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

BACKGROUND AND OBJECTIVES

Postoperative 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.

METHODS

This double-blinded study included ninety patients scheduled for total abdominal hysterectomy and were randomly assigned into three groups to receive local wound infiltration with 40 mL of 0.25% bupivacaine (group C), plus 2 mg/kg ketamine (group K) or 2 μg/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 24 h postoperatively were measured.

RESULTS

Rescue analgesia was less in K (6.80 ± 3.19 mg) and D (8.39 ± 3.86 mg) compared to C (13.33 ± 4.01 mg) (p < 0.05). First request of analgesia was delayed in K (7.60 ± 4.16 h) and D (6.00 ± 3.73 h) compared to C (4.20 ± 1.13 h) (p < 0.05). Both VAS and R/M were significantly lower in K (all over 24 h) and D (for 8 and 4 h, respectively) compared to C. Stress markers were significantly lower in K and D compared to C at 6 and 24 h, and in K compared to D at 24 h (p < 0.05).

CONCLUSIONS

Local 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.