Follette D M, Fey K, Buckberg G D, Helly J J, Steed D L, Foglia R P, Maloney J V
J Thorac Cardiovasc Surg. 1981 Aug;82(2):221-38.
This study was designed to determine if ischemic damage could be reduced by modifying blood composition upon reperfusion. After control data had been obtained in seven dogs on prolonged cardiopulmonary bypass, 71 dogs underwent 1 hour of ischemic arrest with topical hypothermia (left ventricular temperature 16 degrees C). We measured left ventricular performance (isovolumetric function curves), compliance (intraventricular balloon), blood flow (microspheres), metabolism (oxygen consumption), and water content (wet/dry weights) before and 30 minutes after ischemia. The initial reperfusate was 500 cc of oxygenated blood given over a period of 5 minutes. Without temporary reperfusate modification, postischemic left ventricular performance was depressed 40% +/- 3%, compliance fell 50% +/- 12%, water content rose 2.5% +/- 0.1%, and left ventricular blood flow and oxygen uptake increased only minimally when cardiac work was increased (function curve). These deleterious changes were reduced significantly, but not prevented, by the following isolated reperfusate modifications: (1) lowering amount of ionic calcium available for cell entry, (2) raising pH to 7.8 to counteract acidosis, (3) raising potassium level to maintain arrest and reduce metabolic demands, and (4) increasing osmolarity (mannitol, 360 mOsm) to counteract edema. In contrast, by combining these modifications to achieve a hypocalcemic, hyperkalemic, alkalotic, and hyperosmolar blood perfusate, it was possible to attain 104% +/- 1% recovery of myocardial performance, 80% +/- 1% restoration of compliance, 60% less postischemic edema, and near-normal augmentation of left ventricular flow and oxygen uptake to meet increasing needs.
本研究旨在确定再灌注时通过改变血液成分是否能够减轻缺血性损伤。在7只狗接受长时间体外循环获得对照数据后，71只狗在局部低温（左心室温度16摄氏度）下经历1小时的缺血性停搏。我们在缺血前及缺血后30分钟测量了左心室功能（等容功能曲线）、顺应性（心室内球囊）、血流量（微球）、代谢（氧消耗）和含水量（湿/干重）。初始再灌注液为500毫升含氧血液，在5分钟内输注完毕。在不进行临时再灌注液调整的情况下，缺血后左心室功能降低40%±3%，顺应性下降50%±12%，含水量增加2.5%±0.1%，并且当心脏做功增加时（功能曲线）左心室血流量和氧摄取仅略有增加。通过以下单独的再灌注液调整措施，这些有害变化得到了显著减轻，但并未完全消除：（1）降低可供细胞摄入的离子钙量；（2）将pH值提高至7.8以对抗酸中毒；（3）提高钾水平以维持停搏并降低代谢需求；（4）增加渗透压（甘露醇，360毫渗量）以对抗水肿。相比之下，通过联合这些调整措施以实现低钙、高钾、碱化和高渗的血液灌注液，有可能使心肌功能恢复到104%±1%，顺应性恢复到80%±1%，缺血后水肿减少60%，并且左心室血流量和氧摄取近乎正常增加以满足增加的需求。
