The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform

Soejima Yuji - One of the best experts on this subject based on the ideXlab platform.

A R A Sovijarvi - One of the best experts on this subject based on the ideXlab platform.

  • orthostatic increase of respiratory gas exchange in Hyperventilation Syndrome
    Thorax, 2000
    Co-Authors: L P Malmberg, K Tamminen, A R A Sovijarvi
    Abstract:

    Background—Hyperventilation Syndrome (HVS) is a common disorder which is diYcult to diagnose because of somatic symptoms and its episodic nature. In previous studies respiratory alkalosis in arterial blood was often found during orthostatic tests in patients with HVS. The purpose of this study was to assess these orthostatic changes by non-invasive pulmonary gas exchange measurements and to evaluate whether these responses discriminate patients with HVS from healthy subjects. Methods—Respiratory gases were collected with a face mask and pulmonary gas exchange was measured after 10 minutes at rest and after eight minutes standing upright in 16 patients with HVS and 13 healthy control subjects. In patients with HVS arterial blood samples were also drawn at rest and in the standing position. Results—At rest the variables of respiratory gas exchange did not diVer significantly between the groups. As a response to standing, minute ventilation increased in both study groups but significantly more in the patients with HVS (mean difference 5.4 l/min (95% CI 1.1 to 9.6)). The changes in end tidal CO2 fraction (FETCO2) and in ventilatory equivalents for oxygen (V ~E/V ~O2) and for CO2 (V ~E/V ~CO2) during the orthostatic test were also significantly larger in patients with HVS than in healthy controls. During standing FETCO2 was significantly lower (mean diVerence ‐1.1 kPa; 95% CI ‐1.5 to ‐0.6) and V ~E/V ~O2 (mean diVerence 18.4; 95% CI 7.7 to 29.0) and V ~E/V ~CO2 (mean diVerence 11.7; 95% CI 4.8 to 18.6) were significantly higher in HVS patients than in healthy controls. By using the cut oV level of 4% for FETCO2 the sensitivity and specificity of the test to discriminate HVS were 87% and 77%, respectively, and by using the cut oV level of 37 for V ~E/V ~O2 they were 93% and 100%, respectively. In the HVS patients arterial PCO2 and FETCO2 were closely correlated during the orthostatic test (r = 0.93, p<0.0001). Conclusions—As a response to change in body position from supine to standing, patients with HVS have an accentuated increase in ventilation which distinguishes them from healthy subjects. These findings suggest that non-invasive measurements of pulmonary gas exchange during orthostatic tests are useful in the clinical evaluation of patients with Hyperventilation disorders. (Thorax 2000;55:295‐301)

  • elevated ventilatory equivalents during exercise in patients with Hyperventilation Syndrome
    Respiration, 1993
    Co-Authors: Vuokko L Kinnula, A R A Sovijarvi
    Abstract:

    In Hyperventilation Syndrome (HVS), Hyperventilation is often provoked by exercise. This study was undertaken to investigate gas exchange parameters and their correlation to arterial blood gas values in HVS patients during exercise. Ventilatory equivalents for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were significantly higher in HVS patients than 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 group (p < 0.01). VE/VCO2 during light exercise was 30.0 +/- 3.3 in the controls and 41.8 +/- 6.0 in the HVS group (p < 0.01). In HVS, significantly correlations were observed between VE/VCO2 and PaCO2, and between VE/VO2 and PaCO2 during both light and maximal exercise (p < 0.02). The findings suggest that exercise testing can be used to aid HVS diagnosis without invasive arterial cannulation.

Takao Munemoto - One of the best experts on this subject based on the ideXlab platform.

Takao Ayuse - One of the best experts on this subject based on the ideXlab platform.

Muneki Tanaka - One of the best experts on this subject based on the ideXlab platform.