Comparison of Intravenous Dexamethasone and Dexmedetomidine for Spinal Anesthesia Quality in Opium-Addicted Patients: A Parallel Double-Blind Randomized Clinical Trial

Objectives: We compared the effect of intravenous (IV) administration of dexamethasone versus dexmedetomidine alongside the subarachnoid injection of Bupivacaine in terms of spinal anesthesia (SA) quality in opium-addicted patients. Patients and Methods: This parallel randomized clinical trial (RCT) was conducted on opium-addicted patients aged 18 to 65 with The American Society of Anesthesiologists (ASA) class of I/II candidates for surgery under SA. In one group, dexmedetomidine at a dose of 0.5 μg/kg body weight was injected intravenously 10 minutes before surgery and then at a dose of 0.5 μg/kg body weight during surgery. In another group, 8 mg dexamethasone was injected intravenously 10 minutes before surgery, and then normal saline at a rate of 0.5 μg/kg/h was infused during surgery. The primary outcomes were the onset of sensory block, the onset of motor block, the regression of two levels of sensory block, and the duration of motor block. The secondary outcomes were total analgesia time and the time to the first analgesia requirement. Results: Totally, 57 patients divided into two groups were included in the final analysis. The results showed that the two groups differed significantly in none of the assessed baseline variables (P > 0.05). The mean duration between performing SA and the onset of sensory block in the Dexamethasone and Dexmedetomidine groups was 4.8 ± 2.2 and 4.2 ± 1.9 minutes, respectively (P = 0.290). The mean duration between performing SA and the onset of motor block in the dexamethasone and dexmedetomidine groups was 5.9 ± 2.6 and 5.1 ± 2.3 minutes, respectively (P = 0.251). The mean duration between performing SA and the regression of two levels of sensory block in the dexamethasone and dexmedetomidine groups was 63.6 ± 27.7 and 82.0 ± 17.1 minutes, respectively (P = 0.004). The mean duration of motor block in the dexamethasone and dexmedetomidine groups was 75.0 ± 32.1 and 97.5 ± 19.4 minutes, respectively (P = 0.377). The mean total analgesia time in the dexamethasone and dexmedetomidine groups was 86.9 ± 32.9 and 109.3 ± 16.3 minutes, respectively (P = 0.002). The mean duration between performing SA and the first requirement for analgesic agent administration in the dexamethasone and dexmedetomidine groups was 206.21 ± 93.19 and 267.86 ± 76.02 minutes, respectively (P = 0.008). Conclusions: It seems that the quality of spinal anesthesia in opium-addicted patients who received concurrent IV dexmedetomidine was better than that of those who received concurrent IV dexamethasone.