Importance of luxury flow for critically ill patients receiving a left ventricular assist system

Extracorporeal Life Support: Physiological Concepts and Clinical Outcomes

Extracorporeal life support (ECLS) describes a system that involves drainage from the venous circulation and return via an oxygenator into the arterial circulation (veno-arterial extracorporeal membrane oxygenation). ECLS provides effective cardiopulmonary support, but the parallel circulation has complex effects on the systemic and pulmonary circulatory physiology. An understanding of the physiological changes is fundamental to the management of ECLS. In this review, the key physiological concepts and the implications on the clinical management of ECLS are discussed. In addition, the clinical outcomes associated with ECLS in cardiogenic shock are systematically reviewed. The paucity of clinical trials on ECLS highlights the need for randomized trials to guide the selection of patients.

[Veno-arterial extracorporeal membrane oxygenation. Indications, limitations and practical implementation]

Due to the technical advances in pumps, oxygenators and cannulas, veno-arterial extracorporeal membrane oxygenation (va-ECMO) or extracorporeal life support (ECLS) has been widely used in emergency medicine and intensive care medicine for several years. An accepted indication is peri-interventional cardiac failure in cardiac surgery (postcardiotomy low cardiac output syndrome). Furthermore, especially the use of va-ECMO for other indications in critical care medicine, such as in patients with severe sepsis with septic cardiomyopathy or in cardiopulmonary resuscitation has tremendously increased. The basic indications for va-ECMO are therapy refractory cardiac or cardiopulmonary failure. The fundamental purpose of va-ECMO is bridging the function of the lungs and/or the heart. Consequently, this support system does not represent a causal therapy by itself; however, it provides enough time for the affected organ to recover (bridge to recovery) or for the decision for a long-lasting organ substitution by a ventricular assist device or by transplantation (bridge to decision). Although the outcome for bridged patients seems to be favorable, it should not be forgotten that the support system represents an invasive procedure with potentially far-reaching complications. Therefore, the initiation of these systems needs a professional and experienced (interdisciplinary) team, sufficient resources and an individual approach balancing the risks and benefits. This review gives an overview of the indications, complications and contraindications for va-ECMO. It discusses its advantages in organ transplantation and transport of critically ill patients. The reader will learn the differences between peripheral and central cannulation and how to monitor and manage va-ECMO.

Prediction of outcome in patients with liver dysfunction after left ventricular assist device implantation

Although postoperative liver dysfunction (LD) following left ventricular assist device (LVAD) implantation is associated with high mortality, outcome is difficult to predict in patients with liver dysfunction. We aimed to clarify factors affecting recovery from LD after VAD implantation. A total of 167 patients underwent LVAD implantation, of whom 101 developed early postoperative LD, defined as maximum total bilirubin (max T-bil) greater than 5.0 mg/dl within 2 weeks. We set two different end-points, unremitting LD, and 90-day mortality. The rates of early mortality (90 days) and recovery from LD were 36 % (36/101) and 72 % (73/101), respectively. Univariate analysis showed that preoperative body weight, preoperative mechanical support, preoperative T-bil and creatinine, left ventricular diastolic dimension, right VAD (RVAD) insertion, cardiopulmonary bypass time, postoperative cardiac index, and postoperative T-bil and central venous pressure (CVP) on postoperative day (POD) 3 (non-recovered vs recovered, 12.4 ± 4.5 vs 9.5 ± 3.6 mmHg) were higher in patients with unremitting LD. Preoperative T-bil, RVAD insertion, and T-bil and CVP on POD 3 (non-survivor vs survivor, 12.4 ± 4.4 vs 9.4 ± 3.6 mmHg) were also higher in non-survivors. Multivariate analysis demonstrated that CVP on POD 3 was predictive of recovery from postoperative LD (OR 0.730, P < 0.05) and 90-day mortality (OR 0.730, P < 0.05). A key outcome factor in patients who developed early postoperative LD after LVAD implantation was postoperative liver congestion with high CVP. To overcome postoperative LD, appropriate management of postoperative CVP level is important.

Successful treatment of cerebral hemorrhage using computed tomography angiography in a patient with left-ventricular-assist device

Cerebral hemorrhage is one of the common complications associated with left-ventricular-assist device (LVAD) treatment and leads to a high mortality rate because of excessive bleeding due to frequently unknown causes. Cerebral angiography is used to diagnose cerebrovascular events and is well recognized as being very useful for this purpose. We performed a cerebral angiography for a patient with an LVAD who developed cerebral hemorrhage, and the hemorrhagic source was clearly identified. The patient underwent successful neurosurgical treatment, which was followed by heart transplantation.

Thrombotic occlusion of the ascending aorta after Toyobo LVAD implantation with descending aortic perfusion in a post-Bentall patient

A 35-year-old patient in whom a Toyobo left ventricular assist device (LVAD) was implanted with descending aortic perfusion for the treatment of critical heart failure due to global myocardial infarction after repeat aortic root operations with a mechanical aortic valve developed complete thrombotic occlusion of the ascending aorta. This phenomenon was supposedly brought about by the patient's left ventricular contraction being too poor to open the mechanical aortic valve. The patient has, however, been doing well under LVAD support, with no thromboembolic events occurring for at least 2 years since the device was implanted.