小儿低温体外循环围术期甲状腺功能的变化

The Changes of Thyroid Hormones After Cardiopulmonary Bypass in Children

目的 :探讨先天性心脏病 (先心病 )患儿在围体外循环 (CPB)期甲状腺激素的动态变化与临床意义。方法 :用放射免疫法测定 3 1例先心病 CPB手术 (I组 )围术期的血清甲状腺素水平 ,并与9例普通胸科手术者 ( 组 )作对照。结果 :I组术后即刻出现低 T3、T4,并逐渐加重 ,持续 3～ 5 d后 ,恢复至术前水平 ; 组手术前后甲状腺素水平对比差异无显著意义 (P>0 .0 5 )。 I组术后 FT3水平≤正常值低限者需要机械通气、吸氧、IUC时间及总住院日数均较 >正常低限值者显著延长(P<0 .0 5 )。未发现年龄、体重、CPB时间、病种对 FT3降低幅度有明显影响。结论 :先心病术后发生的一过性低 T3、T4综合征与 CPB有关 ,与术后心肺功能有一定关系 ,与病种、年龄、体重、CPB时间无关。

Objective:To study the changes and clinical significance of thyroid hormones after cardiopulmonary bypass(CPB) in children.Methods:The plasma concentration of thyroid hormones was measured in 31 children(group I) before and after cardiac surgery,and compared with that in 9 patients(group Ⅱ) undergoing thoracic surgery.Results:In group I at postoperation ,the plasma concentrations of TT3,FT3,TT4,FT4,TSH were strikingly low;while in group Ⅱ,there were no signi ficant changes in postoperative plasma concentrations of thyroid hormones.The duration of mechanical ventilation and ICU treatment was significantly prolonged in patients with low FT3.The type of diseases ,age,body weight and duration of CPB had no significant impact on the FT3 reduction.Conclusion:The transient secondary hypothyroidism in children undergoing CPB may contribute to the postoperative cardiac and respiratory dysfunction.