Objectives: To examine the risk factors, outcomes, and contributing factors associated with perioperative pulmonary aspiration.
Material and Method: Pulmonary aspiration incidents were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between March 1, 2003, and February 28, 2004, and analyzed using descriptive statistics.
Results: Thirty — two incidents of aspiration were reported. Passive regurgitation occurred more frequently than active vomiting. Aspiration occurred more commonly in elective rather than emergency surgery, with 59% of incidents taking place during the induction of anesthesia and intubation period. While a major immediate physiological disturbance was common, long term morbidity was not. Death ensued in 5 cases, most of which had significant co — morbidities. Most cases (62.5%) were appropriately treated. The majority of incidents occurred in ASA class 2 (56.3%), age group 15 — 64 years (59.4%), non obese (92.9%) and non — difficult intubation (71.9%). Most cases were incomplete fasted or had prolonged gastric emptying time. Nasogastric aspiration and rapid sequence induction with cricoid pressure were infrequently used (12.5, 25%). Factors reported as contributing to the incidents included failure of technique and error of judgement. Additional training, continuing medical education and quality assurance tended to minimize the incidents.
Conclusion: Aspiration occurred commonly in patients with incomplete fasted or had prolonged gastric emptying time and underwent elective surgery. Additional training, continuing medical education and quality assurance tended to minimize the incidents.

Keywords : Pulmonary aspiration, Anesthesia, Multicenter study, Complication, Adverse outcomes