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

• Published in: The American journal of emergency medicine Vol. 65; pp. 16 - 23
• Main Authors: Martín-Rodríguez, Francisco, Ortega, Guillermo J., Castro Villamor, Miguel A., del Pozo Vegas, Carlos, Delgado Benito, Juan F., Martín-Conty, José L., Sanz-García, Ancor, López-Izquierdo, Raúl
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-03-2023; Elsevier Limited
• Subjects: Acidosis; Acidosis, Lactic; Adult; Ambulances; Calibration; Clinical decision making; Cohort analysis; Cohort Studies; Comorbidity; Data collection; Decision making; Emergency medical care; Emergency Medical Services - methods; Hospital Mortality; Hospitals; Humans; Intensive Care Units; Lactate; Lactic Acid; Lactic acidosis; Mortality; Patients; Polyesters; Pre-hospital care; Prospective Studies; Public health; Regression analysis; Retrospective Studies; Variables; Lactate; Pre-hospital care; Acidosis; Clinical decision-making; Mortality
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2022.12.030

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.
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.
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).
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.
•Prehospital lactic acidosis (PLA) score identify risk of 2 day mortality.•A total of 3334 patients were considered in a derivation - validation cohort study.•PLA presented an AUC of 0.941(95% CI:0.914–0.967) for the prediction of mortality.•PLA improves lactate's results.