Infective Endocarditis Case Studies

Question 1

What are key risk factors for infective endocarditis?

Answer 1

abnormal heart valves and risk of bacteremia
Aberrant flow results in platelet-fibrin thrombus on injured
Bacteria enter bloodstream through skin or mucosal surfaces and adhere to thrombus

Question 2

What predisposing heart conditions can increase chance of getting IE?

Answer 2

prosthetic valves
mitral prolapse w/ regurg or thickened leaflets
Rheumatic heart disease
Complex congential heart
mitral regurg/ AS/ aortic regurg/ ventricular septal defect

Question 3

What procedures can predispose you to IE?

Answer 3

Dental work or poor hygiene- especially associated w/ bleeding
Hemodialysis
IV drug use (Right sided especially)
Focal infection with typical organism

Question 4

What are common clinical presentations for IE?

Answer 4

Almost always fever, and heart murmur. Often have chills and sweats with occasional anorexia/malaise
Lab abnormalities and non-cardiac manifestations 5-50%

Question 5

What noncardiace manifestations appear with IE?

Answer 5

Emolic events 25-50% time… often to CNS (extremeties/spleen or kidneys)
Splenomegaly, clubbing, petechiae less common

Question 6

What peripheral manifestations are seen with IE?

Answer 6

Splinters hemorrhages in the finger nails
Oslers
Janeways
Roths

Question 7

When are Splinter hemorrhages more concerning for IE?

Answer 7

when they are proximal or mid nail and more if they are red/purple (opposed to brown)

Question 8

tender violaceious subQ nodes in the fingers or toes. D/t inflammation and immune complexes

Answer 8

Osler nodes

Question 9

nontender erythematous or hemorrhagic macules or papules in fingertips, palms or soles dt septic emboli

Answer 9

Janeway lesions seen in IE

Question 10

What are roth spots?

Answer 10

retinal lesions–hemorrhagic with white central spot, immunologic process seen in IE

Question 11

What key lab anormalities do we see in IE

Answer 11

anemia 70-90% time
leukocytosis 20-30% time
microscopic hematuria 30-50%
and elevated sed rate and CRP

Question 12

Most common organisms in IE in acute cases:

Answer 12

Staphylococcus aureus

Question 13

Most common organisms in IE in prosthetic valves :

Answer 13

coagulase-negative Staph

Question 14

Most common organisms in IE in elderly:

Answer 14

Enterococcus sp.

Question 15

Most common organism in IE in a native valve

Answer 15

streptococci

Question 16

Most common organism in IE in early prosthetic valve replacement:

Answer 16

Coag-Neg staph or possibly staph aureus, but not steptoccocci in early valve replacement (more common for a native valve)

Question 17

Most common organism in IE in late prosthetic valve replacement:

Answer 17

streptococci (almost same as it would be for native)

Question 18

Your patient has IE and you identify the causitive agent as strep bovis, what else should you be concerned about?

Answer 18

assoc. with colonic lesions

Question 19

Are gram - rods or fungi associated with IE?

Answer 19

not usually but if they are more likely due to prosthetic valve or IV drug users

Question 20

S. aureus, Candida parapsilosis and pseudomonas are causitive IE agents seen in which patients?

Answer 20

IV drug users

Question 21

Your patient has an elevated fever, chills and weight loss. You hear a murmur and strongly suspect IE after you see evidence in the echo. You take cultures but the cultures are negative… what would you change your DDx to?

Answer 21

don’t necessarily… some IE can be ‘culture-negative’

Question 22

What are our common ‘culture negative’ causitive agents of endocarditis

Answer 22

Haemophilus
Actinobacillus
Cardiobacterium
Eikenella
Kingella
HACEK

Question 23

which is more sensitive for evaluating prosthetic valves, perivalvlar exctension, myocardial abcesses, fistulas and valve perfs?
Transthoracic or transesophageal

Answer 23

Transesophageal echo or TEE

Question 24

echo that is rapid and noninvasive but sensitivity is less then 70%

Answer 24

Transthoracic echo or TTE

Question 25

Echo that is sensitive up to 95%

Answer 25

transesophageal or TEE

Question 26

How do you make a diagnosis of IE?

