Randomized Controlled Trial Between Auto-titration and Manual Titration of Non-invasive Ventilation in Obesity Hypoventilation Syndrome

Effectiveness of Noninvasive Ventilation Adjusted Automatically in the Obesity Hypoventilation Syndrome

Primary Objectives: To evaluate the effectiveness in the obesity hypoventilation syndrome (OHS) treatment with non-invasive ventilation (NIV) set manually by polysomnography compared to the same treatment with a respirator with automatic NIV adjustment, analyzing as primary variable PaCO2 and as operational variables dropout rate for medical reasons and mortality. Secondary objectives: cost-effectiveness, clinical and functional improvement in wakefulness and during sleep, quality of life, blood pressure monitoring for 24 hours, incidence and evolution of cardiovascular events and use of health resources. Other objectives: 1) effectiveness of treatments in the following subgroups of patients: gender, age, socioeconomic status, severity of sleep apnea, VNI compliance, quality of life and comorbidities; 2) To evaluate the profile of patients with poor adherence to NIV based on clinical severity, gender, age and socioeconomic status in the whole sample and in both intervention groups.

Method: Prospective, blind researchers, randomized, controlled non-inferiority and cost-effectiveness relationship, with two parallel open groups. 200 OHS patients will be divided into two groups by simple randomization 1:1 and followed for one year. The premise of non-inferiority is -2 at the lower limit of the confidence interval 95% for the change in PCO2 between the arms being assessed by analysis of covariance, adjusted for 2-sided, age, sex, body mass index in intention-to-treat and per-protocol analysis. The cost-effectiveness will be performed by Bayesian techniques with sensitivity analysis.

Inclusion Criteria:

1. Obesity Hypoventilation Syndrome defined by obesity (IMC≥30) and Hypercapnic respiratory failure (PCO 2> 45 mm Hg) in stable phase (PH≥7.35 without clinical signs of worsening in at least one previous month).
2. Age between 18-80 years.
3. Absence of other diseases causing hypercapnia as moderate or severe chronic obstructive pulmonary disease (FEV1> 70% predicted if FEV1 / FVC <70), neuromuscular, thoracic wall or metabolic disease; d) Absence of narcolepsy or restless legs syndrome.
4. Overcome correctly a 30 minutes test of treatment with VNI in wakefulness.

Exclusion Criteria:

1. Psychophysical disability for questionnaires.
2. Patients who cannot be evaluated by quality of life questionnaires because they present debilitating chronic disease.
3. Chronic nasal obstruction that prevents the use of NIV.
4. Pregnancy.
5. No informed consent obtained.