Extracorporeal Membrane Oxygenation for Refractory Asthma Exacerbations With Respiratory Failure

1. Download : Download high-res image (134KB)
2. Download : Download full-size image

     

Extracorporeal Membrane Oxygenation Using the Tandem Heart System's Catheters

We describe the initial—and successful—use of the TandemHeart System''s catheters to provide extracorporeal membrane oxygenation (ECMO), in 2 patients. In 1 patient, who was experiencing severe primary respiratory failure, the catheters provided a standard venovenous ECMO circuit. In the other patient, who had severe, acute pulmonary hypertension and right-heart failure, the catheters enabled a novel right atrial-to-left atrial circuit for ECMO. We discuss the potential of the TandemHeart System''s catheters to provide novel and possibly superior vascular routes for the delivery of ECMO in different types of cardiopulmonary failure.Key words: Extracorporeal circulation, extracorporeal membrane oxygenation/instrumentation/methods, heart failure/therapy, heart-assist devices, hemodynamics, methods, pneumonia/complications, respiratory insufficiency/therapy, technology assessment, biomedical, treatment outcomeExtracorporeal membrane oxygenation (ECMO) first came into wide clinical use as a tool to enable open-heart surgery through cardiopulmonary bypass (CPB) in the 1960s.^1,2 By the 1970s, there was hope that ECMO technology could provide effective temporary oxygenation in patients who had a major, yet reversible, lung injury but in whom mechanical ventilation was not completely effective.³ A generation later, ECMO technology is a well-established, widely used method of support in neonatal and pediatric patients who experience severe respiratory failure.⁴ In contrast, progress in the application of ECMO to improve outcomes of respiratory failure in adults has been much slower. A large National Institutes of Health-sponsored trial of ECMO use in severe respiratory failure of various causes⁵ failed to show a benefit and thereby dampened enthusiasm for this application for more than a decade. New technology and implementation methods, however, have reinvigorated interest in the use of ECMO when severe respiratory failure occurs in adults.^6,7 Indeed, data from the recently completed, large, prospective CESAR trial suggest that ECMO may already be of great usefulness in patients who are experiencing severe respiratory failure.^8–10There have also been encouraging reports of the successful use of ECMO to support patients who are experiencing acute right-heart failure,¹¹ acute refractory left-heart failure,¹² postcardiotomy heart failure,¹³ prolonged cardiac arrest,¹⁴ and postoperative cardiogenic shock.¹⁵ In these circumstances, ECMO has served temporarily (sometimes along with mechanical hemodynamic support) until heart recovery, or as a bridge to heart transplantation, heart–lung transplantation, or the placement of a left ventricular (LV) assist device.The TandemHeart® PTVA® System (CardiacAssist, Inc.; Pittsburgh, Pa) is a new, percutaneously placed, ventricular assist device that has proved to be effective in the short-term management of acute heart failure.¹⁶ The system features innovative vascular-access catheters that enable a minimally invasive approach to mechanical LV assistance. We report here the 1st experience of using these catheters to perform ECMO, in 2 patients. One patient had severe primary respiratory failure, and the other had respiratory failure and right-heart failure caused by severe pulmonary hypertension. The TandemHeart catheters were placed in different intravascular locations in each patient. Our experience suggests that the TandemHeart catheter system can offer innovative and superior options for ECMO delivery to different populations of patients who experience cardiopulmonary failure.     

超声心动图在体外膜肺氧合对心脏支持的应用价值

目的：探讨超声心动图在体外膜肺氧合(ECMO)支持辅助中对心脏的监测作用。方法：2004年12月～2005年8月间连续10例因低心排接受 Veno-Aterial ECMO 支持,其中心脏外科术后8例,心肌病急性心力衰竭拟心脏移植的2例患者,年龄13～60岁,平均(44±12)岁。仪器为 Philips iE33和 sonos 5500彩超仪,均在床旁进行检查,分别在 ECMO 安置前、ECMO 辅助后(撤机前30 min 内流量减至最低)前后观察患者左心室射血分数(INEF)、左心室舒张末前后径(LVEDD)等指标,结合患者临床资料(心率、血压、左心房压及血氧饱和度)对比。并观察并发症情况。结果：10例患者 ECMO 辅助后的 LVEF、LVEDD、心率、血压、左心房压及动脉血氧饱和度均有改善。并发症的检出：机械瓣异常、左心房血栓、心包血凝块、二尖瓣狭窄未纠正各1例。结论：彩色多普勒超声心动图可无创实时评价 ECMO 辅助前后心脏结构及功能变化,及时发现其并发症。