Comparison of the hemodynamic responses to laryngoscopy and intubation on induction with etomidate, propofol-ketamine or propofol-etomidate: A randomized trial

Background

Haemodynamic stability is desirable during induction of anaesthesia. Intravenous induction agents have differing haemodynamic effects. We compared the haemodynamic effects of combinations of propofol-ketamine (PK) and propofol-etomidate (PE) with etomidate alone during induction of anaesthesia and laryngoscopy and endotracheal intubation.

Material and methods

This randomized controlled study was conducted on 90 ASA I patients aged 18–50 years undergoing elective surgery requiring endotracheal intubation under general anaesthesia who were randomly allocated to either Group E (Etomidate 0.3 mg/kg), Group PE (Propofol 1 mg/kg + Etomidate 0.15 mg/kg) or Group PK (Propofol 1 mg/kg + Ketamine 1 mg/kg). Mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and bispectral index (BIS) values were compared at different time points.

Results

After anaesthesia induction, the percentage fall in mean, systolic and diastolic blood pressure was least in the PK group. Laryngoscopy and intubation led to a rise in haemodynamic parameters in all groups. The mean, systolic and diastolic blood pressures were significantly higher in Group E at 1 min after intubation as compared to the other two groups. With etomidate, the fall in MAP prior to intubation was greater as was the intubation response despite lower BIS values. No correlation was found between haemodynamic response and BIS values attained after intubation.

Conclusions

Combinations of propofol with ketamine and etomidate in the selected doses were found to be superior to etomidate alone with respect to haemodynamic stability. Co-induction with propofol and ketamine maybe preferred when haemodynamic stability is required. Ketamine has the advantage of providing potent analgesia in this dose.