Preoperative tramadol combined with postoperative small-dose tramadol infusion after total abdominal hysterectomy: a double-blind, randomized, controlled trial

This double blind, randomized, controlled trial investigated whether a single preoperative intravenous (iv) dose of tramadol (100 mg) given 30 min before abdominal hysterectomy resulted in improved analgesic efficacy, reduced postoperative morphine patient-controlled analgesia (PCA) use and reduced side effects when combined with a postoperative small-dose tramadol infusion. Two-hundred twenty-four patients undergoing elective abdominal hysterectomy were randomly allocated to one of two groups: the tramadol group (n = 113) received iv tramadol (100 mg) 30 min before surgery, and the control group (n = 111) received an equivalent volume of normal saline. Upon awakening from general anesthesia, all patients received a loading dose of 0.5 mg/kg of tramadol and a small-dose infusion of tramadol (0.1 mg/kg/h) for 48 h. In addition, all patients were connected to morphine PCA delivering a morphine bolus of 0.02 mg/kg with a 6-min lock-out. Data on pain intensity at rest and during movement, morphine consumption, side-effects and overall patient satisfaction were recorded. A total of 189 patients completed the study. Preemptive tramadol was associated with superior analgesia at rest and with movement in the first 24 h after surgery (p < 0.01), a longer interval to first morphine PCA request (p = 0.019), and reduced morphine PCA use (p = 0.017). The tramadol group had reduced nausea (p = 0.015), dizziness (p = 0.001) and drowsiness (p = 0.0001), while other side-effects were similar. In conclusion, a single dose of iv tramadol (100 mg) 30 min prior to abdominal hysterectomy improves analgesia, and reduces morphine PCA requirements, nausea, dizziness and drowsiness when combined with a postoperative small-dose tramadol infusion and morphine PCA when compared to the same analgesic regimen that omitted the preemptive tramadol.