高热大鼠用冷致不同程度寒战对体温及生化指标影响的实验研究

Influence of different degrees of shivering induced by ice pack therapy on temperature and biological test results of febrile rats

目的探讨高热大鼠用冷发生不同程度寒战对其体温及生化指标的影响。方法选取健康雄性SD大鼠76只,随机分为4组,每组19只。采用20%干酵母混悬液复制高热大鼠模型,成功后分别使用10mL、20mL、40mL清水冰袋对各组大鼠用冷30min,对照组不用冷,构建无寒战、轻度寒战、重度寒战大鼠模型。每组随机选取10只大鼠监测降温后0、15、30、45、60、75、90、120、180、240、300、360min的肛温,采用重复测量方差分析比较各组大鼠体温差异;每组中另9只大鼠,于用冷结束时采集血标本检测生化指标并分析各组差异。结果与对照组比较,无寒战大鼠在用冷结束后75min内体温显著降低;发生轻度寒战大鼠用冷结束后45min内体温显著降低;发生重度寒战大鼠用冷结束后30min内体温显著降低(P<0.05,P<0.01)。各组大鼠用冷结束时生化指标差异无统计学意义(均P>0.05)。结论寒战对高热大鼠降温效果有影响,且寒战程度越重,对降温效果影响越大,并呈现一定等级效应关系。冰袋物理降温过程中寒战的发生会降低冷疗效果,寒战产热会加快体温上升。因此,冷疗过程中应避免寒战发生,尤其防止重度寒战的发生。若发生寒战应立即采取措施使其停止。

Objective To explore the influence of different degrees of shivering induced by ice pack therapy on temperature and biolo- gical test results of febrile rats. Methods A total of 76 healthy male SD rats were randomly and evenly divided into 4 groups （n： 19）. Then pyrexia was induced by 20% dry yeast in all rats. Three groups of febrile rats were subjected to 10 ml., 20mL, 40mL ice pack therapy for 30 minutes to built non-shivering, mild shivering, severe shivering model. The control group received no cooling treatment at all. Ten rats in each group were randomly selected for the observation of temperature on 0,15,30,45,60,75,90,120, 180,240,300 and 360 minutes after intervention. ANOVA for repeated measurement was used to compare temperature differences among the groups. The other 9 rats in each group were used for blood drawing when the ice packs were removed to test biochemical indexes, with which group difference was compared. Results Compared with the control group, the temperature decreased signifi eantly within 75 minutes for non shivering rats,within 45 minutes for mild shivering rats, and within 30 minutes for severe shive- ring rats,after ice pack removal（P〈0.05 ,P〉0.01）. There was no significant difference in the level of biochemical indexes among the groups （P〈0.05 for all）. Conclusion Shivering can jeopardize the effect of ice pack therapy for febrile rats; the more severe shivering, the less effect, indicating a degree-effect relationship. Shivering thermogenesis can speed up the body temperature rises, which counteracts the antipyretic effect of ice pack therapy. Measures should be taken to avoid occurrence of shivering, especially severe shivering, during the process of cooling therapy.