Infective Endocarditis October 11, 2005 Dr. Kanagala.
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Transcript of Infective Endocarditis October 11, 2005 Dr. Kanagala.
Microbiology: Organisms Microbiology: Organisms ResponsibleResponsible
Bacteria are the predominant causeFungiRickettsiaChlamydiaMicroorganisms vary dependent on risk
factors predisposing patient to IEStaph Aureus= single most common cause
Native Valve EndocarditisNative Valve Endocarditis
Streptococcus responsible for more than 50% of cases
StaphylococciEnterococciInfection occurs most frequently in those
with preexisting valvular abnormality
StaphylococciStaphylococci
Causes endocarditis in those with normal and abnormal valves
Most are coagulase positive S.AureusCauses destruction of valves, multiple distal
abscesses, myocardial abscesses, conduction defects, and pericarditis
EnterococciEnterococci
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
DiagnosisDiagnosis
Negative culture can occur in 5% of patients.
1/3 to ½ are negative due to prior antibiotic use
In patients with culture negative IE, advise lab to allow specialized testing to recover the causative organism which is needed to adequately treat
IDU associated IEIDU associated IE
Skin flora and contaminated injection devices are the most frequent sources involved in IDU-associated IE
S. Aureus – Most common (50% of cases) Streptococcal species Gram negative Bacilli
– Pseudomonas– Serratia species
Fungi– Candida
Prosthetic Valve EndocarditisProsthetic Valve Endocarditis
Most commonly occur during the perioperative period 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
Clinical FeaturesClinical Features
Acute IE – Rapid onset of high fevers and rigors with hemodynamic deterioration and death within days to weeks if not treated– Assoc. with highly virulent organisms such as Staph
Aureus Subacute IE – Indolent course with progressive
constitutional signs and symptoms and gradual deterioration– Assoc. with avirulent organisms such as viridans
streptococci
Clinical FeaturesClinical Features
Bacteremia can produce signs and symptoms that are often nonspecific usually within 2 weeks of infection– 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 IE
work up
Cardiac Clinical FeaturesCardiac Clinical Features
Heart murmurs are present in up to 85% of cases of IE.– Most commonly regurgitant lesions secondary to valvular
destruction Acute or progressive CHF is the leading cause of death
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
Embolic Clinical FeaturesEmbolic Clinical Features
Extracardiac manifestations are the result of arterial embolization 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 with arrhythmias)– Splenic infarction (LUQ abdominal pain)– Renal emboli (flank pain or hematuria)
Clinical FeaturesClinical Features
Persistent bacteremia can stimulate the humoral and cellular immune systems resulting in circulating immune complexes
Petechiae – Red, nonblanching lesions that become brown after several days (20-40%)– Conjunctivae, buccal mucosa, and extremities
Splinter hemorrhages – Linear dark streaks under the fingernails (15%)
Osler’s nodes – Small tender subcutaneous nodules that develop on the pads of the fingers or toes (25%)
Janeway lesions – Small hemorrhagic painless plaques located on the palms or soles
Roth spots – Oval retinal hemorrhages with pale centers located near the optic disc
DiagnosisDiagnosis
Diagnosis of IE requires hospitalization– Cultures– Echocardiogram– Clinical observation
Duke Criteria – 90% sensitive– Major Criteria– Minor Criteria
Major CriteriaMajor 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
Major CriteriaMajor Criteria
Echocardiographic involvement:– Mass on valve– Abscess– Dehiscence of prosthetic valve– New valvular regurgitation
Minor CriteriaMinor Criteria
Predisposition: Heart condition or injection drug use
Fever > 38 degrees C Vascular: Emboli, conjunctival hemorrhages,
janeway lesions Immunological: Glomerulonephritis, osler’s
nodes, roth spots, and rheumatoid fever Positive blood cultures Echocardiographic findings c/w IE
Duke CriteriaDuke Criteria
Definite infective endocarditis– Microorganisms demonstrated by culture or histologic examination 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 days of abx
DDx and Consideration of IEDDx and Consideration of IE
IE should be considered in:– All febrile IDUs– Pts with a cardiac prosthesis and fever (or
malaise, 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)
Evaluation of BacteremiaEvaluation of Bacteremia
All patients with suspected bacteremia should 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 bottleMinimum of one hour between first and last
bottle
Diagnostic TestsDiagnostic Tests
ECG should be done in all pts with suspected IE– Nonspecific usually– Conduction abnormalities ( new LBBB, Prolonged PR
interval, 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
EchocardiographyEchocardiography
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, right sided valvular lesions and favorable precordial windows.
Transesophageal Echo(TEE) has a higher sensitivity and specificity than TTE– Recommended for the following:
Prosthetic valves Pts with obesity, chest wall deformities, COPD Intermediate or high probability of IE
TreatmentTreatment
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
Empiric TreatmentEmpiric Treatment
Therapy of suspected Bacterial Endocarditis– Uncomplicated history
Ceftriaxone or nafcillin plus gentamycin
– IVDU, Congenital heart disease, MRSA, current abx use
Nafcillin plus gentamycin plus vancomycin
– Prosthetic heart valve Vancomycin plus gentamycin plus rifampin
Most patients will require 4 to 6 weeks of antibiotic therapy
Surgical TreatmentSurgical 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
AnticoagulationAnticoagulation
Anticoagulation for native valve endocarditis has not been shown to be beneficial– Increase the risk of intracranial hemorrhage
Pts with prosthetic valves who are treated with anticoagulation can be maintained on their regimen with proper caution for CNS complications
IE ProphylaxisIE 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
IE ProphylaxisIE 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
Question 1:Question 1:
T/F Streptococcus is responsible for more than 50% of Native Valve Endocarditis.
Question 2:Question 2:
Embolic clinical features of infective endocarditis include:
A) CNS complications
B) Pulmonary complications
C) Coronary Artery Emboli
D) All of the above
Question 3:Question 3:
Small hemorrhagic painless plaques located on palms or soles are called?
A) Janeway lesions
B) Osler’s nodes
C) Roth Spots
D) Splinter hemorrhages