Comparison of Efficacy of Intravenous Morphine and Sublingual Buprenorphine for Analgesia after Lower Limb (below the Knee) Orthopedic Surgery

Background and Objective: Postoperative pain is a common post operative side effect that can postpone patient's discharge from hospital. Pain control in orthopedic patients can significantly reduce limitation range of motion and patients can quickly return to normal life. In this study we aimed to compare the efficacy of Iv Morphine with sublingual Buprenorphine in postoperative pain control following orthopedic surgery of the lower extremities.

Methods: This double blind clinical trial was performed on 60 patients ASA class I&II (American Society of Anesthesiologists) referring to orthopedic surgery of the lower extremities and under spinal anesthesia. The patients were divided into two groups of sublingually Buprenorphine (0.4 mg, every 8h hours) and PCA Morphine Pump (20 mg in 100 cc). This trial was practiced after surgery and in the recovery room. The amount of Meperidine usage, pain score and side effects including nausea and vomiting, level of sedation and itching were recorded at 1, 8, 16 and 24 hours after surgery.

Results: 60 Patients in Morphine and Buprenorphine groups were studied. There were no significant difference between the two groups in terms of gender distribution (p=0.766), average age (p=0.350), weight (p=0.195), ASA score (p=0.519) and operation time (p=0.510). The average pain score in the Buprenorphine group was significantly lower than the Morphine group in 8 (p=0.025), 16 (p<0.044) and 24 (p<0.003) hours after surgery. The need to meperidine usage during the first 24 hours after surgery in Buprenorphine group (38±16 mg) were significantly lower than that in the Morphine group (49±19 mg) (p=0.019). There were no significant difference between the two groups in terms of side effects (nausea and vomiting, level of sedation and itching).

Conclusion: This study showed that Sublingual Buprenorphine administration after orthopedic surgery of the lower extremities can lead to better postoperative pain control in comparison to Morphine PCA pump. Also it has minimal side effects and is compatible with Morphine in this field.