Nasal Continuous Positive Airway Pressure and Airway Patency in Obese Patient

Inclusion Criteria:

Body Mass Index:30 to 50 kg/ m2, Age: 18-65 years old ASA physical status classification: I-III Requiring general anesthesia for elective surgery

Exclusion Criteria:

1. Patients with major cardiovascular disease, respiratory disease, cerebral vascular disease or American Society of Anesthesiologists physical status class IV or greater.
2. Abnormal vital signs on the day of admission for surgery [heart rate (HR, >100 bpm or <40 bpm), blood pressure (BP, >180/100 mmHg or <90/60 mmHg), room air transcutaneous oxyhemoglobin saturation (SPO2) <96%] that are not correctable with his or her routine medication or commonly used pre-operative medication.
3. Having claustrophobia and not able to tolerate the mask.
4. Any person with an anticipated difficult airway or those with a history of difficult airway. This will include subjects who require or may require either a fiberoptic intubation or intubation while awake.
5. Gastric-esophageal reflex disease that is refractory to treatment or a full stomach.
6. The subject has been in bed for more than 24 hours.
7. Neurological symptoms associated with neck extension, a neurological deficit from a previous stroke or spinal cord injury, a recent stroke or transient ischemic attack (TIA) within 2 weeks.
8. Pregnant women and women less than one month post-partum. Ruling out pregnancy will be conducted by careful history and physical examination as performed routinely prior to surgery. If the history is believed to be unreliable, the patient will be excluded unless a pregnancy test is performed and the result of the test is negative.

9. Emergency cases and subjects who have not adhered to the ASA NPO (Nil Per Os) guidelines.

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