closure for Mucorales infections suggests increased pathogenicity of this mold type in these wounds.…”

“…Further analyses have examined risk factors, clinical outcomes, and the effect of an early IFI diagnosis practice guidance (10,11). In a recent analysis, IFI case patients had significantly greater residual limb shortening, more amputation level revisions, and a longer time to initial wound closure than a control patient group without fungal-infected wounds matched on injury pattern (12).…”

Challenges in definitive fracture management of blast injuries

“…The infected tissue has a grayish appearance, and the diagnosis is verified by biopsy and fungal cultures. Independent risk factors for developing IFI have been shown to be blast injury while on foot patrol, above knee amputations, and massive transfusions (>20 units) of packed red blood cells within 24 h post-injury [42]. IFI must be treated with serial, aggressive debridement and often result in the loss of large volumes of muscle tissue, as well as length of the residual limb.…”

Combat-Related Pythium aphanidermatum Invasive Wound Infection: Case Report and Discussion of Utility of Molecular Diagnostics

“…Blast injuries from IEDs have the potential for severe disruption of skin and bone and contamination of wounds with organic material such as soil and plant matter (13). Risk factors associated with IFIs include dismounted injuries while on foot patrol and large-volume blood transfusions (11,14).…”

“…Notably, large-volume PRBC transfusion (Ͼ20 units) may represent a marker for severe disease rather than an independent risk factor (14).…”