The relation between tidal volume and inspiratory and expiratory times during steady‐state carbon dioxide inhalation in man

Abstract

TI, and (c)

Influence of rate of induction of hypoxia on the ventilatory response

“…Some controversy regarding the latter finding persists (Jennett, Russell & Warnock, 1974), as does controversy regarding the decrease in expiratory duration at low tidal volumes (Clark & Euler, 1972). However, Gardner's (1977) recent study appears to have confirmed the pattern of breathing described above for steady-state CO2 inhalation. On the other hand in his studies on awake cats, Gautier (1975) showed that steady-state hypoxia shortened inspiratory time, a finding that contrasted with his earlier studies of hypercapnia.…”

“…Remmers (1976) has interpreted this hypercapnic effect as an augmentation of inspiratory drive and suppression of expiratory braking without alteration of the timing of the inspiratory 'off-switch'. At higher tidal volumes, hypercapnia appears also to shorten inspiratory time (Clark & Euler, 1972;Gardner, 1977). Some controversy regarding the latter finding persists (Jennett, Russell & Warnock, 1974), as does controversy regarding the decrease in expiratory duration at low tidal volumes (Clark & Euler, 1972).…”

“…When the respiratory cycle is analysed in terms of tidal volume vs. inspiratory and expiratory time, differences between T, and TE responses to hypercapnia and hypoxia become apparent. For example, hypercapnia at first evokes an increase in tidal volume and a reduction in the duration of expiration whereas inspiratory time changes little C. K. MAHUTTE AND A. S. REBUCK (Gautier, 1969;Gardner, 1975;Gardner, 1977;Gautier, Remmers & Bartlett, 1973;Cunningham, Pearson & Gardner, 1972). Remmers (1976) has interpreted this hypercapnic effect as an augmentation of inspiratory drive and suppression of expiratory braking without alteration of the timing of the inspiratory 'off-switch'.…”

Ventilation.

“…(2) Subdivisions of ventilation Minute volume is the product of tidal volume and frequency (VE = VT xf) and separate measurement of these components is important in the analysis of control of breathing (Hey, Lloyd, Cunningham, Jukes & Bolton, 1966;Clark & von Euler, 1972;Newsom-Davies & Stagg, 1975). Ventilatory responses to exercise and carbon dioxide have been investigated in this way (Cunningham & Gardner, 1972;Cunningham, Drysdale & Gardner, 1977;Gardner, 1977) as have those to vagus nerve blockade (Guz, Noble, Widdicombe, Trenchard, Mushin & Makey, 1966; and certain drugs (Gautier & Gaudy, 1978).…”

The effects of beta‐adrenoceptor blockade on breathing during progressive exercise in normal man.

“…However, other authors have shown in animals that, whereas a major component of the ventilatory response is mediated via the arterial chemoreceptors, a significant component is the result of direct effects on the central nervous system (Eldridge & Gill-Kumar, 1980;Winn et al, 1979). Folgering (1980) (Hey et al, 1966;Cunningham & Gardner, 1977;Gardner, 1977 (Bailey, 1959).…”