Ihnken K, Winkler A, Schlensak C, Sarai K, Neidhart G, Unkelbach U, Mülsch A, Sewell A
Department of Cardiothoracic and Vascular Surgery, Johann-Wolfgang-Goethe University, Frankfurt, Germany.
J Thorac Cardiovasc Surg. 1998 Aug;116(2):327-34. doi: 10.1016/s0022-5223(98)70134-5.
Hyperoxic cardiopulmonary bypass is widely used during cardiac operations in the adult. This management may cause oxygenation injury induced by oxygen-derived free radicals and nitric oxide. Oxidative damage may be significantly limited by maintaining a more physiologic oxygen tension strategy (normoxic cardiopulmonary bypass).
During elective coronary artery bypass grafting, 40 consecutive patients underwent either hyperoxic (oxygen tension = 400 mm Hg) or normoxic (oxygen tension = 140 mm Hg) cardiopulmonary bypass. At the beginning and the end of bypass this study assessed polymorphonuclear leukocyte elastase, nitrate, creatine kinase, and lactic dehydrogenase, antioxidant levels, and malondialdehyde in coronary sinus blood. Cardiac index was measured before and after cardiopulmonary bypass.
There was no difference between groups with regard to age, sex, severity of disease, ejection fraction, number of grafts, duration of cardiopulmonary bypass, or ischemic time. Hyperoxic bypass resulted in higher levels of polymorphonuclear leukocyte elastase (377 +/- 34 vs 171 +/- 32 ng/ml, p = 0.0001), creatine kinase 672 +/- 130 vs 293 +/- 21 U/L, p = 0.002), lactic dehydrogenase (553 +/- 48 vs 301 +/- 12 U/L, p = 0.003), antioxidants (1.97 +/- 0.10 vs 1.41 +/- 0.11 mmol/L, p = 0.01), malondialdehyde (1.36 +/- 0.1 micromol/L,p = 0.005), and nitrate (19.3 +/- 2.9 vs 10.1 +/- 2.1 micromol/L, p = 0.002), as well as reduction in lung vital capacity (66% +/- 2% vs 81% +/- 1%,p = 0.01) and forced 1-second expiratory volume (63% +/- 10% vs 93% +/- 4%, p = 0.005) compared with normoxic management. Cardiac index after cardiopulmonary bypass at low filling pressure was similar between groups (3.1 +/- 0.2 vs 3.3 +/- 0.3 L/min per square meter). [Data are mean +/- standard error (analysis of variance), with p values compared with an oxygen tension of 400 mm Hg.]
Hyperoxic cardiopulmonary bypass during cardiac operations in adults results in oxidative myocardial damage related to oxygen-derived free radicals and nitric oxide. These adverse effects can be markedly limited by reduced oxygen tension management. The concept of normoxic cardiopulmonary bypass may be applied to surgical advantage during cardiac operations.
高氧体外循环在成人心脏手术中广泛应用。这种管理方式可能会导致氧衍生自由基和一氧化氮引起的氧合损伤。通过维持更接近生理状态的氧张力策略（常氧体外循环），氧化损伤可能会得到显著限制。
在择期冠状动脉搭桥手术期间，40例连续患者接受了高氧（氧张力 = 400 mmHg）或常氧（氧张力 = 140 mmHg）体外循环。在体外循环开始和结束时，本研究评估了冠状窦血中的多形核白细胞弹性蛋白酶、硝酸盐、肌酸激酶和乳酸脱氢酶、抗氧化剂水平以及丙二醛。在体外循环前后测量心脏指数。
两组在年龄、性别、疾病严重程度、射血分数、移植血管数量、体外循环持续时间或缺血时间方面无差异。与常氧管理相比，高氧体外循环导致多形核白细胞弹性蛋白酶水平更高（377±34 vs 171±32 ng/ml，p = 0.0001）、肌酸激酶（672±130 vs 293±21 U/L，p = 0.002）、乳酸脱氢酶（553±48 vs 301±12 U/L，p = 0.003）、抗氧化剂（1.97±0.10 vs 1.41±0.11 mmol/L，p = 0.01）、丙二醛（1.36±0.1 μmol/L，p = 0.005）和硝酸盐（19.3±2.9 vs 10.1±2.1 μmol/L，p = 0.002）升高，同时肺肺活量降低（66%±2% vs 81%±1%，p = 0.01）和用力呼气1秒量降低（63%±10% vs 93%±4%，p = 0.005）。低充盈压下体外循环后的心脏指数在两组间相似（3.1±0.2 vs 3.3±0.3 L/min每平方米）。[数据为平均值±标准误差（方差分析），p值与400 mmHg的氧张力进行比较。]
成人心脏手术期间的高氧体外循环会导致与氧衍生自由基和一氧化氮相关的氧化心肌损伤。通过降低氧张力管理，这些不良反应可得到明显限制。常氧体外循环的概念可应用于心脏手术以获得手术优势。
