Cardiovascular responses to orotracheal intubation in patients undergoing coronary artery bypass grafting surgery. Comparing fiberoptic bronchoscopy with direct laryngoscopy.

BACKGROUND The intubation by using fiberoptic brochoscop (FOB) can avoid the mechanical stimulus to oropharyngolaryngeal structures thereby it is likely to attenuate hemodynamic response during orotracheal intubation. Based on this hypothesis, we compared the hemodynamic responses to orotracheal intubation using an FOB and direct laryngoscope (DLS) in patients undergoing general anesthesia for coronary artery bypass grafting (CABG) surgery. METHODS Fifty patients with ASA physical status II and Mallampati score I and II were scheduled for elective CABG surgery under general anesthesia requiring orotracheal intubation were randomly allocated to either DLS group (n = 25) or FOB group (n = 25). The same protocol of anesthetic medications was used. Invasive systolic and diastolic blood pressure (SBP & DBP) and heart rate (HR) were recorded before and after anesthesia induction, during intubation and in the first and second minutes after intubation. The differences among the hemodynamic variables recorded over time and differences in the circulatory variables between the two study groups were compared. RESULTS Duration of intubation was shorter in DLS group (19.3 +/- 4.7 sec) compared with FOB group (34.9 +/- 9.8 sec; p = 0.0001). In both study groups basic SBP and DBP and HR were not significantly different (P > 0.05). During the observation, there were no significant differences between the two groups in BP or HR at any time points or in their maximal values (all p values > 0.05). CONCLUSION We conclude that the FOB had no advantage in attenuating the hemodynamic responses to orotracheal intubation in patients undergoing CABG surgery.