Association of admission serum copeptin with hemorrhagic shock severity in adult trauma patients

Abstract Hemorrhagic shock remains a major cause of potentially preventable death after trauma, and early assessment of its severity is essential. This prospective observational biomarker study evaluated admission serum copeptin in 103 adult trauma patients. The primary analysis compared hemorrhagic shock stage 1 (n = 73) with stage ≥ 2 (n = 30). Median copeptin was 602.4 pg/mL (Q1–Q3, 519.3–646.6) in stage 1 and 679.5 pg/mL (650.5–744.3) in stage ≥ 2 (Mann–Whitney U = 371.5, p < 0.001); the Hodges–Lehmann location shift was 104 pg/mL (95% CI, 65–143). Copeptin discriminated stage ≥ 2 with an area under the curve of 0.830 (95% CI, 0.753–0.908). A sample-derived threshold of ≥ 642 pg/mL yielded 83.3% sensitivity and 71.2% specificity. In a model adjusted for age, sex, and Injury Severity Score, each 100-pg/mL copeptin increase was associated with higher odds of stage ≥ 2 (adjusted odds ratio, 2.235; 95% CI, 1.001–4.994; p = 0.050). Admission copeptin was associated with hemorrhagic shock severity, but the data-derived threshold and borderline adjusted association require external validation. Copeptin should be considered an exploratory adjunct rather than a standalone decision tool.