Comparison of Induction Characteristics of two Anaesthetic Agents: Etomidate-lipuro and Propofol for Day Care Surgery

Introduction: Induction of anaesthesia is the most critical stage of anaesthesia. Thus, an induction agent with less side effect should be used. Aim: To compare the newer formulation of Etomidate in lipid formulation (Etomidate-lipuro) and propofol-lignocaine admixture in patients undergoing day care gynaecological surgery. Materials and Methods: Hundred ASA I and II patients in the age group 18-60 years, scheduled for dilatation and curettage procedure were randomly allocated to receive either Etomidate-lipuro 0.2 mg/kg or propofol 2 mg/kg. Both groups received intravenous midazolam 0.05 mg/kg and fentanyl 2 mu g/kg as premedication. After induction with the desired agent titrated to Response Entropy (RE) 40, the time to achieve values to 40 (RE 40 time) were measured. Heart Rate (HR), Mean Arterial Pressures (MAP) were recorded at baseline, at induction and every minute for 15 minutes. Incidence of pain at injection site, myoclonus, apnea and thrombophlebitis were observed. Statistical analysis was done using Chi-square test and Student unpaired t-test. Results: Haemodynamic parameters (HR and MAP) were well maintained with etomidate. There was a significant decline in HR and MAP with propofol as compared to etomidate (p<0.001). Onset of anaesthesia (Time to achieve RE 40) was 81.22 +/- 2.79 s and 77.60 +/- 230 s in propofol and Etomidate-lipuro respectively (p<0.001). The incidence of pain was more with propofol-lidocaine admixture (40%) as compared to no pain with etomidate (p<0.05). None of the patients had myoclonus and postoperative thrombophlebitis in our study. Incidence of postoperative nausea was high with etomidate use (22%) than with propofol (14%) but statistically insignificant (p>0.05). None of the patient in our study had vomiting. Incidence of apnoea was higher with propofol (58%) as compared to etomidate (14%) (p<0.001). Conclusion: Etomidate-lipuro can be a valuable induction agent due to its haemodynamic stability and lesser side effect profile for day care surgery.