Inadvertent postanesthetic hypothermia is unintentional drop in core body temperature <36C (96.8F) immediately following an operation, caused by multiple factors, and had lead to negative outcomes. In our institute, a study in 2011 reported an incidence of postoperative hypothermia in PACU of 45.4% (95% CI 39.61%- 51.23%). After that, various interventions aimed to prevent perioperative hypothermia were implemented. This study is initiated to determine the incidence of postoperative hypothermia and associated factors of postoperative hypothermia in adult patients underwent surgery at Siriraj hospital.

Inadvertent postanesthetic hypothermia is unintentional drop in core body temperature <36C (96.8F) immediately following an operation, which is a common problem in post anesthesia care unit (PACU). It has been implicated in negative outcomes in surgical patients, including prolonged effects of intraoperative anesthetic medication, increased insulin resistance, postoperative morbidity, delayed surgical wound healing; and prolonged stay in the recovery room and hospital1-7.

In the operating room (OR), patients have to expose to a low ambient temperature with little or no clothing, evaporation from the surgical area, an irrigated fluid in surgical area; and an administration of intravenous fluids. Moreover, many anesthetic agents have an influence on the autonomic thermoregulatory mechanism which causes vasodilatation. All these factors promote patients' unintentional loss of heat and cause hypothermia.

Even of a lot of efforts to keep patients warm intraoperatively and minimize hypothermia including optimizing ambient OR temperature and using of various warming devices, the incidences of postoperative hypothermia in PACU are still high with the reported magnitude ranges from 50%- 90%7. In Siriraj hospital, a study in 2011 reported an incidence of postoperative hypothermia in PACU of 45.4% (95% CI 39.61%- 51.23%)8. After that, various interventions aimed to prevent perioperative hypothermia were implemented such as maintaining the ambient room temperature of an OR; warming intravenous fluids, blood products, and irrigants; heated, humidified anesthetic gases; and using warming blankets, forced-air warming, layering drapes and head wraps. This study is initiated to determine the incidence of postoperative hypothermia and associated factors of postoperative hypothermia in adult patients underwent surgery at Siriraj hospital.

Inclusion Criteria:

• All patients >18 years undergoing surgery with anesthesia service
• Stay at Postanesthetic care unit of Syamindra building, fifth floor, Siriraj hospital

Exclusion Criteria:

• Procedure performed under local anesthesia
• Patients with missing data of temperature

Adult patients of age more than 18 years old who undergoing anesthesia and surgery in Siriraj hospital.