Week 8: Chp 30: Infective Endocarditis Flashcards
IE can be classified as
native (own) or prosthetic or as right or left sided
What valves does IE affect?
mostly the native mitral or aortic valves
Risk Factors for Infective Endocarditis
- age (>60)
- immunodeficiency
- IV drug use
- diabetes mellitus
- presence of prosthetic heart valves
- prior history of endocarditis
- congenital or structural heart disease
- presence of an intravascular access or implanted cardiac device
- poor oral hygiene or periodontal disease
- patients on hemodialysis
- patients with frequent exposure to the healthcare system or invasive procedures
- rheumatic heart disease
What is Infective Endocarditis
infection of the innermost layer of the heart, the endocardium, most typically affecting the heart valves
How does IE begin?
begins with damage to the endocardial lining of the heart, which can occur as a result of turbulent blood flow; turbulent blood flow is often caused by valve dysfunction
Pathophysiology of IE; path of how it develops
begins with damage to the endocardial lining of the heart (due to turbulent flow)
- platelet and fibrin deposit onto the injured area, forming what is known as a nonbacterial thrombotic endocardial lesion
- microorganisms introduced into the bloodstream through patient exposures circulate and can become trapped under the layers of platelet and fibrin deposits
- these microorganisms and deposits grow into clumps known as vegetation which can severely damage the valves of the heart
Most common causative organism of IE are
- Staphylococcus and Streptococcus
- can also be caused by other bacteria, viruses, and fungi
- the source of exposure to microorganisms in the blood has been historically linked to dental and other invasive procedures; but repeated exposures to microorganisms are more likely to cause IE than a exposure during a single dental or other invasive procedure
Etiology of IE
generally bacterial origin
-Staphylococcus and Streptococcus
Vegetation
microorganisms and deposits grow into clumps known as vegetation
-which can severely damage the valves of the heart
Clinical Manifestations
- Osler’s nodes: red, painful nodes in the pads of the fingers and toes
- Janeway Lesions: red, painless spots on the palms and soles
- splinter hemorrhages: tiny blood clots that run vertically under nails
- heart murmur; the sound heard when there is turbulent blood flow across a heart valve
- also experience HF, arrhythmias, weight loss, or night sweats
- fever, fatigue, confusion (in older adults)
Diagnostic Tests
Tests used to confirm IE are blood cultures, two sets from different sites
- transthoracic echocardiogram (TTE) or
- transesophageal echocardiogram (TEE)
Diagnostic Tests: Echocardiography
can identify valve dysfunction, vegetative growth, abscesses, and changes in heart size and pumping ability that can occur with IE
Medication management
consists of IV antibiotic therapy
- increasing trend of microbial resistance has led to the use of combination therapy
- standard duration of treatment is 4 to 6 weeks; may be longer if you have prosthetic valves
- often discharged home on IV antimicrobial therapy
- Oral antimicrobial therapy are rarely used as initial treatment
- repeated blood cultures may be obtained until results are negative, indicative of adequate bactericidal effects
- prophylactic use of oral antibiotics is not routinely recommended but is used for patients at high risk
Safety Alert
to prevent IE and reduce valvular disease, prophylactic antibiotics are recommended before dental procedures, and meticulous oral hygiene should be encouraged for patients at highest risk, such as those with a history of IE, intracardiac prosthetic material such as valves and defect closure devices, cardiac transplant, and congenital heart disease
How to choose Antimicrobial Agents
complex and based on the organism cultured and the sensitivity report, right sided versus left sided IE, native versus prosthetic valve involvement, patient comorbidity, and other factors
-infectious disease specialists are often consulted
Various antimicrobials for the treatment of IE
-Penicillin G, ceftriaxone, vancomycin, nafcillin, and gentamicin may be considered in various combinations
Treatment of IE
- medications
- surgical management
- supportive treatment for the common complications of IE, especially HF, is also indicated to optimize cardiac output and tissue perfusiom
Surgical Management
- valve repair or replacement
- surgery can remove infected tissue and reduce mortality and complications but has significant risks
- timing of surgery is controversial, due to lack of definitive evidence but early surgery is recommended for cases in which antimicrobial therapy has been ineffective in controlling the infection or when complications such as embolic events or HF are observed