Answer 26

based on clinical, lab and echo criteria; Modified Duke criteria of 2 major or one major plus 3 minor

Question 27

Major Duke criteria to Dx IE

Answer 27

Microorganism from 2 seperate blood cultures --if its an unusual IE organism has to be persistantly positive -or positieve serology C.burnetti Evidence of endocardial involvement; new vavlular regurg or positive echocardiogram

Question 28

Minor Duke criteria to Dx IE

Answer 28

Predisposition: heart abnormalities or IV use Fever Vascular phenomena: excluding petechiae or splinter Immunologic phenomenoa; RH factor, Oslers or Roths

Question 29

Because bacteria are in vegitative configuration in IE, what do we need to do in therapy to overcome that?

Answer 29

must have PROLONGED and bacteriaCIDAL therapy (bc they are metabolically inactive and inaccessible to host) ***MUST KILL EVERY BACTERIUM

Question 30

Rx for penicillin susceptible IE caused by streptococcis

Answer 30

Penicillin or Ceftriaxone x4-6wks | with Vanco x 5-6 weeks

Question 31

Rx for intermediate penicillin susceptible IE caused by streptococcis

Answer 31

Pen or Ceph x 4-6 wks with Gent x 2-6 wks | – Vancomycin x 4-6 wks

Question 32

Rx for IE caused by enterococci

Answer 32

Pen or Amp x 4-6 wks with Gent x 2-6 wks | – Vanco with Gent x 6 wks

Question 33

Pt has a native heart valve and IE caused by staph... Rx?

Answer 33

Nafcillin or Oxacillin (+/-Gentamicin x 3-5 days) – Cefazolin (+/- Gentamicin x 3-5 days) – Vancomycin

Question 34

PT has a prosthetic heart vavle and IE d/t Staph... Rx?

Answer 34

– Nafcillin or Oxacillin + Rifampin (+/- Gent x 2 wks) – Vancomycin + Rifampin (+/- Gent x 2 wks)

Question 35

What Rx do we give patient for IE caused by HACEK?

Answer 35

Ceftriaxone x 4-6 wks • Amp/sulbactam x 4-6 wks • Ciprofloxacin x 4-6 wks

Question 36

What are some possible indications for surgery in patient with IE?

Answer 36

congestive HF, prosthetic valve endocarditis, valve perforation or rupture, new heart block, mult embolic events, uncontrolled infection on appropriate rx

Question 37

When do we expect to see fever dissipate in pts with IE?

Answer 37

half within 3 days of | starting treatment, 75% within one week

Question 38

Pt has prolounged fever, a week after they started tx for IE, what are my most likley causitive agents?

Answer 38

more likely associated with S.aurues, GNR, fungi | --see this associated with other complications

Question 39

What cardiac complications arise as a result of IE?

Answer 39

congestive heart failure, heart block, valve failure, abscess or fistula

Question 40

What neurologic and systemic complications arise dt IE?

Answer 40

embolic stroke, mycotic aneurysm and menigits | systemically: septic emboli and abcesses

Question 41

Most common peripheral MCA, usually at bifurcations and more common with virdians step... can be caused by direct emboli or infection of wall or immune complex

Answer 41

Mycotic aneurysms

Question 42

A patient that has IE asks about prophylaxis so she doesn't get IE again in the future... how would you educate her?

Answer 42

inform her bacterimia is more likely doing to result from daily activities such as not brushing teeth then from a procedure and that prophylaxis antiB prevent few, if any IE cases thus risk of taking vs not need to be weighed. MAITAIN ORAL HYGIENE!!!!!

Question 43

Pt has several surgeries scheduled for the next few months. He has a scaling and root planing appointment with his hygenist and then an endoscopy. Which appts does he need to premedicate with if he had previous IE?

Answer 43

for the scaling and planing | not for GI or GU

Question 44

Recommended pre-med for dental appointments that involve gingiva or perforation or oral mucosa

Answer 44

``` Dental—single dose, 30-60 min before – Amoxicillin 2 grams PO – Clindamycin 600 mg – Ampicillin 2 grams IV – Ceftriaxone 1 gram IV ```