Abstract: PURPOSE: To evaluate the relationship between body mass index(BMI) and body temperature in patients undergoing combined radical neck dissection and evaluate the effect of different thermal preservation measures. METHODS: Sixty patients who underwent combined radical neck dissection and surgery in our hospital were enrolled in this study according to stratified sampling method. The patients were divided into 3 groups(n=20), i.e. normal weight (group N, BMI 18.5-22.9 kg/m²); over obesity (group O,BMI 23-24.9 kg/m²), and mild obesity (group L, BMI 25.0-29.9 kg/m²). Nasopharyngeal temperature of all patients was monitored immediately, 10 min (T1), 30 min (T2), 60 min (T3), 90 min (T4) and 120 min (T5) after tracheal intubation. Another 40 patients with BMI of 18.5-22.9 kg/m² were randomly divide into warm liquid instrument group ( group NA, n=20) and warm liquid instrument combined with constant temperature blanket group (group NB, n=20). Temperature data were collected in the same way. The data were analyzed with SPSS 20.0 software package. RESULTS: Compared with the same time point between the groups with different BMI values: the temperature of group N and group O showed significant difference only at T4 and T5 (P<0.05). There was significant difference in body temperature between group N and group L at T2-T5 (P<0.05). Difference in temperature was not statistically significant at each time point between group O and group L (P>0.05). Intra-group comparison: temperature at T1 and T3, T4 and T5 was significantly different in group N (P<0.05); temperature at T2 was significantly different between T4 and T5 (P<0.05); the difference between T3 and T4 was statistically significant. In group O: there was significant difference at T1, T4 and T5. In group L: no significant difference was found at each time point. At the same time point, temperature in group NA and group NB was significantly higher at T3, T4 and T5 (P<0.05). In the group NA , there was significant difference between T1 and T4 (P<0.05); hypothermia at T2 and T5 (P<0.05); there was no significant difference in temperature change between T3 and T5 (P>0.05), there was no significant difference in temperature at each time point in group NB. CONCLUSINS: Patients with high BMI are more likely to maintain stable body temperature during combined radical neck dissection under the same condition. Warm liquid instrument has exact effect on heat preservation, but the effect of warm liquid instrument combined with thermostatic blanket is better.

Key words: Body mass index, Low body temperature, Combined radical neck dissection