Anaesthesia for extracorporeal shock-wave lithotripsy. A comparison of propofol and methohexitone infusions during high frequency jet ventilation.

A continuous infusion of propofol 2.0-2.5 mg/kg for induction followed by 9 mg/kg/hour for the first 30 minutes and 6 mg/kg/hour thereafter, was compared with methohexitone 1.5 mg/kg for induction followed by 4.8 mg/kg/hour thereafter for maintenance of anaesthesia in a randomised study of 40 patients who underwent extracorporeal shock-wave lithotripsy using high frequency jet ventilation (HFJV). Systolic blood pressure was significantly lower in the propofol group after induction of anaesthesia, tracheal intubation, placement in the semirecumbent position in the hoist, bath immersion and after 5, 10 and 30 minutes of treatment. Diastolic blood pressure was significantly lower in the propofol group after intubation, placement in the hoist, bath immersion and after 5, 10 and 15 minutes of treatment. Heart rate was significantly lower in the propofol group after induction, intubation, placement in the hoist and bath immersion. There was no significant difference in the quality of induction between the two groups. Quality of maintenance of anaesthesia was judged to be poor in six out of 20 patients who received methohexitone compared with one out of 20 who received propofol but this difference did not reach statistical significance. There was no significant difference between the recovery times for the two groups but six out of 20 patients who received methohexitone were judged to have a poor recovery from anaesthesia compared with none in the propofol group (p less than 0.05). Propofol was associated with excellent induction, maintenance and recovery characteristics but it had a propensity to produce greater decreases in blood pressure, which were most marked when the patient was placed in the semirecumbent position in the hoist.