Bupivacaine-Sufentanil Versus Bupivacaine-Fentanyl in Spinal Anesthesia of Patients Undergoing Lower Extremity Surgery

BACKGROUND: The addition of intrathecal opioids to local anesthetics seems to improve the quality of analgesia and prolong the duration of analgesia, when using a subarachnoid block in Iranian patients with their specific pain tolerance. OBJECTIVES: The aim of this study was to evaluate the effects of adding fentanyl or sufentanil, to intrathecal bupivacaine, in terms of the onset and duration of; sensory block, motor block, hemodynamic effects and postoperative pain relief. PATIENTS AND METHODS: This randomized clinical trial included 90 patients who underwent orthopedic lower limb surgeries. Subjects were divided into experimental groups; intrathecal fentanyl 25 µg (F), and sufentanil 2.5 µg (S), along with a placebo 0.5 mL normal saline (C) group, which were added to bupivacaine 0.5%, 15 mg. Duration of complete and effective analgesia was recorded (by a visual analogue scale-VAS). The pain scores were assessed postoperatively. Intraoperative mean arterial pressure (MAP), heart rate and oxygen saturation (SPO(2)) were recorded. The incidence of side effects such as; nausea, vomiting, pruritus, shivering, bradycardia and hypotension were also recorded. RESULTS: MAP and heart rate results showed no significant changes at the designated time points among the three groups (P > 0.05). However, SPO2 and VAS showed significant changes at the designated time points among the three groups (P < 0.05). The duration of complete and effective analgesia was also significantly longer in the sufentanil group (P < 0.05). Motor block did not exhibit any significant difference (P = 0.67). Only pruritus as a side effect was significantly higher in the sufentanil group (P < 0.05), while all other evaluated side effects were significantly lower in the sufentanil group (P < 0.05). CONCLUSIONS: The addition of 2.5-3 mcg sufentanil to 15 mg 0.05% bupivacaine maintained the patient’s hemodynamic stability similar to fentanyl. Intrathecal sufentanil added to bupivacaine,when compared with fentanyl, may lead to prolonged duration of analgesia, facilitate the spread of the sensory block, increase mean SPO2 levels, and reduce overall side effects.