Dexmedetomidine as an adjunct in postoperative analgesia following cardiac surgery: A randomized, double-blind study

OBJECTIVES: The purpose of this study was to determine analgesic efficacy of dexmedetomidine used as a continuous infusion without loading dose in postcardiac surgery patients. SETTINGS AND DESIGN: A prospective, randomized, double-blind clinical study in a single tertiary care hospital on patients posted for elective cardiac surgery under cardiopulmonary bypass. INTERVENTIONS: Sixty-four patients who underwent elective cardiac surgery under general anesthesia were shifted to intensive care unit (ICU) and randomly divided into two groups. Group A (n = 32) received a 12 h infusion of normal saline and group B (n = 32) received a 12 h infusion of dexmedetomidine 0.4 μg/kg/h. Postoperative pain was managed with bolus intravenous fentanyl. Total fentanyl consumption, hemodynamic monitoring, Visual Analogue Scale (VAS) pain ratings, Ramsay Sedation Scale were charted every 6(th) hourly for 24 h postoperatively and followed-up till recovery from ICU. Student's t-test, Chi-square/Fisher's exact test has been used to find the significance of study parameters between the groups. RESULTS: Dexmedetomidine treated patients had significantly less VAS score at each level (P < 0.001). Total fentanyl consumption in dexmedetomidine group was 128.13 ± 35.78 μg versus 201.56 ± 36.99 μg in saline group (P < 0.001). A statistically significant but clinically unimportant sedation was noted at 6 and 12 h (P < 0.001, and P = 0.046 respectively). Incidence of delirium was less in dexmedetomidine group (P = 0.086+). Hemodynamic parameters were statistically insignificant. CONCLUSIONS: Dexmedetomidine infusion even without loading dose provides safe, effective adjunct analgesia, reduces narcotic consumption, and showed a reduced trend of delirium incidence without undesirable hemodynamic effects in the cardiac surgery patients.