Endocarditis Flashcards
There are 3 layers of the heart wall, describe each
- EPICARDIUM = Outer Layer, Visceral Pericardium
- MYOCARDIUM = Middle Layer, Makes up majority of the heart mass
- ENDOCARDIUM = Inner Layer, Lines the chambers, valves, & vessels
how does IE occur?
when bacteria enters the bloodstream and lodges onto a heart valve, esp those with prior damage or turbulent blood flow
what is a common contributor to the etiology of IE? examples?
oral source
Dental extraction, periodontal surgery, tooth brushing, chewing candy
other causes of bacteremia besides the main one?
IV drug use, EGD, colonoscopy, TURP, IV catheters
The localization of infection is partly determined by ?
the production of turbulent blood flow
what type of IE is MC, when is it not?
Left-sided IE is more common, except among IVDU
MC pathogen to cause native valve endocarditis
Staph aureus; Streptococcus is next
Valve/Heart disorders that increase risk for IE:
- Rheumatic valvular disease
- Congenital heart disease – PDA, VSD, tetralogy of Fallot
- MVP with MR
- Degenerative heart disease, AS due to bicuspid AV, Marfan syndrome
Common causes/types of endocarditis
- Prosthetic Valve Endocarditis
- IV Drug User Endocarditis
- Native Valve Endocarditis
- Nosocomial/Healthcare-associated Endocarditis
- Fungal Endocarditis
MC pathogenetic cause of Prosthetic Valve Endocarditis
- Staphylococci (coagulase-negative and coagulase-positive) - early (within 2 months)
- Streptococci - Late (>2months)
MC pathogenetic cause of IV Drug User Endocarditis? where is the infection MC?
- Staph aureus is the MC causative organism
- Streptococci (viridans) and enterococci are next most frequent
- Tricuspid valve
leading causes of Nosocomial/Healthcare-associated Endocarditis
Central and peripheral IV catheters, pacemakers and ICDs, HD shunts, and permacaths
MC pathogenetic cause of nosocomial/healthcare-associated endocarditis
G+ cocci - S. aureus, enterococci, nonenterococcal streptococci
what type of endocarditis is More commonly found in IVDU and ICU patients who receive broad-spectrum abx
Fungal Endocarditis
complications with endocarditis
- Rupture of valve tissue or chordal structures, leading to valvular regurgitation
- Vegetation may obstruct the valve orifice or create a large embolus
- Conduction system affected by myocardial abscess
- Infection may invade the interventricular septum, causing intramyocardial abscesses or septal rupture
- Septic systemic and pulmonary emboli
MCC of death in pts with IE
Heart Failure
Presentation of IE
- within 2 wks - 6 months
- sx of systemic infection, emboli, or other complications (CHF)
- MC fever (90%), chills, weakness, shortness of breath, night sweats, loss of appetite and weight loss
- MSK sx, such as back pain, are common
- heart murmurs (80%)
- CHF is present in up to 2/3 of cases
- Septic emboli
- Pulmonary emboli
- Systemic emboli
However, what pt population with TV endocarditis have murmur only 1/3 of the time
IVDU
pleuritic chest pain, cough with blood-tinged sputum, and cavitating lesions on chest x-ray
what could be the cause?
Pulmonary emboli
Systemic emboli OF IE to what arteries
renal, cerebral, coronary and mesenteric arteries
Physical findings of peripheral manifestations in IE caused by vasculitis/emboli:
- Petechiae (red, non blanching lesions in crops on conjunctiva, buccal mucosa, palate, extremities) - vasculitis or emboli
- Splinter hemorrhages (linear, red-brown streaks in nail beds) - vasculitis or emboli
- Janeway lesions - PAINLESS patches on palms/ soles
Emboli; Staph - Osler nodes - PAINFUL nodules on pads of fingers/toes
Vasculitis; Strep - Roth spots - Oval, pale lesions surrounded by hemorrhage
Vasculitis; Strep
petechiae seen in IE is MC caused by what pathogen
Strep and staph common causes
Splinter hemorrhages is MC caused by what pathogen
Strep and staph common causes
erythematous/hemorrhagic macular or nodular, painless patches on palms or soles
what is this?
MC pathogen?
Janeway lesions
Staph
painful nodules on pads of fingers or toes) caused by vasculitis
what is this?
MC pathogen?
Osler nodes
strep
oval, pale retinal lesions surrounded by hemorrhage caused by vasculitis in IE
what is this
Roth spots
one of the most serious complications of IE
CNS embolization
what must be in DDx in young pt with CVA? s/s?
