title: Almost simultaneous measurement of cardiovascular and gas exchange variables during maximal exercise.
abstract: We measured gas exchange variables such as oxygen uptake, carbon dioxide output, and lung diffusing capacity using noninvasive techniques almost simultaneous with assessment of cardiovascular variables such as pulmonary blood flow at several levels of treadmill exercise up to and including maximal capacity. We utilized a single breath exhalation technique for measurement of diffusing capacity and cardiac output and breath by breath methodology for evaluating oxygen uptake. The equipment required for these measurements--rapid gas analyzers, oximeters, on-line computation, and pneumatic valves--are well within the capabilities of many exercise laboratories and are not difficult to use with subjects even at the heaviest levels of exercise. The results agreed well with values reported in the literature. From these entirely noninvasive measures, we calculated mixed venous oxygen saturation and maximal tissue oxygen diffusing capacity.
authors.affiliation: Department of Medicine, University of California Irvine, Orange 92668, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Savariryan
authors.forename: N
authors.initials: N
authors.lastname: James
authors.forename: D
authors.initials: D
authors.lastname: Mukai
authors.forename: E
authors.initials: E
authors.lastname: Nishimura
mesh_terms: D000328:Adult; D001944:Breath Tests; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011653:Pulmonary Diffusing Capacity; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests / Q000379:methods*