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A2453 - Short-Term Effects of Non-Invasive Ventilation During Exercise in Hypercapnic Patients with Very Severe COPD - A Randomized Controlled Cross-Over Trial
Author Block: T. Schneeberger1, R. Gloeckl2, A. Stegemann2, U. Schonheit-Kenn2, J. Oversohl3, V. Andrianopoulos4, K. Kenn2, A. R. Koczulla5; 1Pulmonary Rehabilitation, Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany, 2Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany, 3Philipps-University of Marburg, Marburg, Germany, 4Respiratory Medicine and Pulmonary Rehabilitation, Schoen Klinik Berchtesgadener Land, Schönau am Königssee, Germany, 5Philipps University Marburg, Marburg, Germany.
Background There has been increasing interest in the use of non-invasive ventilation (NIV) during pulmonary rehabilitation (PR) as an additional tool to augment PR benefits in patients with advanced COPD. There are some hints that hypercapnic patients utilizing NIV during exercise might train for longer durations and/or at higher levels of exercise intensity. However, there is only little evidence to support this so far. Objective Aim of this study was to investigate short-term effects of using NIV during exercise in hypercapnic patients with very severe COPD. Methods Within a comprehensive 3-week inpatient PR program 20 hypercapnic (PCO2>50mmHg at rest and/ or during exercise) COPD patients (GOLD stage IV) took part in this randomized-controlled cross-over trial. The day after an initial incremental cycle ergometer test, patients performed two constant work rate tests (CWRT) at 60% of the peak work rate (PWR), with and without NIV, in randomized order and with a resting time of 1 hour between tests. The inspiratory positive airway pressure (IPAP) was individually adjusted to provide sufficient pressure to relieve the work on patients breathing muscles and to decrease PCO2 levels during NIV. Cycle endurance time (primary outcome), transcutaneous PCO2 (TcPCO2), oxygen saturation (SpO2) and perceived dyspnea/ leg-fatigue (10-point Borg scale) during CWRTs were investigated. Results Participants (age 60±6yrs; FEV1 19±4%/pred.; PaCO2 51.0±6.8mmHg; PaO2 54.5±9.1mmHg; 6MWD 243±71m) performed CWRT at 26±11W (PWR 42±16W). NIV via full face-mask was performed with IPAP/EPAP levels of 27±3/ 6±1cmH2O. During CWRTs patients cycled with NIV 663 sec and without 476 sec. This treatment effect of 187 sec 95%CI [44 to 329] in favor of CWRT with NIV was significant (p=0.013) and clinically relevant. At isotime (=time of CWRT with shortest duration) TcPCO2 was significantly lower (-6.1mmHg 95%CI [-7.4 to -4.7] and SpO2 was significantly higher (3.6% 95%CI [1.4 to 5.7] with NIV. Furthermore, patients after CWRT with NIV perceived less dyspnea (p=0.008) with comparable leg-fatigue (p=0.79). For all outcomes no carryover effect was found (all p>0.05). Conclusion We found that by using NIV during exercise hypercapnic patients with very severe COPD had a clinically relevant increase (>minimal important difference of 105s) in endurance time. Besides cycling for a longer duration using NIV, at isotime, TcPCO2 was lower, SpO2 was higher, and at the end of the test, patients perceived less dyspnea. NIV during exercise seems to be feasible and could be an opportunity to improve endurance training outcomes in very selected patients.