IE
HA or develop seizures, possibly due to toxic encephalopathy, meningoencephalitis
diagnostic testing for IE
- START WITH: CBC, blood cx
- Nonspecific labs are possible
- Anemia - obtain CBC
- inflammation - elevated erythrocyte-sedimentation rate, CRP, LDH, lactic Acid (these are very non specific markers for inflammation)
- UA - proteinuria and hematuria - Bacteremia
- Blood cx should be obtained prior to initiation of antibiotics
- At least 3 sets of blood cx obtained from different venipuncture sites, with the first and last samples drawn at least 1 hour apart
- May be negative, due to previous antibiotics, or fastidious organisms, such as Legionella, Bartonella, Chlamydia or fungi
collect 3 sets of what type of blood cx?
- aerobic bacteria
- anaerobic bacteria
- fungi
what diagnostic testing is recommended in all cases of suspected IE? which is most sensitive?
- echo
- TTE may be sufficient
- TEE is more sensitive, especially for small vegetations, in patients with large body habitus
diagnostic criteria used for IE
Duke Criteria
1. Major criteria
- Positive blood culture for IE - Typical organisms, 2 or more positive cultures
- Evidence of endocardial involvement on echo
intracardiac mass on a valve or supporting structure - myocardial abscess; partial dehiscence of a prosthetic valve
- New regurgitant murmur
2. Minor criteria
- Predisposing heart condition or IVDU
- Fever (>38 C or >100.4 F)
- Vascular and embolic phenomena - including major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, or Janeway lesions
- Immunologic phenomena - glomerulonephritis, Osler nodes, Roth spots, and rheumatoid factor
- Microbiologic evidence - Single positive blood culture or serologic evidence of active infection with typical organism
diagnostic criteria interpretation of duke diagnosis
- Definitive IE
- 2 major criteria, or 1 major and 3 minor, or 5 minor - Possible IE
- 1 major and 1 minor, or 3 minor
overall management for IE
- Management of patients with IE involves multiple aspects
- Antibiotic therapy (Involve ID for this)
- Management of CHF
- Management of systemic/pulmonary sequelae
- Surgery
- dental eval
abx tx for IE (all types)
- Antibiotic therapy - 4 to 6 weeks
- Native valve IE - Pen G and gentamicin, vancomycin (MRSA)
- IVDU - Nafcillin, gentamicin, vancomycin
- Prosthetic valve IE - Vancomycin, gentamicin, and rifampin
- Fungal IE - Amphotericin B (not curative), surgery (definitive tx)
Subsequent antibiotic choice is based on blood or pathology culture results
surgery management for IE usually involves what 3 things?
- Involves open sternotomy valve replacement, repair or debridement
- Timing and necessity is individualized for each patient (only ~25% undergo surgery)
- Prosthetic valve IE rarely occurs after valve replacement for IE, so delaying surgery to prolong antibiotic therapy is never appropriate if patient remains hemodynamically unstable or fulfills one of the following criteria
7 indications for surgery in IE
- CHF refractory to standard medical therapy (MC indication)
- Fungal IE
- Persistent sepsis after 72 hrs of abx
- Recurrent septic emboli, esp after 2 weeks of abx
- Ruptured aneurysm of the sinus of Valsalva
- Conduction disturbances caused by septal abscess
- Kissing infection of anterior mitral leaflet with IE of AV
what eval should be thoroughly evaluated to identify and eliminate oral disease for IE
dental eval
should focus on periodontal inflammation and pocketing around teeth and caries that may result in infection and subsequent abscess
A full series of intraoral radiographs should occur when the patient is stable
Maintaining ____ is just as effective as abx for Endocarditis Prophylaxis
good oral hygiene
only 10% of IE cases can be prevented by the administration of preprocedure antibiotics
the most common source of spontaneous bacteremias in IE (oral health)
Gingivitis
Antibiotic prophylaxis is reserved for who?
- high risk for IE and only for those procedures that have higher likelihood of bacteremia
risks:
- Prosthetic heart valves
- Prior endocarditis
- Cyanotic congenital heart disease (unrepaired, repaired, or partially repaired)
- Cardiac transplantation recipients who developed cardiac valvulopathy
Endocarditis Prophylaxis Procedures
- Dental procedures
- Any procedure involving manipulation of gingival tissue or the periapical region of teeth, or perforation of the oral mucosa - Respiratory tract procedures
- Tonsillectomy or adenoidectomy
- Other invasive procedures involving incision of the respiratory mucosa - Procedures on infected skin or musculoskeletal tissue including I&D of an abscess
No longer recommended for GI or GU procedures
abx regimen for Endocarditis Prophylaxis
- Amoxicillin
- If allergic to penicillin:
- Clindamycin 600 mg PO
- Cephalexin 2 grams PO
- Azithromycin or clarithromycin 500 mg PO - If unable to take PO:
- Ampicillin 2 grams IM or IV
- If allergic to penicillin: Cefazolin or ceftriaxone 1 gram IM or IV, or clindamycin 600 mg IV
