BACKGROUND Measurement of variables of metabolic gas exchange during exercise is widely used to assess the severity of heart failure. The variables derived however, are potentially dependent on motivation of the patient and duration of exercise. METHODS The data from exercise tests in 23 patients with exertional breathlessness were analysed to derive the following three common indices of exer...

The purpose of the study was to investigate the effects of implementing additional respiratory dead space during cycloergometry-based aerobic training. The primary outcome measures were respiratory exchange ratio (RER) and carbon dioxide production (VCO2). Two groups of young healthy males: Experimental (Exp, n = 15) and Control (Con, n = 15), participated in this study. The training consisted ...

A 3-month-old infant of 33 weeks' gestation was hospitalized with pneumonia caused by Bordetella pertussis. Respiratory insufficiency worsened, and on hospital day 3, there was severe pulmonary dysfunction (arterial oxygen pressure/fraction of inspired oxygen ratio: 120), extreme leukocytosis (white blood cell count 104,000/mm3), and severe pulmonary hypertension as assessed by 2-dimensional ec...

The gas exchange ratio (R) represents the ratio of carbon dioxide output to oxygen uptake by the lungs. In the steady state it also represents the ratio of carbon dioxide produced by the tissues to tissue oxygen consumption—the RQ. When this exchange is presented on an oxygen/carbon dioxide diagram (Rahn and Fenn, 1955) it is plotted in terms of fractional concentrations (or tensions) to produc...