Human ventilatory response to 8 h of euoxic hypercapnia.

  title={Human ventilatory response to 8 h of euoxic hypercapnia.},
  author={J G Tansley and Michala E. F. Pedersen and Christine Clar and Peter A. Robbins},
  journal={Journal of applied physiology},
  volume={84 2},
Ventilation (VE) rises throughout 40 min of constant elevated end-tidal PCO2 without reaching steady state (S. Khamnei and P. A. Robbins. Respir. Physiol. 81: 117-134, 1990). The present study investigates 8 h of euoxic hypercapnia to determine whether VE reaches steady state within this time. Two protocols were employed: 1) 8-h euoxic hypercapnia (end-tidal PCO2 = 6.5 Torr above prestudy value, end-tidal PO2 = 100 Torr) followed by 8-h poikilocapnic euoxia; and 2) control, where the inspired… 

Figures and Tables from this paper

Ventilatory effects of 8 h of isocapnic hypoxia with and without beta-blockade in humans.

Evidence is not provided that changes in sympathetic activity acting via beta-receptors play a role in the mediation of ventilatory changes observed during 8 h of isocapnic hypoxia, and beta-Blockade did not significantly alter either the rise in VE or the changes observed in the acute hypoxicventilatory response and residual VE in hyperoxia over that period.

Respiratory effects in humans of a 5-day elevation of end-tidal PCO2 by 8 Torr.

The results do not support the hypothesis that the ventilatory adaptation to chronic hypercapnia would be much greater with constant elevation of alveolar PCO2 than with constant Elevated end-tidalPCO2, as has been used in previous studies and in which the feedback loop between ventilation and alveolars is left intact.

Identification of fast and slow ventilatory responses to carbon dioxide under hypoxic and hyperoxic conditions in humans

It is concluded that the rapid and slow components of the ventilatory response to CO2 can be separately identified, and that a rapid component persists under conditions of hyperoxia.

Effects of subanaesthetic sevoflurane on ventilation. 1: Response to acute and sustained hypercapnia in humans.

It is suggested that 0.1 minimum alveolar concentration of sevoflurane does not significantly affect the acute ventilatory response to hypercapnia and does not modify the progressive changes in ventilation and pattern of breathing that occur with sustainedhypercapnia.

Effect of work intensity on time delay in mediation of ventilation by arterial carbon dioxide during recovery from impulse exercise.

Results indicate that PaCO(2 pre) drives V(.)E with a time delay and that higher work intensity induces a shorter time delay.

Role of acid-base balance in the chemoreflex control of breathing.

  • J. Duffin
  • Biology
    Journal of applied physiology
  • 2005
A steady-state modeling approach is used to describe the effects of changes in acid-base balance on the chemoreflex control of breathing, and demonstrates that the relationship between Pco(2) and [H(+)] should not be neglected when modeling the che more Flexibility Control of breathing.

Selected contribution: Ventilatory response to CO2 in high-altitude natives and patients with chronic mountain sickness.

Values for the slow (central) time constant were significantly greater for HA and CMS subjects than for SL subjects, and the total and central chemoreflex sensitivity to CO(2) in euoxia was higher in HA subjects than in SL subjects.

Effect of low dose inhaled anaesthetic agents on the ventilatory response to carbon dioxide in humans: a quantitative review

The results suggest that the hypercapnic response is more resistant to the effects of anaesthetics than the hypoxic ventilatory response, and possible ways in which subject arousal might interact in the brain with the chemoreflexes.

The ventilatory response to hypoxia in mammals: mechanisms, measurement, and analysis.

The mechanisms underlying the HVR and its adaptations to chronic changes in ambient oxygen concentration are discussed, with emphasis on the carotid bodies that contain oxygen sensors and initiate the response, and on the contribution of central neurotransmitters and brain stem regions.

Plasticity in Respiratory Motor Control Selected Contribution : Ventilatory response to CO 2 in high-altitude natives and patients with chronic mountain sickness

The ventilatory responses to CO2 of high-altitude natives and patients with chronic mountain sickness were studied and compared with sea-level natives living at SL and values for the slow time constant were significantly greater for HA and CMS subjects than for SL subjects.



The influence of oxygen on the ventilatory response to carbon dioxide in man.

There is a contribution to ventilation of the peripheral chemoreceptors during hyperoxia in man and apart from peripheral oxygen‐carbon dioxide interaction, there is evidence for central oxygen‐ carbon dioxide interaction in human subjects.

Response of the goat carotid body to acute and prolonged hypercapnia.

Hypoxic depression of ventilation in humans: alternative models for the chemoreflexes.

Chamber for controlling end-tidal gas tensions over sustained periods in humans.

A chamber in which subjects can be comfortable for many hours while having their end-tidal gas composition monitored and controlled and deviations of the actual PETO2 and PETCO2 from the desired values are corrected by a feedback mechanism that adjusts the inspired gas composition accordingly.

Ventilation volume as a stimulus to spontaneous ventilation after prolonged artificial ventilation

Investigations on paretic patients in which the tidal volume imposed during artificial ventilation was varied, but the end-tidal PCO2 and the ventilatory frequency were kept constant are reported.

A prediction-correction scheme for forcing alveolar gases along certain time courses.

A computerized prediction-correction scheme has been devised for the control of alveolar gases to achieve the commanded inspiratory PCO2 and PO2 (CO2 and O2 partial pressures, respectively).


An analytical model that describes the operation of α‐hexathienylene (α‐6T) thin‐film‐transistors (TFTs) is presented. The current‐voltage characteristics of TFTs with channel lengths ranging from

Step changes in end-tidal CO2: methods and implications.

The delay in the ventilation response after the change in end-tidal CO2 is less in hypoxia than in normoxia and reflects the action of a transport delay and that of a virtual delay.