Lecture 32+33 Endocardititis Flashcards
What is the origin(s) of endocarditis?
traditionally associated with heart valves (prosthetics, damaged native valves, rheumatic heart disease, mitral valve prolapse, CHD)
most frequently mitral or aortic valves ⇒ related to degree of mechanical stress (pressure resting on closed valve) = MV > AV > TV > PV
What are the main risk factors for endocarditis?
health care contact, injection drug use
What are the organisms associated with endocarditis?
slow growing, fastidious Gram (-) bacilli (most commonly found in oral flora)
HACEK ⇒ H. parainfluenzae, Aggregatibacter actinomycetemcomitans or Aggregatibacter aphrophilus, Cardiobacterium hominis, Eikenella corodens, Kingella kingae
along with viridans group strep, Streptococcus bovis, S. aureus, enterococci
What are predisposing factors for endocarditis?
Valvular disease - mitral valve prolapse with regurgitation, prosthetic heart valves, acquired valvular dysfxn (ex. rheumatic heart disease, previous this)
Congenital abnormalities - congenital bicuspid mitral valve or surgically constructed shunts or conduits
Hypertrophic myopathy
Turbulent blood flow
Injection drug use (IDU)
indwelling catheters or lines
What is the pathogenesis of endocarditis?
A: valve surface changes + turbulent blood flow
B: development of non-bacterial thrombus on valve
C: transient bacteremia exposes thrombus to bacterial colonization
D: development of IE - embolization of septic fragments that can cause hematogenous complications in other organs (spleen, brain, lungs, small vessels)
What are some clinical findings in endocarditis?
Fever
fatigue
new heart murmur
petechiae - occur in about 20-40% and can appear in the conjunctivae, buccal mucosa, palate, extremities, red, non blanching, become barely visible after 2-3 days
Osler’s nodes - arteriolar intimal proliferation with extension to venules and capillaries and may be accompanied by thrombosis, necrosis, immune complex invasion
Janeway lesions - consists of bacteria, neutrophilic infiltration, necrosis, SC hemorrhage
Roth spots - lymphocytes surrounded by edema and hemorrhage in nerve fibre layer of retina, oval and pale retinal lesions usually near optic disk
splinter hemorrhages are linear reddish brown streaks in fingernails or toenails
clubbing
What is involved in the pathologic criteria of the Modified Duke Criteria?
A: microorganisms demonstrated by culture or histologic exam of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen OR
B: pathologic lesion, vegetation or intracardiac abscess confirmed by histologic examination showing active this
What is involved in the clinical criteria of the Modified Duke Criteria?
Definitive diagnosis is made based on: 2 major criteria, 1 major criterion and 3 minor criterion OR 5 minor criteria
Possible this: 1 major criterion and 1 minor criterion OR 3 minor criteria
Rejected Diagnosis: firm alternate diagnosis explaining evidence of IE OR resolution of IE syndrome with antibiotic tx for </= 4 days OR no pathologic evidence of IE at surgery or autopsy, with antibiotic tx for </= 4 days OR doesn’t meet criteria for possible IE
What is involved in the MAJOR criteria of the Modified Duke Criteria?
.1. Blood culture positive for IE ⇒ A: typical microorganisms consistent with IE from 2 separate blood cultures; VGS, S. bovis, HACEK, S. aureus OR B: community acquired enterococci, in absence of a primary focus OR C: microorganisms consistent with IE from persistently positive blood cultures: i - at least 2 positive cultures of blood samples drawn > 12 hours apart OR ii - all of 3 or a majority of 4 or more separate cultures of blood (first and last sample drawn at least 1 hour apart) OR iii - single positive blood culture for Coxiella burnetti or antiphase I IgG antibody titer > 1:800
- evidence of endocardial involvement ⇒ A: ECG positive for IE: i - oscillating intracardiac mass on valve or supporting structures, in path of regurgitant jets, or on implanted material in absence of alternative anatomic explanation OR ii - abscess OR iii - new partial dehiscence of prosthetic valve
B: new valvular regurgitation (worsening or changing of preexisting murmur not sufficient)
What is involved in the MINOR criteria of the Modified Duke Criteria?
predisposition, predisposing heart condition or IDU
fever, temp >38
vascular phenomena, major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, Janeway lesions
immunologic phenomena: glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor
microbiologic evidence: + blood culture but doesn’t meet major criterion or serologic evidence of acute infection with organisms consistent with IE
What is empiric treatment for endocarditis?
Vancomycin 15 mg/kg IV Q8-12H + Ceftriaxone 2 g IV QD
if severe penicillin/cephalosporin allergy: Vancomycin 15 mg/kg IV Q8-12H + Gentamicin 1 mg/kg IV Q8H
What is the recommended treatment for MSSA endocarditis?
