Van Raemdonck D E, Jannis N C, Rega F R, De Leyn P R, Flameng W J, Lerut T E
Center for Experimental Surgery and Anaesthesiology, Katholieke Universiteit Leuven, Belgium.
Ann Thorac Surg. 1996 Aug;62(2):331-7.
If lungs could be retrieved for transplantation after circulatory arrest, the shortage of donors might be significantly alleviated. However, in such non-heart-beating donors, there is great concern that even a short period of warm ischemia will be deleterious for lung tissue, jeopardizing the transplant recipient. It was the purpose of this study to look for the efficacy of different methods of lung cooling inside a cadaver after circulatory arrest.
New Zealand white rabbits were sacrificed with an intravenous overdose of pentobarbital and left at room temperature. Subcutaneous, rectal, lung core, lung surface, and endobronchial temperatures were measured at intervals after death. Cooling of the lung during ischemia differed between groups (n = 6 in each group): lungs left deflated at room temperature (24 degrees C) (group 1 = control non-heart-beating donors), lungs ventilated with cooled (4 degrees C) room air (group 2), lungs left deflated plus topical cooling (1 degree C) of both the cadaver and its lungs (group 3), and lungs flushed in situ immediately after circulatory arrest with a cold (4 degrees C) crystalloid solution followed by ex vivo deflated storage in cold (1 degree C) saline solution (group 4 = control heart-beating donors).
There was a slow decline in lung core, lung surface, and endobronchial temperatures toward room temperature in group 1 (1.5 degrees +/- 0.0 degree C/h, 1.8 degrees +/- 0.2 degree C/h, and 1.9 degrees +/- 0.1 degree C/h, respectively). In contrast, all three lung temperatures immediately ( < 5 minutes) dropped to less than 10 degrees C in group 4. Hypothermic ventilation (group 2) decreased endobronchial temperature (p < 0.05 at 30 minutes) but not lung surface, rectal, or subcutaneous temperature when compared with group 1. Cooling rate for lung surface and endobronchial temperatures during the first 4 hours after death was faster (p < 0.01) in group 3 (6.6 degrees +/- 0.3 degree C/h and 6.1 degrees +/- 0.2 degree C/h, respectively) when compared with group 2 (2.5 degrees +/- 0.3 degree C/h and 3.9 degrees +/- 0.1 degree C/h, respectively), but slower (p < 0.001) when compared with group 4 (9.2 degrees +/- 0.1 degree C/h and 8.7 degrees +/- 0.1 degree C/h, respectively).
These data demonstrate that in the non-heart-beating donor, (1) in situ cold flush will result in immediate cooling of the lung, (2) ventilation with cooled air will only accelerate the decline in endobronchial temperature but has no effect on lung surface temperature, and (3) topical cooling of the cadaver is more efficacious in decreasing lung temperature than hypothermic ventilation.
如果能在循环停止后获取肺部用于移植，供体短缺的问题可能会得到显著缓解。然而，对于此类非心跳供体，人们极为担心即使是短时间的热缺血也会对肺组织有害，从而危及移植受者。本研究的目的是探寻循环停止后尸体内部不同肺冷却方法的效果。
给新西兰白兔静脉注射过量戊巴比妥钠处死，置于室温环境。死后每隔一段时间测量皮下、直肠、肺核心、肺表面及支气管内温度。缺血期间肺的冷却方法在各实验组有所不同（每组n = 6）：室温（24℃）下肺保持萎陷（第1组 = 对照非心跳供体）；用冷却（4℃）的室内空气进行通气（第2组）；肺保持萎陷并对尸体及其肺进行局部冷却（1℃）（第3组）；循环停止后立即用冷（4℃）晶体溶液原位冲洗肺，然后在冷（1℃）盐溶液中离体萎陷保存（第4组 = 对照心跳供体）。
第1组肺核心、肺表面及支气管内温度缓慢下降至室温（分别为1.5℃±0.0℃/小时、1.8℃±0.2℃/小时和1.9℃±0.1℃/小时）。相比之下，第4组所有三个肺温度立即（<5分钟）降至10℃以下。与第1组相比，低温通气（第2组）降低了支气管内温度（30分钟时p < 0.05），但对肺表面、直肠或皮下温度无影响。与第2组（分别为2.5℃±0.3℃/小时和3.9℃±0.1℃/小时）相比，第3组死后前4小时肺表面和支气管内温度的冷却速度更快（p < 0.01）（分别为6.6℃±0.3℃/小时和6.1℃±0.2℃/小时），但与第4组（分别为9.2℃±0.1℃/小时和8.7℃±0.1℃/小时）相比更慢（p < 0.001）。
这些数据表明，在非心跳供体中，（1）原位冷冲洗可使肺立即冷却；（2）用冷空气通气只会加速支气管内温度下降，但对肺表面温度无影响；（3）对尸体进行局部冷却在降低肺温度方面比低温通气更有效。
