Booth B P, Henderson M, Milne B, Cervenko F, Marks G S, Brien J F, Nakatsu K
Department of Pharmacology, Faculty of Medicine, Queen's University, Kingston, Ontario, Canada.
Anesth Analg. 1991 Apr;72(4):493-7. doi: 10.1213/00000539-199104000-00013.
The effectiveness of glyceryl trinitrate (nitroglycerin) in controlling myocardial ischemia and blood pressure during coronary artery bypass graft surgery is frequently lost during surgery, possibly as a result of drug sequestration by the cardiopulmonary bypass circuit. The objective of this study was to utilize a gas-liquid chromatographic assay to determine the extent of removal of glyceryl trinitrate from the priming fluid by the bubble and membrane oxygenators. The apparatus was maintained at either 25 or 37 degrees C, the two extreme temperatures experienced by the patient during bypass surgery. At apparent steady state, the circulating glyceryl trinitrate concentration was decreased by 20.6%, 46.6%, and 67.3% with the Maxima membrane oxygenator, Cobe membrane oxygenator, and Bentley bubble oxygenator, respectively. The three-layer defoaming filters that are used in the Bentley bubble oxygenator were studied by immersing each of the three filters in fluid containing 60 nM glyceryl trinitrate and monitoring the drug concentration in Plasmalyte. The filters sequestered approximately 90% of the glyceryl trinitrate from the bathing solution of which 31% was recovered with a single methanol wash of the polyurethane filter. These data demonstrate that the different oxygenators used in the cardiopulmonary bypass circuit remove glyceryl trinitrate to varying degrees from the circulating fluid.
冠状动脉搭桥手术期间，硝酸甘油（硝化甘油）在控制心肌缺血和血压方面的有效性在手术过程中常常丧失，这可能是由于体外循环回路对药物的隔离所致。本研究的目的是利用气液色谱分析法来确定鼓泡式氧合器和膜式氧合器从预充液中去除硝酸甘油的程度。该装置维持在25或37摄氏度，这是患者在体外循环手术期间经历的两个极端温度。在明显的稳态下，使用Maxima膜式氧合器、Cobe膜式氧合器和Bentley鼓泡式氧合器时，循环中的硝酸甘油浓度分别降低了20.6%、46.6%和67.3%。通过将Bentley鼓泡式氧合器中使用的三层消泡过滤器分别浸入含有60 nM硝酸甘油的液体中，并监测Plasmalyte中的药物浓度，对这些过滤器进行了研究。这些过滤器从浸泡溶液中隔离了约90%的硝酸甘油，其中31%可通过对聚氨酯过滤器进行单次甲醇洗涤回收。这些数据表明，体外循环回路中使用的不同氧合器从循环液中去除硝酸甘油的程度各不相同。
