Stephen A. Esper

Extracorporeal membrane oxygenation in the adult: a review of anticoagulation monitoring and transfusion.

Extracorporeal membrane oxygenation (ECMO) is a method of life support to maintain cardiopulmonary function. Its use as a medical application has increased since its inception to treat multiple conditions including acute respiratory distress syndrome, myocardial ischemia, cardiomyopathy, and septic shock. While complications including neurological and renal injury occur in patients on ECMO, bleeding and coagulopathy are most common. ECMO is associated with an inflammatory response promoting a hypercoagulable state, requiring anticoagulation to avoid thromboembolism originating in the nonendothelial surfaced circuit. However, excessive anticoagulation may result in bleeding complications including intracerebral hemorrhage. Monitoring anticoagulation for ECMO has its origins in cardiopulmonary bypass for cardiac surgery; however, there is no ideal level of anticoagulation, no standardized method to monitor anticoagulation, nor are all centers standardized on what is used for anticoagulation. Multiple blood products are used in an effort to decrease bleeding in the setting of anticoagulation, often in the setting of recent surgery, and this leads to significant increases in cost for patients on ECMO and transfusion-related complications. In this review article, we discuss the evolution of the various modalities of ECMO, indications, contraindications, and complications. Furthermore, we review the different strategies for anticoagulation and treatment of coagulopathy while on ECMO. Finally, we discuss the cost of ECMO and associated blood product transfusion.

Intra-operative cell salvage: a fresh look at the indications and contraindications

Numerous approaches are used to avoid transfusion of allogeneic blood. Primary methods include, but are not limited to, erythropoietin and iron supplementation, pre-operative autologous donation, acute normovolaemic haemodilution, haemoglobin-based blood substitutes and infusible oxygen-carrying fluids, and the use of cell salvage systems. While currently unavailable in North America and Europe because of an increased risk of myocardial infarction and death1,2, research continues in the areas of haemoglobin-based blood substitutes and infusible oxygen-carrying liquids. Of the accepted strategies mentioned above, cell salvage offers the medical community a safe, resource-saving, and relatively inexpensive method to avoid allogeneic red cell transfusion. Currently, incorrect information and misconceptions regarding the use of cell salvage systems frequently portray them as expensive, ineffective, and inappropriate for use in certain clinical situations. In addition to addressing these misconceptions, this article will discuss indications and contraindications for the use of such systems.

Extracorporeal membrane oxygenation as a bridge to lung transplantation in the United States: an evolving strategy in the management of rapidly advancing pulmonary disease.

OBJECTIVE Improvements in technology have led to a resurgence in the use of extracorporeal membrane oxygenation as a bridge to lung transplantation. By using a national registry, we sought to evaluate how short-term survival has evolved using this strategy. METHODS With the use of the United Network for Organ Sharing database, we analyzed data from 12,458 adults who underwent lung transplantation between 2000 and 2011. Patients were categorized into 2 cohorts: 119 patients who were bridged to transplantation using extracorporeal membrane oxygenation and 12,339 patients who were not. The study period was divided into four 3-year intervals: 2000 to 2002, 2003 to 2005, 2006 to 2008, and 2009 to 2011. With Kaplan-Meier analysis, 1-year survival was compared for the 2 cohorts of patients in each of the time periods. A propensity score-adjusted Cox regression model was used to estimate the risk of 1-year mortality. RESULTS Of the total number of recipients, 4 (3.4%) were bridged between 2000 and 2002, 17 (14.3%) were bridged between 2003 and 2005, 31 (26.1%) were bridged between 2006 and 2008, and 67 were bridged (56.3%) between 2009 and 2011. Recipients bridged using extracorporeal membrane oxygenation were more likely to be younger and diabetic and to have higher serum creatinine and bilirubin levels. The 1-year survival for those bridged with extracorporeal membrane oxygenation was significantly lower in subsequent periods: 25.0% versus 81.0% (2000-2002), 47.1% versus 84.2% (2006-2008), and 74.4% versus 85.7% (2009-2011). However, this survival progressively increased with each period, as did the number of patients bridged using extracorporeal membrane oxygenation. CONCLUSIONS Short-term survival with the use of extracorporeal membrane oxygenation as a bridge to lung transplantation has significantly improved over the past few years.

