Objective: Although numerous methods are available for postoperative pain (POP) management, new approaches are constantly being investigated. This feasibility study assessed the buprenorphine transdermal therapeutic system (Bup-TTS) for the treatment of POP after gynecological open surgery.
Research design and methods: Forty-five patients were prospectively randomized to different Bup-TTS dosages (17.5, 35, or 52.5 μg/h). Patients were blinded with regard to patch dose.
Main outcome measures: Efficacy was evaluated in terms of rescue boluses (intravenous morphine 2 mg in the first six postoperative hours, intravenous ketorolac 30 mg thereafter) required to achieve a static and dynamic Numerical Rating Scale (sNRS and dNRS) score ≤4. Side effects were evaluated from patch application (12 hours before surgery) until the 72nd postoperative hour. Patient satisfaction regarding POP management was assessed via anonymous questionnaire.
Results: All Bup-TTS groups required additional postoperative analgesia, particularly in the first postoperative hour. No between-group differences in sNRS/dNRS values were recorded at emergence from anesthesia. A significant inverse correlation occurred between Bup-TTS dosage and use of morphine (p = 0.04), ketorolac (p = 0.04) or both rescues (p = 0.02). Postoperative nausea/vomiting occurred in 3.1% of assessments, with no between-group differences and a significant correlation with morphine amount (p = 0.01). No serious side effects occurred. Despite no between-group difference, patient satisfaction was inversely correlated with the number of rescue doses (p < 0.001). Study limitations include the small sample size, the absence of a control group treated with a more conventional technique for POP relief, the focus on selected patients at low perioperative risk and the presence of slightly different types of open surgery (hysterectomy vs myomectomy only).
Conclusion: Bup-TTS efficacy was directly proportional to its dosage, although additional analgesia was required, particularly in the first postoperative hour. Moreover, the consumption of morphine and ketorolac was inversely correlated to the Bup-TTS dosage. Increasing Bup-TTS doses were not associated with an increased incidence of side effects. Bup-TTS appears a safe and feasible approach for moderate POP management; further larger studies are warranted.