Research on Intraoperative Hypothermia Risk Prediction Model and Temperature Management Strategy for Elderly Patients During Surgery Based on Dynamic Incremental Training

Research on Intraoperative Hypothermia Risk Prediction and Temperature Management Strategies in Elderly Patients: Construction of Intraoperative Hypothermia Prediction Model Based on Dynamic Incremental Training and Evaluation of Clinical Application Effectiveness

With the support of partial dual temperature monitoring (comparing the specific difference between standardized axillary temperature monitoring and esophageal temperature), this trial is divided into the following three parts:

1. Multi center observational study: Establish and validate a dynamic incremental training intraoperative hypothermia prediction model - Intelligent Care for the Elderly (ICE) - Intraoperative hypothermia warning system, and provide ICE Offline for use by healthcare professionals and ICE Online for further model updates when needed for clinical or research purposes.
2. Multi center non randomized controlled clinical trial: Conduct a multi center stratified temperature management clinical trial based on ICE Offline after dynamic incremental training to verify the clinical and economic benefits of the model and active warming.
3. Pre and post comparative study: Collect data before ICE application and compare it with data after ICE promotion.

Study Overview

• Status: Completed
• Conditions: Intraoperative Hypothermia
• Intervention / Treatment: Diagnostic test: Prediction of intraoperative hypothermia risk; Device: Inflatable warming system; Other: Measurement of tympanic membrane temperature; Other: The difference between axillary temperatature and core temperature in elderly patients

• Study Type: Interventional
• Enrollment (Actual): 1323
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 400010
      • First Affiliated Hospital of Chongqing Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Elderly patients (aged 60 and above) undergoing non cardiac elective surgery under general anesthesia;
• 30 minutes ≤ Estimated surgical duration ≤ 240 minutes ;
• Normal preoperative bleeding and clotting time
• American society of Aneshesiologists physical status classification system:Ⅰ～Ⅳ

Exclusion Criteria:

