Effect of intra-articular dexmedetomidine on postoperative analgesia after arthroscopic knee surgery.
BACKGROUND
Alpha-2-adrenergic agonists have peripheral analgesic effects. We have assessed the potential analgesic effect of dexmedetomidine after intra-articular administration in arthroscopic knee surgery.


METHODS
Sixty patients undergoing arthroscopic knee surgery were randomly assigned into three groups in a double-blind placebo controlled study. The control group received i.v. and intra-articular saline, the intra-articular group received i.v. saline and intra-articular dexmedetomidine, and the i.v. group received i.v. dexmedetomidine and intra-articular saline. Haemodynamic changes, pain visual analogue scale (VAS), sedation score, the time to first postoperative analgesic request, and the total postoperative analgesic use during the first 24 h were evaluated.


RESULTS
Dexmedetomidine administration resulted in a significant reduction in pain scores for 6 h after operation in the intra-articular group but only for 1 h in the i.v. group. The time to first postoperative analgesic request was longer in the intra-articular group [312.0 (SD 120.7) min] compared with the control group [71.0 (50.1) min] and the i.v. group [102.1 (54.4) min] (P<0.001). Total diclofenac requirement was significantly lower in the intra-articular group [90.0 (46.2) mg] than in the control group [165.0 (52.2) mg] and in the i.v. group [129.3 (54.3) mg] (P<0.05).


CONCLUSIONS
Intra-articular dexmedetomidine enhanced postoperative analgesia after arthroscopic knee surgery, with an increased time to first analgesic request and a decreased need for postoperative analgesia.
Al-Metwalli
R R
RR
Department of Anaesthesia, Faculty of Medicine, King Faisal University, Saudi Arabia.
Mowafi
H A
HA
Ismail
S A
SA
Siddiqui
A K
AK
Al-Ghamdi
A M
AM
Shafi
M A
MA
El-Saleh
A-R
AR
D000328:Adult; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage*; D001182:Arthroscopy; D001794:Blood Pressure / Q000187:drug effects; D020927:Dexmedetomidine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007270:Injections, Intra-Articular; D007275:Injections, Intravenous; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000517:prevention & control*
D018712:Analgesics, Non-Narcotic; D020927:Dexmedetomidine