Low-dose propofol reduces the incidence of moderate to severe local pain induced by the main dose.
BACKGROUND
Local pain on injection of propofol remains a considerable problem in clinical anaesthesiology. As slow infusion of a low dose of propofol induces little or no pain at the site of injection, and as propofol-induced pain fades during prolonged exposure, this randomized, double-blind, clinical cross-over study was designed to test whether pain on injection of propofol is attenuated by initial slow injection of a low dose of propofol by the same intravenous line.


METHODS
Seventy-seven adult surgical patients were cannulated in a dorsal vein on each hand. In each cannula, a 0.5-ml priming dose of either propofol 10 mg/ml dissolved in an emulsion of medium- and long-chain triglycerides or aqueous sodium chloride 9.0 mg/ml was injected over 30 s, and followed 120 s later by a main dose of 2.0 ml of the same propofol formula over 6 s. After each injection, the patients were asked by a blind investigator to score the maximal pain intensity on a visual analogue scale (VAS).


RESULTS
Although the decrease in maximal pain intensity did not reach statistical significance (P= 0.070), significantly fewer patients reported moderate or severe pain intensity (corresponding to 3.0 VAS units or more) after the main dose of propofol was preceded by a priming dose of propofol than by sodium chloride (P= 0.041).


CONCLUSIONS
The incidence of moderate to severe local pain induced by intravenous propofol can be decreased by a readily applicable technique in which a low dose of propofol emulsion is slowly administered by the same intravenous route 2 min in advance.
Liljeroth
E
E
Department of Anaesthesiology and Intensive Care Medicine, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden.
Karlsson
A
A
Lagerkranser
M
M
Akeson
J
J
D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006225:Hand / Q000098:blood supply; D006801:Humans; D015994:Incidence; D007275:Injections, Intravenous / Q000379:methods; D008297:Male; D010146:Pain / Q000139:chemically induced / Q000517:prevention & control*; D010147:Pain Measurement / Q000379:methods; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects*; D012720:Severity of Illness Index; D013997:Time Factors
D018686:Anesthetics, Intravenous; D015742:Propofol