ELEVATED VENTILATORY EQUIVALENTS DURING EXERCISE IN PATIENTS WITH HYPERVENTILATION SYNDROME

In hyperventilation syndrome (HVS), hyperventilation is often provoked by exercise. This study was undertaken to investigate gas exchange pa rameters and their correlation to arterial blood gas values in HVS pat ients during exercise. Ventilatory equivalents for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were significantly higher in HVS patients th an in the controls. (VE/VO2) during light exercise (40-50 W) was 23.1/-2.7 (n = 10) in the controls and 35.2+/-8.2 (n = 10) in the HVS grou p (p < 0.01). VE/VCO2 during light exercise was 30.0+/-3.3 in the cont rols and 41.8+/-6.0 in the HVS group (p < 0.01). In HVS, significant c orrelations were observed between VE/VCO2 and PaCO2, and between VE/VO 2 and PaCO2 during both light and maximal exercise (p < 0.02). The fin dings suggest that exercise testing can be used to aid HVS diagnosis w ithout invasive arterial cannulation.