The Haemodynamic Response to Endotracheal Intubation at Different Time of Fentanyl Given During Induction: A Randomised Controlled Trial

Endotracheal intubation elicits huge spectrum of stress responses which are hazardous in high-risk patients. Numerous drugs and techniques have been applied to attenuate the stress responses. In this double-blind study, one hundred and forty-five patients over 20 years old, ASA physical status I and II, undergoing elective surgeries requiring general anaesthesia with endotracheal intubation were included. Patients were randomly divided into three groups which fentanyl 2 mcg/kg was given at either 1, 2, 3 minutes before intubation. All groups received midazolam 0.05 mg/kg, lidocaine 0.5 mg/kg, propofol 2 mg/kg and rocuronium 1 mg/kg before intubation. Haemodynamic parameters were recorded for 10 minutes after induction. Two-level longitudinal hierarchical linear models were used for data interpretation and P < 0.05 was considered statistically significant. The study demonstrated significantly lower haemodynamic responses in the group who received fentanyl 2 minutes before intubation (P < 0.05). Confounding factors such as smoking, hypertension, diabetes mellitus and preoperative intravenous fluid supplement were analysed. In conclusion, fentanyl injection 2 minutes before intubation is recommended in order to obtain the most stable haemodynamic status.