探究术前甲状腺功能减退对中老年患者体外循环下心脏手术术后认知功能障碍（postoperative cognition dysfunction，POCD）的影响。
选取 2016 年 03 月至 2017 年 12 月期间在四川大学华西医院拟行体外循环下心脏瓣膜置换术年龄≥50 岁的患者，根据促甲状腺激素（thyroid stimulating hormone，TSH），游离三碘甲状腺原氨酸（free triiodothyronine 3，FT3）及游离四碘甲状腺原氨酸（free triiodothyronine 4，FT4）水平分为 Hypo 组［甲状腺功能减退组（TSH>4.2 mU/L 或 FT3<3.60 pmol/L 或 FT4<12.0 pmol/L）］和 Eu 组［甲状腺功能正常组（TSH，FT3 及 FT4 均在正常参考值范围内）］。术前 1 d 及术后 7 d 由一名固定的研究人员使用简易精神状态量表（mini-mental state examination，MMSE）及一系列认知功能量表对患者进行认知功能评估。主要指标为术后 7 d POCD 发生率，次要指标为各项单项认知功能测试中认知减退率及术前术后得分或所用时间。
无论用 MMSE 量表还是一系列认知功能量表评估认知功能，Hypo 组 POCD 发生率均高于 Eu 组。用 MMSE 量表评估认知功能时，差异有统计学意义（55.56% vs. 26.67%，P=0.014）, 用一系列认知功能量表评估认知功能时差异无统计学意义（55.56% vs. 44.44%，P>0.05）。在各个单项认知功能测试中，Hypo 组术后在反应语言储备量、流畅度、归类能力的言语流畅测试中认知减退率明显高于 Eu 组（48.15%vs. 20.00%，P=0.012），Hypo 组和 Eu 组在其他单项认知功能测试中认知减退率无明显差异；术前 Hypo 组和 Eu 组在各个单项认知功能测试中得分或使用时间无明显差异，术后 Hypo 组言语流畅测试得分明显低于 Eu 组（26.26±6.55 vs. 30.23±8.00，P=0.034），Hypo 组和 Eu 组术后在其他单项认知功能测试中得分或所用时间无明显差异。
术前合并甲状腺功能减退的中老年患者体外循环下心脏手术后 POCD 发生率较高，主要受影响的认知功能为语言储备量、流畅度、归类能力，提示术前甲状腺功能减退可能与该类人群 POCD 的发生密切相关。
To explore the effect of preoperative hypothyroidism on postoperative cognition dysfunction (POCD) in elderly patients after on-pump cardiac surgery.
Patients who were no younger than 50 years and scheduled to have on-pump cardiac surgeries were selected in West China Hospital from March 2016 to December 2017. Based on hormone levels, patients were divided into two groups: a hypo group (hypothyroidism group, TSH >4.2 mU/L or FT3 <3.60 pmol/L or FT4 <12.0 pmol/L) and an Eu group (euthyroidism group, normal TSH, FT3 and FT4). The mini-mental State Exam (MMSE) test and a battery of neuropsychological tests were used by a fixed researcher to assess cognitive function on 1 day before operation and 7 days after operation. Primer outcome was the incidence of POCD. Secondary outcomes were the incidence of cognitive degradation, scores or time cost in every aspect of cognitive function.
No matter cognitive function was assessed by MMSE or a battery of neuropsychological tests, the incidence of POCD in Hypo group was higher than Eu group. The statistical significance existed when using MMSE (55.56% vs. 26.67%, P=0.014) but was absent when using a battery of neuropsychological tests (55.56% vs. 44.44%, P>0.05). The incidence of cognitive deterioration in Hypo group was higher than that in the Eu group in Verbal Fluency Test z(48.15%vs. 20.00%, P=0.012). The difference of cognitive deterioration incidence between the Hypo group and the Eu group was not statistically different in the other aspects of cognitive function. There was no statistical difference about scores or time cost between the Hypo group and the Eu group in all the aspects of cognitive function before surgery. After surgery, the difference of scores between the Hypo group and the Eu group was statistically different in Verbal Fluency Test(26.26±6.55 vs. S 30.23±8.00, P=0.034)while was not statistically significant in other aspects of cognitive function.
The incidence of POCD is high in elderly patients complicated with hypothyroidism after on-pump cardiac surgery and words reserve, fluency and classification of cognitive function is significantly impacted by hypothyroidism over than other domains, which indicates hypothyroidism may have close relationship with POCD in this kind of patients.
Postoperative cognition dysfunction;