Blood Lactate Level and the Predictor of Death in Non-shock Septic Patients

OBJECTIVE: To evaluate the association of initial blood lactate with mortality and subsequent septic shock in non-shock septic patients. MATERIALS AND METHODS: A retrospective cohort study was conducted at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University, Muang, Chiang Mai, Thailand. Inclusion criteria included septic patients admitted to a non-critical medical ward and had initial serum lactate at the emergency department (ED). Shock and other causes of hyperlactatemia were excluded. RESULTS: A total of 448 admissions were included with median age [interquartile range (IQR)] of 71 (59, 87) years and 200 males (44.6%). Pneumonia was the most common cause of sepsis (47.5%). The median systemic inflammatory response syndrome (SIRS) and quick sequential organ failure assessment (qSOFA) scores were 3 (2, 3) and 1 (1, 2), respectively. The median initial blood lactate was 2.19 (1.45, 3.23) mmol/L. The high blood lactate (≥2 mmol/L) group; N = 248, had higher qSOFA and other predictive scores and had significantly higher 28 days mortality (31.9% vs 10.0%; p < 0.001) and subsequent 3 days septic shock (18.1% vs 5.0%; p < 0.001) than the normal blood lactate group; N = 200. A combination of blood lactate above or equal to 2 mmol/L plus the national early warning score (NEWS) above or equal to 7 showed the highest prediction of 28 days mortality with the area under receiver-operating characteristic curve (AUROC) of 0.70 [95% confidence interval (CI): 0.65–0.75]. CONCLUSIONS: An initial blood lactate level above or equal to 2 mmol/L is associated with high mortality and subsequent septic shock among non-shock septic patients. The composite of blood lactate levels and other predictive scores yields better accuracy to predict mortality. HOW TO CITE THIS ARTICLE: Noparatkailas N, Inchai J, Deesomchok A. Blood Lactate Level and the Predictor of Death in Non-shock Septic Patients. Indian J Crit Care Med 2023;27(2):93–100.