浅低温体外循环心脏不停跳瓣膜置换的肺保护

背景：浅低温体外循环心脏不停跳治疗可能减轻心内直视手术后肺损伤，但进一步的作用机制尚未明确。目的：探讨浅低温体外循环心脏不停跳下二尖瓣置换术肺保护效果。方法：纳入二尖瓣置换患者40例，随机数字表法均分为实验组与对照组，实验组采用浅低温体外循环心脏不停跳治疗，对照组采用中低温心脏停跳体外循环治疗。分别于置换开始和体外循环后30 min两个时点收集支气管肺泡灌洗液，检测肿瘤坏死因子α、白细胞介素8、髓过氧化物酶水平；体外循环前及体外循环后30 min分别取左右心房血测定中性粒细胞并计算跨肺差值；体外循环前、停机时、停机后1，8 h查动脉血气分析，计算呼吸指数。结果与结论：①两组支气管肺泡灌洗液中肿瘤坏死因子α、白细胞介素8、髓过氧化物酶水平及中性粒细胞跨肺差值在体外循环后30 min明显升高(P < 0.01)，但实验组明显低于对照组(P < 0.05)。②两组呼吸指数在体外循环停机时、停机后1，     8 h各时点升高(P < 0.05)，但实验组升高明显低于对照组(P < 0.05)。提示浅低温体外循环心脏不停跳能减轻二尖瓣置后的肺损伤，有较好的肺保护效果。

Lung protection of mitral valve replacement operation on beating-heart with mild hypothermic cardiopulmonary bypass

BACKGROUND:The treatment of beating-heart with mild hypothermic cardiopulmonary bypass (CPB) may lessen lung injury after intracardiac operation underdirects vision, but mechanism of action remains unclear.OBJECTIVE:To evaluate the lung protection of mitral valve replacement operation on beating-heart with mild hypothermic CPB. METHODS:A total of 40 patients underwent mitral valve replacements which were randomly divided into experimental group and control group. Patients in the experimental group were performed operation on beating-heart with mild hypothermic CPB, while patients in the control group received operation on arrested heart with moderate hypothermia CPB. Bronchoalveolar lavage fluid (BALF) was collected at 30 minutes (two time points) replacement started and after CPB. The levels of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8) and myeloperoxidase (MPO) in BALF were measured. Neutrophil was measured by left and right atrial blood respectively before CPB and 30 minutes after CPB, and then the transpulmonary polymorphonuclear was calculated. Respiratory index (RI) was calculated before CPB, at the end of CPB, 1 hour and 8 hours after CPB. RESULTS AND CONCLUSION:The levels of TNF-α, IL-8, MPO in BALF and transpulmonary polymorphonuclear in blood at 30 minutes after CPB were significantly increased in experimental group and control group (P < 0.01). But levels of those in the experimental group were lower significantly than that in the control group (P  < 0.05). The levels of RI at the end of CPB, 1 hour and 8 hours after CPB were significantly increased in two groups (P < 0.05), but the level in the experimental group was lower significantly than that in the control group (P  < 0.05). It is indicated that mitral valve replacement operating on beating-heart with mild hypothermic CPB can lighten lung injury and has a better effect on lung protection.