A longitudinal evaluation of sleep and breathing in the first year after cervical spinal cord injury

Objectives: To establish the incidence of sleep disordered breathing (SDB) after acute tetraplegia and to determine the relation between the Apnea-Hypopnea Index (AHI) score and the previously postulated predictors of SDB in tetraplegia. Design: Inception cohort. We performed full polysomnography immediately after acute tetraplegia and at 2, 4, 13, 26, and 52 weeks postinjury. Spirometry, maximum inspiratory and expiratory pressures, medication usage, and neck and abdominal.girth were also assessed. Preinjury SDB was estimated using the multivariate apnea prediction equation. Setting: Acute care, subacute care, and community. Participants: Consecutive sample with acute tetraplegia. Thirty subjects (25 men) were initially included. Thirteen completed 12 months of follow-up. Interventions: Not applicable. Interventions: Not applicable. Main Outcome Measures: SDB (AHI score > 10 events/h) and respiratory function. Results: Three subjects (10%; 95% confidence interval [CI], 2%-28%) had probable SDB before injury. In the first 48 hours after injury, no subject had SDB. At 2 weeks, 60% (95% Cl, 26%-88%) had SDB; at 4 weeks, 62% (95% CI, 38%-82%); at 13 weeks, 83% (95% CI, 61%-95%); at 26 weeks, 68% (95% CI, 44%-88%); and at 52 weeks, 62% (95% CI, 32%86%). No consistent relation was found between the previously postulated predictors and SDB. Conclusions: SDB is highly prevalent within 4 weeks of acute tetraplegia.