​Kembara Xtra - Medicine - Infective Endocarditis

​Kembara Xtra - Medicine - Infective Endocarditis 
Introduction 

An infection of the inner layer of the heart, known as infectious endocarditis (IE), can affect the valves (native or prosthetic), interventricular septum, intracardiac devices, chordae tendineae, and mural endocardium. IE is a widespread problem that, if neglected, almost always results in death.
An infection of the valvular (most commonly) and/or mural (in extremely rare cases) endocardium
Synonym(s): bacterial endocarditis; subacute bacterial endocarditis (SBE); acute bacterial endocarditis (ABE) 
Affected System(s): Cardiovascular, Endocrine/Metabolic, Hematologic/Lymphatic, Immunologic, Pulmonary, Renal/Urologic, Skin/Exocrine, Neurologic Affected System(s): Cardiovascular, Endocrine/Metabolic

Epidemiology (Prevalence and Incidence) 

Males are affected more frequently (the odds range from 3:2 to 9:1). Individuals older than 60 years of age account for more than fifty percent of all cases in the United States.

Variable rates of occurrence are associated with native valve endocarditis due to the evolution of the disease's definition over the course of time.
1.5% to 3% incidence one year after prosthetic valve replacement; 3% to 6% incidence five years after replacement
Can be obtained in the community or in hospitals; most usually affects the mitral valve and aortic valve (increased left-sided pressures and turbulent flow). Increasing incidence of cardiovascular device–related infections due to higher frequency of implantable devices.

Causes and effects: etiology and pathophysiology 

IE is most frequently brought on by a thrombus that is not made of bacteria and that attaches to an endocardial surface, in conjunction with a bacterial source that is adequate to seed the thrombus. This may be the result of direct bacterial invasion or trauma to the valvular tissue:
Native valve endocarditis – Acute: Staphylococcus aureus; Streptococcus groups A, B, C, G; Streptococcus pneumoniae; Staphylococcus lugdunensis; Enterococcus spp.; Haemophilus influenzae or parainfluenzae; Neisseria gonorrhoeae Native valve endocarditis – Suba
Intravenous drug abuse endocarditis (IVDA) (most usually affecting the tricuspid valve): Staphylococcus aureus and Enterococcus species; Pseudomonas aeruginosa, Burkholderia cepacia, and other gram-negative bacilli; Candida species.
● Prosthetic valve endocarditis
– Early (≥12 months after valve implantation): S. aureus,
S. epidermidis; gram-negative bacilli; Candida spp.,
Aspergillus spp.
– Late (>12 months after valve implantation): α-hemolytic
streptococci, S. aureus, Enterococcus spp., S.
epidermidis, Candida spp., Aspergillus spp.
Culture-negative endocarditis accounts for ten percent of cases and can be caused by Bartonella quintana (found in homeless people), Brucella spp., fungi, Coxiella burnetii (which causes Q fever), Chlamydia trachomatis, Chlamydophila psittaci, and HACEK organisms.
coagulase-negative staphylococci or S. aureus are the bacteria of choice for device-related endocarditis.

Risk Factors 

Injection drug usage, intravenous catheterization, certain cancers (colon cancer), bad dentition or infection, persistent hemodialysis, age greater than 60 years, and male sex are all risk factors.
High risk with the following conditions: structural heart disease, artificial cardiac valves, valvular disease, implanted devices, and complete parenteral nutrition
- Earlier Version of IE
- Congenital heart disease (CHD): unrepaired cyanotic CHD, including palliative shunts and conduits; repaired CHD with prosthetic device during the first 6 months; repaired CHD with residual abnormalities at or near prosthetic site; cardiac transplant with valvulopathy; cyanotic CHD that has not been repaired.

Prevention
observing proper dental hygiene Antibiotic prophylaxis is only suggested for patients who have a high risk of bad consequences in the event that IE develops. Administer thirty to sixty minutes before the surgery, with the exception of vancomycin, which needs to be given one hundred and twenty minutes before the procedure.
Procedures that require prophylaxis - Procedures and biopsies of the oral cavity and upper respiratory tract:
Amoxicillin, 2 grams taken orally 30 to 60 minutes before the procedure, or ampicillin, 2 grams given intravenously or intramuscularly, are the prophylactic options that come first.
Clindamycin is no longer advised for use as a dental prophylaxis since it is linked to more frequent and severe adverse effects (such as an increased risk of contracting an infection caused by Clostridium difficile).
- GI/GU: Patients who have an existing infection and are scheduled to undergo procedures are the only ones who should have coverage for enterococcus (with penicillin, ampicillin, piperacillin, or vancomycin).
- Perioperative cefazolin 1 to 2 g IV 30 minutes before to surgery or vancomycin 15 mg/kg (maximum 1 g) may be administered in the case of cardiac valvular surgery or the insertion of prosthetic intracardiac or intravascular materials. (penicillin-allergic patients) 60 minutes preoperative (1)[B]
– Skin and soft tissue: incision and drainage of contaminated tissue; use of medicines active against skin infections (such as cefazolin 1 to 2 g IV q8h or vancomycin 15 mg/kg q12h; maximum 1 g) if the patient is allergic to penicillin or if methicillin-resistant Staphylococcus aureus (MRSA) is suspected.

