Objective To explore the influencing factors of postoperative hypothermia in patients treated with bone and joint replacement surgery, and construct a risk prediction model for postoperative hypothermia in these patients.

Methods A total of 300 patients treated with orthopedic joint replacement surgery were selected, and divided into the hypothermia group(81 cases) and non-hypothermia group(219 cases) according to the postoperative temperature.Univariate analysis and logistic regression analysis were used to analyze various risk factors, and a nomogram model for predicting postoperative hypothermia in bone and joint replacement patients was established.

Results The postoperative hypothermia in 81 patients(27.0%) were found.The results of univariate analysis showed that, compared to the non-hypothermia group, patients in the hypothermia group were older, lower body mass index (BMI), lower hemoglobin, more blood loss, longer anesthesia time, higher proportion of ASA grade Ⅲ, higher rate of intraoperative fluid volume < 2 000 mL, and higher rate of intraoperative blood transfusion, with statistical significance(P < 0.05 to P < 0.01).The results of multivariate logistic regression analysis showed that old age, low hemoglobin, high ASA grade, low BMI, low intraoperative fluid volume and intraoperative blood transfusion were the independent risk factors of postoperative hypothermia in bone and joint replacement patients(P < 0.05 to P < 0.01).A nomogram model was constructed.The area under the curve of the model was 0.791(95%CI: 0.731-0.851), the sensitivity was 82.7%, and the specificity was 76.5%.The H-L deviation test of the nomogram model before and after internal verification showed that the nomogram model fitted well(P>0.05).The Bootstrap method repeated sampling 1 000 times to verify the nomogram, which indicated that the nomogram model had a good calibration degree.

Conclusions Age, hemoglobin levels, ASA class, BMI, intraoperative fluid infusion, and intraoperative blood transfusion are the independent influencing factors of postoperative hypothermia in bone and joint replacement patients.The incidence of hypothermia after bone and joint replacement can be evaluated individually by using the nomogram, and then targeted measures are taken to protect high-risk patients with hypothermia to reduce the incidence of hypothermia.