Comparison of intrathecal fentanyl and nalbuphine: A prospective randomized controlled study in patients undergoing total abdominal hysterectomy
Abstract
Objectives: 0.5% bupivacaine used in subarachnoid block provides only about 3 hours of analgesia. Opioids especially morphine and fentanyl are used as adjuvants to produce extended postoperative analgesia. Nalbuphine is an agonist antagonist and does not require a narcotic license, which is a must for procuring other opioids, so is easily available even in peripheral hospitals. This study was carried out to evaluate the efficacy of nalbuphine versus fentanyl as intrathecal adjuvant.
Methodology: One hundred ASA 1-3 patients, aged 30-65 years posted for elective total abdominal hysterectomy (TAH) were included in this study and were randomly divided into two groups of fifty each. Group FB received 15 mg of 0.5% bupivacaine (3 ml) plus 25 µg of fentanyl (0.5 ml) and Group NB received 15 mg 0.5% bupivacaine (3 ml) plus 1 mg nalbuphine (0.5 ml). No sedative or analgesic was given preoperatively. The parameters noted were; the time for sensory block to reach T10 dermatome, time for the sensory level to fall from T6 to T8 dermatome, time for the first request of rescue analgesia, duration of motor block and any untoward side effect or complications. The statistical analysis was performed by STATA 11.2 (College Station TX USA). Students t-test were performed for to find the significance difference between the study parameters.
Results: The onset of sensory blockade, time to attain peak sensory block and complete motor block was significantly faster in Group FB (p < 0.001). The duration of motor block was comparable in both the groups. The time for sensory block to regress by two segments was significantly longer in Group NB, 97.72 ± 9.50 min, than in Group FB, 88.88 ± 9.48 min. The time to first analgesic requirement in Group NB was 460.78 ± 77.98 min compared to 283.44 ± 78.97 min in Group FB (p < 0.001). No statistical difference was seen in terms of adverse effects. Two patients in both groups complained of nausea. Hypotension and pruritus were seen in two and one patient respectively in Group FB.
Conclusion: Although the time to onset and peak sensory level is longer with nalbuphine as intrathecal adjuvant than fentanyl, time for sensory level to regress by two segments and the postoperative analgesia time is longer with nalbuphine. So, nalbuphine is a good adjuvant in spinal anesthesia and has an advantage in centers without narcotics license.
