Saucha Wojciech, Sołek-Pastuszka Joanna, Bohatyrewicz Romuald, Knapik Piotr
Clinical Department of Cardiac Anesthesia and Intensive Care of Silesian Center of Heart Diseases, Medical University of Silesia, Zabrze, Poland.
Anaesthesiol Intensive Ther. 2015;47(4):368-71. doi: 10.5603/AIT.2015.0051.
Extracorporeal Membrane Oxygenation (ECMO) is a well-established method of support in patients with severe respiratory and/or circulatory failure. Unfortunately, this invasive method of treatment is associated with a high risk of neurological complications including brain death. Proper diagnosis of brain death is crucial for the termination of futile medical care. Currently, the legal system in Poland does not provide an accepted protocol for apnea tests for patients on ECMO support. Veno-arterial ECMO is particularly problematic in this regard because it provides both gas exchange and circulatory support. CO₂ elimination by ECMO prevents hypercapnia, which is required to perform an apnea test. Several authors have described a safe apnea test procedure in patients on ECMO. Maximal reduction of the sweep gas flow to the oxygenator should maintain an acceptable haemoglobin oxygenation level and reduce elimination of carbon dioxide. Hypercapnia achieved via this method should allow an apnea test to be conducted in the typical manner. In the case of profound desaturation and an inadequate increase in the arterial CO₂ concentration, the sweep gas flow rate may be increased to obtain the desired oxygenation level, and exogenous carbon dioxide may be added to achieve a target carbon dioxide level. Incorporation of an apnea test for ECMO patients is planned in the next edition of the Polish guidelines on the determination of brain death.
体外膜肺氧合（ECMO）是治疗严重呼吸和/或循环衰竭患者的一种成熟的支持方法。不幸的是，这种侵入性治疗方法与包括脑死亡在内的神经并发症高风险相关。正确诊断脑死亡对于终止无效医疗至关重要。目前，波兰的法律体系未为接受ECMO支持的患者提供公认的呼吸暂停测试方案。在这方面，静脉-动脉ECMO尤其成问题，因为它既提供气体交换又提供循环支持。ECMO消除二氧化碳可防止高碳酸血症，而高碳酸血症是进行呼吸暂停测试所必需的。几位作者描述了一种针对接受ECMO治疗患者的安全呼吸暂停测试程序。将氧合器的吹扫气体流量最大程度降低应能维持可接受的血红蛋白氧合水平并减少二氧化碳的消除。通过这种方法实现的高碳酸血症应允许以典型方式进行呼吸暂停测试。在严重低氧饱和度和动脉二氧化碳浓度升高不足的情况下，可增加吹扫气体流速以获得所需的氧合水平，并可添加外源性二氧化碳以达到目标二氧化碳水平。波兰关于脑死亡判定的指南下一版计划纳入针对ECMO患者的呼吸暂停测试。
