The purpose of this study is to determine if an Autoadjusting CPAP machine is better than
the regular CPAP machine in treatment of Obstructive Sleep Apnea in the postoperative
1. Known OSA patients well-controlled by CPAP (not hypoxemic i.e. SaO2 ≥ 89% and
post-treatment AHI <10) and compliant ( > 3 hours per night) presenting for elective
inpatient surgery to MetroHealth Medical Center
2. Elective extremity or lower abdominal surgery
3. Age >18 years
1. Surgery that may cause hypoxemia from causes other than the effect on upper airway
patency e.g. any thoracic surgery, upper abdominal surgery, head and neck surgery.
2. Surgery on the upper-airway.
3. Any condition that may interfere with application of CPAP mask e.g. trauma, surgery
on the face, vomiting, naso-gastric intubation etc.
4. OSA treated with a device other than CPAP e.g. Bilevel positive pressure or V-PAP
5. OSA needing very high levels of CPAP i.e. > 16 cms to achieve adequate control
6. OSA or other underlying cardiopulmonary conditions that require supplemental oxygen
7. Patients with decompensated congestive heart failure or advanced COPD (FEV1<35% of
8. Patients with neuromuscular impairment
9. Patients with central sleep apnea
10. Pregnant patients
11. Decisional impaired subjects who are not able to consent
Inderjeet S Brar, MD
MetroHealth Medical Center, Case Western Reserve University