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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: Pending further study under tactical conditions, red-green lighting is tentatively recommended for treating battlefield wounds in low-light environments.

Red-Green Versus Blue Tactical Light: A Direct, Objective Comparison.

BACKGROUND: Success in Special Operations Forces medicine (SOFMED) depends on maximizing visual capability without compromising the provider or casualty when under fire. There is no single light that has been deemed "ideal" for all SOFMED environments. METHODS: We used the Farnsworth-Munsell (FM) hue test to determine color vision of normal subjects under white, red-green, and blue flashlights to determine color discrimination. Then we used a timed color-determination visual test to determine how quickly normal subjects can identify color correctly. We had subjects perform a simulated surgery illuminated by a normal white-light source, then by red-green or blue light-emitting diode (LED) tactical light. RESULTS: The total error score for white light was 49.714, 272.923 for red/green light, and 531.4 for blue light. The subjective perception of simulated trauma wounds was not substantially different with red-green LED tactical light when compared with white LED light. However, simulated surgery under the blue LED was more difficult compared with simulated surgery under the red-green LED light. CONCLUSION: Red-green was a superior light source for SOFMED and military first responders in this study, especially, where light was required to allow accurate and efficient application of Tactical Combat Casualty Care to injured personnel.