Background: There is a continuing trend to have more elective surgical operations performed on an outpatient basis.
Objective: To determine the proportional distribution of anesthetic procedures performed in ambulatory elective surgery at different levels of hospitals across Thailand.
Material and Method: A prospective and descriptive study was conducted at 20 hospitals comprising seven universities, five regional, four general and four district hospitals across Thailand. Consecutive outpatients who were undergoing elective surgical operation were included and their relevant data were selected and extracted for summary by using descriptive statistics.
Results: From the database of 118,027 anesthetics performed for elective surgical operation, 7,786 (6.6%) were outpatients. According to this, 7,016 (90.1%) were practiced in university hospitals, 656 (8.4%) in regional or tertiary hospitals, 71 (.9%) in general or provincial hospitals, and 43 (0.6%) in district hospitals. The frequency of the ambulatory anesthesia was higher in hospitals in the central region, especially in university hospitals in Bangkok than in other regions. The majority of cases (86%) received their initial preanesthetic evaluation in the operating room while 12% were evaluated at the outpatient office. About 28% of the cases presented with pre-anesthetic abnormal conditions. The relatively common pre-anesthetic diseases were hypertension, diabetes mellitus, anemia, arrhythmia, and asthma.
Conclusion: From the results of the present study, the authors have concluded that the rate of expansion of ambulatory anesthesia in Thailand is relatively slow, and varies according to the type of hospital and its geographic region. This indicates further studies should be formally conducted to determine factors affecting the practice of ambulatory surgery in Thailand. A large proportion of patients receive initial pre-anesthetic evaluation in the operating room on the day of surgery. This indicates that a system of pre-anesthetic evaluation should be set up for outpatients such as a pre-anesthetic care clinic should be set up for outpatients.

Keywords: Ambulatory, Anesthesia, Outpatient