Risk Factors And Establishment Of A Prediction Model For Postoperative Hypothermia In The Post-anesthetic Care Unit Of Patients Underwent General Anesthesia:A Single-center,Retrospective Study

Background:Body temperature is one of the important conditions to maintain the homeostasis of the body and life activities.Under normal circumstances,the body through its own regulatory mechanism(the main regulatory site is located in the hypothalamus)surpport heat production and heat dissipation to achieve a dynamic balance,so that the body temperature can be kept relatively constant.If the heat production of the human body is greater than the heat dissipation,the body temperature will rise;if the heat dissipation is greater than the heat production,the body temperature will drop;and the body temperature will remain in a stable state until the heat production and the heat dissipation get a balance.Body core temperature < 36.0 ? is defined as hypothermia.Postoperative core hypothermia will prolong the action time of drugs,delay the recovery after anesthesia,and increase the incidence of perioperative complications.Although perioperative doctors have realized the harm of hypothermia,they still pay less attention to monitoring core body temperature in clinical practice.In 2015,Yi et al.reported that the incidence of intraoperative hypothermia was as high as 44.3%.With the standardization of perioperative temperature management furthering gradualy,there are few related studies to discuss whether the incidence of hypothermia in patients is further reduced.There are many factors that affect the incidence of hypothermia.According to the questionnaire survey conducted by Macario et al.in anesthesiologists and clinical researchers,the most likely risk factors for postoperative hypothermia include: age,indoor hypothermia,burn patients,preoperative hypothermia,thin patients and massive blood loss.Objective:To evaluate the incidence of hypothermia in the PACU patients after general anesthesia,analyze the related risk factors and initially establish an early warning scoring system.Methods:From July 2018 to October 2018,2683 surgical patients who underwent general anesthesia in Changhai Hospital Affiliated to Naval Medical University and entered thePACU after general anesthesia were selected as the study objects.The temperature of right tympanic membrane was measured by infrared ear temperature gun as a record of body temperature.According to the body temperature recorded immediately after the patient entering the PACU,the patients whose body temperature is less than 36.0? are included in the hypothermia group,and the patients whose body temperature is greater than or equal to 36.0 ? are included in the normal body temperature group.The incidence of hypothermia was compared among patients with different gender,age,body mass index(BMI),operation time,ASA classification,blood loss and transfusion volume.According to the ratio of risk factors,the early-warning scoring system of hypothermia in PACU after general anesthesia was established.Results:There were 377 cases of hypothermia in the PACU after general anesthesia,The incidence of hypothermia was 14.05%(377 / 2683).Logistic regression analysis showed that age ? 60 years old,BMI,infusion volume and ASA grade were independent risk factors of hypothermia.According to the ? score of each independent risk factor,the risk assessment and validation model of hypothermia in the PACU after general anesthesia was established.The area under the curve of the working characteristic curve was 0.683(95%confidence interval 0.654-0.711,P < 0.05).Conclusion:Age ? 60 years old,BMI,infusion volume and ASA grade were independent risk factors for hypothermia.The early warning scoring system constructed in this study has a high accuracy in predicting hypothermia in the PACU after general anesthesia,and is worth further study in clinical practice.