AACN clinical issues最新文献

Acute coronary syndrome (ACS) is defined as the spectrum of diagnoses from angina to sudden cardiac death caused by ischemic coronary artery disease. Although cardiovascular disease is the leading cause of death of adults in the United States, the ability to diagnose ACS is not always definitive. Cardiac markers are laboratory tests that are used to assist in the diagnosis. Research continues to develop new and refine "old" cardiac markers to improve diagnostic testing that then leads to appropriate and timely interventions for patients with ACS. The purpose of this article is to review the cardiac markers and their role in the diagnosing, as well as predicting the risk of ACS.

Accurate assessment and treatment of disturbances in oxygenation are crucial to optimal outcomes in critically ill patients. Oxygenation is dependent upon adequate pulmonary gas exchange, oxygen delivery, and oxygen consumption. Each of these physiologic processes may vary independently in response to pathophysiologic conditions and therapeutic interventions. The author reviews diagnostic measures available to evaluate pulmonary gas exchange, oxygen delivery, and oxygen consumption in critically ill patients. Currently available tools and their potential value as well as key methodological limitations are addressed. Failure on behalf of clinicians to fully appreciate these limitations can lead to misdiagnoses and inappropriate treatment. The aim of this article is to help advanced practice nurses more fully understand the implications and limitations of these diagnostic measures to ensure accurate assessment and treatment of disturbances in oxygenation.

Bedside evaluation of a patient's intravascular volume status is challenging, even for the seasoned practitioner. There is no single diagnostic test to determine whether a patient is hypovolemic, hypervolemic, or euvolemic. Often, underlying or concomitant disease states, medications, and other therapeutics can make available data difficult to interpret. Therefore, a combination of clinical evaluation, laboratory studies, and other diagnostics are required to make a clinical judgment regarding volume status. Patients who demonstrate alterations in their volume status are likely to have electrolyte abnormalities as well, and assessment of serum electrolyte values and potential therapeutic interventions is a vital piece in caring for critically ill patients.

An advanced practice nurse (APN) often encounters patients with alterations in neurologic functioning, regardless of the practice setting. In many situations, the APN will be asked to perform the initial evaluation and determine if additional testing and consultation are indicated. For the APN who does not routinely encounter these patients, the experience may be challenging. This article presents an organized approach to the examination of patients with alterations in mentation and level of consciousness and considerations for differential diagnosis.

Until recently, sudden cardiac death in a young person often remained an unexplained tragedy. However, in the last decade there have been dramatic advances in medical knowledge regarding inheritable dysrhythmias that increase the risk of SCD in otherwise healthy young individuals. The primary mechanism in this group of dysrhythmias appears to be an alteration of cardiac repolarization. In some diseases, the specific genes affected and even precise cellular mechanisms have been identified. The information about these diseases is often complex and rapidly evolving, challenging both healthcare providers and the families who must make important decisions based on emerging and incomplete information. The purpose of this article is to describe current understanding of the repolarization-related dysrhythmias and discuss the clinical implications for advanced practice nurses.

In the United States over 350,000 individuals die annually from sudden cardiac arrest due to ventricular tachyarrhythmias. Numerous large-scale clinical trials have consistently demonstrated that implantable cardioverter defibrillators (ICDs) reduce mortality among appropriately selected patients who have survived an episode of potentially life-threatening ventricular arrhythmia (secondary prevention) or are at risk for ventricular arrhythmia (primary prevention). Despite the demonstrated success of the ICD, many patients often experience unique physical, emotional, and psychosocial needs that can directly impact their overall quality of life (QOL). The most common psychological disturbances following ICD implantation include stress, anxiety, depression, or fear, typical of any chronic illness. Additionally, ICDs impose unique emotional pressures relating to altered body image, painful shocks, and the possibility of hardware failure. The random nature of shocks commonly induces feelings of isolation and powerlessness and the experience of shocks is directly linked to poor QOL outcomes. Lifestyle changes, such as restrictions on driving, eligibility for employment, marital and social relationships, sexual intimacy, or participation in recreational activities can significantly affect the ICD patient's psychological and emotional well-being. The purpose of this article is to review the QOL data from several large-scale clinical trials of ICD patients as well as to examine specific QOL issues such as driving restrictions, occupational, and recreational concerns.

