Changes in serum potassium, calcium and creatine kinase following suxamethonium administration in children with and without strabismus

The immediate changes in serum potassium and calcium and 24-h changes in creatine kinase (CK) following suxamethonium administration were compared in children undergoing strabismus repair or tonsillectomy following induction of anaesthesia with thiopentone or halothane. A separate group of children were anaesthetized with isoflurane and did not receive suxamethonium. There was a significant increase ( P < 0.05) in serum potassium of 0.26 and 0.56 mmolċ⁻¹ following halothane-suxamethonium induction and a significant decrease ( P < 0.05) of 0.35 and 0.13 mmolċ⁻¹ after thiopentone-suxamethonium induction in the strabismus and tonsillectomy groups respectively. There was an increase in the 24 h CK values of 624 and 694 uċl⁻¹ ( P < 0.05) in patients receiving halothane-suxamethonium induction and of 43 (NS) and 247 uċ⁻¹ ( P < 0.05) in patients receiving thiopentone-suxamethonium induction in the strabismus and tonsillectomy groups respectively. Suxamethonium administration was associated with a small but sometimes significant ( P < 0.05) decrease in total serum calcium concentrations (0.036 to 0.049 mmolċ⁻¹). Changes in all indices were minimal in children anaesthetized with isoflurane. It is concluded that the administration of halothane and suxamethonium is the main cause for the changes in serum potassium and CK and not the presence of strabismus.