TY - JOUR
T1 - Self-control of level of mechanical ventilation to minimize CO2 induced air hunger
AU - Shea, Steven A.
AU - Harty, Helen R.
AU - Banzett, Robert B.
N1 - Funding Information:
We thank Christopher Kovacs and Karleyton Evans for providing technical assistance, and Professor Robert Lansing for helpful comments during the planning stages of this study. This work was supported by a grant from the National Institute of Health (HL-46690). Helen Harty's travel from the UK was sponsored by The Wellcome Trust, and The Royal Society.
PY - 1996/2
Y1 - 1996/2
N2 - Hypercapnia produces an uncomfortable urge to breathe ('air hunger'), which is alleviated by increasing breathing. It has been postulated that awake humans control breathing partly to minimize these sensations; such behavioral control presumably involves the forebrain. To test this postulate, we compared the ventilatory response to hypercapnia when the subject breathed spontaneously to the response when the subject used forebrain commands to control ventilation - on the basis of minimizing air hunger (achieved with subject-controlled positive pressure ventilation). In six healthy adults during hypercapnia (46 mmHg), spontaneous ventilation significantly exceeded, by 17%, the level of (mechanical) ventilation needed to alleviate air hunger. This suggests that spontaneous breathing is not behaviorally controlled to minimize discomfort. Alternatively, mechanical ventilation confers an additional relief of air hunger beyond that provided by spontaneous breathing. Since mechanical ventilation (with reduced respiratory muscle contraction) was more effective than spontaneous breathing in relieving air hunger, our results also suggest afferents that signal the degree of respiratory muscle contraction do not contribute to air hunger relief.
AB - Hypercapnia produces an uncomfortable urge to breathe ('air hunger'), which is alleviated by increasing breathing. It has been postulated that awake humans control breathing partly to minimize these sensations; such behavioral control presumably involves the forebrain. To test this postulate, we compared the ventilatory response to hypercapnia when the subject breathed spontaneously to the response when the subject used forebrain commands to control ventilation - on the basis of minimizing air hunger (achieved with subject-controlled positive pressure ventilation). In six healthy adults during hypercapnia (46 mmHg), spontaneous ventilation significantly exceeded, by 17%, the level of (mechanical) ventilation needed to alleviate air hunger. This suggests that spontaneous breathing is not behaviorally controlled to minimize discomfort. Alternatively, mechanical ventilation confers an additional relief of air hunger beyond that provided by spontaneous breathing. Since mechanical ventilation (with reduced respiratory muscle contraction) was more effective than spontaneous breathing in relieving air hunger, our results also suggest afferents that signal the degree of respiratory muscle contraction do not contribute to air hunger relief.
KW - Control of breathing, air hunger
KW - Hypercapnia
KW - Mammals, humans
KW - Mechanical ventilation, positive pressure ventilation
KW - Sensation, respiratory, air hunger
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U2 - 10.1016/0034-5687(95)00086-0
DO - 10.1016/0034-5687(95)00086-0
M3 - Article
C2 - 8833543
AN - SCOPUS:0029873136
SN - 0034-5687
VL - 103
SP - 113
EP - 125
JO - Respiration Physiology
JF - Respiration Physiology
IS - 2
ER -