心内直视手术对甲状腺激素代谢的影响及其临床意义

为了解体外循环心脏直视手术对甲状腺激素代谢的影响并探讨其临床意义。作者选择２１例心脏直视手术病人，用放免法分别于术前、术中、术后２、２４小时测定其血浆Ｔ３、Ｔ４、游离Ｔ３（ＦＴ３）、游离Ｔ４（ＦＴ４）、反Ｔ３（ｒＴ３）及促甲状腺激素ＴＳＨ的含量。结果发现Ｔ４、ＦＴ４术中降低，术后２小时恢复正常（Ｐ＜０．０５）。Ｔ３、ＦＴ３呈下降趋势，术后２４小时降至最低（Ｐ＜０．０１）。ｒＴ３进行性升高。ＴＳＨ术中一过性升高。结论：甲状腺激素在ＣＰＢ时变化为术中低Ｔ３、Ｔ４综合征，术后为低Ｔ３综合征。提示ＣＰＢ后Ｔ３补充治疗有利于病人康复及某些术后难治性心功能不全的处理。

Effect of Open Heart Surgery Under Cardiopulmonary Bypass on Thyroid Hormones

Aim:The purpose of this prospective study was to determine the effect of cardiopulmonary bypass(CPB) on the concentrations of thyroid hormones Method:Blood samples were obtained from 21 patients at the following intervals:(1)before operation;(2)10 minutes after administration of heparin (Hep);(3)at the lowest point of hypothermia (Hypo);(4)5 minutes after the aortic declamping(5)at the end of operation;(6)2 hours after operation;(7)24 hours after operation.The thyroid-stimulating hormone(THS), total thyroxine (T4),total triiodothyronine(T3), free thyroxine (FT4),free triiodothyronine (FT3)(an active metabolite of thyroid) and reverse T3 (rT3) were measured by radioimmunoassay. Results: The results showed significant decline of T3 and FT3(P<0.01) during and after CPB and of FT4 (P<0.01) during CPB but a returnto normal at the end of operation. A significant rise of rT3 was demonstrated at 24 hours after operation. TSH showed slight rise during CPB and returned to normal range with the return of FT4 content.Conclusion:The results indicate that CPB resulted in "low T3,T4 syndrome" during operation and "low T3 syndrome"after operation.These changes correlated with the severity of the illness and prognosis.It is suggested that T3 supplement therapy may be beneficial to the management of heart dysfunction refractory to conventional treatment.