Non Invasive Mechanical Ventilation in Chronic Respiratory Insufficiency Patients During Rehabilitation

Overview

Patients with Chronic Obstructive Pulmonary Disease (COPD) and chronic respiratory insufficiency (CRI) have severe dyspnoea during exercise at low load. Physiological studies performed in these patients during a unique session of training have shown a positive effect on exercise tolerance if non-invasive mechanical ventilation (NIV) was added during incremental effort test or endurance. Menadue and coworkers (2009) have shown in CRI patients with hypercapnia, secondary to COPD or cifoscoliosis, that combination of NIV during arm effort test improved ability to perform the exercise. Similar result was not reached using NIV during walking. Further studies have underlined a positive effect of the ventilation therapy during exercise within specific programs of pulmonary rehabilitation (Corner 2009). Moreover, the addition of NIV to an exercise training (ET) program in COPD patients may produce greater benefits in exercise tolerance and quality of life than exercise training alone (Garrod 2000). A great improvement in health-related quality of life, functional status and gas exchange in COPD patients with chronic hypercapnic respiratory failure with nocturnal NIV compared with patients in pulmonary rehabilitation alone has been also shown by Duieverman (2008). However, in the same study Duieverman did not show any significant difference between groups in terms of tolerance to effort test. Aim of the study is to evaluate if application of daily NIV during physical training may increase the benefits of rehabilitation in CRI patients with nocturnal NIV compared with patients with nocturnal NIV performing training under spontaneous breathing.

INTERVENTION Group 1 (NIV during training + nocturnal NIV): This group of patients will use the usual NIV during night and will perform a rehabilitative program of at least 20 sessions of training at cycloergometer under NIV. NO INTERVENTION Group 2 (training in Spontaneous Breathing \[SB\] + nocturnal NIV): This group of patients will use the usual NIV during night and will be trained in a rehabilitative daily program without NIV. This group will be considered the "control" group. Sessions: 30 minutes/session, 2 times/day, 4-5 times a week for a total of 20-25 session in 3 weeks. Intensity: each patient will start at 50% of each individual's maximum work capacity (cycloergometer) increasing up to the maximum tolerated, according to Maltais's protocol. NIV SETTING: Training: Facial mask with usual setting (Inspiratory Positive Airway Pressure \[IPAP\] 10-15; Expiratory Positive Airway Pressure \[EPAP\] 4-6 cmH20) with a possible adjustment in agreement with the comfort. The adjustment of ventilation during training will be only within the first 3 sessions according to the following protocol: COPD patients: increase up to 3 cmH2Os of EPAP and decrease up to 3 cmH2Os of IPAP. Restricted patients: increase up to 3 cmH2Os of IPAP. Nocturnal ventilation: mask and usual setting The primary outcome of the study is evaluation of effort tolerance measured by 6 minutes Walking Test (6-min Walking Test). The hypothesis is to verify a percentage of variation between the two groups equal to 10% after the rehabilitative program. To get a study power of 80% and an alpha error \<5% 25 patients for group had to be enrolled.