C-853-01. Anti-Xa–Guided LMWH Prophylaxis in Adult Burn Patients: A Systematic Review of Current Evidence

Abstract Introduction Burn injury creates a prothrombotic and pharmacokinetically unstable state complicating venous thromboembolism (VTE) prophylaxis. Fixed-dose low-molecular-weight heparin (LMWH) often yields subprophylactic anti-Xa levels, prompting interest in anti-Xa–guided dosing. To date, no comprehensive review has focused exclusively on anti-Xa–guided LMWH in burn patients. We synthesized evidence comparing anti-Xa–guided LMWH with fixed dosing in adult burn inpatients and outlined implications for practice and research. Methods We systematically searched PubMed, Embase, and Cochrane with a medical librarian through September 2025. We included adult burn studies of LMWH prophylaxis comparing anti-Xa–guided adjustment with fixed dosing, reporting VTE, bleeding, anti-Xa levels, dose changes, or mortality. Two reviewers independently screened and extracted data. Heterogeneity in targets, monitoring schedules, and populations precluded pooling. Results Seven studies spanning 2004–2025 met inclusion criteria. No randomized trials were identified; all were single-center observational designs, majority retrospective. Sample sizes ranged from small case series to cohorts exceeding 800 patients. Across studies of fixed-dose LMWH prophylaxis, a large proportion of burn patients failed to achieve prophylactic anti-Xa levels. In cohorts where anti-Xa–guided adjustment was implemented, attainment of target levels improved substantially. VTE events were reported in both strategies, but trends favored anti-Xa–guided protocols, with several studies noting fewer DVT or PE events in adjusted groups. Importantly, bleeding complications were infrequent overall and did not increase with anti-Xa monitoring or dose escalation. Mortality was variably reported and not consistently different between groups. Conclusions Evidence, though limited and low certainty, indicates fixed-dose LMWH often leaves burn patients subtherapeutic, while anti-Xa–guided adjustment improves adequacy without added bleeding. Although observational and susceptible to bias, these findings support individualized dosing as a potential strategy to lower VTE risk, warranting prospective validation. Applicability of Research to Practice Until definitive trials, burn centers should recognize high risk of subtherapeutic anticoagulation with fixed-dose LMWH, especially in patients with large TBSA burns, obesity, or fluid shifts. Centers with resources may adopt structured anti-Xa monitoring with standardized timing and escalation algorithms, paired with surveillance for bleeding and VTE, as an interim quality-improvement measure. Funding for the study N/A.