Utilization of age-adjusted shock index in a resource-strained setting

Background: Identification of injury severity and appropriate triage are critical to effective surgical care, especially where medical and surgical resources are strained. We hypothesized that pediatric age-adjusted shock index (SIPA) would outperform traditional shock index (SI) in a middle-income country (MIC) setting. Methods: Injured children hospitalized in two trauma centers (South Africa and the United States) from 2012 to 2017 were reviewed. Maximum heart rate and minimum systolic blood pressure defined SI. SI > 0.9 defined elevation. SIPA elevation was based on SI stratified by age: 1–6 years (SI > 1.22), 7–12 years (SI > 1.0), and 13–17 years (SI > 0.9). SI and SIPA were compared using univariate analyses and area under the receiver operating characteristic curves (AUROC). Results: 1648 patients (741 MIC and 907 high-income country (HIC)) were evaluated with a median [IQR] age of 11 [6–15] years. SI was elevated in 377 (51%) MIC children, whereas SIPA was elevated in 248 (34%). In both the HIC and MIC, elevated SIPA was more associated with ISS ≥ 25, ICU admission, and mortality. In MIC patients specifically, elevated SIPA improved discrimination for in-hospital mortality (AUROC 0.66 vs AUROC 0.57, p < 0.01). Conclusion: In a multinational cohort including MIC patients, SIPA facilitated identification of injured children with altered physiology, reflecting greater injury severity and poorer outcomes. Use of SIPA has the potential for more effective resource utilization in MICs. Level of evidence: Level III.