Point-of-care lactate as a predictor of 7-day morbidity and mortality in critically ill patients presenting to the emergency department in Kenyatta National Hospital

Abstract

Objectives: Hyperlactatemia is associated with increased risk of mortality. Point-of-care (POC) lactate levels have been used worldwide in the emergency department (ED) and critical care units for risk stratification. The aim of this study was to determine whether POC lactate levels are predictive of outcomes in our low-resource setting. Materials and Methods: This was a non-interventional prospective cohort study carried out at the ED Critical Care wards in Kenyatta National Hospital between June 12, 2021, and July 25, 2021. The study included consecutively consenting adults above 18 years at the ED who were critically ill as indicated by a Modified Early Warning Score of equal to or above 5. Lactate was measured using a handheld Statstrip lactate meter. Patients were followed up for 7 days, and outcomes were documented. Results: Two hundred and eighty-one patients were enrolled in the study. The mean lactate level was 4.0 mmoL/L with a median interquartile range of 3.0. Hyperlactatemia was evident in 161 (57%) using a cutoff of 2.5 mmoL/L. The all-cause mortality rate was 33.8%. Type A hyperlactatemia was the most common at 84.3% and 17.7% in Type B. Type A hyperlactatemia mortality rate was 37.1% and Type B 15.9% (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 1.3– 7.3, P = 0.006). In the high lactate group, the 7-day mortality rate was 42.2% compared to a mortality rate of 22.5% in the normal lactate group (OR: 2.5, 95% CI: 1.5–4.3, P = 0.001). Hyperlactatemia was associated with an increased need for intensive care unit admission (OR: 2.2, 95% CI: 1.3–3.7, P = 0.002) and organ support mainly mechanical ventilation (OR: 2.6, 95% CI: 1.5–4.4, P = 0.001) and inotropic/vasopressors support (OR: 2.7, 95% CI: 1.2–6.2, P = 0.016). Conclusion: POC lactate is an independent predictor of 7-day mortality with a 2-a fold increased risk of mortality and was associated with increased need for organ support.