Extracorporeal membrane oxygenation support in acute coronary syndromes complicated by cardiogenic shock

Acute coronary syndrome (ACS) complicated by shock is associated with high mortality despite the use of percutaneous support devices. Extracorporeal membrane oxygenation (ECMO) offers cardiopulmonary support but its safety and efficacy in the ACS setting is still under investigation.

Pathophysiology of Cardiopulmonary Bypass: Current Strategies for the Prevention and Treatment of Anemia, Coagulopathy, and Organ Dysfunction.

The techniques and equipment of cardiopulmonary bypass (CPB) have evolved over the past 60 years, and numerous numbers of cardiac surgical procedures are conducted around the world using CPB. Despite more widespread applications of percutaneous coronary and valvular interventions, the need for cardiac surgery using CPB remains the standard approach for certain cardiac pathologies because some patients are ineligible for percutaneous procedures, or such procedures are unsuccessful in some. The ageing patient population for cardiac surgery poses a number of clinical challenges, including anemia, decreased cardiopulmonary reserve, chronic antithrombotic therapy, neurocognitive dysfunction, and renal insufficiency. The use of CPB is associated with inductions of systemic inflammatory responses involving both cellular and humoral interactions. Inflammatory pathways are complex and redundant, and thus, the reactions can be profoundly amplified to produce a multiorgan dysfunction that can manifest as capillary leak syndrome, coagulopathy, respiratory failure, myocardial dysfunction, renal insufficiency, and neurocognitive decline. In this review, pathophysiological aspects of CPB are considered from a practical point of view, and preventive strategies for hemodilutional anemia, coagulopathy, inflammation, metabolic derangement, and neurocognitive and renal dysfunction are discussed.

Anesthetic management in upper extremity transplantation: the Pittsburgh experience.

BACKGROUND: Hand/forearm/arm transplants are vascularized composite allografts, which, unlike solid organs, are composed of multiple tissues including skin, muscle, tendons, vessels, nerves, lymph nodes, bone, and bone marrow. Over the past decade, 26 upper extremity transplantations were performed in the United States. The University of Pittsburgh Medical Center has the largest single center experience with 8 hand/forearm transplantations performed in 5 recipients between January 2008 and September 2010. Anesthetic management in the emerging field of upper extremity transplants must address protocol and procedure-specific considerations related to the role of regional blocks, effects of immunosuppressive drugs during transplant surgery, fluid and hemodynamic management in the microsurgical setting, and rigorous intraoperative monitoring during these often protracted procedures. METHODS: For the first time, we outline salient aspects of upper extremity transplant anesthesia based on our experience with 5 patients. We highlight the importance of minimizing intraoperative vasopressors and improving fluid management and blood product use. RESULTS: Our approach reduced the incidence of perioperative bleeding requiring re-exploration or hemostasis and shortened in-hospital and intensive care unit stay. Functional, immunologic and graft survival outcomes have been highly encouraging in all patients. CONCLUSIONS: Further experience is required for validation or standardization of specific anesthetic protocols. Meanwhile, our recommendations are intended as pertinent guidelines for centers performing these novel procedures.

Blood Pressure Monitoring for the Anesthesiologist: A Practical Review.

