What Factors Are Associated With Acute Compartment Syndrome After Gunshot Injuries to the Upper Extremity?

BACKGROUND Firearm-related injuries are a growing cause of morbidity and mortality in the United States, with varying odds of acute compartment syndrome (ACS) and other complications reported in the research. ACS is associated with higher complications after injury, including infection, need for repeat surgery, and functional loss, with the forearm being one of the most common sites for ACS. Although ACS in gunshot-related injuries has been studied, existing research documents wildly variable odds of developing ACS, with much of these data derived from military sources with high-energy weapons or inclusive of upper and lower extremity injuries. QUESTIONS/PURPOSES (1) What proportion of patients with upper extremity gunshot wounds (GSWs) experienced ACS? (2) Which patient- or injury-related factors, such as vascular injury, are associated with the development of ACS? (3) What postoperative complications are associated with ACS after gunshot injuries? METHODS Between May 2018 and January 2023, we treated 1740 patients with GSWs presenting to a single, urban Level 1 trauma center. After excluding lower limb and torso injuries, 773 patients with upper extremity injuries were identified, of which 42 left hospital care prior to assessment and therefore had no data for analysis, leaving 731 for inclusion. As part of our institutional standard, GSWs are trauma activations with a recommended 12 to 24 hours of observation followed by discharge with strict and specific return precautions and education on the signs and symptoms of compartment syndrome. Patient demographics, injury characteristics, and outcomes were collected through reviews of the electronic medical record (EMR) and a longitudinally maintained trauma database, which reflects a combination of 60% blunt and 40% ballistic injuries. Institutionally, the population with GSWs is predominantly male (90%), with a mean age of 32 years and injuries to the torso, pelvis and acetabulum, and the long bones, as well as periarticular fractures. Identification of patients with ACS was performed using the institutional trauma database followed by a search of the EMR for relevant Current Procedural Terminology codes and clinical documentation of gunshot injury and compartment syndrome, followed by manual chart review that specifically included patients without signs of ACS to capture those at risk, even if they did not go on to surgery. Univariate analysis was conducted to identify associations with ACS. RESULTS In patients with gunshot injuries to the upper extremity, we found that 2% (12 of 731) developed ACS, with all subsequent surgically treated patients undergoing forearm fasciotomy. Vascular injury was the only factor associated with the development of ACS OR 47 [95% confidence interval (CI) 12 to 181]; p < 0.001). Other variables, including fracture location and polytrauma, were not associated with the development of ACS. Patients who developed ACS had a high risk of persistent postoperative neurologic deficits (50% [6 of 12] of patients) compared with those without ACS, and patients with ACS had higher odds of having persistent neurologic deficits (OR 4.25 [95% CI 1 to 18]; p = 0.01). CONCLUSION Evaluation of a large group of patients with upper extremity GSWs demonstrated that at least 2% developed ACS. Although higher odds of ACS may occur, the protocols and monitoring observed in this study reduce but do not eliminate the risk that ACS development is higher. This study demonstrated that vascular injury has a strong independent association with ACS, regardless of fracture presence or injury location, and a high level of suspicion for ACS in these patients is warranted. While the overall risk of ACS in patients with upper extremity GSWs is small, the outcomes of missed ACS are severe, and close monitoring as well as discharge precautions outlining signs and symptoms necessitating return to the emergency department are recommended. Further research is warranted to improve early detection strategies, such as specialized imaging, remote monitoring, or standardized observation protocols. LEVEL OF EVIDENCE Level III, prognostic study.