Serum potassium levels after induction of epidural anaesthesia using mepivacaine with and without adrenaline.

The short-term effect of epidural anaesthesia (EDA) on the serum potassium (S-K) concentration was studied in 40 elderly men scheduled for minor urological surgery. In Group I, EDA was induced with mepivacaine 2% + adrenaline 1:200,000 (n = 20) and in Group II mepivacaine 2% was used (n = 20). When EDA had been induced, the mean plasma level of adrenaline was tripled in Group I, while it had decreased in Group II. In Group I there was a decrease in the arterial S-K concentration of up to 0.75 mmol.l-1 with a mean of 0.31 mmol.l-1, s.d. 0.20 (P less than 0.001). In Group II, a small but significant decrease of the S-K level was recorded in arterial (0.14 mmol.l-1, s.d. 0.14; P less than 0.001) but not in venous serum. Two-way analysis of variance showed that the addition of adrenaline to the local anaesthetic solution, but not the choice of using arterial or venous serum for analysis, significantly correlated to the lowering of the S-K concentration (P less than 0.001).

RCT Entities:   Population Interventions Outcomes