Percutaneous ventricular assist devices for cardiogenic shock

Post-partum spontaneous coronary artery dissection and the use of veno-arterial extra-corporeal membrane oxygenation

AIMS

To present a rare case of a post-partum spontaneous coronary artery dissection (SCAD), a rarely seen condition which does not yet have a universally agreed treatment method and the role of the intensive care unit (ICU) nurse when caring for the adult ECMO patient.

BACKGROUND

The use of extra-corporeal membrane oxygenation (ECMO) for the adult patient has increased slowly since the first reported successful treatment in 1972 (Hill et al., 1972) and is seen increasingly as a successful therapy when conventional medical treatment has failed. In this case, a young lady 2 weeks post-partum presented with acute coronary syndrome secondary to a SCAD. ECMO was used successfully as a bridge to myocardial recovery following coronary artery bypass grafts and cardiogenic shock.

DESIGN AND METHOD

A case study underpinned by a review of existing literature relating to spontaneous coronary artery dissection and extra-corporeal membrane oxygenation.

RESULTS AND CONCLUSIONS

ECMO is still a relatively new and invasive technology but continues to improve survival rates in critically ill patients where conventional medical treatment has failed. This article highlights requirement for further research into several aspects of care for the adult ECMO patient. Questions to be answered raised in this case study include recommendations for the weaning of inotropes and vasoconstrictors, frequency of blood gas sampling and whether it remains essential to have two nurses caring for the ECMO patient.

RELEVANCE TO CLINICAL PRACTICE

As medical treatment progresses, there is an increasing demand for therapies such as ECMO to become more readily available for the care of the critically ill adult patient. This article highlights challenges that may be faced and what changes could be made to further improve standards of care and survival rates for ECMO patients.

Percutaneous ventricular assist devices: new deus ex machina?

The development of ventricular assist devices has broadened the means with which one can treat acute heart failure. Percutaneous ventricular assist devices (pVAD) have risen from recent technological advances. They are smaller, easier, and faster to implant, all important qualities in the setting of acute heart failure. The present paper briefly describes the functioning and assets of the most common devices used today. It gives an overview of the current evidence and indications for left ventricular assist device use in cardiogenic shock and high-risk percutaneous coronary intervention. Finally, extracorporeal life support devices are dealt with in the setting of hemodynamic support.

Imaging of mechanical cardiac assist devices

Diagnostic imaging plays an important role in the assessment of patients with mechanical cardiac assist devices. Therefore, it is important for radiologists to be familiar with the basic components, function, and radiographic appearances of these devices in order to appropriately diagnose complications. The purpose of this pictorial essay is to review indications, components, normal imaging appearances, and complications of surgically and percutaneously implanted ventricular assist devices, intra-aortic balloon pumps, and cardiac meshes.

Emergency cardiac surgery in patients with acute coronary syndromes: a review of the evidence and perioperative implications of medical and mechanical therapeutics

Patients with acute coronary syndromes who require emergency cardiac surgery present complex management challenges. The early administration of antiplatelet and antithrombotic drugs has improved overall survival for patients with acute myocardial infarction, but to achieve maximal benefit, these drugs are given before coronary anatomy is known and before the decision to perform percutaneous coronary interventions or surgical revascularization has been made. A major bleeding event secondary to these drugs is associated with a high rate of death in medically treated patients with acute coronary syndrome possibly because of subsequent withholding of antiplatelet and antithrombotic therapies that otherwise reduce the rate of death, stroke, or recurrent myocardial infarction. Whether the added risk of bleeding and blood transfusion in cardiac surgical patients receiving such potent antiplatelet or antithrombotic therapy before surgery specifically for acute coronary syndromes affects long-term mortality has not been clearly established. For patients who do proceed to surgery, strategies to minimize bleeding include stopping the anticoagulation therapy and considering platelet and/or coagulation factor transfusion and possibly recombinant-activated factor VIIa administration for refractory bleeding. Mechanical hemodynamic support has emerged as an important option for patients with acute coronary syndromes in cardiogenic shock. For these patients, perioperative considerations include maintaining appropriate anticoagulation, ensuring suitable device flow, and periodically verifying correct device placement. Data supporting the use of these devices are derived from small trials that did not address long-term postoperative outcomes. Future directions of research will seek to optimize the balance between reducing myocardial ischemic risk with antiplatelet and antithrombotics versus the higher rate perioperative bleeding by better risk stratifying surgical candidates and by assessing the effectiveness of newer reversible drugs. The effects of mechanical hemodynamic support on long-term patient outcomes need more stringent analysis.

Evaluation and management of shock States: hypovolemic, distributive, and cardiogenic shock

Shock states have multiple etiologies, but all result in hypoperfusion to vital organs, which can lead to organ failure and death if not quickly and appropriately managed. Pharmacists should be familiar with cardiogenic, distributive, and hypovolemic shock and should be involved in providing safe and effective medical therapies. An accurate diagnosis is necessary to initiate appropriate lifesaving interventions and target therapeutic goals specific to the type of shock. Clinical signs and symptoms, as well as hemodynamic data, help with initial assessment and continued monitoring to provide adequate support for the patient. It is necessary to understand these hemodynamic parameters, medication mechanisms of action, and available mechanical support when developing a patient-specific treatment plan. Rapid therapeutic intervention has been proven to decrease morbidity and mortality and is crucial to providing the best patient outcomes. Pharmacists can provide their expertise in medication selection, titration, monitoring, and dose adjustment in these critically ill patients. This review will focus on parameters used to assess hemodynamic status, the major causes of shock, pathophysiologic factors that cause shock, and therapeutic interventions that should be employed to improve patient outcomes.