Impact of NIV on Oxygen Levels in Peripheral and Respiratory Muscles During High-intensity Exercise

Apr 21, 2023

The following is a summary of “ Effect of Adding Non-invasive Ventilation to High-Intensity Exercise on Peripheral and Respiratory Muscle Oxygenation,” published in the March 2023 issue of Respiratory Care by Goulart et al.

The objective of the researcher’s study was to evaluate the efficacy of non-invasive ventilation (NIV) as a supplementary treatment to high-intensity exercise (HIEx) in comparison to exercise alone or exercise with sham in individuals who have both chronic obstructive pulmonary disease (COPD) and heart failure (HF). In addition, researchers aimed to determine the impact of this intervention on respiratory and peripheral oxygenation and vascular function. The participants underwent incremental cardiopulmonary exercise testing and three constant load tests, namely HIEx, HIEx+NIV, and HIEx+sham (utilizing bi-level mode, Astral 150), on different days. The study involved randomizing subjects using a 1:1 block allocation method into either the HIEx+NIV group or the HIEx+sham group until the limit of tolerance (Tlim) was reached. Peripheral and respiratory oxygenation was assessed via near-infrared spectroscopy on the respiratory and peripheral musculature, utilizing oxyhemoglobin (O₂Hb) and deoxyhemoglobin (Hb). The assessment of vascular function was conducted through the evaluation of endothelial function utilizing the flow-mediated vasodilation (FMD) technique.

The HIEx+NIV group exhibited a noteworthy augmentation in FMD (mm), FMD (%), and shear stress as compared to HIEx or HIEx+sham (P < .05). The HIEx+NIV group exhibited a decrease in the extraction of oxygen (Hb) in the peripheral and respiratory muscles, with statistical significance (P < .05). Correlations were observed between peripheral muscle oxygenation (O₂Hb) at 80% of Tlim (r = 0.71, P = .009) and the peak of Tlim (100%) (r = 0.76, P = .004) with absolute FMD (mm) immediately following HIEx+NIV. Using non-invasive ventilation (NIV) in conjunction with high-intensity exercise (HIEx) can effectively relieve the respiratory muscles by improving blood flow distribution and positively influencing the function of the endothelium. The findings mentioned above could potentially impact the cardiopulmonary rehabilitation strategy in individuals with concurrent COPD-HF.