Halldorsson A O, Kronon M T, Allen B S, Rahman S, Wang T
Division of Cardiothoracic Surgery, Heart Institute for Children, Hope Children's Hospital, Oak Lawn, Illinois, USA.
Ann Thorac Surg. 2000 Jan;69(1):198-203; discussion 204. doi: 10.1016/s0003-4975(99)01104-2.
Controlled reperfusion with a modified solution limits pulmonary injury following ischemia. Our initial studies infused this modified reperfusate at a pressure of 40 to 50 mm Hg to insure distribution. However, perhaps a lower pressure, which is closer to the normal physiologic pressure in the lung, would improve results by decreasing sheer stress.
Fifteen adult pigs underwent 2 hours of lung ischemia by clamping the left bronchus and pulmonary artery. Five (group 1) then underwent uncontrolled reperfusion by removing the vascular clamps and allowing unmodified blood to reperfuse the lung at a pulmonary artery pressure of 20 to 30 mm Hg. The other 10 pigs underwent controlled reperfusion by mixing blood from the femoral artery with a crystalloid solution, and infusing this modified reperfusate into the ischemic lung through the pulmonary artery for 10 minutes before removing the arterial clamp. In 5 (group 2), the modified solution was infused at a pressure of 40 to 50 mm Hg, and in 5 (group 3) 20 to 30 mm Hg. Lung function was assessed 60 minutes after reperfusion and expressed as percentage of control.
Compared to uncontrolled reperfusion (group 1), controlled reperfusion at a pressure of 40 to 50 mm Hg (group 2) significantly improved postreperfusion pulmonary compliance (77% versus 86%; p<0.001 versus group 1), and arterial/alveolar ratio (a/A) ratio (27% versus 52%; p<0.001 versus group 1); as well as decreased pulmonary vascular resistance (PVR) (198% versus 154%; p<0.001 versus group 1), lung water (84.3% versus 83.5%; p<0.001 versus group 1), and myeloperoxidase (0.35 versus 0.23 optical density/min/mg protein). Reducing the pressure of the modified reperfusate to 20 to 30 mm Hg further improved postreperfusion compliance (92%+/-1%; p<0.001 versus groups 1 and 2) and a/A ratio (76%+/-1%; p<0.001 versus groups 1 and 2); and lowered PVR (133%+/-2%; p<0.001 versus groups 1 and 2), lung water (82.7%+/-0.1%; p<0.001 versus groups 1 and 2), and myeloperoxidase (0.16%+/-0.01%; p<0.001 versus groups 1 and 2).
After 2 hours of pulmonary ischemia, a severe lung injury occurs following uncontrolled reperfusion, controlled reperfusion with a modified solution reduces this reperfusion injury, and lowering the pressure of the modified reperfusate to more physiologic levels (20 to 30 mm Hg) further reduces the reperfusion injury improving pulmonary function.
使用改良溶液进行控制性再灌注可限制缺血后肺损伤。我们最初的研究以40至50毫米汞柱的压力输注这种改良再灌注液以确保其分布。然而，或许更接近肺内正常生理压力的较低压力，通过降低切应力可能会改善结果。
15只成年猪通过钳夹左支气管和肺动脉经历2小时的肺缺血。然后5只猪（第1组）通过移除血管夹并允许未改良的血液以20至30毫米汞柱的肺动脉压力再灌注肺，进行非控制性再灌注。另外10只猪通过将股动脉血与晶体溶液混合，并在移除动脉夹前通过肺动脉将这种改良再灌注液输注到缺血肺中10分钟，进行控制性再灌注。其中5只猪（第2组）以40至50毫米汞柱的压力输注改良溶液，另外5只猪（第3组）以20至30毫米汞柱的压力输注。再灌注60分钟后评估肺功能，并表示为对照的百分比。
与非控制性再灌注（第1组）相比，以40至50毫米汞柱的压力进行控制性再灌注（第2组）显著改善了再灌注后肺顺应性（77%对86%；与第1组相比p<0.001）、动脉/肺泡比（a/A比）（27%对52%；与第1组相比p<0.001）；并降低了肺血管阻力（PVR）（198%对154%；与第1组相比p<0.001）、肺水含量（84.3%对83.5%；与第1组相比p<0.001）以及髓过氧化物酶（光密度0.35对0.23/分钟/毫克蛋白）。将改良再灌注液的压力降至20至30毫米汞柱进一步改善了再灌注后顺应性（92%±1%；与第1组和第2组相比p<0.001）和a/A比（76%±1%；与第1组和第2组相比p<0.001）；并降低了PVR（133%±2%；与第1组和第2组相比p<0.001）、肺水含量（82.7%±0.1%；与第1组和第2组相比p<0.001）以及髓过氧化物酶（0.16%±0.01%；与第1组和第2组相比p<0.001）。
肺缺血2小时后，非控制性再灌注会发生严重肺损伤，使用改良溶液进行控制性再灌注可减轻这种再灌注损伤，将改良再灌注液的压力降至更生理的水平（20至30毫米汞柱）可进一步减轻再灌注损伤并改善肺功能。
