Comparison of High Flow Nasal Oxygenation and Face Mask Oxygenation for Prolongation of Safe Apnoea Time in Obese Patients Undergoing Elective Surgery under General Anaesthesia

This is an interventional parallel group study design to compare high flow nasal oxygenation and face mask oxygenation for prolongation of safe apnoea time in obese patients undergoing elective surgery under general anaesthesia ,since there is a paucity of studies  in the Indian population  for the same.The primary  objective is to compare high flow nasal oxygenation  and face mask oxygenation for prolongation of safe apnoea time in obese patients undergoing elective surgery. The secondary objective are to compare  ventilation  and assess change in hemodynamic parameters and compare patient comfort between the two techniques. Patients will be allocated  in two groups ,with 31 patients in each group . Group A patients will receive preoxygenation with High Flow Nasal Oxygenation at 40L/minute for 1 minute  and 70L/minute  for 2 minutes ; Group B patients  will recieve preoxygenation with 100% oxygen through tightly held face mask at 10L/minute with CPAP of 5 cm of H2O. The primary outcome measures are number  of patients  in each group in whom apnoea time is less than 6 minutes and time taken  for spo2 to reach 94% .The secondary outcome measures are maximum etco2 reached after start of ventilation, arterial blood gas analysis at baseline,at the end of preoxygenation  and at the end of apnoea time, hemodynamic changes and patients comfort level.The data will be collected ,analysed and statistically evaluated  .