Vasovagal syncope is a condition better known as neurocardiogenic or neurally mediated syncope. Dysautonomic syncope is the irregular neuroautonomic response during the body's attempt to maintain homeostasis. Both types of syncope are associated with orthostatic hypotension and are nonlethal. The underlying pathophysiology manifests the vast symptoms suffered by the individual. Research continues to develop new markers to improve diagnostic testing and therapies for treatment. Advanced practice nurses now have a new tool with Head-Up Tilt Training Programs to offer the patients who suffer from frequent and refractory neurocardiogenic and dysautonomic syncope.

Temporary cardiac pacing provides electrical stimulation to a heart compromised by disturbances in the conduction system causing hemodynamic instability. The use of a temporary pacemaker to treat a bradydysrhythmia or in some cases, a tachydysryhthmia, is undertaken when the condition is temporary and a permanent pacemaker is not necessary or available in a timely fashion. Temporary cardiac pacing is utilized in acute situations and for critically ill patient populations requiring immediate therapy. This article discusses the various indications and contraindications to temporary cardiac pacing therapy, reviews the different modalities of temporary pacemakers, and outlines critical considerations in the management of patients being treated with a temporary pacemaker.

Idiopathic ventricular tachycardia in patients with an anatomically normal heart is a distinct entity whose management and prognosis differs from ventricular tachycardia associated with structural heart disease. The tachycardia's QRS morphology on surface electrocardiogram (ECG) predicts the site of origin and is commonly classified as right ventricular tachycardia or left ventricular tachycardia. The tachycardia is further characterized by clinical features such as repetitive monomorphic ventricular tachycardia (VT), paroxysmal sustained VT, or catecholamine dependent VT. The responsiveness of VT to adenosine or verapamil is useful in differentiating the mechanism, which may be reentry or triggered activity. Patients generally tolerate the tachycardia but may present with dizziness, syncope, or palpitations. Sudden cardiac death is rare in this patient population. Patient work-up should include 12-lead ECG, signal-averaged ECG, ambulatory ECG recording, stress testing, and tests to rule out structural heart disease such as echocardiography, cardiac angiography, endomyocardial biopsy, or magnetic resonance imaging. Treatment options include pharmacotherapy or catheter ablation. Although the prognosis of these patients remains excellent, they should continue to have periodic cardiac follow-up to rule out latent progressive heart disease such as arrhythmogenic right ventricular dysplasia or cardiomyopathy or other forms of cardiomyopathies.

Atrial fibrillation (AF) is the most common dysrhythmia in North America. Paroxysmal or persistent AF affects an estimated 2.8 million individuals, causes significant morbidity, and is associated with 1 billion dollars in healthcare costs each year in the United States. An aging population, the prevalence of hypertension, and the emergence of heart failure as the final common pathway of heart disease finds us in an age where the incidence of AF is ever increasing and the management challenges are indeed an expanding clinical problem. Although guidelines for selection of the appropriate pacing mode have been published, device therapy for the control of AF and paroxysmal AF is an emerging clinical management strategy. In 2001 The American College of Cardiology (ACC)/American Heart Association (AHA) published a document to revise the 1998 guidelines for device therapy, and even now these guidelines require elucidation and inclusion for the use of cardiac pacing device therapy for the control of atrial dysrhythmia. Choosing a complex system, in particular for the patient with persistent and symptomatic atrial dysrhythmia, is a most intricate challenge for the healthcare professional and the healthcare system. Rate dependent effects on refractoriness, reduction of ectopy, remodeling of the substrate, and prevention of pauses have been described as the potential mechanisms responsible for the rhythmic control effect attributed to atrial pacing. However, while permanent cardiac pacing is required for patients with symptomatic bradycardia with atrioventricular block and AF, the concept of pacing for the primary prevention of AF is novel. Pacing algorithms, single site, biatrial, and dual-site atrial pacing and site-specific pacing have all been studied as substrate modulators to prevent recurrent atrial dysrhythmia.A dilemma exists surrounding the primary approach for the control of symptomatic AF with rapid ventricular response. The question remains: should it be to maintain the sinus rhythm or to control the ventricular response rate to the AF and anticoagulate? Variations in the population studied, differences in the pacing algorithms and protocols, and a lack of definitive end points account for the variable results of the studies completed thus far. With the current data available, it appears that for individuals with sinus node dysfunction and paroxysmal AF in combination with a bradyarrhythmia indication for pacing, suppression algorithms may play an additive role with full atrial pacing in the management and reduction of episodes and burden of paroxysmal AF. The goal of these therapies is to reduce the symptoms and hopefully decrease the healthcare costs associated with paroxysmal and persistent AF with uncontrolled ventricular response.