Development of a prehospital lactic acidosis score for early-mortality. A prospective, multicenter, ambulance-based, cohort study

Am J Emerg Med. 2023 Mar:65:16-23. doi: 10.1016/j.ajem.2022.12.030. Epub 2022 Dec 22.

Abstract

Background: Lactic acidosis is a clinical status related to clinical worsening. Actually, higher levels of lactate is a well-established trigger of emergency situations. The aim of this work is to build-up a prehospital early warning score to predict 2-day mortality and intensive care unit (ICU) admission, constructed with other components of the lactic acidosis besides the lactate.

Methods: Prospective, multicenter, observational, derivation-validation cohort study of adults evacuated by ambulance and admitted to emergency department with acute diseases, between January 1st, 2020 and December 31st, 2021. Including six advanced life support, thirty-eight basic life support units, referring to four hospitals (Spain). The primary and secondary outcome of the study were 2-day all-cause mortality and ICU-admission. The prehospital lactic acidosis (PLA) score was derived from the analysis of prehospital blood parameters associated with the outcome using a logistic regression. The calibration, clinical utility, and discrimination of PLA were determined and compared to the performance of each component of the score alone.

Results: A total of 3334 patients were enrolled. The final PLA score included: lactate, pCO2, and pH. For 2-day mortality, the PLA showed an AUC of 0.941 (95%CI: 0.914-0.967), a better performance in calibration, and a higher net benefit as compared to the other score components alone. For the ICU admission, the PLA only showed a better performance for AUC: 0.75 (95%CI: 0.706-0.794).

Conclusions: Our results showed that PLA predicts 2-day mortality better than other lactic acidosis components alone. Including PLA score in prehospital setting could improve emergency services decision-making.

Keywords: Acidosis; Clinical decision-making; Lactate; Mortality; Pre-hospital care.

Publication types

  • Multicenter Study

MeSH terms

  • Acidosis, Lactic*
  • Adult
  • Ambulances
  • Cohort Studies
  • Emergency Medical Services* / methods
  • Hospital Mortality
  • Humans
  • Intensive Care Units
  • Lactic Acid
  • Polyesters
  • Prospective Studies
  • Retrospective Studies

Substances

  • Lactic Acid
  • Polyesters