Changes in Potassium Concentration During Opioid Antagonist Induction: Comparison of Two Randomized Clinical Trials

Opioid antagonist induction under general anesthesia or heavy sedation has been criticized due to its associated morbidity and mortality. Information on the potential causes of these complications is limited. We aimed to compare electrolyte concentration changes during rapid opioid antagonist induction under general anesthesia and conscious sedation, and to find out whether these changes are associated with cardiovascular complications.

We used a pooled database analysis of 2 prospective randomized controlled clinical trials carried out in Lithuania between 2002 and 2014. Opioid-dependent patients underwent opioid antagonist induction under general anesthesia (n = 50) or conscious sedation (n = 68). Electrolyte levels were measured before the procedure, 3 hours after antagonist induction, and 3 hours after the end of the procedure.

General anesthesia was associated with initial hyperkalemia, which was followed by rapid reduction in potassium concentration (P < 0.01). Plasma potassium increase was noted in 92% of cases, and in 24%, these levels increased above 6.0 mmol/L, with a highest value of 6.7 mmol/L. Potassium concentration changes in the conscious sedation group were not statistically significant. There were no differences in sodium, calcium, chloride, and magnesium concentrations in both groups.

Plasma potassium concentration changes in the general anesthesia group were significant, whereas conscious sedation had no effect on electrolyte levels. Our data support the recommendation of the American Society of Addiction Medicine and other professional societies that opioid antagonist induction under general anesthesia must not be offered.