CHANGES OF NASAL AIRWAY RESISTANCE CAUSED BY BREATH HOLDING

I. RESULTS IN NORMAL SUBJECTS

Abstract

Various effects upon respiratory and circuratory systems induced by breath holding have been investigated by many physiologists for a long time. For instance, it increases the systoric and diastoric blood pressure, and decreases the rate of finger tip blood flow and finger tip volume.These circuratory effects have been considered by the excitation of the sympathetic nerve.
The nasal mucous membrane is rich in vessels and these vessels are innervated by sympathetic and parasympathetic nerves.
In this paper, it was investigated whether breath holding could have any effect on the vessels in the nasal mucosa. For this purpose, the changes of nasal airway resistance (NAR) were examined.
In fifteen normal adults, NAR was determined before and after breath holding. For the determination of NAR, the combined method was used, and the variant ratio of NAR (NAR after breath holding/NAR before breath holding) was calculated. The mean value of fifteen normal adults was 0.57 and the standard deviation was 0.18
In order to investigate the sympathetic effect on this reflex, changes of NAR by breath holding were estimated in four patients with sudden deafness who were treated by stellate ganglion block.In these patients, changes of NAR were not observed.
In conclusion, this reflex is highly suspected to be transmitted by the sympathetic nerve.