home-based diagnosis and management of sleep-related breathing disorders in spinal cord injury

Conditions: Obstructive Sleep Apnea; Hypercapnia; Spinal Cord Injury

Summary: * patients with spinal cord injury (sci) usually breathe without any mechanical assistance, but significant breathing problems occur often during sleep, either because the upper airway closes (obstructive sleep apnea; osa), or because of weakness/paralysis of the breathing muscles. these problems often go unrecognized, as sci patients face logistical barriers that cause them to refuse appropriate testing in sleep laboratories. we have devised a strategy for diagnosing sleep-disordered breathing in the patient's home, using placement of noninvasive devices that monitor breathing overnight. this project is designed to test the feasibility and utility of this strategy. * after collecting baseline data on symptoms and medical events for four months, the home-based studies are performed noninvasively with fda-approved devices: a type iii sleep system and a recording oxygen saturation/ transcutaneous carbon dioxide monitor. if these studies identify sleep-disordered breathing, noninvasive ventilatory support is prescribed according to standard clinical practice. over the following twelve months, the subjects monitor their symptoms daily, and answer quality-of-life questionnaires every three months. after 3, 6, and 12 months, blood tests are performed to measure blood sugar and cholesterol/lipids. data is downloaded from the ventilator device to monitor compliance and ventilator performance. this study is designed to determine the prevalence of sleep-disordered breathing in sci, the feasibility of home-based testing to establish the diagnosis, and the short term effects on symptoms, quality-of-life, and associated conditions (glucose intolerance, blood lipid disorders).

eligible subjects will sign informed consent, followed by: a 4 month period of maintaining a daily log of symptoms and medical events (such as hospitalization, starting antibiotics). an overnight sleep study will be performed in the subject's home based on the results of the sleep study, noninvasive ventilation (bipap) will be prescribed, according to standard medical practice. a clinical assessment, pulmonary function tests, and blood tests (blood glucose, hemoglobin a1c, and blood lipid profile) will be performed at the same time. quality of life surveys will be performed at months 0, 3, 6, and 12. the daily symptom logs will be continued for 12 months. data from the bipap units will be downloaded and repeat overnight monitoring to measure blood oxygen and carbon dioxide levels will be performed periodically for 12 months after bipap is started. subjects without sleep-disordered breathing will have the same clinical assessments and blood tests as subjects for whom bipap has been described.

Eligibility criteria:
inclusion criteria: * 18 years or older * c1-t6 spinal cord injury for at least 3 months * living within 100 miles of ann arbor, michigan, usa exclusion criteria: * unable to provide informed consent * comorbid condition that limits life expectancy to less than 1 year * ventilator-dependent * established diagnosis of sleep-disordered breathing * prior use of noninvasive positive pressure ventilation (cpap or bipap) for any reason (temporary suse of noninvasive ventilation during a hospitalization is permissible if it was discontinued more than 3 months prior to enrollment) * active duty military personnel

Keywords: obstructive sleep apnea sleep-disordered breathing hypercapnia spinal cord injury