CHANGES IN URINE OSMOLALITY AND URINE FLUORIDE CONCENTRATIONS FOLLOWING METHOXYFLURANE ANAESTHESIA

A study of 41 patients receiving methoxyflurane and 8 patients receiving halothane showed that on the first day after exposure to methoxyflurane there was a significant correlation between the reduction of urine osmolality and the dose of methoxyflurane. On the first and second days after exposure to methoxyflurane the patients who received a relatively large dose had significantly lower urine osmolality values than those who received a smaller dose. The patients who were exposed to large doses of methoxyflurane developed significantly decreased urine osmolality values on the second day after exposure compared with patients receiving halothane. In a study of 47 patients exposed to methoxyflurane a significant correlation was found between the dose of methoxyflurane and the urine fluoride concentration on the first and second days after exposure. These findings are taken as further evidence of a causal relation-ship between renal tubular dysfunction and the increased production of fluoride which follows methoxyflurane anaesthesia. It has been shown that methoxyflurane anaesthesia is associated with an increase in the serum uric aci