Postresuscitation electrolyte changes: role of arrhythmia and resuscitation efforts in their genesis

Hypokalemia frequently occurs after resuscitation from ventricular fibrillation (VF) in man. To test the casual roles of VF and resuscitation variables in this electrolyte change, we studied six groups of dogs: VF with CPR and electrical cardioversion (n = 9), control dogs with no intervention (n = 9), CPR without arrhythmia (n = 5), electrical cardioversion without arrhythmia (n = 5), CPR and cardioversion without arrhythmia (n = 5), and rapid right ventricular pacing (n = 5) (pacing rate 374 +/- 68 beat/min; BP 79/52 mm Hg during pacing). Blood for K, Ca, Mg, and glucose analysis was collected before each intervention (or at baseline in control animals) and sequentially for 3 hr. Mg had a maximum change of 0.3 mEq/L in the VF group 7 min after resuscitation, but did not change in the other groups (p less than .005). Glucose had a maximum change of 79 mg/dl in the VF group 7 min after resuscitation but did not change in the other groups (p less than .005). Ca had a maximum decrease of 0.4 mg/dl in the VF group 15 min after resuscitation but did not decrease in the other groups (p less than .005). K had a maximum decrease of 0.8 mEq/L in the VF group 60 min after resuscitation, whereas decreases were less in the other groups (p less than .005). Thus, VF caused a rapid rise in Mg and glucose followed by a fall in Ca and K. These changes were independent of resuscitation efforts as well as the moderate hypotension induced by rapid right ventricular pacing.(ABSTRACT TRUNCATED AT 250 WORDS)