title: Simplified Approach to Diagnosing Sleep-Disordered Breathing and Nocturnal Hypercapnia in Individuals With Spinal Cord Injury.
abstract: OBJECTIVE
  To evaluate a strategy of home-based testing to diagnose sleep-disordered breathing and nocturnal hypercapnia in individuals with spinal cord injury (SCI).
  
  
  METHODS
  Case series.
  
  
  METHODS
  Referral center.
  
  
  METHODS
  Adults with C1-T6 SCI (N=81). Individuals were eligible if ≥ 18 years old, with SCI of ≥ 3 months' duration, living within 100 miles of the study site, and not meeting exclusion criteria. Of the 161 individuals recruited from the SCI Model System database who were not enrolled, reasons were not interested in participating, change of location, prior positive pressure ventilation use, or medical contraindication. Ten individuals did not complete the study.
  
  
  METHODS
  Performance of an unsupervised home sleep apnea test combined with transcutaneous partial pressure of carbon dioxide/oxygen saturation by pulse oximetry monitoring.
  
  
  METHODS
  Prevalence of sleep-disordered breathing and nocturnal hypercapnia. Clinical and physiological variables were examined to determine which, if any, correlate with the severity of sleep-disordered breathing.
  
  
  RESULTS
  Obstructive sleep apnea (OSA) was found in 81.3% of individuals, central sleep apnea (CSA) was found in 23.8%, and nonspecific hypopnea events, where respiratory effort was too uncertain to classify, were present in 35%. Nonspecific hypopnea events correlated strongly with CSA but weakly with OSA, suggesting that conventional sleep apnea test scoring may underestimate central/neuromuscular hypopneas. Nocturnal hypercapnia was present in 28% and oxygen desaturation in 18.3%. Neck circumference was the primary predictor for OSA, whereas baclofen use and obstructive apnea/hypopnea index weakly predicted CSA. Awake transcutaneous partial pressure of carbon dioxide and CSA were only marginally associated with nocturnal hypercapnia.
  
  
  CONCLUSIONS
  Unsupervised home sleep apnea testing with transcutaneous capnography effectively identifies sleep-disordered breathing and nocturnal hypercapnia in individuals with SCI.
authors: Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI. Electronic address: krisbaum@umich.edu.
authors: Kristy A
authors: KA
authors: Bauman
authors: Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI.
authors: Armando
authors: A
authors: Kurili
authors: Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI; Department of Neurology, Sleep Disorders Center, University of Michigan Health System, Ann Arbor, MI.
authors: Helena M
authors: HM
authors: Schotland
authors: Department of Physical Medicine and Rehabilitation, University of Michigan Health System, Ann Arbor, MI.
authors: Gianna M
authors: GM
authors: Rodriguez
authors: Department of Physical Medicine and Rehabilitation, University of Michigan Health System, Ann Arbor, MI.
authors: Anthony E
authors: AE
authors: Chiodo
authors: Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI.
authors: Robert G
authors: RG
authors: Sitrin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000379:methods*; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000209:etiology*; D013119:Spinal Cord Injuries / Q000150:complications*
keywords: Hypercapnia; Rehabilitation; Spinal cord injuries