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BACKGROUND: The use of intravenous sedation during cardiac surgery to reduce awareness has been practised routinely during past few years and the two most commonly used drugs include propofol and dexmedetomidine, but their effects on hemodynamics and postoperative outcomes in cardiac surgery is continually being evaluated. AIMS: The aim of this study was to compare the effects of anesthesia by dexmedetomidine and propofol on the hemodynamic variables and postoperative outcomes in patients who were planned for elective cardiac surgery. SETTINGS: Cardiac operating room of a tertiary care hospital. DESIGN: A prospective, randomized controlled, double-blind clinical trial. MATERIALS AND METHODS: Sixty patients were randomized to receive either a continuous infusion of propofol (0.25-1 mg/kg/h) or dexmedetomidine bolus of 1 µg/kg over 10 min followed by infusion (0.2-0.6 µg/kg/h) after induction of anesthesia. The anesthesia technique and physiological monitoring including bispectral index monitoring were similar among both the groups. Hemodynamic variables (mean heart rate [HR], mean arterial pressure [MAP]) were noted at predefined time intervals, intraoperative vasopressor or inotrope requirements and postoperative outcomes including postoperative ventilation time and length of stay in the Intensive Care Unit (ICU) were also recorded. STATISTICAL ANALYSIS: Statistics was done using SPSS V 20 (IBM, NY) using Student's t-test, analysis of variance, and Mann-Whitney U-test, and a P < 0.05 was considered to indicate a significant difference. RESULTS AND CONCLUSIONS: HR and MAP were significantly less in dexmedetomidine group compared to propofol group (P < 0.05). Both the groups had a similar requirement of vasopressors and inotropes. The duration of postoperative ventilation and length of stay in the ICU were significantly shorter in the dexmedetomidine group (P < 0.05). The risk of delirium was significantly less in dexmedetomidine group (P < 0.05). From our study we concluded, that the perioperative infusion of dexmedetomidine produces better hemodynamic stability, reduces the risk of postoperative delirium, and leads to shorter ICU stay.
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Background Awareness during general anesthesia is undesired and unanticipated patient wakefulness during surgery or recall of intraoperative events. Incidence of awareness in patients undergoing cardiac surgery is significantly higher than the overall incidence of 1% during general surgery. Awareness during cardiac surgery can be prevented by a number of methods. One such method is the supplemental, intraoperative use of sedative agents. Propofol, a bisubstituted phenol, is an intravenous general anesthetic that has been shown to reduce the incidence of awareness. Dexmedetomidine-an alpha2-adrenergic agonist with anxiolytic, opioid, and general anesthetic-sparing properties-is being considered for maintaining intraoperative depth of anesthesia. The purpose of this study was to evaluate the effect of dexmedetomidine on depth of anesthesia and to compare it with the effect of propofol in cardiac surgery. Methods This was a prospective, randomized, double-blind study conducted in a tertiary-care hospital. Sixty patients with American Society of Anesthesiologists (ASA) physical status I-III planned for elective open heart surgery were randomized into two groups of 30 patients each. Each patient of the dexmedetomidine group received an initial loading dose of dexmedetomidine at 1 mcg kg-1 over 10 minutes followed by infusion at the rate of 0.2-0.6 mcg kg-1 hr-1. Patients of the propofol group received propofol infusion at the rate of 0.25-1 mg kg-1 hr-1. An identical technique-of standard general anesthesia and routine physiological monitoring-was used in both groups. Bispectral scores were recorded at predetermined intervals during surgery and the target bispectral index (BIS) was kept at 50±10. The patients were assessed for awareness and recall 24 hours after tracheal extubation using the Brice Questionnaire. Results Intraoperative BIS scores remained within the target range in both groups; however, the BIS scores showed variable trends between the groups and were significantly lower in the dexmedetomidine group (p < 0.001). None of the patients in either group had recall of intraoperative events. Conclusion Administration of dexmedetomidine was as effective in reducing awareness and recall in cardiac surgery compared to propofol. Thus, dexmedetomidine can be used as an alternative sedative agent to prevent awareness and recall in cardiac surgery.
