Effect of spinal anaesthesia on plasma concentrations of glutathione S-transferase

Background. Plasma glutathione S-transferase (GST) concentration measurement is a sensitive and specific index of hepatocellular injury. GST concentration increases after anaesthesia with most volatile anaesthetic agents, but not after propofol. Such increases are thought to result from reduced liver blood flow. The effect on GST concentration of spinal (subarachnoid) anaesthesia, which might also reduce liver blood flow, is not known. Methods. We studied the effects of spinal anaesthesia on GST concentrations measured by specific radioimmunoassay in 33 patients undergoing intermediate orthopaedic, general or gynaecological surgery. GST concentrations were measured before anaesthesia and 3, 6 and 24 h after induction of anaesthesia. Hypotension (systolic blood pressure <70% of pre-induction value) was rapidly corrected with i.v. ephedrine. Results. Mean duration of surgery was 41 min (range 11-80). No increase in GST concentration was observed at any time, but at 24 h GST concentration was significantly reduced (P<0.05). One patient in whom hypotension was not treated developed a greatly increased GST concentration at 3 h. Conclusion. We found no association between spinal anaesthesia and disturbance of hepatocellular integrity when hypotension does not occur or is rapidly corrected.