Venous Thromboembolism Prophylaxis in Emergency General Surgery: A Retrospective Cohort Study of Timeliness, Prescribing, and Administration.

Background Venous thromboembolism (VTE) is a preventable cause of hospital-associated morbidity and mortality. In emergency general surgery, timely prophylaxis can be challenging because decisions regarding bleeding risk and urgent procedures must be balanced against the need for prompt pharmacological prophylaxis. This study quantified time to first pharmacological prophylaxis and compared VTE prevention processes across two sequential emergency general surgery cohorts. Methods We conducted a single-centre retrospective cohort study of adult emergency general surgical admissions across two predefined inpatient cohorts assessed approximately one month apart and separated by implementation of a targeted thromboprophylaxis practice change. Patient-level electronic prescribing and medication-administration records were used to measure time from admission to first low-molecular-weight heparin (LMWH) administration among patients for whom pharmacological prophylaxis was appropriate and a first administration time was assessable, and to evaluate VTE risk assessment, dose appropriateness, mechanical prophylaxis, and other process measures. Duplicate carry-over records, an elective admission, and records predating the implementation cutoff were excluded from the primary comparison. Categorical outcomes were compared using Fisher's exact test and continuous variables using the Mann-Whitney U test. Results Seventy-two emergency admissions were included (42 in the earlier cohort and 30 in the later cohort). Among patients with an assessable first LMWH administration time, the median admission-to-first-LMWH interval decreased from 20.8 hours (IQR: 13.9-27.9) to 16.4 hours (IQR: 10.5-21.5; p = 0.120), while administration within 14 hours increased from 8/32 (25.0%) to 9/24 (37.5%; p = 0.384). Correct completion of the electronic VTE risk-factor form increased from 8/42 (19.0%) to 26/30 (86.7%), an absolute increase of 67.6 percentage points (95% CI: 50.6-84.6; p < 0.001). Mechanical prophylaxis prescribing increased from 33/42 (78.6%) to 30/30 (100%; p = 0.008). Overall composite compliance did not change significantly. Conclusions In this retrospective cohort study, time to first LMWH administration improved numerically but remained frequently beyond the 14-hour threshold. Electronic VTE risk documentation and mechanical prophylaxis prescribing improved substantially in the later cohort. The findings identify a persistent gap between VTE assessment and timely pharmacological prophylaxis, highlighting medication-delivery processes as an important area for further evaluation and quality improvement in emergency general surgery.