Evaluating nocturnal oxygen desaturation in COPD--revised.

BACKGROUND: Although in patients with COPD, the approach to daytime hypoxemia using long-term oxygen therapy (LTOT) is established, the best approach to transient nocturnal desaturation varies among clinicians. An understanding of the prevalence of nocturnal desaturation in COPD, in the absence of other respiratory co-morbidities, is an important step towards its standardized management. METHODS: We conducted a 5 site cross-sectional study of stable patients with COPD and mild-to-moderate daytime hypoxemia (PaO(2) 56-69 mmHg). Nocturnal saturation was monitored using home oximetry on 2 occasions over a 2-week period. Patients were classified in 3 categories: (A) no significant nocturnal desaturation; (B) significant nocturnal desaturation without evidence of sleep apnea; (C) significant nocturnal desaturation with evidence of sleep apnea. RESULTS: In 128 patients (mean FEV(1): 37% predicted), we noted an excellent test-retest reliability between the 2 oximetries. Forty-nine patients (38%) were classified as nocturnal desaturators without evidence of sleep apnea, and 20 patients (16%) were classified as desaturators with evidence of sleep apnea. Nocturnal desaturation without sleep apnea could not be predicted by any patient characteristic or physiological measure. CONCLUSIONS: A significant proportion (38%) of patients with moderate-to-severe COPD who do not qualify for home oxygen therapy based on their daytime PaO(2) have nocturnal oxygen desaturation without evidence of sleep apnea. Home oximetry is an effective practical method for screening this population.

Sleep-disordered breathing in patients enrolled in an inpatient stroke rehabilitation program.

OBJECTIVE: To report the prevalence of sleep-disordered breathing in an inpatient stroke rehabilitation unit and to explore correlations with functional status and health-related quality of life. DESIGN: Cross-sectional study. SETTING: Rehabilitation center. PARTICIPANTS: Consecutive patients (N=45; mean age, 67+/-12y) (28 men) enrolled in inpatient rehabilitation after ischemic (84%) or hemorrhagic stroke (16%). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Overnight respiratory polysomnography was performed on all subjects. Interviewer-administered scales of sleepiness (Epworth Sleepiness Scale) and functional status (FIM, Barthel Index) were completed. Health-related quality of life was assessed by using a general questionnaire (Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]). RESULTS: Of the 45 subjects tested, only 4 (9%) had an apnea-hypopnea index of less than 10 per hour. The mean apnea-hypopnea index was 32.2 (19.4) per hour; most events were obstructive. There was no relationship between the respiratory index and the components of SF-36 (P values>.2). CONCLUSIONS: There was a dramatically high prevalence of respiratory events in patients after stroke enrolled in an inpatient stroke rehabilitation unit. The awareness of this will influence patient evaluation and management.