The Comparison of the Effect of Pressure-controlled Ventilation and Volume-controlled Ventilation on the Gastric Insufflations in I-gel

The purpose of this study is to investigate whether the pressure controlled ventilation can reduce gastric insufflation compared to the volume controlled ventilation in patients who were mechanically ventilated with the i-gel.

Inclusion Criteria:

• adult patients aged over 20 yrs who are scheduled for surgery under general anesthesia

Exclusion Criteria:

• upper gastrointestinal surgery,
• surgery of long duration more than 4 hours,
• anticipated difficult intubation,
• body mass index more than 35 kg/m2,
• pregnancy