The effect of lung inflation on breathing in man during wakefulness and sleep.
To determine whether the Hering-Breuer inflation reflex could be demonstrated in the presence and absence of behavioral influences on breathing, lung inflation was performed via the tracheal stoma in eleven laryngectomized subjects: seven seated at rest with their eyes closed and six recumbent during their deepest non-rapid eye movement sleep. Laryngectomized subjects were chosen for study since their permanent tracheal stoma and absence of a glottis abolished the sensation of inflation in the upper airways, avoided problems with glottic closure and allowed simple, airtight connection to respiratory apparatus. At rest awake, inflation volumes of 500-3050 ml caused no reproducible apnea. During EEG-documented sleep, the inflation reflex was tested on 75 occasions using inflation volumes of 540-2100 ml. On the 66 occasions not associated with subject arousal inflations exceeding approximately 1 L produced apnea terminated by inspiration; greater volumes gave longer apneas. At the end of the study the subjects were woken and retested; no reproducible apnea was found. We conclude that the Hering-Breuer inflation reflex can be demonstrated above the resting tidal volume range in adult man in the absence of the behavioral control of breathing.
Department of Medicine, Charing Cross and Westminster Medical School, London, U.K.
R D
RD
Hamilton
A J
AJ
Winning
R L
RL
Horner
A
A
Guz
D006801:Humans; D007825:Laryngectomy; D008168:Lung / Q000502:physiology*; D012119:Respiration; D012890:Sleep / Q000502:physiology*; D014139:Tracheostomy; D014851:Wakefulness / Q000502:physiology*