This is a randomized controlled study in which morbidly obese patients undergoing bariatric surgery will be recruited in the preoperative clinic. Patients will be randomized into 2 groups to receive oxygen with Boussignac TM continuous positive airway pressure (CPAP) or conventional Venturi mask postoperatively immediately after extubation. The objective of the study is to examine if Boussignac TM CPAP results in improved oxygenation versus Venturi face mask when it is applied immediately after extubation in morbidly obese patients post bariatric surgery.

Inclusion Criteria:

• Patient aged between 18 to 75 years of age
• American Society of Anesthesiologists' (ASA) class I to III
• Morbidly obese with a body mass index > 35 kg/m2
• Patients undergoing bariatric surgery

Exclusion Criteria:

• Patient refusal
• Pre-existing cardiac failure, asthma, chronic obstructive pulmonary disease or interstitial pulmonary disease
• Systolic blood pressure less than 90 mmHg despite pharmacotherapy
• Hb < 70 g/L
• Impaired gastric emptying
• Severe psychiatric disorder
• Language barrier