Extracorporeal treatment of metforminassociated lactic acidosis in clinical practice: a retrospective cohort study

Abstract

PurposeTo assess whether extracorporeal treatment (ECTR) improves outcome of patients with metformin-associated lactic acidosis (MALA) and to evaluate the clinical applicability of the Extracorporeal Treatments in Poisoning Workgroup (EXTRIP) criteria for starting ECTR in metformin poisoning.MethodsPatients with metformin serum concentrations above 2 mg/l who were admitted in the Deventer Teaching Hospital between January 2000 and July 2019 and complied with the definition of MALA (pH < 7.35 and lactate concentration > 5 mmol/l) were included. Mortality and clinical parameters of patients treated with ECTR or not were compared. In addition, treatment of MALA in clinical practice was verified against the criteria of EXTRIP.ResultsForty-two patients were included. Lactate (13.8 versus 10.5 mmol/l, p = 0.01), creatinine (575 versus 254 umol/l, p < 0.01)), metformin (29.4 versus 8.6 mg/l, p < 0.01) concentrations, and vasopressor requirement (72% versus 23%, p < 0.01) were significantly higher in the ECTR-group. Blood pH (7.05 versus 7.19, p = 0.03) and bicarbonate (6 versus 11 mmol/l, p < 0.01) were significantly lower. Mortality, length of hospital stay, and mechanical ventilation requirement were not statistically different. In 83% of patients, treatment of MALA was in accordance with the EXTRIP criteria.ConclusionsAlthough there was no statistical benefit in mortality shown from ECTR, ECTR might be lifesaving in MALA, considering the ECTR-group was significantly sicker than the non-ECTR-group.The majority of patients were treated in line with the EXTRIP criteria. Severity of lactic acidosis and renal impairment were the main indications for initiating ECTR.