Propofol ('Diprivan') for outpatient cystoscopy. Efficacy and recovery compared with althesin and methohexitone

Abstract

In two non-concurrent investigations, propofol was compared with methohexitone and with Althesin as an intravenous anaesthetic for cystoscopy in outpatients. In the comparison between propofol and methohexitone the 60 patients also received alfentanil in similar dosage; in comparison with Althesin (43 patients) the Cremophor formulation of propofol was used. During induction of anaesthesia propofol caused fewer excitatory effects than either methohexitone or Althesin, and less pain than methohexitone. There was no difference in the incidence of apnoea caused by propofol 1.5 mg/kg and Althesin 0.05 ml/kg, or propofol 2 mg/kg and methohexitone 1.5 mg/kg. Induction of anaesthesia by propofol was faster than that by Althesin. The use of alfentanil 7 micrograms/kg at induction of anaesthesia apparently increases the incidence of apnoea seen at that time and during maintenance of anaesthesia, but an overall dose of approximately 1 mg reduces the mean dose of propofol required from 0.459 mg/kg/min to 0.192 mg/kg/min and improves the quality of anaesthesia. During maintenance of anaesthesia propofol produced less myoclonia and movement than Althesin, and fewer hiccups than methohexitone, but the mean minimum systolic arterial pressure observed in the propofol group was less than that seen in the methohexitone group. Immediate recovery of consciousness was faster and better after propofol than methohexitone, and fewer complications were seen after propofol than Althesin. Recovery of coordination and perception, tested by the digit substitution test, was faster after propofol than methohexitone. Exact comparisons of recovery of ocular tone (Maddox Wing test) between the anaesthetics were not possible as both Althesin and methohexitone rendered some patients incapable of taking the tests in the early post-operative period. In response to a take-home questionnaire, patients stated that they were drowsy for a shorter time, and ate earlier after propofol than after methohexitone. No patient who received propofol vomited or was nauseated and all would wish to receive the same anaesthesia again. The studies suggest that propofol is preferable to both Althesin and methohexitone for intravenous anaesthesia for cystoscopy in outpatients.