The Thai Anesthesia Incidents Study (THAI Study) of anesthetic outcomes: I. Description of methods and populations

Since anesthesia, unlike medical or surgical specialties, does not constitute treatment, The Royal College of Anesthesiologists of Thailand host the Thai Anesthesia Incidents Study (THAI Study) of anesthetic outcomes to determine factors related to anesthesia related adverse events.

A prospective descriptive study of occurrence screening was conducted in 20 hospitals comprised of 7 university, 4 general and 4 district hospitals across Thailand. Anesthesia personnels were required to fill up patient-related, surgical-related, anesthesia-related variables and adverse outcomes on a strutured data entry form. The data included preanesthetic evaluation intraoperative period and 24 hr postoperative period. Adverse events specific form was recorded when adverse events occurred. All data were keyed in data management unit with double entry technique and descriptive statistics was used in the first phase of this study.

A total of 163403 consecutive cases were recorded in one year. The mean (S.D.) of age, weight and height of patients were 38.6(2.3) yrs, 53.9(17.7) kgs and 153.4(22.7) cm respectively. There were more female (52.9%) than male (47. 1%) patients with ASA PS 1, 2, 3, 4, 5 = 50.8%, 36.3%, 10.7%, 2.0%, 0.2% respectively. Hypertension (11.6%), anemia (7.7%) and diabetes melitus (6.8%) were the three most common abnormalities in preanesthetic history taking. Mallampati score of 111870 patients grade 1, 2, 3, 4 were 54.0%, 39.7%, 5.6%, 0.7% and laryngoscopic grade 1, 2, 3, 4 of 74888 patients were 81.0%, 15.5%, 3.0% and 0.5% respectively.

The first phase of THAI study epidemiological project can represent both the anesthesia and surgical profiles in Thailand. The collected data available should be useful for the improvement of the quality of anesthesia, guidelines for clinical practices, medical education and for further research.