Modeling Musculoskeletal Combat Casualty Care: NATO Trauma System Performance in Large Scale Combat Operations.

Background: It is unclear whether the current North Atlantic Treaty Organization (NATO) trauma system will be effective in the setting of Large-Scale Combat Operations (LSCO). We sought to model the efficacy of the NATO trauma system in the setting of LSCO. We also intended to model novel scenarios that could better adapt the current system to LSCO. Methods: We developed a discrete-event simulation model for patients with combat musculoskeletal injuries treated within the standard NATO system. The primary outcome of the model was survival. The model's health states were characterized as stable, hypovolemia, sepsis, shock, or death. The model simulated combat intensity by increasing the number of casualties up to 192 casualties per 24 hours. We explored how an augmented system (FC) and Field Hospital (FH) moved closer to the battlefront would change performance. Results: Mortality rates rose precipitously from a 10% baseline to 61% at 12 casualties per 24 hours in the base model. This performance was not significantly different from that of the FC model at any casualty rate. Successful evacuation of casualties was significantly more for the FH model versus the base model at 12 casualties/24 hours (47.5% vs. 39%; p = 0.046), 48 casualties/24 hours (45.5% vs. 33%; p = 0.008), and 192 casualties/24 hours (25% vs. 15.5%; p = 0.02). Conclusions: The current NATO model experiences high rates of mortality in LSCO. The most effective modification entails situating Field Hospitals within one-hour of ground transport from the battlefront. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence.