Treatment for Obstructive Sleep Apnea Hypopnea Syndrome and Obesity Hypoventilation Syndrome (OHS)
Condition: Sleep Apnea, Obstructive; Obesity Hypoventilation Syndrome
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Hypoventilation; Obesity Hypoventilation Syndrome; Obesity; Syndrome
Study type: Interventional

Summary: 
      Sleep Apnea Hypopnea Syndrome (OSAHS), is common in patients with OHS, compared to single
      Obesity Hypoventilation Syndrome (OHS) or OSAHS ,patients with both of them are more
      susceptible to have serious hypoxia and carbon dioxide retention during sleep, and much more
      likely to result in pulmonary hypertension and cor-pulmonale.

      At present, the most widely and valid method for these patients is the Bilevel Positive
      Airway Pressure (BiPAP) ventilation, while, recently, the investigators discovered a
      completely novel device, namely auto-trilevel Ventilator. In contrast to the traditional
      therapy, auto-trilevel Ventilator has a more flexible expiratory positive airway pressure
      (EPAP), with which it can removing residual obstructive sleep apnea hypopnea events and
      correcting hypercapnia without contradiction. Treated with auto-trilevel ventilator may delay
      the progression of disease and improve life quality. The overall purpose of this study is to
      determine the curative effects of auto-trilevel ventilators on patients with OHS and OSAHS.
    

Detailed description: 
      The main contradiction in treatment for OSAHS complicated OHS is how to improve hypercapnia
      because of narrower difference between inspiratory positive airway pressure (IPAP) and
      expiratory positive airway pressure (EPAP), and meanwhile to eliminate apnea and popnea
      events which may easily occur at the end of expiration For ordinary Bipap ventilator. If the
      IPAP is set to higher, the patients may feel discomfort, if the pressure difference between
      IPAP and EPAP is too narrow or the expiratory positive airway pressure (EPAP) too high,
      hypercapnia may occur. If the EPAP is too low, redusual apnea and hypopnea event may become
      common.

      Auto-trilevel ventilation, with a lower airway pressure at the beginning of expiration to
      prevent hypercapnia and a higher airway pressure at the end of expiration to prevent residual
      apnea events, should be able to provide a novel ventilation mode with a higher efficacy and
      lower average airway pressure for OSAHS patients complicated with OHS. To prove the
      hypothesis, comparison is made between ordinary BiPAP and auto-Trilevel ventilation modes
      during treatment for patients with OSAHS and OHS.

      In this study, the investigators compare the changes of related indexes (including apnea
      hypopnea index、minimal pulse oxygen saturation、arousal index, sleep quality,PaCO2 and
      sleepiness scores) before and after treatment. Meanwhile, curative effects will be compared
      between BiPAP and auto-Trilevel ventilation modes. The investigators will analyze the changes
      and then confirm our hypothesis.
    

Intervention name(s): ventilator
Intervention type(s): Device
Intervention description(s): Noninvasive ventilation including fixed BiPAP ventilation and auto-trilevel ventilation. Using the same IPAP, treatment include one night with BiPAP ventilation mode 1, one night with BiPAP ventilation mode 2 and one night with auto-trilevel ventilation mode. Each treatment last 8 hours for each night.
Other intervention name(s): Auto-trilevel ventilation
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: OSAHS: Obstructive Sleep Apnea hypopnea Syndrome; OHS: Obesity Hypoventilation Syndrome; Auto-trilevel ventilation; BiPAP ventilation