Conditions That Often Occur Together 

The majority of people diagnosed with IE have one or more prior illnesses.

Diagnosis 

● Modified Duke Criteria (definite: 2 major criteria, or 1 major and 3 minor criteria, or 5 minor criteria; possible: 1 major and 1 minor or 3 minor criteria)
● Major clinical criterion
- Isolation of a characteristic bacterium for infectious endocarditis from two different blood cultures or persistently positive blood culture constitutes a positive blood culture.
– A single positive blood culture for C. burnetii or an anti–phase-1 IgG antibody titer that is greater than 1:800
– New valvular regurgitation (change in existent murmur is not significant) – Positive echocardiogram: presence of vegetation, abscess, or new partial dehiscence of prosthetic valve
Minor requirements include the presence of a predisposing cardiac disease or the usage of intravenous drugs.
- Fever ≥38.0°C (100.4°F)
- Vascular manifestations including arterial emboli, septic pulmonary infarcts, mycotic aneurysms, cerebral hemorrhages, conjunctival hemorrhages, and Janeway lesions
glomerulonephritis, Osler nodes, Roth spots, and rheumatoid factor (RF) are examples of immunologic phenomena.
- Microbiologic evidence

Providing an Account of History 

Fever (temperature more than 38 degrees Celsius), chills, cough, dyspnea, orthopnea; particularly in subacute endocarditis: night sweats, weight loss, and fatigue
Please go over the potential dangers.
The patient presented with symptoms consistent with a transient ischemic attack (TIA), a cerebrovascular accident (CVA), or a myocardial infarction (MI).

The Patient's Clinical Examination
The majority of people who have IE have a new murmur or a change to an already present murmur. If the function of the valves is impaired, heart failure symptoms are likely to present themselves.
splinter hemorrhages in fingernail beds, Osler nodes, Roth patches, Janeway lesions, palatal/conjunctival petechiae, splenomegaly, and hematuria are some of the peripheral stigmata of infectious endocarditis.
Neurologic findings associated with a cerebral vasculature accident

Differential Diagnosis 

Vasculitis, temporal arteritis, fever of unknown origin, infected central venous catheter, marantic endocarditis, connective tissue disorders, intra-abdominal infections, rheumatic fever, salmonellosis, brucellosis, Lyme disease, malignancy, TB, atrial myxoma, septic thrombophlebitis; these are just few of the conditions that can be caused by

Results From the Laboratory 

If the patient is not in a severe condition, three separate blood culture samples should be taken at least two hours apart from three different sites prior to the administration of antibiotics. Subsequent blood samples should be taken every 48 to 72 hours until the bacteria are gone.

If the patient is severely unwell, three separate blood culture samples should be taken over the course of an hour before beginning any empirical treatment.

Anemia; reduced C3, C4, CH50; and RF in subacute endocarditis Elevated serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) Hematuria Serologies for Chlamydia, Q fever, Legionella, and Bartonella should be considered in "culture-negative" endocarditis.

CT scan Emboli, abscesses, and/or infarction Transthoracic (TTE) or transesophageal echocardiogram (TEE [recommended]) echocardiography

● Immune-complex glomerulonephritis
Initial Tests (lab, imaging)
Findings from routine laboratory procedures are frequently vague and frequently represent secondary sequelae of infectious endocarditis (IE).
Results from the laboratory:
- Nonspecific
• Increased levels of inflammatory markers • Leukocytosis, plus radiofrequency
Anemia that is neither normochromic nor normocytic
- Observations that are associated with the involvement of the secondary system RBC casts Microscopic hematuria, proteinuria, and pyuria
● Imaging – ECG: In many cases, the presence of new or evolving indications of conduction illness, such as atrioventricular blocks and/or bundle branch blocks, is an indication of paravalvular and/or myocardial involvement.
- TTE/TEE: presence of vegetations, newly developed or worsening valvular regurgitation, newly developed partial dehiscence of prosthetic valve, newly developed intracardiac shunting.
Additional Examinations, as well as Other Important Factors
Follow-up imaging, if necessary, to assess the possibility of involvement of secondary systems or to rule out other potential causes:
A chest x-ray has the potential to identify symptoms of congestive heart failure or evidence of septic pulmonary emboli.
Chest, abdominal, and pelvic CT scans should be used to evaluate distal locations of infection and/or infarction.

