A non invasive estimate of dead space ventilation from exercise measurements.

Autor: Paola Gargiulo, Anna Apostolo, Pasquale Perrone-Filardi, Susanna Sciomer, Paolo Palange, Piergiuseppe Agostoni
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: PLoS ONE, Vol 9, Iss 1, p e87395 (2014)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0087395
Popis: RATIONALE: During exercise, heart failure patients (HF) show an out-of-proportion ventilation increase, which in patients with COPD is blunted. When HF and COPD coexist, the ventilatory response to exercise is unpredictable. OBJECTIVES: We evaluated a human model of respiratory impairment in 10 COPD-free HF patients and in 10 healthy subjects, tested with a progressive workload exercise with different added dead space. We hypothesized that increased serial dead space upshifts the VE vs. VCO2 relationship and that the VE-axis intercept might be an index of dead space ventilation. MEASUREMENTS: All participants performed a cardiopulmonary exercise test with 0, 250 and 500 mL of additional dead space. Since DS does not contribute to gas exchange, ventilation relative to dead space is ventilation at VCO2 = 0, i.e. VE-axis intercept. We compared dead space volume, estimated dividing VE-axis intercept by the intercept on respiratory rate axis of the respiratory rate vs. VCO2 relationship with standard method measured DS. MAIN RESULTS: In HF, adding dead space increased VE-axis intercept (+0 mL = 4.98±1.63 L; +250 mL = 9.69±2.91 L; +500 mL = 13.26±3.18 L; p
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