Factors Related to Intraoperative Oxygen Desaturation in Geriatric Patients in a Thai University Hospital
Decha Tamdee MSc*, Yodying Punjasawadwong MD**, Somrat Charuluxananan MD***, Chamaiporn Tawichasri MSc**, Pin Sriprajittichai MD***, Oranuch Kyokong MD***, Jayanton Patumanond MD**, Pornarun Sirichotvithayakorn MD***
Affiliation : * Faculty of Nursing, Chiang Mai University, Chiang Mai, Thailand ** Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand *** Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Background : As a site of the Thai Anesthesia Incidents Study (THAI Study) of anesthetic adverse outcome, the
authors continued the institutional data collection to determine the incidence of intraoperative oxygen
desaturation of geriatric patients (age 65 years and over) and relative factors representing a Thai university
hospital.
Material and Method: Between July 1, 2003 and March 31, 2007, an anesthesia registry was conducted at
King Chulalongkorn Memorial Hospital. Anesthesiologists and anesthesia residents were requested to record
perioperative variables and adverse outcomes including oxygen desaturation (SpO2 < 90% for 3 minutes or
SpO2 < 85%) on a structured data record form. Univariable analysis was used to identify factors related to
intraoperative oxygen desaturation. Multivariable generalized linear regression for risk ratio was used to
investigate independent factors with significant association to intraoperative oxygen desaturation. A forward
stepwise algorithm was chosen. A p-value < 0.05 was considered as statistically significant.
Results : Among 54,419 cases in the registry, 8,905 geriatric patients underwent non-cardiac surgery receiv-
ing anesthesia. Among these, 21 patients developed intraoperative oxygen desaturation with an incidence of
23.6 (95% CI 10, 30):10000 anesthetics. Variables that predict intraoperative oxygen desaturation by multi-
variable analysis were ASA physical status 3 [RR 4.6 (95% CI 1.6, 13.6)], ASA physical status 4-5 [RR 29.8
(95% CI 8.7, 102.8)], history of difficult airway [RR 13.1 (95% CI 1.7, 102.2)], recent respiratory failure [RR
6.0 (95% CI 1.2, 29.3)], and anesthetic agents used such as: pethidine [RR 6.2 (95% CI 1.9, 19.9)], and
ketamine [RR 5.6 (95% CI 1.2, 25.9)].
Conclusion : The incidence of intraoperative oxygen desaturation of geriatric patients who underwent
non-cardiac surgery in a Thai university hospital was 23.6:10000 anesthetics, which was comparable to
others. The higher ASA physical status, history of difficult intubation and recent respiratory failure were risk
factors of intraoperative oxygen desaturation. Pre-anesthetic evaluation particularly airway evaluation and
identification of high-risk patients are crucial for prevention of oxygen desaturation.
Keywords : Adverse effects, Aged, Anesthetics, Hypoxia, Geriatrics, Intraoperative complications, Oximetry, Oxygen desaturation, Patient safety
