A prospective, randomised trial of preoperative rectal diclofenac: are we closing the gate after the horse has gone?
BACKGROUND
Diclofenac sodium is a non-steroidal anti-inflammatory agent commonly used to provide analgesia post-surgery. It is common clinical practice to administer a diclofenac suppository at induction to contribute to pre-emptive analgesia (PEA). Diclofenac takes up to 30 minutes to attain maximal plasma level after rectal administration.


OBJECTIVE
To compare post-operative analgesia in patients who received diclofenac 30-45 minutes preoperatively, or at induction of anaesthesia.


METHODS
A prospective, randomised, double-blind controlled trial in 157 patients undergoing varicose vein surgery. Group A (control) received a rectal placebo 30-45 minutes preoperatively, group B received diclofenac 100 mg 30-45 minutes preoperatively and group C received placebo 30-45 minutes preoperatively and diclofenac 100 mg at induction. Outcome measures were Visual Analogue Scores (VAS) and requirement for rescue analgesia.


RESULTS
Patients in group A had significantly poorer analgesia than patients in groups B and C. There were no significant differences in VAS values and requirements for rescue analgesia between groups B and C 3-4 hours and 18-22 hours postoperatively.


CONCLUSIONS
For patients undergoing varicose vein surgery preoperative administration of rectal diclofenac significantly improves post-operative analgesia and this effect is independent of whether it is given at induction or 30-45 minutes preoperatively.
Lyons
J B
JB
Department of Anaesthesia, Waterford Regional Hospital, Dublin. Ireland.
Niazi
A
A
Lowe
D
D
Sheehan
S J
SJ
Moriarty
J
J
D000285:Administration, Rectal; D000328:Adult; D000698:Analgesia / Q000379:methods; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D004008:Diclofenac / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control*; D011229:Preanesthetic Medication; D011300:Preoperative Care; D011446:Prospective Studies; D013488:Suppositories; D013997:Time Factors
D000894:Anti-Inflammatory Agents, Non-Steroidal; D013488:Suppositories; D004008:Diclofenac