The Fog of War: Delirium Prevalence in a Combat Intensive Care Unit

Delirium is a fluctuating disturbance in consciousness associated with increased mortality. Injured warriors represent a unique unstudied population. We hypothesized delirium is common because of high injury severity scores and multidrug sedation regimens.

Mandatory delirium screening using the confusion assessment method (CAM) was initiated at Craig Joint Theater Hospital in Bagram, Afghanistan. Data were collected in July to August 2012 from the first 50 English-speaking trauma patients with CAM for the Intensive Care Unit (ICU) scores.

Patients were male with mean age of 27.8 years; 88% of them were U.S. military personnel. Injury mechanisms were blast (68%) and gunshot (26%). Mean injury severity score was 20. Average ICU length of stay was 2.3 days; 64% were ventilated (for mean 1.2 days). Average time from arrival to CAM assessment was 7 hours, and 26 hours from the time of injury. Of patients, 44% were delirious, 36% at first CAM assessment. Fentanyl (62%) and ketamine (16%) were used for pain control (62%) and propofol for sedation (52%). There was no relationship between delirium and mechanism (p = 0.5) or ketamine on first ICU day (p = 0.2262). Delirium increased with vent days (p < .0001) and was associated with admission and mechanical ventilation (p = 0.0025).

This study demonstrates a high rate of delirium in this unique population.