Red-Green Tactical Lighting Is Preferred for Suturing Wounds in a Simulated Night Environment

Delivering medical care in nighttime conditions is challenging, as 25% of Special Operations medical Operators have reported that problems with lighting contributed to poor casualty outcomes. Red light is often used in nighttime operations but makes blood detection difficult and diminishes depth perception and visual acuity. Red-green combination lighting may be superior for differentiating blood from tissue and other fluids but had not been tested versus red-only or green-only lighting for combat-related medical procedures, such as wound suturing.

Dark-adapted medical resident physicians (N = 24) sutured 6cm long, 3cm deep, full-thickness lacerations in deceased swine under red-only, green-only, and red-green lighting provided by a tactical flashlight using a randomized within-subjects design. Time to suture completion, suture quality, user ratings, and user preference data were contrasted at p < .05. This study was approved by Naval Medical Center Portsmouth IRB.

Suture completion time and suture quality were similar across all lighting conditions. Participants rated red-green lighting as significantly easier for identifying blood, identifying instruments, and performing suturing (p < .01). Red-green lighting was preferred by 83% of participants compared to 8% each for red-only and green-only (p < .001).

Pending further study under tactical conditions, red-green lighting is tentatively recommended for treating battlefield wounds in low-light environments.