Background: Safety in anesthesia can be improved through monitoring and analysis of anesthetic complications. We conducted the present Perioperative and Anesthetic Events in Thailand (PAAd Thai) incident reporting study to determine the current frequency distribution of incidents related to the anesthetic complications, factors contributing to the incidents, and corrective strategies. Objectives: The Perianesthetic Anesthetic Adverse Events in Thailand (PAAd Thai) study aimed to investigate patient, surgical, and anesthetic profiles, and suggestive strategies for prevention of adverse events. Methods: A prospective descriptive study was conducted in 22 hospitals across Thailand. Each hospital was invited to report, on an anonymous basis, any perianesthetic adverse incident during 12 months (between January 1 and December 31, 2015). A standardized incident report form was completed to determine the type of incident, and where, when, how, and why it occurred using closed and open-ended questionnaires. Data regarding main anesthetic techniques were also reported monthly. Descriptive statistics and comparative statistics were used as appropriate. Results: Twenty-two hospitals across Thailand participated in this study. Fourteen of them (63.6%) were non-university (service directed) hospitals while eight of them (36.4%) were university (academic) hospitals. The majority of hospitals were involved in residency training and teaching medical students (77.3%), while half of them (57.1%) were involved in training nurse anesthetists. The ratio of anesthesiologists to an operating room was 0.67:1 and the ratio of nurse anesthetists to an operating room was 2.03:1. During 12 months period, there were 333,219 cases, 2,206 incident reports with 3,028 critical incidents. The incidents commonly occurred in male patients (52.0%), aged <10 y (13.0%) and >70 y (18.2%). The incidence of adverse events included cardiac arrest within 24 h (15.5:10,000), death (13.0:10,000), reintubation (11.1:10,000), esophageal intubation (8.5:10,000), difficult intubation (8.0:10,000), endobronchial intubation (8.5:10000), failed intubation (0.7:10000), pulmonary aspiration (1.3:10000), suspected pulmonary embolism (0.5:10000), total spinal block (0.3:10000), awareness (0.4:10000), coma/cerebrovascular accident/convulsion (1.5:10000), nerve injury (0.6:10000), suspected myocardial infarction/ischemia (1:10000), serve arrhythmia (14:10000), anaphylaxis/anaphylactoid reaction/allergy (2.3:10000), medication error (3.2:10000), equipment malfunction/failure (1.4:10000), anesthesia personnel hazard (0.6:10000), transfusion mismatch (0.2:10000), wrong patient/wrong site/surgery (0.2:10000) and malignant hyperthermia (1:200000). General, cardiothoracic neurological and otorhinolaryngological surgical specialties posed a high risk of incidents. Operating room and recovery room were common locations for incidents. 
Conclusion: In the past decade, there were dramatic reductions of perioperative cardiac arrests and pulmonary complications particularly difficult intubations. Common factors related to critical incidents were inexperience, emergency, inadequate preanesthetic evaluation, inappropriate decisions, lack of vigilance, and inexperienced assistants. Suggested corrective strategies are compliance with guidelines, additional training, and improvement of supervision and quality assurance.