Intraoperative Hypothermia

The goal of this observational study is to learn whether warming patients before surgery, called "prewarming," affects blood lactate levels (a marker of how well tissues are getting oxygen) and recovery in adults having planned (elective) kidney removal surgery (nephrectomy). The main questions this study aims to answer are: * Does prewarming lower the rise in blood lactate seen during and after surgery? * Does prewarming affect time spent in the intensive care unit (ICU), the need for a blood transfusion, or the rate of complications after surgery? Researchers will compare two groups of adults having this surgery. One group receives brief active warming before anesthesia (the "prewarming" group). The other group does not receive this warming (the "control" group). The anesthesia team decides whether to use prewarming and for how long, as part of routine care; the study does not change this decision. Researchers will compare the two groups to see whether prewarming is linked to lower lactate levels and better recovery. Participants will: * Receive their usual, routine surgery and anesthesia care * Have blood pressure, heart rate, body temperature, and blood tests, including lactate, checked before and after surgery, as already done in routine care * Have their ICU stay, need for blood transfusion, and any complications recorded This study does not add any extra tests, procedures, or blood draws beyond routine clinical care.

Intraoperative hypothermia is common in patients having major surgery and the compliance with intraoperative temperature monitoring and management remains poor. Studies suggest that intraoperative hypothermia is an important risk factor of postoperative delirium, which is associated with worse early and long-term outcomes. Furthermore, perioperative hypothermia increases stress responses and provokes immune suppression, which might promote cancer recurrence and metastasis. In a recent trial, targeted temperature management reduced intraoperative hypothermia and emergence delirium. There was also a trend of reduced postoperative delirium, although not statistically significant. This trial is designed to test the hypothesis that intraoperative targeted temperature management may reduce postoperative delirium and improves progression-free survival in older patients recovering from major cancer surgery.

Brief Title: Predicting Hypothermia in Gynecological Laparoscopic Surgery Using Machine Learning Brief Summary: This study aims to develop and validate a machine learning model for predicting intraoperative hypothermia (IOH) in patients undergoing gynecological laparoscopic surgery based on preoperative clinical indicators. This prospective, multicenter case-control study will enroll female patients aged 18 years and older who are scheduled for laparoscopic surgery across multiple hospitals from 2026 to 2027. The primary objective is to identify high-risk patients who may experience IOH, defined as a core temperature below 36.0°C during surgery. Participants will be classified into two groups: the IOH group, consisting of patients who experience hypothermia, and the normal temperature group, comprising patients who maintain a core temperature of 36.0°C or higher. Data collection will include demographics, comorbidities, surgical details, anesthesia information, and preoperative laboratory results. The primary outcome measure will be the area under the curve (AUC) of the model, assessing its predictive performance at various thresholds. Secondary outcomes will include sensitivity, positive predictive value, negative predictive value, and F1 score. The study hypothesizes that the developed machine learning model will significantly improve the accuracy and timeliness of predicting IOH, thereby enhancing patient safety during surgery and postoperative recovery. This research is expected to inform clinical practices related to preventative warming strategies, ultimately improving patient outcomes in gynecological laparoscopic surgery.