Predictors of mortality in close proximity blast injuries during Operation Iraqi Freedom

Blast injury is an increasingly common problem faced by military surgeons in the field. Because of urban terrorism worldwide, blast injury is becoming more common in the civilian sector as well. Blast injuries are often devastating and can overwhelm medical resources. We sought to determine whether simple factors easily obtained from the clinical history and primary survey could be used to triage patients more effectively.

A retrospective review of 18 consecutive close-proximity blast injury patients presenting to a forward deployed surgical unit in Iraq was performed. Patients' injuries and outcomes were recorded. We compared the presence of sustained hypotension, penetrating head injury, multiple (three or more) long-bone fractures, and associated fatalities (whether another patient involved in the same explosion died) between nonsurvivors and survivors using Fisher's exact test.

All patients who presented alive but exhibited sustained hypotension (n = 5) died, versus 0% who did not exhibit sustained hypotension (n = 9, p < 0.01). There was no marked increase in mortality with presence of multiple long-bone fractures, penetrating head injury, or associated fatalities individually. Having two or more of these factors was associated with a mortality of 86% (6 of 7) versus 20% (2 of 10, p = 0.015) in those who had less than two factors.

Blast injury can overwhelm military and civilian trauma systems alike. Sustained hypotension and presence of two or more easily determined factors, including three or more long-bone fractures, penetrating head injury, and associated fatalities, are associated with increased mortality and can potentially help triage patients and allocate scarce resources more efficiently.