Effect of sevoflurane with morphine or fentanyl on haemodynamic response to laryngoscopy and tracheal intubation: a prospective, randomised, double-blind study

Background: Multimodal therapy can be used for obtundation of the haemodynamic response to laryngoscopy and tracheal intubation. The current study was undertaken to compare the haemodynamic response to laryngoscopy and tracheal intubation after administration of 0.2 mg/kg morphine or 2 μg/kg fentanyl with 2% end tidal sevoflurane during induction of anaesthesia. Methods: Sixty patients were randomised into two equal groups to receive either 2% end tidal sevoflurane + fentanyl 2 μg/kg (Group SF) or 2% end tidal sevoflurane + morphine 0.2 mg/kg (Group SM). General anaesthesia technique was standardised for both the groups. Haemodynamic parameters heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded for 15 min. Results: The maximum increase in HR compared to baseline was statistically significant in Group SM (16.5%, P = 0.0002) which occurred at one min after tracheal intubation. The maximum increases in SBP, DBP and MAP compared to baseline occurred at one min after tracheal intubation in both the groups, Group SF (7.04%, 6.5% and 7.9% respectively) and Group SM (6.2%, 8.2% and 8.1% respectively) which was not statistically significant. The attenuation of haemodynamic response between the two groups was not statistically significant (for HR P = 0.1428, for SBP P = 0.8558, for DBP P = 0.1958 and for MAP P = 0.5303). Conclusions: With 2% end tidal sevoflurane during induction of anaesthesia, both 0.2 mg/kg morphine and 2 μg/kg fentanyl were equally effective in attenuating haemodynamic response to laryngoscopy and tracheal intubation. However morphine appeared to be less effective in attenuating the chronotropic response resulting in a greater increase in heart rate from baseline.