New Article Review

This week an interesting Phase 3 RCT evaluating the effect of Bicarbonate on outcomes among critically ill patients was published

Sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit (BICAR-ICU): a multicentre, open-label, randomised controlled, phase 3 trial
Samir Jaber et al ; www.thelancet.com Published online June 14, 2018 http://dx.doi.org/10.1016/S0140-6736(18)31080-8

Sodium Bicarbonate infusions have been used quite extensively in ICUs for acidotic patients with varied thresholds and targets of pH.
There are both proponents as well as opponents to this approach.
The BICAR-ICU study evaluated the effect of 125-250 ml of 4.2% NaHCO3 on the 28 day mortality amongst a varied cohort of critically ill patients. Total volume was capped at 1000ml. A total of 389 patients were randomized to control and intervention groups. The pH threshold was <7.20 and the target was 7.30. Nearly half the patients had septic shock. Blood gases were done 1-4 hrs after the completion of the infusion. Primary endpoint was 28 day mortality. Patients with AKI (AKIN st 2-3 ) were identified as a subgroup apriori. The investigators found no difference in the entire cohort, between the two groups in relation to the primary outcome. However, a positive effect was noted in the subgroup of patients with AKI. The patients who received NaHCO3 needed lesser no of RRT sessions and came off RRT quicker. But there was no difference either in ICU or hospital length of stay.

My opinion: The use of bicarbonate in this study happened at a pH higher than what is generally considered as a "dangerous" pH. The volume of drug used also was higher than normally used. There may be some role in AKIN 2-3 AKI but the solution used was hyperosmolar. We need to identify patients who benefit from this intevention