The Thai Anesthesia Incidents Study (THAI Study) of Perioperative Allergic Reactions
Somboon Thienthong MD*, Thanoo Hintong MD**, Aksorn Pulnitiporn MD***
Affiliation : Departments of Anesthesiology, Faculty of Medicine, *Khon Kaen University, **Chiang Mai University, ***Khon Kaen Regional Hospital, Thailand
Objectives : To determine the incidence, risk factors, signs, symptoms and management of perioperative
allergic reactions in the Thai Anesthesia Incidents Study (THAI Study).
Materials and Methods : Between February 1, 2003, and January 31, 2004, a descriptive, prospective, multicenter
study was conducted in 20 hospitals across Thailand. All patients receiving anesthetic and medical agents
were monitored for allergic reactions for the first 24 postoperative-hours. Signs and symptoms of suspected
allergic reactions included skin reactions, wheezing and unexpected hypotension. The details of allergic
reactions were reviewed and recorded.
Results : Allergic reactions occurred in 30 of the 163,403 patients included in this study. The reaction-
incidence was approximately 1 in 5,500 cases of anesthesia. Forty-eight percent of the affected patients had a
history of allergic reactions. The manifestations were skin reactions, hypotension and wheezing in 38, 22 and
19 percent of the overall symptoms, respectively. Reactions were mild, moderate and severe in 40, 23 and 37
percent of the patients, respectively. The three drugs most suspected of causing the reaction(s) were antibiotics
(19%), muscle relaxants (17%) and propofol (15%). All of the affected patients recovered after treatment
including the one who suffered cardiac arrest because of the allergic reaction.
Conclusion : The incidence of perioperative allergic reactions was 1 in 5,500 cases of anesthesia. History of
allergies was obtained from half of the patients and the most common sign was a skin reaction. The drugs
most suspected of causing an allergic reaction were antibiotics. All of the patients responded well to rescue
treatment.
Keywords : Allergic reactions, Anesthetic agents, Perioperative, Multicenter study
