Patterns of Reflex Responses to Dynamic Stimulation of the Human Respiratory System

Cunningham, D. J.; Metias, Emile F; Howson, M. G.; Petersen, E. Strange

doi:10.1007/978-3-642-68657-3_15

Cited by 3 publications

(3 citation statements)

References 3 publications

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“…In particular, is there any dissociation, using sinusoidal stimuli, between volumes, mean flows and durations as has been reported for (1) VT and T1 in response to steps of alveolar CO2 in high 02 (Gardner, 1980), (2) VT and TE in response to steps of alveolar hypoxia at constant CO2 (Gardner, 1980), and (3) VT and T1 for a brief hypoxic stimulus (Jennett et al 1981)? In addition the question is asked whether there is any dissociation between the inspiratory and expiratory variables as has been reported with stimuli of higher frequency (Ward & Cunningham, 1977;Cunningham, Metias, Howson & Petersen, 1983).…”

Section: Introductionmentioning

confidence: 99%

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

Cunningham¹,

Robbins²

1984

The Journal of Physiology

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SUMMARY1. Sine waves of alveolar CO2 at constant high alveolar 2, and sine waves of alveolar hypoxia (1/(PA, 02-C) where C -32 torr) at constant alveolar CO2 have been administered to three subjects in each case.2. Six different periods of the sine waves were studied, ranging between 900 and 30 s for the CO2 sine waves and 300 and 20 s for the hypoxic sine waves.3. The sinusoidal variations in inspiratory and expiratory volumes (VT I, VT, E), durations (T1, TE) and mean flows (VI, VME) produced by these manoeuvres were calculated, and the results analysed from the phase shifts of the responses. 4. For the CO2 sine-wave results, the peak in the T1 oscillation generally appeared after the minima for VT I and VI, but before their maxima. The peak in the TE oscillation was variable.5. For the hypoxic sine-wave results, the peak in the T1 oscillation showed no over-all tendency to lead or lag the peaks of VT I and VI. The peak in the TE oscillation generally appeared after the maxima for VT E and WE but before their minima.6. For the CO2 sine-wave results, expiratory mean flow led inspiratory mean flow, with the volumes showing no significant difference. For the hypoxic sine-wave results expiratory volumes and mean flows led inspiratory volumes and mean flows.7. The results are discussed in relation to the transient responses of the components of breathing pattern obtained from other perturbations of chemical drive.

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Section: Introductionmentioning

confidence: 99%

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

Cunningham¹,

Robbins²

1984

The Journal of Physiology

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“…part of this experiment (published as Fig. 6 of Cunningham et al 1983) showed consecutive rather than simultaneous alternation of these two variables. the distribution for b.b.c.…”

Section: The Inspiratory-expiratory Linkagementioning

confidence: 61%

“…(5) can these patterns be related to any of the current accounts of the neural organization of breathing? A preliminary account of some of this work has been published (Cunningham, Metias, Howson & Petersen, 1983).…”

Section: Introductionmentioning

confidence: 99%

Patterns of breathing in response to alternating patterns of alveolar carbon dioxide pressures in man.

Cunningham¹,

Howson²,

Metias³

et al. 1986

The Journal of Physiology

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The time profile of alveolar PCO2 within the respiratory cycle has been forced to follow contrasting patterns in alternate breaths, in two different ways. Within‐breath changes (w.b.c., with a CO2‐rich inspirate supplied early or late in alternate inspirations) involved minimal alternation of end‐tidal PCO2. Between‐breath changes (b.b.c., with whole inspirates of CO2‐free or CO2‐rich gas) involved large swings of end‐tidal PCO2. As previously reported (Metias, Cunningham, Howson, Petersen & Wolff, 1981), both patterns of forcing were associated with alternation of ventilation, but only when hypoxia was present. The patterns of the alternating reflex responses in 118 runs on four human subjects in steady hypoxia are described in terms of alternation of inspiratory and expiratory tidal volume, time and mean flow. These patterns often disappeared, or changed unpredictably in mid‐run. The inspiratory pattern of reflex alternation depended in part on the type of forcing, but alternation of inspiratory tidal volume was usually observed with both types. No single pattern of expiratory alternation emerged as predominant. The pattern of reflex expiratory alternation was surprisingly independent of the pattern of inspiratory alternation: indeed, in w.b.c., but not in b.b.c., alternation of mean expiratory flow and of mean inspiratory flow were mutually exclusive. It is concluded that in man, as in cats and dogs, the arterial chemoreceptor pathway has access to various parts of the respiratory pattern generator, the exact response depending to some extent on the timing within the respiratory cycle. In particular, expiratory variables may be influenced directly through the arterial chemoreceptor pathway, i.e. without any supposedly mediating inspiratory alternation being demonstrable. The results are discussed briefly in relation to some current views on the organization of respiratory control.

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Integration of Respiratory Responses to Changes in Alveolar Partial Pressures of CO ₂ and O ₂ and in Arterial pH

Cunningham¹,

Robbins

Wolff

1986

Comprehensive Physiology

142

167

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Patterns of Reflex Responses to Dynamic Stimulation of the Human Respiratory System

Cited by 3 publications

References 3 publications

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

Patterns of breathing in response to alternating patterns of alveolar carbon dioxide pressures in man.

Integration of Respiratory Responses to Changes in Alveolar Partial Pressures of CO ₂ and O ₂ and in Arterial pH

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Patterns of Reflex Responses to Dynamic Stimulation of the Human Respiratory System

Cited by 3 publications

References 3 publications

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

The pattern of breathing in man in response to sine waves of alveolar carbon dioxide and hypoxia.

Patterns of breathing in response to alternating patterns of alveolar carbon dioxide pressures in man.

Integration of Respiratory Responses to Changes in Alveolar Partial Pressures of CO 2 and O 2 and in Arterial pH

Contact Info

Product

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Integration of Respiratory Responses to Changes in Alveolar Partial Pressures of CO ₂ and O ₂ and in Arterial pH