Dexmedetomidine versus remifentanil for sedation under monitored anesthetic care in complex endovascular aortic aneurysm repair: a single center experience with mid-term follow-up

BACKGROUND: Sedation protocols in patients undergoing complex endovascular aortic aneurysm repair are not fully investigated. The aim of this study was to compare a dexmedetomidine (DEX) based sedation protocol with a remifentanil-based sedation protocol. METHODS: Seventy-nine consecutive patients undergoing complex endovascular aortic repair were enrolled and retrospectively analyzed. Forty-two received 0.03 mg/kg midazolam intravenous bolus with remifentanil (0.075-0.1 μg/kg/min for 10 minutes followed by continuous infusion 0.050-0.25 μg/kg/min) and 37 DEX (1 μg/kg over 10 minutes and continuous infusion 0.50-0.75 μg/kg/hour) to achieve an Observer Assessment of Alertness/Sedation Scale (OAAS) ≤4, a Richmond Agitation/Sedation Scale (RASS) ≤-2 and a Visual Analogic Scale (VAS) <4. The primary endpoint was patients’ satisfaction. Secondary endpoints included assessment of sedation and pain, the incidence of perioperative hemodynamic or gas exchange imbalance, and 36 month-mortality. RESULTS: Remifentanil group showed a higher satisfaction rate than DEX (P<0.001). Patients on DEX were more sedated than remifentanil according to OAAS (3 [2-3] vs. 4 [3-4]; P=0.001) and RASS (-2[-3/-2] vs. -2[-2/-2]; P=0.001) with no difference in VAS (2 [1-3] vs. 2 [1-3]; P=0.41). DEX provides reliable sedation with lower patient’s satisfaction. A higher number of patients were discharged from the recovery room on vasopressors in the DEX group compare with the remifentanil group (5 vs. 0; P=0.045, respectively). The two groups showed a non-significant difference in the survival rate at 36-month (DEX 67% vs. remifentanil 73%; (P=0.90). CONCLUSIONS: In this setting remifentanil provides reliable sedation with higher patient’s satisfaction and less hemodynamic effect than DEX.