Clinical Trial: The Obesity-hypoventilation Syndrome Study of Clinical Characteristics and Predictive Factors of Response to Treatment

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: The Obesity-Hypoventilation Syndrome: A Study Of Clinical Characteristics And Predictive Factors Of Response To Treatment With Continuous Positive Airway Pressure (CPAP) A

Brief Summary:

Main objective:

To describe clinical and functional characteristics of the obese hypoventilating patient; to study the relation between the obesity-hypoventilation syndrome (OHS) and the obstructive sleep apnea hypopnea syndrome (OSAHS). In the second stage of the study, to assess patient response to non-invasive mechanical ventilation (NIV) and continuous positive airway pressure (CPAP), and to identify predictors of unfavourable response to treatment.

Methodology:

  • Patients: Patients with obesity degree I-III, with pCO2 awake and at rest > 45 mmHg, with no underlying pulmonary or neuromuscular lung disease; two control groups, one of non-hypoventilating obese patients and the other of obese patients with OSAHS, will also be studied over the same period.
  • Design: Prospective observational study. In the first stage anthropometric, clinical, functional and metabolic data will be recorded for the obese hypoventilating patients and the two control groups (obese patients without respiratory pathology, and obese patients with OSAHS).

In the second stage patients with OHS will be divided into two subgroups: group 1: patients with polysomnography (PSG) suggestive of hypoventilation, in whom NIV treatment will be initiated; group 2: patients with PSG suggestive of OSAHS (apnea-hypopnea index >15), who will be administered CPAP. Patients will be examined one month and three months after the start of treatment. The same measurements will be carried out as at the beginning of the study, with the exception of the polysomnographic study. Nonetheless, pulse oximetry and arterial gases will be performed on waking.

Detailed Summary:

HYPOTHESIS:

Patients with OHS may be characterized and differentiated from obese patients without associated respiratory pathology on the basis of clinical, functional and metabolic data.

There is a close relation between OHS and OSAHS. It is important to define this relation more precisely because of its implications for therapy.

There is no consensus on the best ventilatory method for the treatment of OHS. In the case of an association between OSAHS and OHS the International Consensus proposes initial use of CPAP, based on empirical data. We believe that there is a group of patients that do not respond to this treatment and that this unfavorable response can be predicted in advance.

OBJECTIVES:

  • To assess the clinical, functional and metabolic characteristics of the patient with obesity hypoventilation syndrome (OHS).
  • To describe the frequency and characteristics of the relation between OHS and the obstructive sleep apnea hypopnea syndrome (OSAHS).
  • To study the predictive factors of the response to treatment with CPAP in patients with OHS and associated OSAHS.

METHODOLOGY STUDY SETTING: Pneumology and Endocrinology Services at the Hospital de la Santa Creu i Sant Pau. Hospitalization Unit, Sleep Clinic and Pulmonary Function Laboratory.

PATIENTS: Patients from a conventional hospitalization unit, semi-critical care unit, Endocrinology Clinic, Pneumology Clinic and/or Sleep Clinic meeting the following criteria:

  • Sponsor: Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau

    Current Primary Outcome:

    Original Primary Outcome:

    Current Secondary Outcome:

    Original Secondary Outcome:

    Information By: Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau

    Dates:
    Date Received: July 13, 2009
    Date Started: June 2003
    Date Completion:
    Last Updated: July 13, 2009
    Last Verified: July 2009