Effect of local wound infiltration with ketamine versus dexmedetomidine on postoperative pain and stress after abdominal hysterectomy, a randomized trial

Background and ObjectivesPostoperative pain and stress elicit hormonal changes. We aimed at comparing the effects of wound infiltration with ketamine versus dexmedetomidine on postoperative pain and stress response. MethodsThis double-blinded study included ninety patients scheduled for total abdominal hysterectomy and were randomly assigned into three groups to receive local wound infiltration with 40mL of 0.25% bupivacaine (group C), plus 2mg/kg ketamine (group K) or 2g/kg dexmedetomidine (group D). Primary outcome was postoperative morphine consumption; secondary outcomes included first request of analgesia, VAS scores at rest and movement (VAS-R/M) and side effects. Serum cortisol, prolactin and glucose levels at baseline, pre-infiltration, 6 and 24h postoperatively were measured. ResultsRescue analgesia was less in K (6.803.19mg) and D (8.39 +/- 3.86mg) compared to C (13.33 +/- 4.01mg) (p<0.05). First request of analgesia was delayed in K (7.60 +/- 4.16h) and D (6.00 +/- 3.73h) compared to C (4.20 +/- 1.13h) (p<0.05). Both VAS and R/M were significantly lower in K (all over 24h) and D (for 8 and 4h, respectively) compared to C. Stress markers were significantly lower in K and D compared to C at 6 and 24h, and in K compared to D at 24h (p<0.05). ConclusionsLocal wound infiltration with ketamine or dexmedetomidine added to bupivacaine had an opioid-sparing effect, delayed first request of rescue analgesia, and attenuated postoperative stress response, especially with ketamine in patients underwent total abdominal hysterectomy.