IT 20 - Infective Endocarditis 2 - FER

8/12/2019 IT 20 - Infective Endocarditis 2 - FER

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Infective Endocarditis

October 11, 2005

Dr. Kanagala


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Microbiology: Organisms

Responsible Bacteria are the predominant cause

Fungi

Rickettsia

Chlamydia

Microorganisms vary dependent on riskfactors predisposing patient to IE

Staph Aureus= single most common cause


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Native Valve Endocarditis

Streptococcus responsible for more than

50% of cases

Staphylococci

Enterococci

Infection occurs most frequently in those

with preexisting valvular abnormality


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Staphylococci

Causes endocarditis in those with normal

and abnormal valves

Most are coagulase positive S.Aureus

Causes destruction of valves, multiple distal

abscesses, myocardial abscesses,

conduction defects, and pericarditis


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Enterococci

Patients generally have underlying valvular

disease

May occur following manipulation of

genitourinary or lower gastrointestinal tract

Remainder of cases caused by Haemphilus

Actinobacillus, Cardiobacterium, Eikenella,Kingella, Bartonella, or Coxiella Burnetti


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Diagnosis

Negative culture can occur in 5% ofpatients.

1/3 to are negative due to prior antibioticuse

In patients with culture negative IE, advise

lab to allow specialized testing to recoverthe causative organism which is needed toadequately treat


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IDU associated IE

Skin flora and contaminated injection devices arethe most frequent sources involved in IDU-associated IE

S. AureusMost common (50% of cases)

Streptococcal species

Gram negative Bacilli

Pseudomonas

Serratia species

Fungi

Candida


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Prosthetic Valve Endocarditis

Most commonly occur during the perioperativeperiod

S. epidermidis Most frequently isolated organism

Early PVE (w/i 60 days of surgery)

Assoc. with valve dysfunction and fulminant clinical

course Late PVE (beyond 60 days postop)

Disease course is less fulminant

Mycotic PVE (Aspergillus and Candida)

Larger vegetations


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Clinical Features

Acute IERapid onset of high fevers and rigorswith hemodynamic deterioration and death withindays to weeks if not treated

Assoc. with highly virulent organisms such as StaphAureus

Subacute IEIndolent course with progressiveconstitutional signs and symptoms and gradualdeterioration Assoc. with avirulent organisms such as viridans

streptococci


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Clinical Features

Bacteremia can produce signs and symptoms thatare often nonspecific usually within 2 weeks ofinfection

Most common course of disease (fevers, chills, nausea,vomiting, fatigue and malaise)

Fever is the most common symptom

Fever can be absent in pts with antibiotic use,

antipyretic use, severe CHF, or renal failure

Prosthetic valve patient with a fever requires IEwork up


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Cardiac Clinical Features

Heart murmurs are present in up to 85% of casesof IE.

Most commonly regurgitant lesions secondary tovalvular destruction

Acute or progressive CHF is the leading cause ofdeath in patients with IE (70% of patients)

Distortion or perforation of valvular leaflets

Rupture of the chordae tendinae or papillary muscles

Perforation of the cardiac chambers (rare)

Valvular abscesses and Pericarditis

Heart blocks and Arrhythmias


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Embolic Clinical Features

Extracardiac manifestations are the result of arterialembolization of fragments of the friable vegetation

CNS complications occur in 20-40% of cases (embolic

stroke with MCA affected most frequently) Retinal artery emboli may cause monocular blindness

Mycotic aneurysm may cause a SAH

IVDU can cause right sided lesions (tricuspid valve) Pulmonary complications

Pulmonary complications ( pulmonary infarction,

pneumonia, empyema, or pleural effusion)

Coronary artery emboli (Acute MI or myocarditis witharrhythmias)

Splenic infarction (LUQ abdominal pain)

Renal emboli (flank pain or hematuria)


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Clinical Features

Persistent bacteremia can stimulate the humoral andcellular immune systems resulting in circulating immunecomplexes

Petechiae

Red, nonblanching lesions that become brownafter several days (20-40%)

Conjunctivae, buccal mucosa, and extremities

Splinter hemorrhagesLinear dark streaks under the

fingernails (15%) Oslers nodesSmall tender subcutaneous nodules that

develop on the pads of the fingers or toes (25%)

Janeway lesionsSmall hemorrhagic painless plaqueslocated on the palms or soles

Roth spots

Oval retinal hemorrhages with pale centers


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Diagnosis

Diagnosis of IE requires hospitalization

Cultures

Echocardiogram

Clinical observation

Duke Criteria90% sensitive

Major Criteria

Minor Criteria


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Major Criteria

Positive blood culture for:

Strep bovis, Strep viridans, or HACEK group

Staph aureus or Enterococci

Microorganisms c/w IE from persistent positive

blood cultures

2 positive blood cultures drawn >12 hrs apart All of 3 or a majority of 4 or more positive blood

cultures


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Major Criteria

Echocardiographic involvement:

