dead space ventilation in cardiaovascular disease cpet

In December 2019, Wuhan city identified a new type of coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that rapidly spread all over the world and caused an immense global health crisis. Twelve months after severe COVID-19 pneumonia, most of the patients had a peak V′O 2 considered within normal limits but showed ventilatory inefficiency during exercise with increased dead space ventilation that was more pronounced in patients with persistent dyspnea. Peak VD/Vt values were positively correlated with peak D-Dimer plasma concentrations from blood samples collected during ICU stay (r 2 = 0.12 p = 0.02) and to predicted diffusion capacity of the lung for carbon monoxide (D LCO) (r 2 = − 0.15 p = 0.01). Impairments were more pronounced in patients with dyspnea. Peak PetCO 2 was significantly lower in subjects with an abnormal increase of VD/Vt ( p = 0.001). More than half of the patients with a normal peak predicted V′O 2 showed ventilatory inefficiency during exercise with an abnormal increase of physiological dead space ventilation (VD/Vt) (median VD/VT of 0.27 at anaerobic threshold (AT) and 0.29 at peak) and a widened median peak alveolar-arterial gradient for O 2 (35.2 mmHg. Length of ICU stay remained an independent predictor of V′O 2. The majority of the patients (80%) had a peak O 2 uptake (V′O 2) considered within normal limits (median peak predicted O 2 uptake (V′O 2) of 98% ). Mild ground-glass opacities, reticulations and bronchiectasis were the most common CT scan abnormalities.

Twelve months after severe COVID-19 pneumonia, dyspnea was the most frequently reported symptom although only a minority of patients had impaired respiratory function at rest. Lung function at rest and chest computed tomography (CT) scan were also performed. In this prospective single-center study, we performed CPET 12 months after symptom onset in 60 patients that had required intensive care unit treatment for a severe COVID-19 infection. In the context of critical COVID-19, CPET is an ideal approach for assessing long term sequelae.

Cardiopulmonary exercise testing (CPET) is an important clinical tool that provides a global assessment of the respiratory, circulatory and metabolic responses to exercise which are not adequately reflected through the measurement of individual organ system function at rest.

Dead space ventilation in cardiaovascular disease cpet