Home Mechanical Ventilation in Patients With Chronic Obstructive Pulmonary Disease (COPD) and Hypercapnic Response

Home Mechanical Ventilation in Patients With Chronic Obstructive Pulmonary Disease (COPD) Who Develop Nocturnal Hypercapnic Response Associated to Oxygen Therapy

The objective of this study is to evaluate the clinical benefits of home mechanical ventilation associated to oxygen therapy in COPD patients with chronic respiratory failure (CRF) who develop hypercapnia and nocturnal respiratory acidosis secondary to oxygen administration.

We will include clinically stable COPD patients with hypercapnic CRF who develop a nocturnal hypercapnic response to oxygen (PaCO2 increase on awakening, at night with oxygen, >10 mmHg respect to PaCO2 breathing room air and awake). Obstructive sleep apnoea syndrome (OSAS) will previously have been excluded.

Patients will be admitted to the Pneumology ward where a nocturnal pulsioxymetry breathing oxygen therapy will be performed. Arterial blood gas samples will be taken at awakening (7AM).

Patients who develop a hypercapnic response to oxygen will be randomised into 2 treatment groups:

• Oxygen therapy group
• Home mechanical ventilation plus oxygen therapy group Home mechanical ventilation will be performed with a bilevel pressure ventilator. Functional respiratory variables as well as quality of life and sleep at onset and after 6 months treatment will be compared.

The principal outcome will be the evolution of arterial blood gases (PaCO2) between the two groups.

Inclusion Criteria:

• Elderly patients < 80 years old.
• COPD (ERS/ATS (FEV1 < 80%, FEV1/FVC < 70%, TLC > 80%)).
• Oxygen therapy indication (PaO2 < 55 mmHg or 55-59 associated to pulmonary arterial hypertension, chronic Cor Pulmonale, Chronic Heart failure, arrhythmias or polyglobulia).
• PaCO2 > 50 mm Hg.
• Clinically stable at least prior to one month.
• Hypercapnic response: increasing PaCO2 > 10 mmHg at 7 a.m after all night with oxygen compared with PaCO2 when awake and without oxygen therapy.

Exclusion Criteria:

• Active smoker.
• Bronchiectasis or tuberculous after-effects.
• Chronic respiratory failure secondary to thorax cage or neuromuscular diseases.
• BMI > 35 kg/m2
• OSAS.
• Locomotor system problems that disable 6 minutes walking test execution.
• Patients with tracheostomy.
• Other serious comorbidity (i.e chronic heart failure functional class > II NYHA, cancer or chronic renal failure that requires dialysis.