Effects of esmolol, lidocaine and fentanyl on P wave dispersion, QT, QTc intervals and hemodynamic responses to endotracheal intubation during propofol induction: a comparative study.

BACKGROUND AND OBJECTIVES: In our study we aimed to investigate the effect of esmolol, lidocaine and fentanyl on P-wave dispersion (Pwd), QT and corrected QT (QTc) durations and hemodynamic responses to endotracheal intubation during propofol induction.

METHODS: A total of eighty adult patients, American Society of Anesthesiologists (ASA) Physical Status I or II aged 18 to 60 years were included in this prospective, randomised, double-blind study. All patients had control electrocardiograms (ECGs) done before anesthesia induction. The patients were randomised into four equal groups. The control group (Group C) received saline 5mL, the esmolol group (Group E) received esmolol 0.5mg.kg(-1), the fentanyl group (Group F) received fentanyl 2μg.kg(-1) and the lidocaine group (Group L) received lidocaine 1.5mg.kg(-1) before anesthesia induction. Anesthesia was induced with intravenous propofol. ECGs for all patients were performed during the 1(st) and 3(rd) minutes of induction, 3minutes after administration of muscle relaxant, and at 5minutes and 10minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. Heart rate (HR) and mean arterial pressure (MAP) were recorded before and after induction of anesthesia, immediately after intubation, and 1, 3, 5, 7 and 10minutes after intubation.

RESULTS: Compared with control, HR significantly increased in Group C, Group L and Group F after intubation. However, in Group E, there was no significant difference in HR values between control and after intubation. Compared with control, MAP significantly increased in Group C and Group L after the intubation. However, in Group E and Group F, there was no significant difference in MAP values between control and after the intubation. Compared with control, Pwd significantly increased in Group C after intubation. In Group L, Group F and Group E, there was no significant difference in Pwd values between control and after the intubation. Compared with control, QTc duration significantly increased in Group C and L after the intubation. In Group F and Group E, there was no significant difference in QTc durations between control and after the intubation.

CONCLUSION: We concluded that administration of esmolol before intubation prevents tachycardia and an increase in MAP, Pwd and QTc duration caused by laryngoscopy and tracheal intubation.