Utility of blood lactate level in triage

Prognostic value of lactate in prehospital care as a predictor of early mortality

BACKGROUND

Prehospital Emergency Medical Services must attend to patients with complex physiopathological situations with little data and in the shortest possible time. The objective of this work was to study lactic acid values and their usefulness in the prehospital setting to help in clinical decision-making.

STUDY DESIGN

We conducted a longitudinal prospective, observational study on patients over 18 years of age who, after being evaluated by the Advanced Life Support Unit, were taken to the hospital between April and June 2018. We analyzed demographic variables, prehospital lactic acid values and early mortality (<30 days). The area under the curve of the receiver operating characteristic was calculated for the prehospital value of lactic acid.

RESULTS

A total of 279 patients were included in our study. The median age was 68 years (interquartile range: 54-80 years). Overall 30-day mortality was 9% (25 patients). The area under the curve for lactic acid to predict overall mortality at 30 days of care was 0.82 (95% CI: 0.76-0.89). The lactate value with the best sensitivity and specificity overall was 4.25 mmol/L with a sensitivity of 84% (95% CI: 65.3-93.6) and specificity of 70% (95% CI: 65.0-76.1).

CONCLUSIONS

The level of lactic acid can be a complementary tool in the field of prehospital emergencies that will guide us early in the detection of critical patients.