PT  - JOURNAL ARTICLE
AU  - Miguel Rodrigues
AU  - Mayron Oliveira
AU  - Erika Treptow
AU  - Aline Souza
AU  - J. Alberto Neder
TI  - Additive effects of non-invasive ventilation to hyperoxia on pre-frontal cerebral oxygenation during exercise in patients with COPD
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - 3313
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/3313.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/3313.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Rationale: Changes (Δ) in cerebral oxygenation (COx) during exercise are modulated by the dynamic coupling between O2 delivery (cerebral blood flow and arterial O2 content) and O2 utilization. Non-invasive positive pressure ventilation (NIV) per se may improve the central haemodynamic responses to exercise thereby enhancing COx in patients with chronic obstructive pulmonary disease (COPD). Objective: To investigate the effects of NIV (inspiratory pressure= 16 cmH2O and end-expiratory pressure= 5 cmH2O) plus hyperoxia (HiOx, FIO2= 0.4) versus HiOx alone on COx during ramp-incremental exercise in patients with moderate-to-severe COPD. Methods: Thirteen non-hypercapnic males (FEV1=48.8± 15.1% predicted) were randomly assigned to receive each intervention on different days. ΔCOx was determined by near infrared spectroscopy (fold-changes in HbO2), oxyhemoglobin saturation by pulse oximetry (SpO2), and cardiac output (QT) by impedance cardiography. Results: As expected, SpO2 remained near 100% throughout the tests (p>0.05). Area under ΔCOx on HiOx was significantly correlated with ΔQT (r=0.82). Peak exercise capacity did not differ between interventions (74± 20 W vs. 78 ± 19 W; p<0.05). NIV-HiOx was associated with larger increases in ΔCOx at sub-maximal levels of exercise compared to HiOx (p<0.05). Iso-work rate QT was larger with NIV-HiOx than HiOx (2.0± 0.5 vs 1.6± 0.6 fold-changes, p<0.05) and related to improved stroke volume (p<0.05). Conclusions: NIV adds benefit to HiOx in increasing pre-frontal cerebral oxygenation in patients with COPD, an effect associated with enhanced central haemodynamic responses to exercise.