Patient factors | (a) Full stomach |
· Emergency surgery | |
· Inadequate fasting time | |
· Gastrointestinal obstruction | |
(b) Delayed gastric emptying | |
· Systemic diseases, i.e., diabetes mellitus, chronic kidney disease | |
· Recent trauma | |
· Opioids | |
· Raised intracranial pressure | |
· Previous gastrointestinal surgery | |
· Pregnancy (including active labor) | |
(c) Incompetent lower esophageal sphincter | |
· Hiatus hernia | |
· Recurrent regurgitation | |
· Dyspepsia | |
· Previous upper gastrointestinal surgery | |
· Pregnancy | |
(d) Esophageal diseases | |
· Previous gastrointestinal surgery | |
· Morbid obesity | |
Surgical factors | Upper gastrointestinal surgery |
· Lithotomy or head down position | |
· Laparoscopy | |
· Cholecystectomy | |
Anesthetic factors | Light anesthesia |
· Supraglottic airways | |
· Positive pressure ventilation | |
· Length of surgery >2 h | |
· Difficult airway | |
Device factors | First-generation supraglottic airway devices |