Timing of thromboprophylaxis in acute spinal cord injury patients: a TQIP study in 15,960 patients

BACKGROUND CONTEXT: Optimal timing of pharmacologic thromboprophylaxis in patients with acute traumatic spinal cord injury (SCI) is unclear. Most guideline recommendations are consensus-based and lacking in primary large-scale data. This study evaluated an ideal timeframe for delivery of thromboprophylaxis in acute SCI. PURPOSE: Determine the ideal timeframe for initiation of chemical thromboprophylaxis in the setting of acute SCI. STUDY DESIGN/SETTING: Retrospective cohort study. North American trauma centers participating in the American College of Surgeons Trauma Quality Improvement Program (2017-2022). PATIENT SAMPLE: Adults (≥ 16 years) with acute SCI secondary to blunt trauma who underwent surgical decompression within 24 hours. OUTCOME MEASURES: Primary: in-hospital venous thromboembolism. Secondary: in-hospital return to the operating room, death during admission and length of stay. METHODS: Restricted cubic splines identified an inflection point defining early versus late thromboprophylaxis initiation, which was used for propensity score-matched comparisons. Covariates for propensity matching included patient, injury, treatment, and hospital characteristics. Effect size was calculated using risk difference (RDs) and odds ratio (OR) for dichotomous outcomes and mean difference (MD) for linear outcomes with associated 95% confidence interval (CI). RESULTS: 15,960 patients across 511 trauma centres were included. Spline analysis indicated increasing risk after 24-48 hours from surgery. In propensity-matched cohorts for postoperative day 1 (i.e. early <48 hours; late ≥48 hours) (N=6,867 per group), early thromboprophylaxis was associated with lower VTE rates (4.7% vs 5.9%; P=0.002; OR 1.26 [95%CI: 1.09, 1.46]), fewer returns to operating room overall (2.2% vs 2.9%; P=0.004; OR 1.38 [95%CI 1.11, 1.71]), no difference in return to operating room for same-level spine procedure (0.7% vs 1.0%; P=0.07; OR 1.4 [95%CI 0.98, 2.02]), lower mortality (4.0% vs 4.9%; P=0.003; OR 1.28 [95%CI: 1.09, 1.51]), and shorter length of stay (15.8 vs 16.9 days; P<0.001; MD 1.06 days [95%CI: 0.47, 1.65]). CONCLUSIONS: Thromboprophylaxis by postoperative day 1 after was associated with a decreased risk of venous thromboembolism, decreased returns to the operating room, no increased return to the operating room for related spine procedure, decreased risk of death, and decreased length of stay. Administration of thromboprophylaxis by postoperative day 1 for acute SCI patients may represent a new clinical standard for optimal patient outcomes.