The effects of calcium and sodium bicarbonate on severe hyperkalaemia during cardiopulmonary resuscitation: A retrospective cohort study of adult in-hospital cardiac arrest

Aim: Calcium and sodium bicarbonate (SB) are frequently used in treating patients with severe hyperkalaemia. We evaluated the efficacy of these medications for the treatment of severe hyperkalaemia during cardiopulmonary resuscitation (CPR). We also hypothesised that the effects of these medications might be associated with serum potassium level during CPR. Methods: We conducted a retrospective observational study in a single medical centre. From adult patients who had suffered an in-hospital cardiac arrest from 2006 through 2012, we included those with a serum potassium level>6.5. mEq/L measured during CPR. We used multivariable logistic regression analysis to study the association of calcium/SB with sustained return of spontaneous circulation (ROSC). Results: Among the 109 patients included in our analysis, 40 (36.7%) patients achieved sustained ROSC, and only four (3.7%) patients survived to hospital discharge. The mean serum potassium level was 7.8. mEq/L. The analysis indicated that administration of SB was positively associated with sustained ROSC when serum potassium level was <7.9. mEq/L (odds ratio [OR]: 10.51; 95% confidence interval [CI]: 1.50-112.89; p: 0.03); administration of calcium and SB was also positively associated with sustained ROSC when serum potassium level was <9.4. mEq/L (OR: 51.11; 95% CI: 3.12-1639.16; p: 0.01). Conclusion: The use of calcium and SB might be effective in the treatment of severe hyperkalaemia during cardiac arrest. The efficacy of SB/calcium correlated with serum potassium level. However, because the number of patients included in the analysis was small, this conclusion should be further examined in the future.