Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1990-2-26
pubmed:abstractText
1. The transient ventilatory response to CO2, measured using short pulses at constant inflow, was compared with the steady-state response at rest and during exercise at 50 W, and with the rebreathing response at rest, in nine healthy subjects. At rest CO2 was given at flow rates of 0.2 and 0.4 l min-1 and during exercise, to compensate for the smaller inhaled CO2 fraction as ventilation increased, at flow rates of 0.4 and 0.8 l min-1. 2. We calculated two indexes of gain for the transient response: the ratio of the peaks of the ventilation and PCO2 pulses, and the ratio of their integrals. 3. The steady-state response was greater than the transient response at rest and during exercise, but there was no correlation between the two. The rebreathing response was greater than both. Both the transient and the steady-state responses were greater during exercise than at rest. 4. To assess alinearity, the steady-state responses to the two CO2 flow rates were compared. At rest, there was no significant difference. During exercise, the response was greater to 0.4 than 0.8 l min-1, indicating alinearity concave downwards. 5. We conclude that the transient response as we calculate it is not representative of steady-state gain, and that the CO2 response in light exercise is steeper, and concave downwards in shape. The rebreathing technique overestimates CO2 sensitivity near the control point.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-3040968, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-3086022, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-3112108, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-3115662, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-3928580, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-4522362, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-457565, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-4702981, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-5037410, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-5666882, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-6028163, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-6032026, http://linkedlifedata.com/resource/pubmed/commentcorrection/2515277-7118642
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3751
pubmed:author
pubmed:issnType
Print
pubmed:volume
411
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-96
pubmed:dateRevised
2010-8-25
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Transient, steady-state and rebreathing responses to carbon dioxide in man, at rest and during light exercise.
pubmed:affiliation
Department of Medicine I, St George's Hospital Medical School, London.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't