ABSTRACT
Over the last 30 years, there has been a significant change in the nature of infective endocarditis (IE). This has resulted from the rise of S. aureus valvular infections brought about by the development of various intravascular devices, prosthetic heart valves, the aging of the population, and the epidemic of intravenous drug abuse. In addition, there has been a corresponding increase in the immunosuppressed population caused by a variety of diseases and their treatments. Nowhere are these changes better reflected than in the patients cared for in the CCU. Most cases of CCU valvular infections should be classified as nosocomial IE (NIE) or healthcare-associated IE (HCIE). This term describes cases of IE in individuals who have been admitted to a hospital at least 72 hours prior to the onset of symptoms (NIE) or who have had a history of an invasive procedure with potential for producing a bloodstream infection during a hospitalization less than 8 weeks prior (HCIE). The term HCIE may be preferable to NIE, since it covers all sites that care for patients, such as infusion centers.
Patients who are admitted after major cardiac surgery for postoperative care are especially susceptible to developing NIE because of the wide variety of invasive monitoring, therapeutic lines, and urinary catheters within these units. Reasons for admitting IE cases to the CCU include congestive heart failure (64%) septic shock (21%), neurological deterioration (15%), and cardiopulmonary arrest (9%). While in the CCU, multiorgan failure developed in 64% of patients. Prosthetic valve endocarditis (PVE) occurred in 21%. Inpatient mortality was 84% for those treated medically and 35% for those undergoing surgical approaches. Staphylococcal species, including methicillin-sensitive S. aureus, methicillin-resistant S. aureus, and coagulase-negative staphylococci, account for 45% of cases. Streptococcal species constitute approximately 25%. Only 3%–4% were due to Candida spp. and Aspergillus spp., with a smaller percentage of gram-negative endocarditis.
A differential diagnosis of both infectious and non-infectious diseases is presented in this chapter. The non-classical signs and symptoms of NIE and HCIE are discussed. Formulating a working diagnosis and empiric therapeutic approach to ACCUIE is a clinical syndromic one based on combining characteristic clinical findings of the history, physical examination, non-specific laboratory clues, and key imaging studies. A similar approach is used to interpret the results of the definitive diagnostic tests as well as to understand the complications and prognosis of the valvular infection.
