改良白细胞滤器对体外循环模型犬肺保护的实验研究

目的 观察犬体外循环（CPB）管路静脉端使用改良白细胞滤器（LD-1）进行短时间白细胞滤过对犬肺的保护作用。方法 16只健康杂种犬建立CPB模型后，随机分为LD-1组和对照组。LD-1组在CPB管路的静脉端安装LD-1，CPB初期开放白细胞滤器5min。对照组无LD-1。于CPB前、CPB5、10、40、70min、主动脉开放5min、停机、鱼精蛋白中和后5min、停CPB 2h 9个时点测血常规。于CPB前、鱼精蛋白中和后5min、停CPB 2h检测氧合指数、肺组织的病理变化和血浆中IL-6、IL-8的水平。于停CPB 2h检测肺泡灌洗液（BALF）中IL-6、IL-8的水平。结果 LD-1组白细胞计数在CPB 5min明显低于对照组，差异有统计学意义（P＜0．05），但从CPB 40min至停CPB 2h各时点两组间差异均无统计学意义（P＞0．05）。鱼精蛋白中和后5min、停CPB 2h氧和指数LD-1组明显高于对照组，差异有统计学意义（P＜0．05）；LD-1组肺组织白细胞浸润和肺泡壁水肿明显轻于对照组。鱼精蛋白中和后5min两组血浆IL-6和IL-8的水平差异无统计学意义（P＞0．05）；停CPB 2h LD-1组明显低于对照组，差异有统计学意义（P＜ 0．05）。停CPB2h两组BALF中IL-6水平差异无统计学意义（P＞0．05）；而LD-1组IL-8水平低于对照组（P＜0．05）。结论 在犬CPB管路静脉端使用改良LD-1进行短时间白细胞滤过，能明显减少循环中自细胞的数目，减少血浆中IL-6、IL-8的水平，减轻CPB后肺部的炎性反应，对犬肺有保护作用。

The Pulmonary Protective Effects of Leukocyte Depletion with a Modified Filter Located at the Cardiopulmonary Bypass (CPB) Venous Line in Canine

OBJECTIVE: To investigate the pulmonary protective effects of short-term leukocyte depletion with a modified filter located at the CPB venous line in canine. METHODS: Sixteen healthy hybrid canines were randomly allocated to the LD-1 group, with an LD-1 filter installed in the CPB venous-line for a 5-minute leukocyte depletion at the beginning of the CPB, and to the control group. Blood samples were taken for routine test respectively at 9 time-points, namely pre-CPB, at 5, 10, 40, 70 min of the CPB, 5 min after aortic cross-clamp being off, at the discontinuation of the CPB, 5 min after protamine being administered, and 2 h after the CPB. Oxygen index (OI), pulmonary pathology and levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in plasma were measured at pre-CPB, 5 min after protamine being administered and 2 h after the CPB respectively. The levels of IL-6 and IL-8 in the bronchial alveolar lavage fluid (BALF) were measured at 2 h after the CPB. RESULTS; In LD-1 group, white blood cell (WBC) counts were significantly less than those in control group at 5 min of the CPB (P < 0.05), the filtration rate of WBC was (65.72 +/- 9.36)%. The WBC counts showed no significant difference in either group from 40 min of the CPB to 2 h after the CPB. OI was higher in LD-1 group than that in control group (P < 0.05) at 5 min after protamine being administered and 2 h after the CPB. There was significantly less WBC infiltration and alveolar edema of the lung in LD-1 group than that in control group at 5 min after protamine being administered and 2 h after the CPB. There were no significant differences of IL-6 and IL-8 in plasma between the two groups at 5 min after protamine being administered (P > 0.05), but the levels of IL-6 and IL-8 were much lower in the LD-1 group than those in the control group at 2 h after CPB. At 2 h after the CPB, IL-6 level in the BALF showed no significant difference in each group (P > 0.05); however, the level of IL-8 was lower in LD-1 group than that in control group (P < 0.05). CONCLUSION: The LD-1 filter in the CPB venous-line in canine model used for short-term leukocyte depletion filtration could reduce WBC counts significantly, decrease the levels of IL-6 and IL-8 in plasma, attenuate inflammatory response in the lung after CPB, so it has protective effect on canine lung.