Medication 

First in Line: Begin treatment based on clinical judgment after three separate sets of blood cultures have been taken. Results guide treatment.
— For native valves, intravenous ampicillin-sulbactam combined with intravenous and intramuscular gentamicin. Vancomycin IV combined with gentamicin IV/IM and ciprofloxacin PO/IV should be used in patients who are allergic to penicillin (2) [A].
- If it has been less than 12 months since your operation, you should take vancomycin intravenously together with gentamicin intravenously or intramuscularly and rifampin orally. If it has been more than 12 months, follow the native valve regimen.

Viridans streptococci that are susceptible to penicillin or S. bovis – Native valve: penicillin G IV continuously or ceftriaxone IV/IM for a period of four weeks (1)[B]
- Prosthetic valve: penicillin G intravenously for six weeks or ceftriaxone intravenously and intramuscularly (IV/IM) for two weeks of treatment.
● Penicillin-resistant viridans streptococci or S. bovis
- Native valve: penicillin G IV + gentamicin IV/IM (1)[B]
- Gentamicin IV/IM for 2 weeks and either penicillin G IV or ceftriaxone IV/IM for 6 weeks to treat prosthetic valve infections.
oxacillin or nafcillin administered intravenously for a period of six weeks for patients with penicillin-susceptible Staphylococcus aureus who have a native valve. Vancomycin administered intravenously for a period of six weeks is recommended for oxacillin-resistant strains.
oxacillin or nafcillin administered intravenously, rifampin administered intravenously and orally for a period of six weeks, and gentamicin administered intravenously during the first two weeks. Vancomycin intravenously (IV), rifampin intravenously or orally (IV/PO), and gentamicin intravenously or intramuscularly (IV/IM) for the first two weeks of treatment of oxacillin-resistant strains.
• Staphylococcus aureus resistant to penicillin: native valve treatment with vancomycin for six weeks or daptomycin intravenously for six weeks
– Prosthetic valve: vancomycin + rifampin IV/PO + gentamicin IV/IM for 2 weeks. – Penicillin-sensitive enterococcus – Native or prosthetic valve: ampicillin IV or penicillin G IV + gentamicin IV for 4 to 6 weeks.

HACEK organisms: ceftriaxone intramuscularly or intravenously for a period of four weeks (1)[B]; ampicillin-sulbactam intravenously for a period of four weeks; or ciprofloxacin orally or intravenously for a period of four weeks 

Surgical Methods and Operations 

In half of all cases of IE, surgical treatment is necessary. Indications: Heart failure owing to aortic or mitral valve disease - Prevention of embolism: aortic or mitral valve vegetations greater than 10 millimeters with previous embolic events; isolated very big vegetation greater than 15 millimeters; in patients who have had a major ischemic stroke, surgery is delayed for at least 4 weeks, if possible.

Uncontrolled infection: fever that does not go away and positive cultures for more than seven to ten days; infection caused by fungi or a resistant organism; presence of abscess, fistula, false aneurysm, or growing vegetations
Initial implantation of a prosthetic valve IE

Keep in Touch 

Patient Monitoring Perform a baseline electrocardiogram, and continue to monitor ECG for conduction abnormalities and MI over the first several weeks of treatment.

* TTE at the end of the course of treatment
● Blood cultures q48h till negative
PROGNOSIS
The mortality rate of IE after one year is thirty percent. Late complications contribute to poor prognosis. Heart failure, re-infection, and brain emboli are some of these conditions. There is a 60%–90% chance of surviving after 10 years.

Complications 

Cerebral problems are the most common and serious of all the sequelae, affecting 15–20% of patients.

Emboli: arterial, infectious (e.g., abscesses of heart, lung, brain, meninges, bone, and pericardium) - Emboli can be seen in the pericardium, bone, and meninges. Patients diagnosed with IE who need to be admitted to the intensive care unit most frequently develop neurological problems. In twenty percent of instances, the first sign or symptom of IE is an ischemic stroke.

Disorders of the immune system and inflammation (such as arthritis, myositis, and glomerulonephritis)
Additional concerns include congestive heart failure, a ruptured valve cusp, an aneurysm in the sinus of Valsalva, arrhythmia, and mycotic aneurysms.

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