T5 - IE4 - Infectious Diseases - Fong - Line Infection & Infective Endocarditis (IE)

Enterococcus spp. Penicillin and gentamicin susceptible 2 β-lactams treatment

Ampicillin (2 g IV q4H) 6 weeks

PLUS

Ceftriaxone (2 g IV q12h) 6 weeks

Synergy and use for two β-lactams discovered in 2012

Enterococcus spp. Penicillin and gentamicin susceptible treatment

Ampicillin (2g IV q24h) 4-6 week duration*

or

Penicillin G (18-30 million units / 24h IV continuously or in 6 equally divided doses) 4-6 week duration*

PLUS

gentamicin 1 mg/kg IV q8H 4-6 week duration*

*4 weeks if symptoms <3 months, 6 weeks if symptoms > 6 months or prosthetic valve

enterococcus spp

Staphylococcus spp. PROSTHETIC valve (MRSA, CoNS) treatment

vancomycin (dosed to target trough ~15 mg/L) ≥ 6 weeks

PLUS

rifampin (300 mg IV q8h); consider several day delayed start 2/2 resistance; ≥ 6 weeks

PLUS

gentamicin (3 mg/kg IV Q24h) 2 weeks

Staphylococcus spp. - PROSTHETIC valve MRSA, CoNS

Staphylococcus spp. PROSTHETIC valve (MSSA, CoNS) treatment

Nafcillin / Oxacillin (2g IV q4H) ≥ 6 weeks

PLUS

Rifampin (300 mg IV q8H) - considered several day delayed start 2/2 resistance; ≥ 6 weeks

PLUS

Gentamicin 3 mg / kg IV q24h 2 weeks

Staphylococcus spp. prosthetic - MSSA, CoNS

What is the benefit of de-escalating from vancomycin to nafcillin or cefazolin for treating MSSA?

A. less toxicity

B. narrower spectrum

C. easier dosing

D. lower mortality

E. all of the above

F. none of the above

All of the above

Nafcillin / cefazolin will have less nephrotoxicity, narrower spectrum which prevents resistance, easier dosing and has been proven since β-lactams have lower mortality in MSSA than vancomycin

Highly susceptible VGS and S. gallolyticus (bovis), PROSTHETIC valve treatment

penicillin G (24 million units / 24hr IV continuously or in 4-6 equally divided doses) for 6 weeks

OR

ceftriaxone 2 mg IV q24H for 6 weeks

±

gentamicin 3 mg / kg IV q24h or 1 mg / 1 kg IV q8h for 2 weeks

Highly susceptible VGS and S. gallolyticus - PROSTHETIC

Organisms of IE: streptococcus spp. - _______ ____________ / _________ ___________ are a significant risk factor

- poor dentition / dental procedures (are a significant risk factor)

Modified Duke Criteria - minor criteria for diagnosis IE: immunologic

glomerulonephritis

Osler's nodes

Roth's spots

rheumatoid factor

Modified Duke Criteria - Major Criteria for Diagnosis IE: Blood Culture - organism consistent with ____________ _______ in ___ separate blood cultures

- (consistent with) infective endocarditis

- 2 (separate blood cultures)

Mitral valve location

between left atrium and left ventricle

MitraL = left

Tricuspid = right

IE

infective endocarditis

Infective endocarditis

IE

When do we get blood cultures: just about ______ _____ ______

- all the time (regardless of source)

Systemic sign / symptoms of infection in hospitalized patients

Blood cultures are systemic _____ / ____________ of infection in hospitalized patients

- (systemic) sign / symptoms (of infection)

Incidence of bacteremia

community acquired pneumonia: as low as 5%

UTI: up to 15%

cellulitis: 10%

intra-abdominal infections: < 10%

infective endocarditis: > 80%

How to obtain good blood cultures: ____ ____ sets from ___ different sites

- ≥ 2 (sets)

- 2 (different sites)

