Enflurane metabolism and postoperative renal function

Inorganic fluoride concentrations in blood and urine were measured in 22 gynaecological patients during and after anaesthesia with enflurane and post-operative renal function was investigated. Ten patients (group I) were given 0.6 vol.% enflurane, and 12 patients (group II) a mixture of 0.6 and 0.8 vol.% enflurane. The serum fluoride concentration of arterial blood reached, in group I, after 120 min 18,99 micronmol/1 whereas in group II the concentration was 21 micronmol/1. One hour after the end of anaesthesia the fluoride concentration in venous blood were nearly identical in both groups and decreased in the following 12 h evenly. In all patients relatively high postoperative fluoride concentrations were observed in the urines. No evidence of renal dysfunction was found after anaesthesia.