Category: Critical Care
Keywords: sodium bicarbonate, bicarb, OHCA, cardiac arrest, CPR, resuscitation (PubMed Search)
Posted: 2/8/2023 by Kami Windsor, MD
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Background: The use of sodium bicarbonate in the treatment of out-of-hospital cardiac arrest (OHCA) has been longstanding despite conflicting data regarding its benefit, outside of clear indications such as toxic ingestion or hyperkalemic arrest.
Study: A recent retrospective cross-sectional study by Niederberger et al.1 examined prehospital EHR data for ALS units responding to nonpregnant adults with nontraumatic OHCA, noting use of prehospital bicarb and the outcomes of 1) ROSC in the prehospital encounter and 2) survival to hospital discharge. They created propensity-matched pairs of bicarb and control patients, with a priori confounders: age, sex, race, witnessed status, bystander CPR, prearrival instructions, any defibrillation attempt, use of CPR feedback devices, any attempted ventilation, length of resuscitation, number of epi doses.
There were 23,567 arrests (67.4% asystole, 16.6% PEA, 15.1% VT/VF), 28.3% overall received sodium bicarb.
Results:
In the propensity-matched sample, survival was higher in bicarb group (5.3% vs. 4.3%; p=0.019).
There were no differences in rate of ROSC overall, but looking at the different rhythms, ROSC was higher in the bicarb group with asystole as the presenting rhythm (bicarb 10.6 vs 8.8%; p=0.013) but not PEA or VT/VF.
*There is no indication by the authors as to the dosing of bicarb most associated with survival to hospital discharge (or ROSC in asystole) in the study, however a previous study has indicated that a single amp of bicarb is unlikely to significantly improve severe metabolic acidosis (pH <7.1),2 so the general recommendation of at least 1-2mEq/kg should be employed.
Bottom Line: The use of sodium bicarb may increase survival in OHCA with initial PEA/asystole. The recommended initial dose is 1-2mEq/kg; giving at least 2 amps of bicarb (rather than the standard 1) should achieve this in many patients.
Between 1/2019 and 12/2020, there were 23,567 arrests that met inclusion criteria.
Overall EMS ROSC: 18.4%
Overall survival to hospital discharge: 7.6%
In the propensity-matched sample – survival was higher in bicarb group (5.3% vs. 4.3%; p=0.019).
There were no differences in rate of ROSC overall, but looking at the different rhythms, ROSC was higher in the bicarb group with asystole as the presenting rhythm (bicarb 10.6 vs 8.8%; p=0.013) but not PEA or VT/VF.
Overall, bicarb use was associated with improved survival (OR 1.25 (1.04-1.51) / aOR 1.3 (1.06-1.59) but not increased ROSC.
