Induction of anaesthesia with propofol using a target-controlled infusion system.
Sixty patients premedicated with temazepam were allocated randomly to receive an infusion of propofol designed to achieve and maintain a target blood concentration of 3, 4 or 5 micrograms.ml-1. Induction time was measured from the start of infusion to loss of verbal contact. The success rate of inducing anaesthesia within 3 min of achieving the target concentration was 40% when the predicted target concentration was 3 micrograms.ml-1, 75% when the predicted target was 4 micrograms.ml-1 and 90% when the target was 5 micrograms.ml-1. There were no significant differences between the three groups for time to loss of verbal contact in patients who were induced successfully within 3 min. There were significant reductions in arterial pressure 3 min after achieving the target concentrations within the groups but not between them. The frequency of apnoea and pain on injection was small in all groups. Selecting a target concentration of 5 microgram.ml-1 would successfully induce anaesthesia in the majority of patients premedicated with temazepam without major haemodynamic or respiratory side effects.
Chaudhri
S
S
University Department of Anaesthesia, Royal Infirmary, Glasgow.
White
M
M
Kenny
G N
GN
D000293:Adolescent; D000328:Adult; D000368:Aged; D000771:Anesthesia, Intravenous; D016503:Drug Delivery Systems; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011229:Preanesthetic Medication; D015742:Propofol / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology; D011897:Random Allocation; D013693:Temazepam; D013997:Time Factors
D013693:Temazepam; D015742:Propofol