Abstract WMP58: The Portable Sleep Study as an Early Obstructive Sleep Apnea Screening Tool In Acute Ischemic Stroke
Background: Prompt diagnosis of obstructive sleep apnea (OSA) after acute ischemic stroke (AIS) is critical for optimal clinical outcomes, but full bedside polysomnograms are not routinely practical. To validate a potentially practical diagnostic portable cardiopulmonary sleep study (PSS) after such strokes, we compared it to conventional polysomnography (PSG).
Methods: Simultaneous bedside Level 3 (Embletta X100) PSS and PSG studies were performed in patients <72 hours from stroke onset. The accuracy of PSS was compared to PSG using: Chi-square tests, Receiver-Operatory Characteristic curves, Bland-Altman plot, paired Student t-test /Wilcoxon signed rank test and calculation of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV).
Results: Twenty one out of 23 acute ischemic stroke patients (age 61+ 9.4; 52% male; 58% African-American), successfully completed both of the simultaneous screenings (9% technical failure). Ten AIS patients (48%) were diagnosed with OSA. Nearly all (90%) had Mallampati IV posterior oropharynx; the mean neck circumference was 17.3± 1.3 inches; the mean BMI was 35.1 ±5 kg/m2. The Apnea Hypopnea Index (AHI) provided by PSS was similar to that provided by PSG (29.1± 16.8 vs. 27.6 + 20.2, respectively; p=0.10). In identifying patients with AHI ≥ 5 on PSG, PSS screening had the following parameters: sensitivity 100%; specificity 85.7%; PPV 91%; NPV 100%. For AHI ≥ 15 on PSG, PSS screening parameters were as follows: Sensitivity 100%; Specificity 83.3%; PPV 71.4%; NPV 100%. Bland-Altman plotting showed overall diagnostic agreement between PSS and PSG modalities for an AHI cutoff of > 5, despite finer-grained differences in estimated AHIs.
Conclusions: Compared with PSG, PSS provides similar diagnostic information when run simultaneously in acute ischemic stroke patients. PSS potentially can serve as a reliable screening tool for early diagnosis of obstructive sleep apnea in acute ischemic stroke patients.
- © 2012 by American Heart Association, Inc.