浅低温降低流量体外循环在心脏不停跳直视手术中血液保护的探讨

Investigating on the blood conservation in beating heart surgery with mild hypothermia and low flow cardiopulmonary bypass

目的探讨浅低温降低流量体外循环在心脏不停跳直视手术中血液保护的作用。方法选择30例符合条件的心脏不停跳二尖瓣置换手术患者,根据体外循环温度及流量控制的不同分成两组。实验组:浅低温(鼻温30～32℃),降低流量2.0～2.2 L/(min·m^2);对照组:采用传统的不停跳体外循环方式[鼻温(33～35℃),流量2.6～3.2 L/(min·m^2)]。抽取颈静脉血检测转机前及转机后20、40、60 min血浆游离血红蛋白(FHb)含量。结果实验组转机20、40、60 min FHb数值(mg/L)分别为(243.73±104.52)、(342.33±115.78)和(386.13±122.79),而对照组数值分别为(513.60±213.47)、(607.53±291.93)和(742.80±282.74)。两组各时间点对照分析比较,差异有统计学意义(P<0.01)。结论浅低温降低流量体外循环在心脏不停跳直视手术中血液破坏较传统不停跳体外循环方式小,具有血液保护的作用。

Objective To explore the role of blood conservation of mild hypothermia and low flow cardiopul- monary bypass（CPB） in beating heart surgery under direct vision. Methods Thirty patients who were eligible for beating heart mitral valve replacement surgery, according to different CPB temperature and flow, were randomly di- vided into two groups ： experimental group ： mild hypothermia （ nasal temperature 30 - 32 ℃ ）, reducing the flow rate 2. 0 -2. 2 L/（ min·m2） ; control group：the traditional beating CPB （nasal temperature 33 -35 ℃ ）, flow rate 2. 6 3.2 L/（ min·m2 ）. Jugular venous blood was taken to check the plasma free hemoglobin content before CPB and at 20, 40, 60 min after CPB. Results At 20 min, 40 min, 60 min after CPB, the plasma free hemoglobin values （ mg/ L） in the experimental group was （243.73 ± 104. 52）, （342.33 ± 115.78）, （386. 13 ± 122. 79） while （513.60 ± 213.47）, （607.53 ±291.93）, （742. 80 ± 282. 74） in control group. The plasma free hemoglobin values between two groups at each time point were compared, and the difference was statistically significant. Conclusion Mild hypo- thermia and low flow CPB in the heating heart surgery under direct vision has the role of blood conservation.