title: Sleep-related breathing disorders in obese patients presenting with acute respiratory failure.
abstract: BACKGROUND
  The study was conducted to assess the clinical and polysomnographic characteristics of patients with sleep-related breathing disorders who presented to the intensive care unit (ICU) with acute respiratory failure and the practicability of performing polysomnography for such patients.
  
  
  METHODS
  We analyzed clinical presentation, cause of admission to the ICU, ICU course and outcome of 11 subjects with acute respiratory failure who were diagnosed to have sleep disordered breathing based on polysomnography between October 1999 and January 2003. Subjects were compared to 11 patients with obstructive sleep apnea syndrome matched to each subject using body mass index, age and apnea hypopnea index measured at the time of diagnosis (matched comparison group). Repeated arterial blood gases and polysomnography were done for 8 subjects compliant to treatment 6-8 months after discharge from ICU.
  
  
  RESULTS
  The reason for ICU admission for all subjects was hypercapnic respiratory failure. pH and daytime PaO2 were significantly lower in studied subjects compared to the matched comparison group while awake daytime PaCO2 was significantly higher. Subjects had frequent episodes of hypoventilation. Follow up arterial blood gases and polysomnography 6-8 months after treatment (non-invasive ventilation) in compliant subjects showed significant improvement in all blood gases parameters.
  
  
  CONCLUSIONS
  Early polysomnography (or portable cardio-respiratory monitoring) allows accurate diagnosis and institution of the appropriate ventilation method Further studies should assess the evolution of respiratory drive in patients with sleep disordered breathing and hypercapnia under therapy (non-invasive ventilation).
authors.affiliation: Sleep Disorders Center, Respiratory Unit, Department of Medicine, College of Medicine, King Saud University, PO Box 2925, Riyadh 11461, Saudi Arabia. ashammam2@yahoo.com
authors.forename: Ahmed
authors.initials: A
authors.lastname: BaHammam
authors.forename: Suhail
authors.initials: S
authors.lastname: Syed
authors.forename: Abdelrahman
authors.initials: A
authors.lastname: Al-Mughairy
mesh_terms: D000208:Acute Disease; D001784:Blood Gas Analysis; D015992:Body Mass Index; D016022:Case-Control Studies; D003422:Critical Care; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D017286:Polysomnography; D012121:Respiration, Artificial; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome