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February 22, 2023
Clinical Updates for Managing Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Adults: Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) are infections with notably high morbidity and mortality. High rates of persistent bacteremia and resource constraints have prompted practitioners to examine novel treatment modalities to improve patient outcomes. New literature has evaluated combination therapy with vancomycin or daptomycin with beta-lactam antibiotics as well as sequential long-acting lipoglycopeptides to facilitate early discharge in patients with MRSA BSI.
Upon completion of the chapter, the reader will be able to:
Differentiate the causes and development of infective endocarditis (IE).
Classify patient risk factors for potential causative organisms for IE.
Identify the clinical presentation and laboratory evaluation for IE.
Assess diagnostic criteria used to evaluate a patient suspected of having IE.
Discuss the most likely causative pathogens of IE, particularly in specific patient populations.
Develop appropriate pharmacologic treatment recommendations for patients with IE.
Describe oral step-down therapy options appropriate for specific types of IE and organisms.
Define appropriate patient populations requiring prophylactic treatment and differentiate appropriate drug regimens.
Devise a monitoring plan for patients with IE to determine treatment efficacy and discern any adverse effects.
Infective endocarditis (IE) is a serious infection affecting the lining and valves of the heart. Although this disease is mostly associated with infection of the heart valves, whether native or prosthetic valves, septal defects or intravascular devices may also become involved in some cases. Bacteria are the primary cause of IE; however, fungi and atypical organisms may also be responsible pathogens.
Typically, IE is classified into two categories: acute or subacute. Differences between the two categories are based on the progression and severity of the disease. Acute disease is more aggressive, characterized by high fevers, leukocytosis, and systemic toxicity, with death occurring within a few days to weeks. This type of IE is often caused by more virulent organisms, particularly Staphylococcus aureus. Subacute disease is often caused by less virulent organisms, such as viridans group streptococci, producing a slower and more subtle presentation. It is characterized by nonspecific symptoms including fatigue, low-grade fever, and weight loss, with death occurring in several months.
Successful management of patients with IE is based on proper diagnosis, treatment with appropriate therapy based on organism identification and susceptibilities, and monitoring for complications, adverse events, or development of resistance. IE has varied clinical presentations; therefore, patients with this infection may be found in any medical subspecialty (ie, medicine, surgery, and critical care).
In the United States, there are roughly 40,000 new cases annually, accounting for an incidence of approximately 3 to 15 cases per 100,000 persons-years.1-4 Although the exact number of cases is ...