ISSN:
1439-6327
Keywords:
Chemosensitivity
;
Maximal oxygen uptake
;
Acute hypoxia
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The aim of this study was to evaluate the influence of peripheral chemosensitivity estimated by hypoxic ventilatory response (HVR) on arterial oxygen saturation (S aO2) during maximal exercise in acute hypoxia. A group of 16 healthy men performed maximal exercise in two conditions of partial pressure of inspired oxygen (P IO2/149 and 70 mm Hg, 19.8 and 9.3 kPa). Measurements of maximal oxygen uptake ( $$\dot VO_{2\max } $$ ) andS aO2 using an ear-oximeter were carried out in both conditions ofP IO2. The HVR was measured at rest by progressive isocapnic hypoxia and evaluated by the slope of the linear regression between the ventilatory flow ( $$\dot V_E $$ ) and theS aO2 ( $$\Delta \dot V_E /\Delta S_a O_2 $$ ). The absolute value of HVR (in litres per minute per percentage saturation per kilogram) was correlated to maximal expired $$\dot V_E $$ (r = 0.85,P 〈 0.001), ventilatory equivalent for CO2 (r = 0.83,P 〈 0.001) andS aO2 (r = 0.60,P 〈 0.05) determined during maximal exercise in hypoxia: a significant decrease in $$\dot VO_{2\max } $$ (37%) andS aO2 (32%) forP IO2 of 70 mm Hg (9.3 Pa) was observed (P 〈 0.001). The correlation between the decline of $$\dot VO_{2\max } $$ and arterial oxygen desaturation failed to reach statistical significance (r = 0.47, P = 0.1). The present findings indicated that the peripheral ventilatory chemosensitivity contributed to the interindividual variability of $$\dot V_E $$ andS aO2 during maximal exercise in acute hypoxia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00964122
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