Blood lactate level as a predictor of patients\u2019 outcome at the Respiratory Intensive Care Unit of Zagazig University Hospitals

Abstract

BackgroundMany variables measured in critically ill patients have been used to predict patient outcomes; however, it is unlikely that one measurement can replace all, but lactate levels may come close.AimThis study aims to evaluate the role of blood lactate level as a predictor of patients’ outcome at Respiratory Intensive Care Unit at Zagazig University Hospitals (RICU-ZUH).Patients and methodsA prospective cohort study was conducted on 52 patients recruited from RICU-ZUH. All patients’ functional conditions were assessed on admission by the Simplified Acute Physiology Score II scoring system, Glasgow Coma Scale (GCS), and Sequential Organ Failure Assessment scores as well as assessment of sepsis. The blood lactic acid level was measured at H0 (initial blood lactate level), H6, H12, H24, and H48 (in mmol/l). Patients were classified into two groups: (i) normal blood lactate level group, and (ii) hyperlactatemia group. Lactate clearance and lactime were also measured.ResultsOut of the 52 cases studied, hyperlactatemia was present in 30 (57.6%) patients, whereas a normal blood lactate level was found in 22 (42.4%) patients. H0 was significantly high (P<0.01) in the hyperlactatemia group (4.41 ±1.69 mmol/l), with lactime 42.4±10.5 h; also, lactate clearance at H6 was nonsignificantly high (P>0.05). The Simplified Acute Physiology Score II and Sequential Organ Failure Assessment scores were significantly positively correlated with H0 and lactime, but significantly negatively correlated with lactate clearance, whereas GCS was negatively correlated in a significant way with H0 and lactime and positively correlated with lactate clearance. The significant highest mortality risk of 2.86 was reported with lactime more than 48 h, followed by a 2.28 risk of mortality with H0 blood lactate level more than 3.9 mmol/l, and the least risk was reported with GCS less than 10.5.ConclusionHyperlactatemia at admission and a prolonged lactime are valuable independent predictors of mortality of RICU patients.