Invasion vs insurgency: US Navy/Marine Corps forward surgical care during Operation Iraqi Freedom.

HYPOTHESIS: The transition from maneuver warfare to insurgency warfare has changed the mechanism and severity of combat wounds treated by US Marine Corps forward surgical units in Iraq.

DESIGN: Case series comparison.

SETTING: Forward Resuscitative Surgical System units in Iraq.

PATIENTS: Three hundred thirty-eight casualties treated during the invasion of Iraq in 2003 (Operation Iraqi Freedom I [OIF I]) and 895 casualties treated between March 2004 and February 2005 (OIF II).

INTERVENTIONS: Definitive and damage control procedures for acute combat casualties.

MAIN OUTCOME MEASURES: Mechanism of injury, procedures performed, time to presentation, and killed in action (KIA) and died of wounds (DOW) rates.

RESULTS: More major injuries occurred per patient (2.4 vs 1.6) during OIF II. There were more casualties with fragment wounds (61% vs 48%; P = .03) and a trend toward fewer gunshot wounds (33% vs 43%; P = .15) during OIF II. More damage control laparotomies (P = .04) and more soft tissue debridements (P < .001) were performed during OIF II. The median time to presentation for critically injured US casualties during OIF I and OIF II were 30 and 59 minutes, respectively. The KIA rate increased from 13.5% to 20.2% and the DOW rate increased from 0.88% to 5.5% for US personnel in the First Marine Expeditionary Force area of responsibility.

CONCLUSIONS: The transition from maneuver to insurgency warfare has changed the type and severity of casualties treated by US Marine Corps forward surgical units in Iraq. Improvised explosive devices, severity and number of injuries per casualty, longer transport times, and higher KIA and DOW rates represent major differences between periods. Further data collection is necessary to determine the association between transport times and mortality rates.