Setting targets for sedation with a target-controlled propofol infusion.
We studied 30 unpremedicated patients undergoing muscle biopsy under femoral nerve block to determine sedation levels reached with a Diprifusor target-controlled propofol infusion, in order to establish the equivalent of the ED50 for different levels of depth of sedation. Infusion was started at 0.8 microg x ml(-1) and altered by increments of 0.1 microg x ml(-1) after equilibrium between target and calculated concentrations, until the desired level of sedation was reached. The ED50 target propofol concentrations for sedation at sedation levels 2 (drowsy), 3 (drowsy, responds to verbal stimulation) and 4 (responsive to physical stimulation only) were 1.0 microg x ml(-1), 1.6 microg x ml(-1) and 2.1 microg x ml(-1), respectively. At sedation level 3, several patients exhibited spontaneous movement, hindering surgery. Oxygen supplementation is recommended for sedation at level 4.
Academic Unit of Anaesthesia, Leeds Teaching Hospitals, UK.
P R
PR
Janzen
W J
WJ
Hall
P M
PM
Hopkins
D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D016292:Procedural Sedation / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D016503:Drug Delivery Systems; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies
D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D015742:Propofol