Hemodynamic and catecholamine response to tracheal intubation: direct laryngoscopy compared with fiberoptic intubation.

Study Objective: To compare the stress response following tracheal intubation using direct laryngoscopy to that using fiberoptic bronchoscopy technique.

Design: Randomized, prospective study.

Setting: Operating rooms in a teaching hospital.

Patients: 51 ASA physical status I and II patients who were scheduled for an elective surgery with general anesthesia.

Interventions: Patients were randomly assigned to receive either direct laryngoscopy or fiberoptic orotracheal intubation, as part of general anesthesia. A uniform protocol of anesthetic medications was used.

Measurements: Blood pressure and heart rate were measured before induction, before endotracheal intubation, and 1, 2, 3, and 5 minutes afterwards. Catecholamine (epinephrine and norepinephrine) blood samples were drawn before the induction, and 1 and 5 minutes after intubation.

Main Results: Duration of intubation was shorter in the direct laryngoscopy group (16.9 (16.9 +/- 7.0 sec, range 8 to 40) compared with the fiberoptic intubation group (55.0 +/- 22.5 sec, range 29 to 120), p < 0.0,001. In both groups, blood pressure and heart rate were significantly increased at 1, 2, and 3 minutes after intubation, but there was no significant difference between the two study groups. Catecholamine levels did not increase after intubation and did not correlate with the hemodynamic changes.

Conclusions: The use of either direct laryngoscopy or fiberoptic bronchoscopy produces a comparable stress response to tracheal intubation. Catecholamine levels do not correlate with the hemodynamic changes.