Blood pressure, heart rate and catecholamine response during riberoptic nasotracheal intubation under general anesthesia

The physiologic impact of transnasal flexible endoscopy

OBJECTIVES/HYPOTHESIS

Diagnostic transnasal flexible endoscopy (TNFE) is a commonly used office procedure in otolaryngology. Currently there is a paucity of data on the impact of TNFE on physiologic parameters. This is relevant with the advent of office-based endoscopic procedures. The goal of this study is to measure the impact of topical decongestion, anesthesia, and diagnostic TNFE on vital signs: systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate (HR), and oxygenation (O(2) sat).

STUDY DESIGN

Prospective case control study, in which the patient is his/her control.

METHODS

Vital signs were obtained at baseline, immediately after the application of Neosynephrine, after the application of lidocaine, 5 minutes later, with the scope in the nasopharynx and hypopharynx, and upon completion of the procedure.

RESULTS

Compared to the baseline data, there was a statistically significant increase in HR after the procedure (mean change, 4.06 ± 10.15 bpm; range, -14 to 42 bpm, P = .01). There was also a change in O(2) sat (mean change, 0.42% ± 1.36%; range -3% to 3%, P = .03) after the application of lidocaine. When comparing each data point to the preceding point, there was a statistically significant change in SBP with the scope in the nasopharynx (mean change, 5.34 ± 10.65 mm Hg; range, -22 to 28 mm Hg, P = .001) and in HR with the scope in the hypopharynx (mean change, 3.76 ± 6.41 bpm; range, -9 to 19 bpm, P = .0004).

CONCLUSIONS

Diagnostic TNFE and topical lidocaine can have an impact on physiologic parameters; however, these changes are unlikely to be clinically significant.

The circulatory responses to fibreoptic intubation: a comparison of oral and nasal routes

The circulatory responses to fibreoptic intubation under general anaesthesia were studied in 60 adult female patients who were randomly assigned to receive either the oral or nasal route for insertion. Non-invasive blood pressure and heart rate were recorded before anaesthesia induction (baseline values), immediately after anaesthesia induction (post-induction values), at intubation and every minute for a further 5 min. The product of heart rate and systolic blood pressure (rate pressure product) at every time point was also calculated. The results showed that both fibreoptic orotracheal intubation and fibreoptic nasotracheal intubation resulted in significant increases in blood pressure, heart rate and rate pressure product compared to baseline and post-induction values. The times required to reach the maximum values of systolic blood pressure and heart rate were significantly longer in the fibreoptic nasotracheal intubation group than in the fibreoptic orotracheal intubation group. There were no significant differences between the two groups in blood pressure, heart rate and rate pressure product at any measuring point, or in the maximum values during observation. The time required for recovery of systolic blood pressure to the post-induction value was not significantly different between the two groups, but the time required for recovery of heart rate to post-induction value was significantly longer in the fibreoptic orotracheal intubation group than in the fibreoptic nasotracheal intubation group. It was concluded that both fibreoptic orotracheal and fibreoptic nasotracheal intubations could cause a similar magnitude of circulatory responses in general anaesthetised, female adults, but the tachycardic response to fibreoptic orotracheal intubation lasted longer than that to fibreoptic nasotracheal intubation.

Blood pressure and heart rate changes during intubation: a comparison of direct laryngoscopy and a fibreoptic method

Blood pressure and heart rate changes during nasotracheal intubation under general anaesthesia were studied in 100 patients who were randomly allocated to fibreoptic bronchoscope or direct laryngoscopy intubation. Noninvasive blood pressure and heart rate were recorded before and immediately after anaesthesia induction, at anaesthesia intubation and every minute thereafter for 5 min. Nasotracheal intubation was accompanied by significant increases in blood pressure and heart rate compared to baseline values in both groups. Blood pressure and heart rate at intubation, and the maximum values of blood pressure during the observation were significantly higher in the fibreoptic bronchoscope group. However, the maximum values of heart rate were not significantly different between the two groups. Fibreoptic nasotracheal intubation may result in more severe pressor and tachycardiac responses than direct laryngoscopic nasotracheal intubation.