• Mental illness
• Cirrhosis
• Existence or potential central hyperthermia
• Metabolic thermoregulatory abnormalities
• History of malignant hyperthermia or family history
• Extensive skin burns or injuries
• Seriously infect
• Long term use of nonsteroidal anti-inflammatory drugs
• Expected difficult airway
• Researchers believe that individuals who are not suitable to participate in clinical trial
• Refusal to sign informed consent form
• Withdraw informed consent form
• Severe bleeding or shock during perioperative period.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Model optimization group; Only observe the patient's baseline, intraoperative hypothermia, postoperative complications, and other indicators, and collect data through the electronic Data Capture System to optimize existing intraoperative hypothermia prediction model. The estimated sample size is 600 cases by the incremental learning curve calculating.	Other: Measurement of tympanic membrane temperature; As a intraoperative core temperature reference (measure every 15 minutes) for patients without esophageal temperature or nasopharyngeal temperature monitoring.; Other: The difference between axillary temperatature and core temperature in elderly patients; Previous studies have shown that the difference and standard deviation between esophageal temperature and axillary temperature are core 0.05 ℃ and 0.26 ℃, respectively. In light of 10% dropout rate, a integer sample size of 400 achieves 95% power to detect a mean of paired differences of 0.05 with an estimated standard deviation of paired differences of 0.26 and with a significance level (alpha) of 0.05 using a two-sided paired t-test. So 400 patients in the Model optimization group need to undergo core temperature (esophageal temperature or nasopharyngeal temperature).
Experimental: Intraoperative hypothermia low risk group; Patients included this group are determined by prediction model. Operating room environment temperature was set at not less than 21°C, with a relative humidity of 50% to 60%. Patients are covered from neck to feet with a cotton blanket and the area to be disinfected and operated on is uncovered after induction of anesthesia. All patients will be administered intravenous fluid warmers and irrigation fluid prewarming (37℃~43℃).	Diagnostic test: Prediction of intraoperative hypothermia risk; According to the Intelligent Care For The Elderly (ICE, an optimized model based on the existing prediction model of our research group after dynamic incremental training), patients are divided into intraoperative hypothermia lowrisk group and intraoperative hypothermia high risk group.; Other: Measurement of tympanic membrane temperature; As a intraoperative core temperature reference (measure every 15 minutes) for patients without esophageal temperature or nasopharyngeal temperature monitoring.
Experimental: Intraoperative hypothermia high risk group; Patients included this group are determined by prediction model. In addition to the measures taken in intraoperative hypothermia low risk group, an inflatable warming system, including a forced air warming system and forced air warming blanket, is employed for prewarming before anesthesia initiation and for maintaining body temperature throughout the operation. During the surgery, the insulation blanket will be applied to non surgical areas, and the host temperature will be adjusted to 38 ℃ for warming. If the temperature of the patient is lower than 36 ℃, the temperature of the system can be adjusted to 43 ℃; if the temperature of the patient is higher than 37 ℃, the temperature of the system can be adjusted to 32 ℃. After the patient's temperature is normal, it can be adjusted back to 38 ℃.	Diagnostic test: Prediction of intraoperative hypothermia risk; According to the Intelligent Care For The Elderly (ICE, an optimized model based on the existing prediction model of our research group after dynamic incremental training), patients are divided into intraoperative hypothermia lowrisk group and intraoperative hypothermia high risk group.; Device: Inflatable warming system; Inflatable warming system, including a forced air warming system (IOB, WU505) and forced air warming blanket (IOB-001, IOB-006, IOB-011), is employed for prewarming before anesthesia initiation and for maintaining body temperature throughout the operation. During the surgery, the insulation blanket will be applied to non surgical areas, and the host temperature will be adjusted to 38 ℃ for warming. If the temperature of the patient is lower than 36 ℃, the temperature of the system can be adjusted to 43 ℃; if the temperature of the patient is higher than 37 ℃, the temperature of the system can be adjusted to 32 ℃. After the patient's temperature is normal, it can be adjusted back to 38 ℃.; Other: Measurement of tympanic membrane temperature; As a intraoperative core temperature reference (measure every 15 minutes) for patients without esophageal temperature or nasopharyngeal temperature monitoring.
No Intervention: Group of model benefit evaluation; Data of this group is medical records before the application of the intraoperative hypothermia prediction model, which will be collected from the electronic medical record system.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative hypothermia	Intraoperative hypothermia, defined as a core temperature below 36 °C	Up to 24 hours, from the time of entry into the operating room to the time of exit from the operating room.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The specificity and sensitivity of the model	Conventional parameters for evaluating model accuracy	1 year
Physical sensation	The ASHRAE thermal sensation scale, which was developed for use in quantifying people's thermal sensation, is defined as follows:+3 (hot), +2 (warm), +1 (slightly warm), 0 (neutral), -1 (slightly cool), -2(cool), and -3 (cold)	Perioperative period
Total volume of intraoperative blood loss	Routine intraoperative monitoring indicators	Intraoperative
Postoperative shivering	A compensatory response of the body to hypothermic stimuli that cause rapid rhythmic. Once the operation is completed, the patient will be extubated and the presence or absence of shivering will be recorded up to 60 minutes after the extubation with the Badjatia 2008 scale consisting of a gradual evaluation of 0 to 3 points. With scores greater or equal to 1, shivering is considered established.	Up to 60 minutes
Postoperative coagulation index	Routine postoperative monitoring indicators	Within 24 hours after operation
Postoperative hospital stay	The number of days from the end of surgery to discharge displayed in the electronic medical record system for patients	Through study completion, an average of 1 year
Total hospital stay	The number of days from admission to discharge displayed in the electronic medical record system for patients.	Through study completion, an average of 1 year
Costs of using active warming		Perioperative period
Postoperative hospital costs	The Postoperative hospital cost (￥) from the end of surgery to discharge displayed in the electronic medical record system	Through study completion, an average of 1 year
Total hospital costs	The Total hospital cost (￥) from admission to discharge displayed in the electronic medical record system	Through study completion, an average of 1 year
30-day postoperative readmission	Routine postoperative monitoring indicators	30 days after operation
30-day postoperative complications	Routine postoperative monitoring indicators	30 days after operation
30-day postoperative mortality	Routine postoperative monitoring indicators	30 days after operation
Heart rate	Obtained from multi parameter monitor	Perioperative period
Blood pressure	Obtained from multi parameter monitor	Perioperative period
Blood oxygen saturation	Obtained from multi parameter monitor	Perioperative period

Collaborators and Investigators

• Sponsor: First Affiliated Hospital of Chongqing Medical University
• Collaborators: SHENZHEN REFRESH BIOSENSINGTECHNOLOGY CO.. LTD.

Study record dates

Study Major Dates

• Study Start (Actual): March 11, 2025
• Primary Completion (Actual): December 15, 2025
• Study Completion (Actual): January 14, 2026

Study Registration Dates

• First Submitted: October 31, 2024
• First Submitted That Met QC Criteria: November 5, 2024
• First Posted (Actual): November 6, 2024

Study Record Updates

• Last Update Posted (Estimated): January 16, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Elderly patients; Machine Learning; Prediction model; Active warming; Intraoperative hypothermia
• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: ZZ2024-173-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

Data Data available: Yes Data types: Identified participant data How to access data: atpcr7@yeah.net When available: Within 5years after this trial

Supporting Documents Document types: None

Additional Information Who can access the data: Researchers whose proposed use of the data have been approved by Leader Sponsor and Principal Investigator of this trial.

Types of analyses: To be discussed with the steering committee. Mechanisms of data availability: With investigator support after approval signed data access agreement.

Any additional restrictions: None

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No