Effect of Dexmedetomidine Versus Nalbuphine as an Adjuvant on Paravertebral Block to Manage Postoperative Pain After Mastectomies

Breast cancer is the commonest cancer in women worldwide. Many patients are frequently admitted to the operating theaters for mastectomies. Thoracic paravertebral block (PVB) is increasingly used as an effective means for post-operative pain relief. The present study aimed at evaluating the effectiveness and safety of dexmedetomidine and nalbuphine as an adjuvant to bupivacaine local anesthetic in thoracic paravertebral block in breast cancer surgeries.
A total of 60 female patients aged 18 to 78 were included in the study, and ASA I, II, III were scheduled for mastectomy. These patients were unsystematically assigned into three 20-member groups: group PB received bupivacaine (0.3 mL/ kg) 1 mL (0.9% sodium chloride) normal saline; group PBD received bupivacaine (0.3 mL/kg) dexmedetomidine 1 μg/kg; and Group PBN received bupivacaine (0.3 mL/kg) and 10 mg (1 mL) nalbuphine. Demographic data, intraoperative SPO2, ETCO2, HR, SBP and DBP, pain scores (at rest and movement), and sedation scores were recorded every 30 minutes during the initial 2 hours and 4, 8, 24, and 48 hours from T0. Also, postoperative tramadol consumption, the time to the first analgesic request, and any complications were also recorded.
There were no statistically significant differences among the three groups regarding demographic data, SPO2, ETCO2, HR, SBP and DBP intraoperatively. Moreover, no significant difference was found in HR, SBP and DBP postoperatively. Postoperative pain scores were significantly higher in group BP, whether at rest or movement. The sedation was significantly higher in PBD group in the first 12 hours postoperatively. There was a significantly lower postoperative tramadol consumption in PBN group and a significantly longer time to the first analgesic request than other groups. No complications were reported in any group.
Addition of nalbuphine 10 mg as an adjuvant to bupivacaine local anesthetic in PVB improved the quality of the block and decreased postoperative analgesic requirements than the bupivacaine only group and dexmedetomidine and bupivacaine group. However, adding dexmedetomidine to bupivacaine increased the time to the first analgesic request and more sedation than bupivacaine and bupivacaine and nalbuphine.