EVALUATION OF THE PLATELET PROTECTING EFFECTS OF NITRIC OXIDE (NO) AND APROTININ DURING CARDIOPULMONARY BYPASS

我们进行了这些研究，以检验NO GAS是否可以减少CPB选择性冠状动脉旁路移植术(CABG)患者的血小板活化和失血量。我们还比较了NO GAS和抑肽酶的作用。每小时记录一次胸腔引流，直到引流管被清除。应用抑肽酶的患者在麻醉诱导后CPB开始前缓慢给予50万KiU的抑肽酶，并在泵注预充液中加入50万KiU的抑肽酶。利用特制的流量计，膜式氧合器的扫气流量中没有混合气体。根据TH…对血小板活化进行量化细胞表面P-选择素(CD62)表达增加。GPlb(CD42b)表面表达的降低也被认为是CPB引起的血小板功能的改变，并被量化。使用CELLQuest软件(Beckton Dickinson免疫细胞计数系统)对列表模式数据文件进行分析。在对照组和未治疗的患者中，以CD62PE阳性事件增加为标志的活化血小板在CPB期间和术后显著增加。在接受抑肽酶治疗的患者中，CPB期间血小板活化略有减弱。术后24小时的出血量有轻微减少的趋势。在24小时出血量中，对照组和未治疗组之间没有发现差异。由于目前我们的研究中没有足够的患者数量，我们目前还不能得出任何结论。然而，研究的初步结果表明，在100ppm的膜氧合器扫气中给予NO并不能减少由于CPB合成表面而引起的血小板活化。手术后24小时内的失血量也不会因输注NO气体而改变。另一方面，在我们的研究中使用低剂量的抑肽酶可以减弱血小板的激活，就像先前报道的高剂量的抑肽酶一样。抑肽酶在术后24小时内有减少失血量的趋势，但在这一点上没有统计学意义。我们将增加患者数量，并尝试检测在CPB期间NO气体和抑肽酶对血小板激活的影响。较少

We have undertaken these studies to examine whether NO gas can reduce platelet activation and blood loss in patients who had elective coronary artery bypass grafting (CABG) with CPB.We also compared the effects of NO gas to aprotinin. The data from remaining 20 patients were subsequently analyzed.CPB was performed at a minimal temperature of 28ﾟC with a nonpulsatile flow of 2.4 L/min/kg. Chest tube draignage was recorded hourly until removal of drains. In patietnts who received aprotinin, 500,000 KIU of aprotinin was slowly given after the induction of anesthesia and before the start of CPB,and another 500,000 KIU aprotinin was added to pump priming solution. NO gas was mixed into the sweep gas flow of the membrane oxygenator, with a specially made flow meter. Concentration of oxygen, NO,NO2 were measured immediately before and after the oxygenator, and NO gas flow was adjusted so that 100 ppm NO gas was mixed into the oxygenator sweep gas. Platelet activation is quantified based on th … More e increased surface expression of P-selectin (CD62). The decreased surface expression of GPlb (CD42b) was also regarded as alteration of platelet function caused by CPB,and quantified. Anslysis of list mode data files was performed using CELLQuest software (Beckton Dickinson Immunocytometry Systems).In control and NO treated patients, activated platelets, indicated by increased events positive for CD62PE,significantly increased during and after CPB.In aprotinin-treated patients, platelet activation was modestly attenuated during CPB.There was a tendency that blood loss during the first 24 hrs after operation was modestly decreased by aprotinin treatment, but statistical significance was not achieved at this point. No difference was found between, control and the NO-treated group in 24 hr blood loss.Since currently we do not have enough number of patients in our study, we cannot make any conclusion at this point. However, preliminary results from out study showed that giving NO at 100 ppm to the membrane oxygenator sweep gas does not reduce platelet activation due to the synthetic surfaces of CPB.The amount of blood loss during the first 24 hrs after the operation was also not altered by NO gas infusion. On the other hand, low dose aprotinin employed in our study attenuated platelet activation as previously reported with higher doses of aprotinin. There was a tendency that aprotinin decreased postoperative blood loss in the first 24 hours, but statistical significance was not achieved at this point. We will increase number of patients and also try to examine the effects of NO gas plus aprotinin on platelet activation during CPB. Less