The Prevalence of Sleep Disordered Breathing in Hospitalized Medical Patients

Abstract

Introduction: Obstructive Sleep Apnea (OSA) is underdiagnosed in the outpatient setting. Hospitalized medical patients commonly have diagnoses associated with OSA and limited survey data suggests > 50% may be at-risk for OSA. Identifying OSA in-hospital could improve diagnostic rates as well as impact patient safety and long-term health. We hypothesized that OSA would be highly prevalent in unselected medical inpatients. Methods: This is a prospective study enrolling 100 unselected patients admitted directly to the medical loors of an urban academic medical center. Enrollment criteria: 18-65 y/o, no known OSA or tracheostomy, willing to undergo in-patient polysomnogram (PSG). Enrolled patients underwent a full-night attended inpatient PSG within 48 hours of admission. Results: Of 90 subjects enrolled, 22 were excluded from analysis (11 withdrew consent, 6 insuficient sleep < 100 minutes, 5 technically inadequate study). Baseline characteristics of the remaining 68 subjects (mean+/-standard deviation): Age 46.7 +/- 11.8 y/o, gender 39.7% male, ethnicity - Caucasian 49%, African American 41%, BMI (kg/m2) 30.3 +/- 7.0. Co-morbidities: hypertension (56%), asthma (37%), depression (29%), diabetes (22%), COPD (22%), CVA (10%), CHF (9%), chronic kidney disease (5%), atrial ibrillation (< 2%). Admission diagnosis: COPD or asthma exacerbation (33%), acute gastrointestinal illness (13%), skin or bone infection (10%), renal (9%), CVA (6%), CHF (< 2%), miscellaneous (27%). Inpatient PSG results (mean+/-standard deviation): sleep latency 54.9+/-61.6 minutes, sleep eficiency 60.5 +/- 19.4%, REM 13.9 +/-9.8%. The AHI was > 5 in 51/68 (75%) subjects and > 30 in 13/68 (19%) subjects. Eight subjects with an AHI > 5 had a followup PSG performed (mean 45.4 days later, range 22-126 days) and this conirmed OSA in all, with no difference in mean AHI (P=0.26). Conclusion: Undiagnosed OSA is highly prevalent in hospitalized medical patients. Inpatient PSG can be done safely in hospitalized patients on the general medical loor though is logistically dificult.