Rev. DERC (Online) 2020; 26(1): 20-24

Reflections on the Normality Concept of the Carbon Gas Ventilatory Equivalent

DOI: 10.29327/22487.26.1-4

Abstract

Reflections on the ventilatory equivalent of carbon dioxide (VE/VCO₂) and its slope VE/VCO₂ slope go beyond the simple description of ventilatory inefficiency (or excessive ventilation). Numerous clinical scenarios deserve our attention to identify patterns compatible with relative alveolar hypoventilation and values considered “pseudonormal”. In this sense, we believe that this analytical reflection and the descriptive proposal of VE/VCO₂ slope values within ranges considered as “normoventilatory”, but which should be described as within pseudonormality criteria, is appropriate. Such situations observed during cardiopulmonary exercise tests (CPET) in patients with cardiopulmonary dysfunction (e.g. lung disease (COPD) associated or not with heart failure, (HF), metabolic syndromes and obstructive and central sleep apnea (OSAS)) deserve the following considerations within its global and multifactorial analysis: cardiovascular, ventilatory, metabolic and gas exchange. The relevance of these observations is based on the assessment of the ventilatory class of individuals with ventricular dysfunction and possible indication of heart transplantation when clinical discrepancy occurs, functional (aerobic power) and ventilatory efficiency.