Infective endocarditis
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Transcript of Infective endocarditis
Infective EndocarditisPRATIK KUMAR
080201186
DefinitionInfection of the endocardial surface of heart characterized by - Colonization or invasion of the heart valves (native or
prosthetic) or the mural endocardium by a microbe, - leading to formation of bulky, friable vegetation composed
of thrombotic debris and organisms- often associated with destruction of underlying cardiac
tissue.
Sites involved•Heart valves
•Ventricular septum defects
•Mural endocardium
• Intracardiac devices
• INFECTIVE ENDARTERITIS – analogus
ACUTE ENDOCARDITIS
• Destructive and tumultuous infection, frequently of a previously normal heart valve, with a highly virulent organism
• Hematogenoulsy seeds
• If untreated, leads to death within weeks
SUBACUTE ENDOCARDITIS
• Organisms of low virulence causing infection in a previously abnormal heart, particularly on deformed valves.
• Disease appear insidiously and pursue a protracted course of weeks to month
• Recover after appropriate antibiotic treatment
Classification
CARDIAC AND VASCULAR ABNORMALITIES
• RHD
• Myxomatous mitral valve
• Degenerative calcific valvular stenosis
• Bicuspid aortic valves
• Prosthetic valves
HOST FACTORS
• Neutropenia
• Immunodeficiency
• Malignancy
• Therapeutic immunosuppression
• Diabetes mellitus
• Alcohol
• IV drug abuse
Predisposing factors
Microbiology•Staphylococcus aureus (35%) : Either healthy or deformed valves, IV drug
abusers (polymicrobial), devices
•Streptococcus viridans (32%) : Native but previously damaged/abnormal valves
•Enterococci (8 %)
•CoNS - S. epidermidis (4%): Prosthetic valve endocarditis, devices
•G –ve bacilli of HACEK group (4%)
•Yeast and Fungi(1%)
•Culture negative endocarditis (5 %)
PathogenesisPortal of entry:◦ Dental / Surgical Procedures◦ Contamination by IV drug use◦ Obvious infections (RS/Skin)◦ Occult source from gut, oral cavity◦ Trivial injuries.◦ Intravascular catheter infection◦ Nosocomial wounds◦ Chronic invasive procedures
Endothelial Injury
Uninfected Platelet-Fibrin thrombus (NBTE)
Transient bacteremia and attachment at NBTE
Proliferation and pro-coagulant state
Infected, friable, bulky vegetation
Morphology• Friable, bulky vegetation containing fibrin, inflammatory cells, and microbes
• Aortic and mitral valves involved most commonly.
• Right side valve involvement in iv drug users.
Constitutional symptoms
--- Cytokine release ?
Symptoms
- Damage to intracardiac structures
- Embolization of vegetation fragments
- Hematogenous infection
- Immune complex
Clinical features
Sub-acute Endocarditis
• Persistent fever• Constitutional symptoms• New signs of valve
dysfunction• Heart failure
• Embolic Stroke• Peripheral arterial
embolism
• Other features
Definitive Endocarditis if,
- Two major or,
- One major and three minor or,
- five minor
Possible Endocarditis if,
- One major and one minor or,
- Three minor
Modified Dukes Criteria for diagnosis of Infective Endocarditis
Major CriteriaPositive blood culture ◦Typical organism from two cultures ◦Persistent positive blood cultures taken > 12 hours apart ◦Three or more positive cultures taken over more than 1 hour.
Endocardial involvement ◦Positive echocardiographic findings of vegetations ◦New valvular regurgitation
Minor Criteria
•Predisposition: Predisposing valvular or cardiac abnormality • Intravenous drug misuse •Pyrexia ≥38°C (≥100.4°F)•Embolic phenomenon •Vasculitic/ immunologic phenomenon •Blood cultures suggestive: -organism grown but not achieving
major criteria •Suggestive echocardiographic findings
INVESTIGATIONS
AVINASH BAJJURI
.
Microbiology Blood cultures:Key diagnostic investigation in infective endocarditis.Isolation of microorganism from culture is important for
diagnosis and also for treatment.At least 3 sets of samples should be taken from different
venepuncture sites over 24 hours.
Serology Can be sent when the diagnosis is suspected and the
cultures are negative.They aid in cases where the organisms will not grow in
blood cultures(Coxiella,Legionella,Bartonella)ECG
To detect complications like MI,conduction abnormalities.CHEST X RAY
.
EchocardiographyIt can identify the presence and size of
vegetations,detect intracardiac complications and assess cardiac function.
Transthoracic echocardiography is noninvasive and has high specificity for visualising vegetations.
Transoesophageal echocardiography is more sensitive than TTE.It can detect small vegetations,prosthetic endocarditis and intra cardiac complications.
.
Complete blood counts
may show anamia and increased WBC counts.Urea and Creatinine:
may be elevated due to glomerulonephritisLiver biochemistry:
Serum alkaline phosphatase may be increasedInflammatory markers
CRP,ESR are increased in infection .CRP also helps in monotoring response to therapy.
Urine
proteinuria and hematuria occur frequently.
TREATMENTAntimicrobial Therapy
Therapy requires identification of specific pathogen and its susceptibility to antimicrobials.
Empirical therapy should be started as soon as possible targeting most likely pathogens.
Bactericidal drugs should be used.
Resolution of fever occurs in 5 to 7 days.if fever persists patient should be evaluated for complications like paravalvular abscess and extracardiac abscess.
Serologic abnormalities resolve slowly and do not reflect response to treatment.
Antibotic regimen for infective endocarditis Streptococci
Benzyl penicillin (1.2g 4 hourly) 4-6 weeks
Gentamicin (1mg/kg 8-12 hourly) 4-6 weeksEnterococcio Ampicillin sensitive
Ampicillin (2 g 4 hourly) 4-6 weeks, and
Gentamicin (1mg/kg 8-12 hourly) o Ampicillin resistant
Vancomycin(1g 12hourly) 4-6 weeks, and
Gentamicin (1mg/kg 8-12 hourly)
StaphycoccioPenicillin sensitive
Benzyl penicillin I.V(1.2 g 4 hourly)oPenicillin resistant but methicillin sensitive
Flucloxacillin I.V (2g 4 hourly )oBoth penicillin and methicillin resistant
Vancomycin I.V (1g 12 hourly) and
Gentamicin
.
Surgery
Indications patients with direct extension of infection to
myocardial structuires.Prosthetic valve dysfunction.Congestive heart failure.Badly damaged valves.IE caused by fungi or gram-ve or resistant organisms.Large vegetations on echocardiographyRecurrent embolic attacks.
Prophylaxis
High risk category prosthetic cardiac valvesPrevious bacterial endocarditis,even in absense of
heart disease.Complex cyanotic congenital heart disease(TGA,TOF) Surgically constructed systemic pulmonary shunts.
Moderate risk categoryRheumatic and other valvular dysfunctionCongenital cardiac malformationsHypertrophic cardiomyopathyMitral valve prolapse with valvular regurgitation
Regimen for IE prophylaxis
Standard oral regime
Amoxicillin 2 g 1hr before procedure
Inability to take oral medication
Ampicillin 2g IV or IM 1hr before procedurePenicillin allergy
Clindamycin 600 mg
Clarithromycin 500 mg
Cephalexin 2 g.
Thank you.