Sodium Bicarbonate Administration in Cardiac Arrest with Severe Metabolic Acidosis
Date First Published:
September 3, 2019
Last Updated:
September 3, 2019
Report by:
Sierra Debenham MD, Jason Seamon DO, EM Senior Resident, EM Faculty (Spectrum Health/Michigan State University Emergency Medicine Residency Program)
Search checked by:
Jeffrey Jones MD, Spectrum Health/Michigan State University Emergency Medicine Residency Program
Three-Part Question:
In [adult patients with severe metabolic acidosis during prolonged cardiopulmonary resuscitation], does the [administration of sodium bicarbonate] lead to [higher sustained return of spontaneous circulation]?
Clinical Scenario:
A 67-year-old male with a history of type II diabetes and hypertension presents following an out-of-hospital cardiac arrest. Bystander CPR was initiated immediately. His initial rhythm was ventricular fibrillation and ACLS protocol was followed by EMS prior to arrival. Upon arrival, he remains in refractory ventricular fibrillation. A stat venous blood gas is obtained which reveals a pH of 6.8. You consider whether sodium bicarbonate would significantly increase the chances of obtaining return of spontaneous circulation in this patient.
Search Strategy:
Medline 1966-09/19 using PubMed, Cochrane Library (2019), and Embase
Search Details:
[(exp cardiopulmonary resuscitation OR exp cardiac arrest) AND (exp metabolic acidosis) AND (sodium bicarbonate)]. Limit to English language.
Outcome:
26 studies were identified; two addressed the clinical question.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Sodium bicarbonate administration during ongoing resuscitation is associated with increased return of spontaneous circulation Kim J, Kim K, Park J, Jo YH, Lee JH, Hwang JE, Ha C, Ko YS, Jung E. Feb-16 Republic of Korea | 599 adult patients presenting after cardiac arrest with ongoing CPR | Single-center matched case-control observational study | Return of spontaneous circulation within 20 minutes of arrival | Patients with acidosis had 2.78 times the odds of ROSC when sodium bicarbonate is administered | Observational study; significant baseline differences between two groups; unmeasured variables may affect results; neurologically intact survival not analyzed. |
| Sodium bicarbonate on severe metabolic acidosis during prolonged cardiopulmonary resuscitation: a double-blind, randomized placebo-controlled pilot study Ahn S, Kim YJ, Sohn CH, Seo DW, Lim KS, Donnino MW, Kim, WY. Apr-18 Republic of Korea | 50 adult patients with out of hospital arrest | RCT | Change in acidosis (pH) | Change in pH from 6.90 to 6.99 at 20 minutes (p=0.038) | Empiric rather than weight-based bicarbonate dosing; primary endpoint is not a patient-centered outcome; likely underpowered study for their secondary outcomes. |
| Secondary endpoints: ROSC, survival to hospital admission, and good neurologic outcome at 1 month | No change in sustained ROSC, survival to hospital admission, or good neurological at 1 month |
Author Commentary:
The routine administration of sodium bicarbonate in cardiac arrest has not been shown to improve outcomes in cardiac arrest. In fact, the generation of excess CO2 may lead to the adverse effects of inducing respiratory acidosis and causing acidosis in the cerebrospinal fluid, with subsequent cerebral edema. However, the role of sodium bicarbonate in mitigating severe metabolic acidosis is less clear. These two studies sought to answer this question, and their results are mixed. The larger study found an increase in retrun of spontaneous circulation (ROSC) after controlling for multiple confounders, and the other, smaller study found no significant change using simpler statistical methods. This limited data suggests that rates of ROSC may marginally improve with sodium bicarbonate administration in patients with severe acidosis; however, the patient-centered outcome of neurologically intact survival remains unclear.
Bottom Line:
In adult patients with severe metabolic acidosis during prolonged cardiopulmonary resuscitation, the administration of sodium bicarbonate may lead to a slightly higher sustained return of spontaneous circulation; however, the effect on neurologically intact survival appears to be limited.
References:
- Kim J, Kim K, Park J, Jo YH, Lee JH, Hwang JE, Ha C, Ko YS, Jung E. . Sodium bicarbonate administration during ongoing resuscitation is associated with increased return of spontaneous circulation
- Ahn S, Kim YJ, Sohn CH, Seo DW, Lim KS, Donnino MW, Kim, WY. . Sodium bicarbonate on severe metabolic acidosis during prolonged cardiopulmonary resuscitation: a double-blind, randomized placebo-controlled pilot study