Comparative Analysis of Dexmedetomidine and Propofol Based Sedation Regimens on Anaesthetic Requirements in Cardiac Surgery with On-pump Cardiopulmonary Bypass

Abstract

Introduction: Dexmedetomidine is a selective α2 -agonist that has been successfully used as an anaesthetic adjuvant in cardiac surgery. Aim: To evaluate the effect of dexmedetomidine on intraoperative requirements of isoflurane and opioids for maintenance of anaesthesia during On-pump cardiac surgery and compare the anaesthesia sparing effect with that of propofol. Materials and Methods: This was a randomised, double blind observational study. Morphine consumption and minimum alveolar concentration of isoflurane was compared among 60 patients planned for elective open heart surgeries who were randomised to receive either dexmedetomidine (1 µg/kg bolus over 10 minutes followed by infusion of 0.2 to 0.6 µg/kg/hour) or propofol (0.25-1 mg/kg/hour) throughout the intraoperative period till skin closure. The drug infusions were titrated to target Bispectral Index (BIS) score of 40-60. BIS scores and minimum alveolar concentration of isoflurane were recorded at predetermined intervals during surgery. Total dose of morphine used was also recorded. Statistical analysis was carried out using analysis of variance, Chi-square test, Student’s t-test and Mann-Whitney U test. Results: BIS scores were significantly lower in dexmedetomidine group (p<0.05). Total dose of morphine and minimum alveolar concentration of isoflurane were significantly lower in dexmedetomidine group (p<0.05). Conclusion: From the results we concluded that intraoperatively administered dexmedetomidine during On-pump cardiac surgery has specific analgesic properties and decreases intraoperative anaesthetic requirement. Thus, dexmedetomidine has significant opioid and anaesthetic sparing property.

Keywords

• adjuvant
• anaesthesia
• intensive care
• minimum alveolar concentration
• morphine