sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit bicaricu a multicentre openlabel randomised controlled phase 3 trial background acute acidaemia is frequently observed during critical illness sodium bicarbonate infusion for the treatment of severe metabolic acidaemia is a possible treatment option but remains controversial as no studies to date have examined its effect on clinical outcomes therefore we aimed to evaluate whether sodium bicarbonate infusion would improve these outcomes in critically ill patientsmethods we did a multicentre openlabel randomised controlled phase 3 trial local investigators screened eligible patients from 26 intensive care units icus in france we included adult patients aged 18 years who were admitted within 48 h to the icu with severe acidaemia ph 720 paco2 45 mm hg and sodium bicarbonate concentration 20 mmoll and with a total sequential organ failure assessment score of 4 or more or an arterial lactate concentration of 2 mmoll or more we randomly assigned patients 11 by stratified randomisation with minimisation via a restricted web platform to receive either no sodium bicarbonate control group or 42 of intravenous sodium bicarbonate infusion bicarbonate group to maintain the arterial ph above 730 our protocol recommended that the volume of each infusion should be within the range of 125250 ml in 30 min with a maximum of 1000 ml within 24 h after inclusion randomisation criteria were stratified among three prespecified strata age sepsis status and the acute kidney injury network akin score the primary outcome was a composite of death from any cause by day 28 and the presence of at least one organ failure at day 7 all analyses were done on data from the intentiontotreat population which included all patients who underwent randomisation this study is registered with clinicaltrialsgov number nct02476253findings between may 5 2015 and may 7 2017 we enrolled 389 patients into the intentiontotreat analysis in the overall population 194 in the control group and 195 in the bicarbonate group the primary outcome occurred in 138 71 of 194 patients in the control group and 128 66 of 195 in the bicarbonate group absolute difference estimate 55 95 ci 152 to 42 p024 the kaplanmeier method estimate of the probability of survival at day 28 between the control group and bicarbonate group was not significant 46 95 ci 4054 vs 55 4963 p009 in the prespecified akin stratum of patients with a score of 2 or 3 the kaplanmeier method estimate of survival by day 28 between the control group and bicarbonate group was significant 37 95 ci 2848 vs 54 4565 p00283 corrected metabolic alkalosis hypernatraemia and hypocalcaemia were observed more frequently in the bicarbonate group than in the control group with no lifethreatening complications reportedinterpretation in patients with severe metabolic acidaemia sodium bicarbonate had no effect on the primary composite outcome however sodium bicarbonate decreased the primary composite outcome and day 28 mortality in the apriori defined stratum of patients with acute kidney injuryfunding french ministry of health and the socit