Systemic Prevention and Management for Perioperative Hypothermia and Its Effect on Patients Outcome

Establishment of Systemic Prevention and Management for Perioperative Hypothermia and Its Effect on Patients Outcome-a Prospective Multiple Centers Randomized Controlled Study

This is a randomized, single-blinded, multi-center study clinical trial to determine both clinical and health outcomes of stratified warm strategy to prevent intraoperative hypothermia. Participants enrolled into this trial will be from elective major surgery population in PUMC Hospital, Beijing Hospital and Xuanwu Hospital. investigators plan to enroll approximately 800 participants. Hypothermia risk will be evaluated through PREDICTOR model in all participants. According to hypothermia risk level, these participants will be stratefied into high, moderate and low risk group. Participants in each group will be randomly categorize into warm group and control group. Active warm and fluid warm strategy, prewarm and fluid warm strategy and only prewarm strategy are used for high risk, moderate risk and low risk patients seperately. For controll group traditional passive warm was used.

Cotton Blanket Warming (CBW) starts 30 min preoperatively and then continues throughout the entire operation.

Warm according to different hypothermia risk for low risk ---Forced-air warming(FAW) starts at least 30 min preoperatively and then Cotton Blanket Warming (CBW) continues throughout the entire operation. moderate risk---Forced-air warming(FAW) starts at least 30 min preoperatively and then Cotton Blanket Warming (CBW) and fluid warming continues throughout the entire operation. high risk ----Forced-air warming(FAW) starts at least 30 min preoperatively, FAW and fluid warming continues throughout the entire operation.

Bair HuggerTM Forced-air Warming System to 30min pre- and entire operation warming, combined fluid warming

30 min prewarming The Bair HuggerTM Forced-air Warming System cotton blanket warming and fluid warming through operation

30 min prewarming The Bair HuggerTM Forced-air Warming System and cotton blanket warming through operation

It's a scare to evaluate cognitive function. Total score is 30 . Higher values represent a better cognitive function.

The digit symbol substitution test is an evaluation tool used to assess cognitive functioning. It initially was part of the Wechsler Adult Intelligence Test (WAIS), a well-known test that measures an individual's attention. lower digit symbol test scores were correlated with a higher risk of developing dementia in both the five and 10 year groups.Higher values represent a better cognitive function.

a memory test that involves learning verbal material, usually single words presented in a list, that is continually presented over repeated trials. Higher values represent a better memory functions.

The Stroop Colour and Word Test (SCWT) is a neuropsychological test extensively used to assess the ability to inhibit cognitive interference that occurs when the processing of a specific stimulus feature impedes the simultaneous processing of a second stimulus attribute, well-known as the Stroop Effect. Higher values represent a better ability to inhibit cognitive interference.

a memory test that involves remember a series of numbers test short time memory Higher values represent a better memory functions.

Z score=（postoperative score-preoperative core）/SD of non-surgical group Two or more than two item in cognitive examination Z score<-1.96 Z score=（postoperative score-preoperative core）/SD of non-surgical group Two or more than two item in cognitive examination Z score<-1.96

Inclusion Criteria: Age≥18 Core temperature preoperation ≥36.0 ℃ and ≤37.5℃ ASA I-III Informed consent Exclusion Criteria: emergency operation uncontrolled diebete mellitus with insulin treatment （preoperative blood glucose>250mg/dL） hyperthyroidism and hypothyroidism Raynaud's disease patients with hematopathy and immune disease anticoagulant and non-steroid anti-inflammatory drug intake with 14 days before operation infectious fever within 4 weeks before operation laboratory abnomality as follow Hemoglobin≤10.0g/L Platelet≤100,000/ml White blood cell<3000/dl or>14,000/dl Fibrinogen<200mg/dL Thrombin time>40 second International normalized ratio<70%

Yi J, Xiang Z, Deng X, Fan T, Fu R, Geng W, Guo R, He N, Li C, Li L, Li M, Li T, Tian M, Wang G, Wang L, Wang T, Wu A, Wu D, Xue X, Xu M, Yang X, Yang Z, Yuan J, Zhao Q, Zhou G, Zuo M, Pan S, Zhan L, Yao M, Huang Y. Incidence of Inadvertent Intraoperative Hypothermia and Its Risk Factors in Patients Undergoing General Anesthesia in Beijing: A Prospective Regional Survey. PLoS One. 2015 Sep 11;10(9):e0136136. doi: 10.1371/journal.pone.0136136. eCollection 2015.

Yi J, Zhan L, Lei Y, Xu S, Si Y, Li S, Xia Z, Shi Y, Gu X, Yu J, Xu G, Gu E, Yu Y, Chen Y, Jia H, Wang Y, Wang X, Chai X, Jin X, Chen J, Xu M, Xiong J, Wang G, Lu K, Yu W, Lei W, Qin Z, Xiang J, Li L, Yao M, Huang Y. Establishment and Validation of a Prediction Equation to Estimate Risk of Intraoperative Hypothermia in Patients Receiving General Anesthesia. Sci Rep. 2017 Oct 24;7(1):13927. doi: 10.1038/s41598-017-12997-x.

Yi J, Lei Y, Xu S, Si Y, Li S, Xia Z, Shi Y, Gu X, Yu J, Xu G, Gu E, Yu Y, Chen Y, Jia H, Wang Y, Wang X, Chai X, Jin X, Chen J, Xu M, Xiong J, Wang G, Lu K, Yu W, Lei W, Qin Z, Xiang J, Li L, Xiang Z, Pan S, Zhan L, Qiu K, Yao M, Huang Y. Intraoperative hypothermia and its clinical outcomes in patients undergoing general anesthesia: National study in China. PLoS One. 2017 Jun 8;12(6):e0177221. doi: 10.1371/journal.pone.0177221. eCollection 2017.