The Effect of Adding Noninvasive Ventilation to High-Intensity Exercise on Peripheral and Respiratory Muscle Oxygenation.

BACKGROUND: We sought to assess whether noninvasive ventilation (NIV) as an adjunct with high-intensity exercise (HIEx) is more effective than exercise alone or exercise + sham on respiratory and peripheral oxygenation and vascular function in subjects with coexisting COPD and heart failure (HF). METHODS: On separate days, subjects performed incremental cardiopulmonary exercise testing and 3 constant load tests: HIEx, HIEx+NIV, and HIEx+sham (bi-level mode, Astral 150). Subjects were randomized with a 1:1 block allocation for the HIEx+NIV group and HIEx+sham group until the limit of tolerance (Tlim). Peripheral and respiratory oxygenation were assessed by oxyhemoglobin (O2Hb) and deoxyhemoglobin (Hb) using near-infrared spectroscopy in the respiratory and peripheral musculature. Vascular function was assessed by endothelial function using the flow-mediated vasodilation (FMD) method. RESULTS: There was a significant increase in FMD (mm), FMD (%), and shear stress in the HIEx+NIV group when compared to HIEx or HIEx+sham (P < .05). Less extraction of O2 (Hb) in the peripheral and respiratory muscles was observed in the HIEx+NIV group (P < .05). We also found correlations between peripheral muscle oxygenation (O2Hb) at the moment 80% of Tlim (r = 0.71, P = .009) and peak of Tlim (100%) (r = 0.76, P = .004) with absolute FMD (mm) immediately after HIEx+NIV. CONCLUSIONS: NIV as an adjunct to HIEx can acutely unload the respiratory musculature with better redistribution of available blood flow and beneficially modulate endothelial function. These results may influence the approach to cardiopulmonary rehabilitation in patients with coexisting COPD-HF.

Non-invasive ventilatory support accelerates the oxygen uptake and heart rate kinetics and improves muscle oxygenation dynamics in COPD-HF patients.

BACKGROUND: The aim of this study was to explore the effects of non-invasive positive pressure ventilation (NIPPV) associated with high-intensity exercise on heart rate (HR) and oxygen uptake (V̇O2) recovery kinetics in in patients with coexistence of chronic obstructive pulmonary disease (COPD) and heart failure (HF). METHODS: This is a randomized, double blinded, sham-controlled study involving 14 HF-COPD patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NIPPV (bilevel mode - Astral 150) in a random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin and deoxyhemoglobin were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, Netherland). RESULTS: The kinetic variables of both V̇O2 and HR during the high-intensity constant workload protocol were significantly faster in the NIPPV protocol compared to Sham ventilation (P < 0.05). Also, there was a marked improvement in oxygenation and lower deoxygenation of both peripheral and respiratory musculature in TLim during NIPPV when contrasted with Sham ventilation. CONCLUSIONS: NIPPV applied during high-intensity dynamic exercise can effectively improve exercise tolerance, accelerate HR and V̇O2 kinetics, improve respiratory and peripheral muscle oxygenation in COPD-HF patients. These beneficial results from the effects of NIPPV may provide evidence and a basis for high-intensity physical training for these patients in cardiopulmonary rehabilitation programs.

Can Non-invasive Ventilation Modulate Cerebral, Respiratory, and Peripheral Muscle Oxygenation During High-Intensity Exercise in Patients With COPD-HF?

AIM: To evaluate the effect of non-invasive positive pressure ventilation (NIPPV) on (1) metabolic, ventilatory, and hemodynamic responses; and (2) cerebral (Cox), respiratory, and peripheral oxygenation when compared with SHAM ventilation during the high-intensity exercise in patients with coexisting chronic obstructive pulmonary disease (COPD) and heart failure (HF). METHODS AND RESULTS: On separate days, patients performed incremental cardiopulmonary exercise testing and two constant-work rate tests receiving NIPPV or controlled ventilation (SHAM) (the bilevel mode-Astral 150) in random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin (OxyHb+Mb) and deoxyhemoglobin (DeoxyHb+Mb) were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, The Netherlands). NIPPV associated with high-intensity exercise caused a significant increase in exercise tolerance, peak oxygen consumption ( V · O 2 in mlO2·kg-1·min-1), minute ventilation peak ( V · E in ml/min), peak peripheral oxygen saturation (SpO2, %), and lactate/tlim (mmol/s) when compared with SHAM ventilation. In cerebral, respiratory, and peripheral muscles, NIPPV resulted in a lower drop in OxyHb+Mb (p < 0.05) and an improved deoxygenation response DeoxyHb+Mb (p < 0.05) from the half of the test (60% of Tlim) when compared with SHAM ventilation. CONCLUSION: Non-invasive positive pressure ventilation during constant work-rate exercise led to providing the respiratory muscle unloading with greater oxygen supply to the peripheral muscles, reducing muscle fatigue, and sustaining longer exercise time in patients with COPD-HF.