M. A. Brooke1,2, L. Yeung1,2, E. Miraflor1,2, G. Arturo1,2, G. Victorino1,2 1University Of California – San Francisco,General Surgery,San Francisco, CA, USA 2Highland Hospital,General Surgery,Oakland, CA, USA
Introduction: Despite hemodynamic stability on arrival, trauma patients can have occult severe injuries and may deteriorate with little warning. Early identification of this subset of patients may improve care, especially for those who will require a massive transfusion (MT). Our hypothesis was that an elevated admission lactate predicts the need for MT in hemodynamically normal patients.
Methods: All trauma patients treated at our university-based urban trauma center over a 5 year period were reviewed. Inclusion criteria consisted of hemodynamically normal patients (systolic blood pressure >90 mmHg and heart rate between 60-100 bpm) who had an admission lactate. Demographics and outcomes were analyzed using Chi square and unpaired t-tests, a receiver-operating curve (ROC) and univariate and multivariate regressions.
Results: Out of 5951 hemodynamically normal trauma patients, 3468 (58%) had an admission lactate. Patients who received a MT (n=19) had a higher lactate than those who did not receive a MT (n=3449) (5.6 vs 2.6 mmol/L, p=<0.001). ROC curve analysis for admission lactate as a predictor of MT showed an area under the curve (AUC) of 0.71 and a threshold lactate value of 4 mmol/L. Patients with a lactate of >4mmol/L had increased mortality (8 vs 2%), longer hospital LOS (6 vs 3 days), longer ICU LOS (6 vs 3 days), greater need for MT (2.8 vs 0.3%) and greater amount of blood transfused (219vs 38 ml; all p-values <0.001). After controlling for confounding variables with univariate and multivariate regression, the predictive value of admission lactate>4 for MT remained strong (OR 5.2; 95% CI 1.87-14.2).
Conclusion: The admission lactate is a robust predictor of massive transfusions and is associated with poor outcomes even in hemodynamically normal trauma patients. An admission lactate >4 mmol/L may identify those patients at greater risk of clinical decompensation.