风湿性心脏病二尖瓣置换术前补充甲状腺激素改善正常甲状腺病态综合征研究

目的:观察风心病二尖瓣置换术前补充小剂量甲状腺激素对患者围手术期甲状腺激素水平及心功能的影响。方法:选择拟在体外循环(CPB)下实施二尖瓣置换术的风心病患者36例,随机分为对照组和实验组。实验组于术前7 d,每天按0.5 mg/kg口服甲状腺素片。分别于入院后第1天(t1)、麻醉诱导前(t2)、升主动脉开放前(t3)、术后第1天(t4)、第4天(t5)、第7天(t6)抽取静脉血样,测定总三碘甲状腺原氨酸(T3)、游离三碘甲状腺原氨酸(FT3)、总甲状腺素(T4)、游离甲状腺素(FT4)和促甲状腺素(TSH)的浓度;术后24 h抽取静脉血测定肌酸激酶同工酶(CK-MB)和肌钙蛋白Ⅰ(TnⅠ);同时观察患者的MAP、HR、CVP以及围手术期正性肌力药物的使用情况。结果:t1时两组患者仅FT3和T3同t2时相比均明显降低(P<0.05);CPB后两组患者T3、FT3、T4、FT4同t2时相比均明显降低(P<0.05);同对照组相比,实验组患者t3、t4和t5的FT3和T3明显增高,T4于t2和t3明显增高,FT4只于t2明显增高(P<0.05);两组TSH均无显著性差异。实验组患者的血清CK-MB含量和TnⅠ阳性率均明显低于对照组(P<0.05)。两组各时间点MAP、CVP、HR无显著性差异,但在CPB后至术后第4天,实验组血管活性药物用量明显少于对照组。结论:风心病患者在体外循环(CPB)下行二尖瓣置换术,围手术期会发生正常甲状腺病态综合征(ESS),而手术前补充小剂量甲状腺激素可减轻围手术期的ESS,改善心功能,明显减少正性肌力药物的使用,有一定的心肌保护作用。

Study on the Improvement of Euthyroid Sick Syndrome by Thyroxine Supplement before Mitral Valve Replacement in Patients with Rheumatic Heart Disease

Objective To investigate the effects of preoperative supplement of thyroxine on the thyroid hormone level and heart function during the perioperative period in rheumatic heart disease(RHD) patients underwent mitral valve replacement.Methods Total 36 RHD patients underwent mitral valve replacement under extracorporeal circulation were randomly divided into control group and experimental group.The experimental group were given thyroxine tablets with dose of 0.5 mg/kg daily for 7 days postoperation.The serum levels of T3,FT3,T4,FT4 and TSH were measured at first day in hospital(t1),before anesthesia induction(t2),before AAO liberalization(t3),the first day postoperation(t4),4th day(t5) and 7th day(t6),respectively.The serum levels of CK-MB and TnI were measured at 24h postoperation.The MAP,HR,CVP and the application of inotropic agent during the operation were also recorded.Results The levels of FT3 and T3 in both group at t1 were significantly lower than those at t2(P<0.05).The levels of T3,FT3,T3,FT4 at t1 in both groups were significantly lower than those at t2 after CPB(P<0.05).Compared with control group,the levels of FT3 and T3 in exprimental group significantly increased at t3,t4 and t5,and the levels of T4 was significantly increased at t2 and t3,and FT4 increased at t2.There was no significant difference in TSH level between two groups.Compared with control group,CK-MB content and TnI positive rate in exprimental group were significantly lower in experimental group(P<0.05).There was no significant defference in MAP,CVP and HR between two groups.From post CPB to the postoperative 4th day,the inotropic agent during the perioperative period in exprimental group was less than that in control group.Conclusion The preoperative supplement of thyroxine could relief the euthyroid sick syndrome(ESS) during perioperative period in RHD patients underwent mitral valve replacement,improve the heart function,decrease the dosage of inotropic agent and preserve myocardium.