Die Auswirkungen von nicht-invasiver Beatmung (NIV) auf die periphere Oxygenierung der Muskulatur, Herzkreislauf und körperliche Leistungsfähigkeit bei COPD Patienten mit schwerer Hyperkapnie

Patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnic respiratory failure (CHRF) often have a very poor exercise capacity and are limited in their ability to perform conventional training. The aim of this study was to investigate the acute effects of non-invasive ventilation (NIV) as a supportive tool during exercise in COPD patients with CHRF. The study started with in an incremental cycling test wherein the peak work rate of the study participants was examined. On the following day, the study participants performed in two cycle endurance tests (CET) at 60% of their peak work rate. The study design was a randomized cross-over trial, where patients were randomly assigned in which order to perform a CET in two conditions, with a one-hour break in between the tests. The intervention test (NIV) was performed using high-pressure NIV with an inspiratory positive airway pressure (IPAP) of 26,75 cm H2O (25; 27,25), and an expiratory positive airway pressure (EPAP) of 5,5 cm H2O (5; 6) along with oxygen supplementation, the control test (Control) was performed using only oxygen supplementation. Primary end point was the maximum cycle endurance time achieved in both tests. Further parameters recorded included dyspnea, fatigue of the legs, systolic and diastolic blood pressure, continuous measurement of transcutaneous partial pressure of carbon dioxide (tcpCO2), oxygen saturation (SpO2) and heart rate (HR). Furthermore, we collected data about the peripheral oxygen saturation on the vastus lateralis and intercostal muscle using two near- infrared spectroscopy sensors (NIRS). 20 COPD patients with CHRF (age = 61,00 years (55,75; 65,00); FEV1 pred. = 18,20 % (15,80; 22,55); pO2 = 53,85 mmHg (48,15; 56,85); pCO2 = 51,55 mmHg (47,58; 53,25)) participated in the study. In NIV, the cycle endurance time was significantly longer (p = 0,012; 593 sec. (396,25; 1095,00) in NIV, in comparison with 387,50 sec. (290,00; 567,50) in Control) and dyspnea at the end of exercise was significantly lower (p < 0,001; 3 (1,25; 4) in NIV, compared to 5 (4,00; 6,75) in Control). The systolic blood pressure was significantly lower at the end of exercise and at recovery in NIV (end: p = 0,002; 130 mmHg (105; 145) in NIV, in comparison with 135 mmHg (115; 160) in Control; recovery: p = 0,009; 110 mmHg (93,75; 120) in NIV, in comparison to 120 mmHg (100,00; 130,00) in Control). In NIV, the tcpCO2 was significantly lower at all times of measurement (Baseline: p < 0,001; 44,15 mmHg (41,25; 47,38) in NIV, in comparison with 50,45 mmHg (45,60; 54,90) in Control; Isotime: p < 0,001; 49,10 mmHg (44,9352,43) in NIV compared to 55,40 mmHg (51,30; 60,60) in Control; End: p < 0,001; 50,00 mmHg (45,38; 54,65) in NIV in comparison with 55,4 mmHg (51,80; 60,60) in Control; Recovery: p < 0,001; 45,40 mmHg (42,40; 49,10) in NIV compared to 50,55 (47,25; 55,20) in Control). Furthermore, in NIV the SpO2 was significantly higher at recovery (p = 0,023; 98 % (96,00; 99,00) in NIV in comparison with 97 % (95,75; 99,00) in Control) and the heart rate was significantly higher at baseline and at recovery (baseline: p= 0,008; 91,00 bpm (83,25; 99,75) in NIV compared to 86,00 bpm (78,25; 90,75) in Control; recovery: p = 0,018; 94,00 bpm (83,00; 99,00) in NIV in comparison with 85,50 bpm (79,00; 95,00) in Control). Regarding the results of the NIRS System, no clear effects of NIV could be observed, due to a lack of significance and consistency of results. In conclusion, high pressure NIV with oxygen supplementation increases cycle endurance time, reduces exertional dyspnea and the levels of carbon dioxide throughout exercise. Furthermore it shows beneficial effects on oxygen saturation.