Periodic, quantitative measurement of blood pressure (BP) in humans, predating the era of evidence-based medicine by over a century, is a component of the American Society of Anesthesiologists standards for basic anesthetic monitoring and is a staple of anesthetic management worldwide. Adherence to traditional BP parameters complicates the ability of investigators to determine whether particular BP ranges confer any clinical benefits. The BP waveform is a complex amalgamation of both antegrade and retrograde (reflected) pressure waves and is affected by vascular compliance, distance from the left ventricle, and the 3D structure of the vascular tree. Although oscillometry is the standard method of measuring BP semicontinuously in anesthetized patients and is the primary form of measurement in >80% of general anesthetics, major shortcomings of oscillometry are its poor performance at the extremes and its lack of information concerning BP waveform. Although arterial catheterization remains the gold standard for accurate BP measurement, 2 classes of devices have been developed to noninvasively measure the BP waveform continuously, including tonometric and volume clamp devices. Described in terms of a feedback loop, control of BP requires measurement, an algorithm (usually human), and an intervention. This narrative review article discusses the details of BP measurement and the advantages and disadvantages of both noninvasive and invasive monitoring, as well as the principles and algorithms associated with each technique.

Pain Management Strategies for Thoracotomy and Thoracic Pain Syndromes

Pain after thoracic surgery can be severe and, in the acute phase, contribute to perioperative morbidity and mortality. Unfortunately, patients also incur a significant risk of chronic pain. Although there are guidelines for postoperative pain management in these patients, there is no widespread surgical or anesthetic “best practice.” Here, we review the recent literature on techniques specific to perioperative pain control for thoracic patients, including medical management, neuraxial blockade, and other regional techniques, and suggest an algorithm for developing a multimodal pain management strategy.

Arterial waveform analysis

The bedside measurement of continuous arterial pressure values from waveform analysis has been routinely available via indwelling arterial catheterization for >50 years. Invasive blood pressure monitoring has been utilized in critically ill patients, in both the operating room and critical care units, to facilitate rapid diagnoses of cardiovascular insufficiency and monitor response to treatments aimed at correcting abnormalities before the consequences of either hypo- or hypertension are seen. Minimally invasive techniques to estimate cardiac output (CO) have gained increased appeal. This has led to the increased interest in arterial waveform analysis to provide this important information, as it is measured continuously in many operating rooms and intensive care units. Arterial waveform analysis also allows for the calculation of many so-called derived parameters intrinsically created by this pulse pressure profile. These include estimates of left ventricular stroke volume (SV), CO, vascular resistance, and during positive-pressure breathing, SV variation, and pulse pressure variation. This article focuses on the principles of arterial waveform analysis and their determinants, components of the arterial system, and arterial pulse contour. It will also address the advantage of measuring real-time CO by the arterial waveform and the benefits to measuring SV variation. Arterial waveform analysis has gained a large interest in the overall assessment and management of the critically ill and those at a risk of hemodynamic deterioration.

Practical Implementation of the Coronary Revascularization Heart Team

Multidisciplinary decision making has been shown to be highly effective in various aspects of medicine, most notably with the concept of tumor boards and transplant committees.1 ,2 The most updated guidelines for percutaneous coronary intervention (PCI), published jointly by the American College of Cardiology Foundation, American Heart Association, and the Society for Cardiovascular Angiography and Interventions, assign a class IC recommendation for the use of a collaborative Heart Team approach in the treatment of patients with complex coronary artery disease (CAD).3 The guidelines assert that this recommendation is based on retrospective analyses showing that patients with complex CAD referred for revascularization based on a Heart Team consensus have improved mortality compared with patients merely assigned to a particular strategy in the context of their trial enrollment. Despite the suggestion of improved mortality in this retrospective comparison, the Heart Team approach has not been adopted widely in the current clinical practice of cardiovascular medicine. This multidisciplinary innovation remains in its infancy, and numerous questions remain about its practicality, feasibility, and efficacy. For several reasons, there remains significant variability in the care delivered to patients with complex CAD.4 Numerous reports show that although differences in patient characteristics may explain some of the variability in revascularization decisions, much of this variance is physician driven, such as practicing in a fee-for-service model or high-risk anatomy for low-volume operators.4,5 As emphasis grows on informed decision making and patient-centered care, a critical evaluation of these difficult questions will be essential to discovering whether there is a clinically meaningful effect of the Heart Team approach on patients with complex CAD. Although the longstanding use of tumor boards in the field of oncology represents a functioning model of interdisciplinary care on which the Heart Team may be based, it is critical …