Preoxygenation With High Flow Nasal Cannula Prolongs Normoxia Time During Induction of Anaesthesia of Bariatric Patients and is Superior to Conventional Preoxygenation With Face Mask.

Preoxygenation With High Flow Nasal Cannula Prolongs Normoxia Time During Induction of Anaesthesia of Bariatric Patients and is Superior to Conventional Preoxygenation With Face Mask.

To compare preoxygenation for induction of general anaesthesia with High Flow Nasal Cannula vs preoxygenation with face mask in patients undergoing bariatric surgery. The hypothesis is that preoxygenation with High Flow Nasal Cannula prolongs normoxia time during induction of anaeshesia and is superior to conventional preoxygenation with face mask. Primary endpoint will be the time during which spO2 > 92 %. Secondary endpoint will be paCO2.

Inclusion Criteria:

• age over 18
• elective bariatric surgery
• written consent

Exclusion Criteria:

• preexisting lung diseases, congenital heart diseases
• known difficult airway
• SpO2 < 92% under ambient air conditions
• known diaphragmal hernia
• clinically relevant reflux