Transdermal ketamine as an adjuvant for postoperative analgesia after abdominal gynecological surgery using lidocaine epidural blockade

We examined the postoperative analgesia of a controlled delivery ketamine t ransdermal patch after minor abdominal gynecological surgery using lidocain e epidural blockade. Fifty-two patients were randomized to one of two group s. Epidural anesthesia was performed with 25 mL 2% plain lidocaine. At the end of the surgical procedure, a controlled delivery transdermal patch cont aining either ketamine (25 mg/24 h) (Ketamine group) or placebo (Placebo gr oup) was applied. Pain and adverse effects were assessed hourly postoperati vely for 24 h. LM dipyrone was available at patient request. The two groups were demographically similar. The time to first rescue analgesic was longe r in the Ketamine group (230 +/- 112 min) compared with the Placebo group ( 94 +/- 54 min); (P < 0.00001). There were more dipyrone dose injections in 24 h in the Placebo group compared with the Ketamine group (P < 0.0001). Th e incidence of adverse effects was similar between groups. We conclude that the transdermal-controlled delivery of ketamine prolonged the duration of analgesia after minor gynecological procedures.