Incidence and Risk Factors of Postoperative Hypothermia in Patients With Cardiopulmonary Bypass.

Background: Postoperative hypothermia may result in relevant complications such as adverse cardiovascular events, wound infection, and coagulopathy with consecutive blood loss. Patients with open cardiac surgery using cardiopulmonary bypass are particular at risk for hypothermia. The study of Karalapillai and coworkers, analyzing a huge database incl. 43,158 patients with CPB, revealed 66% of them experiencing postoperative hypothermia during the first 24 hours and 0.3% longer than that. During cardiac surgery great parts of body surface including wound surface are exposed. Many of these patients receive large amounts of infusions and transfusions, and undergo hemodilution during CPB, which may additionally contribute to development of hypothermia.

Objective of the planned study is to find out incidence and duration of postoperative hypothermia and also risk factors for hypothermia in cardiac patients. Further objective is the incidence of postoperative complications and its relation to postoperative core temperature.

Methods: A retrospective chart review 780 patients who had been underwent cardiac surgery with CPB Included are patients ≥ 18 years old. Excluded are patients with preoperative hyperthermia (> 37.8 °C) and hypothermia (> 36 °C).

The following parameters will be recorded: temperature is measured at ICU after arrived and after 6 hours which is primary outcome, biometric data include age, sex, body weight, height, ASA physical status, surgical procedure includes emergency cases, anesthetic and surgical (bypass-) times, infusion/transfusion-regimen, blood loss and urine output, coolest temperature during bypass, method of temperature protection, and the outcome of operation .

All data will be described in number and percent and Pearson chi-square method will be used for analyze correlation between hypothermia and risk factor . P-value <0.05 will be defined to significant.