[Prevention of Perioperative Aspiration Pneumonitis]

To prevent perioperative aspiration pneumonitis, it is necessary to reduce the volume and acidity of gastric content. The guideline for preoperative fasting published by Japanese Society of Anesthesiologists recommends fasting from intake of clear fluids, breast milk and nonhuman milk at least 2h, 4h and 6h, respectively, before elective procedures requiring general anesthesia, regional anesthesia or sedation/analgesia. Gastrointestinal stimulants, histamine-2 receptor antagonists, proton pump inhibitors, antacids, antiemetics, anticholinergics are effective for reduction of the volume or acidity of gastric content. However, the routine preoperative use of these drugs to reduce the risk of pulmonary aspiration in patients who have no apparent increased risk for pulmonary aspiration is not recommended.