Mass on valve

Abscess

Dehiscence of prosthetic valve

New valvular regurgitation


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Minor Criteria

Predisposition: Heart condition or injection druguse

Fever > 38 degrees C Vascular: Emboli, conjunctival hemorrhages,

janeway lesions

Immunological: Glomerulonephritis, oslers nodes,

roth spots, and rheumatoid fever Positive blood cultures

Echocardiographic findings c/w IE


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Duke Criteria

Definite infective endocarditis

Microorganisms demonstrated by culture or histologicexamination of vegetation or emboli

Abscess with active endocarditis

Two major criteria

One major and three minor criteria

Five minor criteria

Possible endocarditis

Findings c/w IE that fall short of definite, but not rejected

Rejected

Firm alternate diagnosis

Resolution of manifestations of IE with abx for < 4 days

No pathologic evidence of IE at surgery or autopsy after 4 daysof abx


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DDx and Consideration of IE

IE should be considered in:

All febrile IDUs

Pts with a cardiac prosthesis and fever (ormalaise, vasculitis or new murmur)

Pts with new murmur or change in murmur

with evidence of vasculitis or embolization Any cardiac risk factor with unexplained fever

Any patient with a prolonged fever (>2 weeks)


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Evaluation of Bacteremia

All patients with suspected bacteremiashould have blood cultures drawn in the ED

prior to abx Blood cultures should be drawn in 3

different sites

Minimum of 10 ml blood in each bottle

Minimum of one hour between first and lastbottle


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Diagnostic Tests

ECG should be done in all pts with suspected IE

Nonspecific usually

Conduction abnormalities ( new LBBB, Prolonged PRinterval, new RBBB, complete heart block)

Junctional tachycardia

Chest Xray

Pulmonic emboli or CHF

Nonspecific lab tests

Anemia (70-90% of cases)

Elevated ESR (>90% of cases)

Hematuria


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Echocardiography

Mandatory in all pts with possible IE

Transthoracic Echo(TTE) should be done first.

Specificity for vegetations is 98%

Sensitivity varies but it is the highest with IDUs

because they more often have larger vegetations, rightsided valvular lesions and favorable precordialwindows.

Transesophageal Echo(TEE) has a higher sensitivity andspecificity than TTE

Recommended for the following:

Prosthetic valves

Pts with obesity, chest wall deformities, COPD

Intermediate or high probability of IE


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Treatment

Initial Stabilization

Rapid airway stabilization secondary to possible

respiratory or hemodynamic compromise( acidosis,

altered mental status, sepsis)

Cardiac decompensation may occur secondary to left

sided valvular rupture

Intraaortic balloon counterpulsation may be

indicated

Neurologic complications such as stroke

Standard stroke protocol


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Empiric Treatment

Therapy of suspected Bacterial Endocarditis

Uncomplicated history

Ceftriaxone or nafcillin plus gentamycin

IVDU, Congenital heart disease, MRSA, current abxuse Nafcillin plus gentamycin plus vancomycin

Prosthetic heart valve

Vancomycin plus gentamycin plus rifampin

Most patients will require 4 to 6 weeks ofantibiotic therapy


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Surgical Treatment

Indications for surgical management:

Severe valvular dysfunction: Acute CHF or

impaired hemodynamic status Relapsing prosthetic valve endocarditis

Major embolic complications

Fungal endocarditis

New conduction defects or arrhythmias

Persistent bacteremia


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IE Prophylaxis

Prophylaxis is indicated for:

Prosthetic heart valves

Congenital cardiac manifestations

Acquired valvular dysfunction

Hypertrophic cardiomyopathy

Mitral valve prolapse with documented regurgitation

History of endocarditis

Not indicated for the following:

MVP without regurgitation

Pacemakers

Physiologic murmurs

Prior CABG, angioplasty, ASD repair, VSD, or PDA


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IE Prophylaxis

Dental, oral, respiratory or esophageal

procedures

Amoxicillin or Ampicillin or Clindamycin

Genitourinary, gastrointestinal procedures

Ampicillin plus Gentamycin plus Ampicillin

(post) or Amoxicillin Alternate regimen: Vancomycin plus

Gentamycin


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Question 1:

T/F Streptococcus is responsible for more

than 50% of Native Valve Endocarditis.


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Question 2:

Embolic clinical features of infective

endocarditis include:

A) CNS complications

B) Pulmonary complications

C) Coronary Artery Emboli

D) All of the above


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Question 3:

Small hemorrhagic painless plaques located

on palms or soles are called?

A) Janeway lesions

B) Oslers nodes

C) Roth Spots

D) Splinter hemorrhages


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Answers

1) T

2) D

3) A

IT 20 - Infective Endocarditis 2 - FER

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