Cloxacillin sensitive - Native Valve: Cloxacillin 2 g IV Q4H OR Cefazolin 2 g IV Q8H for 4-6 weeks
if severe penicillin/cephalosporin allergy ⇒ Vancomycin 15 mg/kg IV Q8-12H for 6 weeks
if intolerant to vanco or vanco MIC >2 ⇒ Daptomycin 8-10 mg/kg IV QD for 6 weeks
Cloxacillin sensitive - Prosthetic Valve: Cloxacillin 2 g IV Q4H for 6 weeks + Gentamicin 1 mg/kg IV Q8-12H for 2 weeks + Rifampin 300 mg PO TID or 600 mg PO BID for 6 weeks
if severe penicillin/cephalosporin allergy ⇒ Vancomycin 15 mg/kg IV Q8-12H for 6 weeks + Gentamicin 1 mg/kg IV Q8-12H for 2 weeks + Rifampin 300 mg PO TID or 600 mg PO BID for 6 weeks
What is the recommended treatment for MRSA endocarditis?
Cloxacillin Resistant - Native Valve: vanco MIC </=2 ⇒ Vancomycin 15 mg/kg IV Q8-12H for 6 weeks
if intolerant to vanco or vanco MIC >2 ⇒ daptomycin 8-10 mg/kg IV QD for 6 weeks
Cloxacillin Resistant - Prosthetic Valve: Vancomycin 15 mg/kg IV Q8-12H for 6 weeks + Gentamicin 1 mg/kg IV Q8-12H for 2 weeks + Rifampin 300 mg PO TID or 600 mg PO BID for 6 weeks
if vanco MIC > 2 or vanco intolerant ⇒ Daptomycin 10 mg/kg IV QD for 6 weeks + Gentamicin 1 mg/kg IV Q8-12H for 2 weeks + Rifampin 300 mg PO TID or 600 mg PO BID for 6 weeks
What is the role of rifampin in endocarditis?
potent antistaphylococcal but can develop resistance quickly ⇒ usually suggested to start after blood cultures have cleared to prevent resistance
synergistic activity for Gram + organisms
active against bacterial biofilms so may have positive role in prosthetic infections
What is the recommended treatment for viridans group streptococci (VGS) in endocarditis?
Penicillin MIC </= 0.12 mcg/mL: Penicillin 3 MU IV Q4H for 4 weeks (N) (P: N/A) OR Ceftriaxone 2 g IV QD for 4 weeks (N) (P: N/A) OR (Penicillin 3 MU IV Q4H for 2 weeks (N) 6 weeks (P) + Gentamicin 3 mg/kg IV Q24H or 1 mg/kg IV Q8H for 2 weeks (N and P)) OR (Ceftriaxone 2 g IV QD for 2 weeks (N) 6 weeks (P) + Gentamicin 3 mg/kg IV Q24H or 1 mg/kg IV Q8H for 2 weeks (N and P))
if severe penicillin/cephalosporin allergy ⇒ Vancomycin 15 mg/kg IV Q8-12H for 4 weeks (N) 6 weeks (P)
Penicillin MIC > 0.12 - < 0.5: Ceftriaxone 2 g IV QD for 4 weeks (N) (P: N/A) OR (Penicillin 4 MU IV Q4H for 4 weeks (N) 6 weeks (P) + Gentamicin 3 mg/kg IV Q24H or 1 mg/kg IV Q8H for 2 weeks (N) 6 weeks (P)) OR (Ceftriaxone 2 g IV QD + Gentamicin 3 mg/kg IV Q24H or 1 mg/kg IV Q8H for 6 weeks of P
if severe penicillin/cephalosporin allergy ⇒ Vancomycin 15 mg/kg IV Q8-12H for 4 weeks (N) 6 weeks (P)
Penicillin MIC 0.5: (Ceftriaxone 2 g IV QD + Gentamicin 3 mg/kg IV Q24H or 1 mg/kg IV Q8H both for 4 weeks (N) 6 weeks (P))
if severe penicillin/cephalosporin allergy ⇒ Vancomycin 15 mg/kg IV Q8-12H for 4 weeks (N) 6 weeks (P)
What is the recommended treatment for E. faecalis in endocarditis?
Amp S, Gent synergy S: (Ampicillin 2 g IV Q4H + Gentamicin 1 mg/kg IV Q8-12H both for 4 weeks) OR (Ampicillin 2 g IV Q4H + Ceftriaxone 2 g IV Q12H both for 6 weeks)
What are some complications that may arise from endocarditis?
HF - should be immediately evaluated for valve replacement surgery
Septic emboli - 22-50% of cases, 65% to CNS and >90% lodge in MCA, usually occurs within first 2-4 weeks of tx
periannular extension of infection
Uncommon/Rare: splenic abscess - requires splenectomy with antibiotics
mycotic aneurysms
In what cases might prophylaxis for endocarditis be indicated in dental procedures?
Cardiac: pt with - prosthetic cardiac valve, previous this, congenital heart disease (CHD), cardiac transplantation recipients who develop cardiac valvulopathy
also for dental procedures that involve manipulation of gingival tissue or periapical region of teeth or perforation of mucosa
