Risk Factors of Intraoperative Oxygen Desaturation: A Case-Control Study of 152,314 Anesthetics

Background: The present study was part of the Thai Anesthesia Incidents Study (THAI Study) of anesthetic adverse outcomes. Objective: To determine factors related to intraoperative oxygen desaturation (SpO2 < 85 % or < 90 % for more than 3 min) Material and Method: During a 12-month period (February 1, 2003- January 31, 2004), a prospective multicentered registry of patients receiving anesthesia was conducted in 20 hospitals across Thailand. Anesthesia personnel filled up patient-related, surgical-related, and anesthesia related variables and adverse outcomes including intraoperative oxygen desaturation. A case-control (1:4) study of patients with and without intraoperative oxygen desaturation in the THAI Study database was done. Univariate and multivariate analysis were used to identify factors related to intraoperative oxygen desaturation. A p-value < 0.05 was considered as significant. Results: Among 152,314 patients without preanesthetic desaturation in the database, 328 cases of intra-operative oxygen desaturation were matched with 1,312 control patients without desaturation. Variables that predict desaturation by multiple logistic regression were age less than 5 years old [OR 9.3 (95 % CI 5.4