TY - JOUR
T1 - Stimulus-response characteristics of CO2-induced air hunger in normal subjects
AU - Banzett, Robert B.
AU - Lansing, Robert W.
AU - Evans, Karleyton C.
AU - Shea, Steven A.
N1 - Funding Information:
We thank our subjects for their time and cooperation. Christopher Kovacs, Emil Millet, Jerzy Krol, and Susan Mahan provided superb technical assistance. Dr. Elisabeth Bloch-Salisbury provided thoughtful comments on the manuscript. We thank Carl Mclsaac of Datex Medical Instrumentation Corp. for technical advice, and Tom Feeney of Intertech Resources Inc. for providing the active humidifier. Supported by HL46690.
PY - 1996/1
Y1 - 1996/1
N2 - Hypercapnia evokes an uncomfortable sensation, termed 'air hunger'. We examined the relationship between PET(CO2) and ratings of air hunger intensity under three conditions in 16 subjects: 1) mechanical ventilation with hyperoxic gas mixtures at fixed frequency and tidal volume (twice resting ventilation), 2) the same mechanical ventilation, but with hypoxic gas mixture, 3) spontaneous breathing with hyperoxic gas mixture. In each case, PET(CO2) was varied randomly among several levels, each held for 5 min. During hyperoxic mechanical ventilation, the mean threshold for air hunger sensation was 43 Torr, i.e., 4 Torr above resting PET(CO2); intolerable air hunger was evoked by 50 Torr. The threshold and tolerable levels of PET(CO2) varied among individuals, but were not well correlated with their ventilatory responses to CO2. Hypoxia (PET(O2) 60-75 Torr) shifted the PET(CO2) at both threshold and tolerance down by only 2 Torr. Breathing greatly reduced the air hunger experienced at any given PET(CO2) (threshold increased 5 Torr, and sensitivity decreased 50%).
AB - Hypercapnia evokes an uncomfortable sensation, termed 'air hunger'. We examined the relationship between PET(CO2) and ratings of air hunger intensity under three conditions in 16 subjects: 1) mechanical ventilation with hyperoxic gas mixtures at fixed frequency and tidal volume (twice resting ventilation), 2) the same mechanical ventilation, but with hypoxic gas mixture, 3) spontaneous breathing with hyperoxic gas mixture. In each case, PET(CO2) was varied randomly among several levels, each held for 5 min. During hyperoxic mechanical ventilation, the mean threshold for air hunger sensation was 43 Torr, i.e., 4 Torr above resting PET(CO2); intolerable air hunger was evoked by 50 Torr. The threshold and tolerable levels of PET(CO2) varied among individuals, but were not well correlated with their ventilatory responses to CO2. Hypoxia (PET(O2) 60-75 Torr) shifted the PET(CO2) at both threshold and tolerance down by only 2 Torr. Breathing greatly reduced the air hunger experienced at any given PET(CO2) (threshold increased 5 Torr, and sensitivity decreased 50%).
KW - Breath hold
KW - Breathlessness
KW - Control of breathing
KW - Dyspnea
KW - Mammals, humans
KW - Sensation, respiratory, air hunger
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U2 - 10.1016/0034-5687(95)00050-X
DO - 10.1016/0034-5687(95)00050-X
M3 - Article
C2 - 8822220
AN - SCOPUS:0029670599
SN - 0034-5687
VL - 103
SP - 19
EP - 31
JO - Respiration Physiology
JF - Respiration Physiology
IS - 1
ER -