Clean site of venipuncture

Avoid indwelling lines unless suspecting line infection

Before antibiotics started

How to obtain good blood cultures

Clean site of venipuncture

Avoid indwelling lines unless suspecting line infection

Before antibiotics started

How to obtain good blood cultures: _________ site of venipuncture

- Clean (site of venipuncture)

How to obtain good blood cultures: ________ indwelling lines unless suspecting line infection

- Avoid (indwelling lines)

How to obtain good blood cultures: ________ antibiotics

- Before (antibiotics)

Goal of good blood cultures

maximize probability of identifying pathogen, minimize probability of contaminants

Interpreting blood culture information: look for number of bottles __________

- (bottles) positive

4/4 vs. 1/4: high-grade bacteremia vs. possible contamination

Interpreting blood culture information: look for number of bottles positive

4/4 vs. 1/4: high-grade bacteremia vs. possible contamination

Depends on bug 4/4 and 1/4, sometimes it doesn't matter may also be quantity of the infection (i.e., if it Staph Aureus, we fear MRSA)

Interpreting blood culture information: organism identified tells you a lot of information

contaminant vs. infection

polymicrobial cultures: contaminants?

Interpreting blood culture information: organism identified tells you a lot of information - polymicrobial cultures...

contaminants

Interpreting blood culture information: generally provide _______, _______ answers

- clues

- NOT (answers)

Contaminants: who they are and why they matter

common contaminants - skin flora

~1-5% of blood cultures have contamination

Common contaminants - who they are and why they matter: Skin Flora

Coagulase - negative Staphylococcus epidermidis (CoNS)

Propionibacterium acnes

Corynebacterium spp.

Bacillus spp.

Contaminants: who they are and why they matter - ___-___% of blood cultures have contamination

- 1-5(% of blood cultures)

Increased cost to patients / healthcare system (~$1000 / patient in 1995)

Requires additional work-up, empiric antibiotics

Contaminants - who they are and why they matter: increased cost to ___________ / ___________ _________

- patients / healthcare system

~$1000 per patient in 1995

Contaminants - who they are and why they matter: requires additional...

work-up

empiric antibiotics

Contaminants - who they are and why they matter: WHEN contaminants matter

present of foreign material (e.g., pacemaker, prosthetic valves)

Skin flora do not set up infection in normal host, but in a patient with many comorbidities then it may cause many problems

Blood culture clinical pearls

There should always be a reason a culture is drawn

A positive blood culture alone does not guarantee true infection

Know the contaminants, but also know the pre-test probability

- pre-test probability: likelihood your test is going to be positive before testing

Blood culture clinical pearls: there should __________ be a reason a culture is ________

- always (be a reason)

- (culture is) drawn

Determine, if the patient has a fever, increased WBC when it was drawn...

Blood culture clinical pearls: a positive blood culture alone does _____ ____________ true infection

- (does) not guarantee (true infection)

Blood culture clinical pearls: know the ____________, but also know the _____-________ ___________

- contaminants

- (know the) pre-test probability

Pre-test probability: likelihood your test is going to be positive before test

Pre-test probability

prevalence (%); likelihood your test is going to be positive before test

When do we believe in blood cultures: _______________ identified fits the ___________ syndrome

- organism (identified fits)

- clinical (syndrome)

S. pneumoniae, in a patient highly suspected to have pneumonia; E. coli in a patient highly suspected to have a UTI

When do we believe in blood cultures: Organism identified fits the clinical syndrome

S. pneumoniae, in a patient highly suspected to have pneumonia

E. coli in a patient highly suspected to have a UTI

When do we believe in blood cultures: can help ________ diagnoses, but also determine ___________ of illness

- (help) confirm (diagnoses)

- (determine) severity (of illness)

Bacteremia often means sicker patients with risk for worse outcomes

When do we believe in blood cultures: can help confirm diagnoses, but also determine severity of illness

Bacteremia often means ________ patients with risk for ________ outcomes

- sicker (patients)

- worse (outcomes)

When do we believe in blood cultures: bacteremia needs a __________

- (needs a) source

Transient bacteremia (e.g. tooth brushing, cuts) rarely causes true infection...

