Abstract 12: Predicting Post-Injury Hemorrhage: The Potential Utility of Point-of-Care Lactate
Background: Standard hemodynamic monitoring of patients in shock may underestimate the severity of hemorrhage given physiologic compensation. Although systolic blood pressure (SBP) ≤90 is currently used in trauma triage and prehospital (PH) trial enrollment; some advocate that SBP ≤110 more accurately defines hypotension. Blood lactate (BL) is an important adjunct in characterizing shock and its use PH could improve triage and selection for clinical trials. The study aim was to assess BL levels with need for transfusion in patients with SBP ≤110.
Methods: Trauma patients admitted to a level I trauma center over a 6 year period with ED SBP ≤110 and BL levels were selected. Proportional hazards regression (assuming an equal time at risk for all patients) was used to estimate risk ratios (RRs) for the association between BL and requiring ≥6 units PRBC within 48 hours post-injury. Models were stratified by SBP and adjusted for age, sex, and injury type.
Results: 2122 patients with SBP ≤110 were included (see Table⇓). There is a significant association between elevated BL and increased risk of requiring ≥6 units PRBC within 48 hours post-injury within SBP categories, as seen with trend p-values. While adjusted RRs are similar across SBP categories for a given BL, increased risk is seen with increased BL, suggesting that BL is a greater predictor of PRBC need than SBP.
Conclusions: In this ED based study, BL is not only a useful adjunct to SBP in determining the need for significant PRBC transfusion, but is a better predictor than SBP alone. These findings suggest BL measurements PH could improve trauma triage and help identify patients for enrollment in interventional trials of hemorrhagic shock. Extension to the PH setting is needed to confirm these results.