心脏局部低温在瓣膜置换心肌保护中的作用探讨

目的：探讨体外循环心直视下心脏瓣膜置换术中心脏局部低温的心肌保护作用。方法80例瓣膜置换的患者按手术类型分层，按随机数字表法分为对照组和试验组。对照组在体外循环心内直视瓣膜手术中心表面放置冰泥予局部降温，试验组则心表面不放置冰泥。用自动生化分析仪分别测定两组患者术前5 min（ T0），主动脉钳开放后5 min（ T1）、6 h（ T2）、24 h（ T3）时点血液肌酸激酶同工酶（ CK-MB）值，观察两组患者在心脏自动复跳率、血管活性药物用量、左侧胸腔渗液、肺不张、膈肌抬升数等方面的差异。结果两组各时点CK-MB差异有统计学意义，双瓣手术后CK-MB变化幅度大于单瓣手术（ P＜0.05）。两组间CK-MB变化差异无统计学意义（ P＞0.05）。两组术后均未见明显心功能不全，无死亡病例。与对照组比较，试验组术后心脏自动复跳率更高，而胸腔积液、肺不张等肺部并发症以及膈肌抬高发生率更低（ P＜0.05）。结论在体外循环心脏停跳心脏瓣膜置换手术中，心表面置冰并不能提供额外心肌保护，反而显著提高了肺部并发症率。

The myocardial protection role of topical hypothermia in heart valve replacement surgery

Objective To investigate the myocardial protection effect of topical ice slush in heart valve replacement during ex -tracorporeal circulation .Methods Eighty patients undergoing heart valve replacement were enrolled in the study .They were randomly divided into experimental and the control group by using stratified random sampling method according to operation types .In the control group,the heart was embedded in topical cooling with ice slush during the surgery .In the experimental group ,topical hypothermia was not used.The CK-MB was measured 5 minute before releasing aortic cross-clamp （T0）,and 5 minute （T1）,6 hour （T2） and 24 hour （T3） after releasing aortic cross-clamp in the both groups.Meanwhile,the heart beat recovery,vascular active drug dosage,left pleural effusion,atelectasis and number of diaphragmatic paralysis were observed .Results The value of CK-MB was increased significantly af-ter operation in the two groups compared to T 0（P〈0.05）.The value of CK-MB was greater after double valve replacement when com-pared with single valve replacement （ P〈0.05 ） .There was no significant difference in the increasing trend of CK-MB between the two groups .No significant cardiac dysfunctions and no deaths appeared in the two groups .Compared with the control group ,the experimental group had highly automatic cardiac rebeating rate and significantly decreased the incidence of pulmonary complications and diaphrag -matic elevation .Conclusion Topical ice slush did not offer any additional cardiac protective benefit in heart valve replacement during cardiac arrest but significantly increased the incidence of pulmonary complications .