Evaluation of the cardiovascular responses to fiberoptic orotracheal intubation with television monitoring: comparison with conventional direct laryngoscopy.

STUDY OBJECTIVE

To evaluate and compare cardiovascular responses to a new method of orotracheal intubation incorporating TV monitoring, with conventional orotracheal intubation via rigid blade laryngoscopy.

DESIGN

Prospective single-blind study.

SETTING

Operating room of a medical college hospital.

PATIENTS

90 ASA physical status I and II surgical patients requiring general anesthesia and orotracheal intubation.

INTERVENTIONS

Patients were randomly allocated to two groups, one for the new intubation method and the other for conventional intubation using a rigid laryngoscope. In the new method, an anesthesiologist inserted an endotracheal tube alone into the trachea via TV monitoring through the bronchoscope, which was inserted by an assistant through the mouth to the middle larynx. The patient's trachea was intubated without extreme stretching of laryngeal tissues or deep insertion of the tip of the bronchoscope. In the conventional method, orotracheal intubation was performed with rigid direct laryngoscopy.

MEASUREMENTS

Noninvasive blood pressure (BP) and heart rate (HR) were measured before arrival at the operating room, and before and after orotracheal intubation.

MAIN RESULTS

Although this method was expected to be a minimally invasive fiberoptic intubation technique, the patients showed significant increases in BP and HR. No significant differences between the two groups were observed in cardiovascular responses immediately after intubation: the systolic BP, 169.5 +/- 28.3 versus 167.0 +/- 23.1 mmHg, and HR, 100.2 +/- 18.2 versus 98.8 +/- 16.6 bpm.

CONCLUSIONS

Insertion of an endotracheal tube may itself be the most invasive stimulus during intubation procedures.