Additive effects of non-invasive ventilation to hyperoxia on cerebral oxygenation in COPD patients with exercise-related O2 desaturation

Rodrigues, Miguel K. [UNIFESP]; Oliveira, Mayron F. [UNIFESP]; Soares, Aline [UNIFESP]; Treptow, Erika [UNIFESP]; Alberto Neder, J. [UNIFESP]

Additive effects of non-invasive ventilation to hyperoxia on cerebral oxygenation in COPD patients with exercise-related O2 desaturation

Data

2013-07-01

Autores

Rodrigues, Miguel K.

Oliveira, Mayron F.

Soares, Aline

Treptow, Erika

Alberto Neder, J.

Tipo

Artigo

Resumo

Background It is currently unknown whether potential haemodynamic improvements induced by non-invasive ventilation (NIV) would positively impact upon cerebral oxygenation (COx) in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). Objective To investigate the effects of NIV on exercise COx in COPD patients presenting with exercise-related O2 desaturation. Methods On a double-blind trial, 13 males (FEV1=48 center dot 8 +/- 15 center dot 1% predicted) were randomly assigned to NIV (16 cmH2O IPS and 5 cmH2O PEEP) plus HOx (FiO2= 0 center dot 4) or sham NIV (7 cmH2O IPS and 5 cmH2O PEEP to overcome breathing circuit resistance) plus HOx during ramp-incremental exercise performed on different days. Near-infrared spectroscopy and impedance cardiography assessed changes () in COx and cardiac output (QT), respectively. Results There were no significant between-intervention differences in peak work rate, ventilation and reported symptoms (0 center dot 05). Peripheral oxyhaemoglobin saturation remained above 98% throughout the tests. NIV+HOx was associated with larger increases in COx, QT and stroke volume at maximal and submaximal exercise (P<0 center dot 05). Increases in the area under the curve (to an iso-work rate) of COx under NIV+HOx were significantly (P<0 center dot 01) correlated with improvements in QT (r=0 center dot 82) and stroke volume (r=0 center dot 87). There was, however, no significant correlation between enhancement in these physiological responses with changes in peak work rate with NIV+HOx (0 center dot 05). Conclusions NIV added benefit to HOx in improving central haemodynamics and COx in O2 desaturators' with COPD. the clinical relevance of such beneficial effects on exercise tolerance, however, remains to be demonstrated.

Citação

Clinical Physiology and Functional Imaging. Hoboken: Wiley-Blackwell, v. 33, n. 4, p. 274-281, 2013.