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Hypoxic Ventilatory Responses and Gas Exchange in Patients with Parkinson’s Disease

1998; Karger Publishers; Volume: 65; Issue: 1 Linguagem: Inglês

10.1159/000029224

1423-0356

Tatiana V. Serebrovskaya, Karaban' In, Man'kovs'ka Im, Luciano Bernardi, Claudio Passino, Otto Appenzeller,

Long-Term Effects of COVID-19

Ventilatory responses to isocapnic, progressive hypoxic rebreathing (HVR), in supine and sitting positions, lung ventilation and gas exchange while breathing air and during 5 min of breathing 11% O₂ in N₂ were studied in 12 healthy young (20–28 years), 5 old (57–73 years) male subjects, and in 7 male patients with Parkinson’s disease (PD) aged 55–67 years. The piecewise linear approximation technique was used for evaluation of the ventilatory response curves, which allowed a separate analysis of slopes during minor and severe hypoxia. It has been shown that body position affected HVR. In the range of P_ETO₂ from 60 to 35 mm Hg, the ventilatory response in the sitting position was higher than supine: in young persons by 43%, in healthy old persons by 76%, and in the PD patients by 211%. No significant differences in HVR to minor hypoxia (P_ETO₂ from 100 to 60 mm Hg) were found in the 3 groups. During severe hypoxia (P_ETO₂ from 60 to 35 mm Hg) the slope of minute ventilation versus O₂ was 4.6 (supine) and 2.6 (sitting) times greater in healthy old men than PD patients’ slopes. PD patients compared to old controls had 32% lower alveolar ventilation, 10% lower P_ETO₂ and 15% elevation of P_ETCO₂ while breathing air; similar differences were found while the patients were breathing 11% O₂. The reduced alveolar ventilation under severe hypoxia in patients with PD could not be attributed to mechanical restriction of lung function. We suggest that the discrepancy in HVR under minor and severe hypoxia results from dysfunction in chemoreception associated with Parkinsonism.