When do we believe in blood cultures: transient bacteremia (e.g. tooth brushing, cuts) rarely causes __________ __________

- (rarely causes) true infection...

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (-) & CVC and AC ≥ 15 CFU

OR

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

CVC

central venous catheter

CFU

colony forming unit

AC

arterial catheter

Streptococcus grows in...

chains

Staphylococcus grows in clusters...

Staphylococcus grows in...

clusters

Streptococcus grows in chains...

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever

Blood cultures (-) & CVC and AC ≥ 15 CFU

FOR S. aureus...

TREAT 5-7 days, monitor closely for signs of infection, repeat blood cultures accordingly

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever

Blood cultures (-) & CVC and AC ≥ 15 CFU

FOR S. aureus: TREAT __-__ days, monitor closely for ______ of infection, ________ blood cultures accordingly

- (TREAT) 5-7 (days)

- (closely for) signs (of infection)

- repeat (blood cultures)

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever

Blood cultures (-) & CVC and AC ≥ 15 CFU

If due to other microbes...

monitor closely for sings of infection

repeat blood cultures accordingly

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Coagulase-negative staphylococci

REMOVE catheter & treat with systemic antibiotic for 5-7 days

If catheter is retained, treat with systemic antibiotic + antibiotic lock therapy for 10-14 days

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Coagulase-negative staphylococci - if catheter is retained, treat with __________ ______ + _________ _____ therapy for 10-14 days

- systemic antibiotic

- antibiotic lock (therapy)

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Coagulase-negative staphylococci - if catheter is _________, treat with systemic antibiotic + antibiotic lock therapy for ___-____ days

- (catheter is) retained

- 10-14 (days)

Rifampin is good for activity against ____________

- (activity against) biofilms

Biofilms

Colonies of bacteria that adhere together and adhere to environmental surfaces.

Biofilms can cause difficult to manage major infections

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Staphylococcus aureus, enterococcus, gram-negative bacilli

We _________ the catheter and treat with ___________ antibiotics

- remove (the catheter)

- (treat with) systemic (antibiotics)

The days of treatment may vary for each one i.e., Staphylococcus aureus ≥ 14 days; enterococcus 7-14 days, gram-negative bacilli 7-14 days

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Candida

We _________ the catheter and treat with ____________ therapy for ____ days after the first negative blood cultuer

- remove (the catheter)

- (treat with) antifungal (therapy)

- 14 (days)

How do you know if it's a line infection - in a patient with a CVC or arterial catheter who has a fever...

Blood cultures (+) & CVC and AC ≥ 15 CFU by roll-plate of ≥ 10^2 sonication methods

Only coagulase-negative staphylococci may we __________ or ________ the catheter

- remove

- (or) retain

All of the other positive blood cultures REQUIRE the removal of catheter

Patients going for a deep-clean at the dentist may require ___________ __________

- (at the dentist may require) antibiotic prophylaxis

Microbiology of line infections figure

Infective endocarditis (IE) pathophysiology: ____________ host / immune system is generally capable of preventing ________ _____________

- Healthy (host / immune system)

- (preventing) infective endocarditis

Transient bacteremia rate from toothbrushing as high as 25%

Most common treatment for line infections...

Vancomycin

Due to vancomycin coverage of gram positive organisms

Approach to line infections: treat when appropriate - pathogen directed

______-________ empiric coverage, pathogen-directed _________ therapy

- gram-positive (empiric coverage)

- (pathogen-directed) definitive (therapy)

Approach to line infections: treat when appropriate - _________ directed

- pathogen (directed)

Gram-postiive empiric coverage, pathogen-directed definitive therapy

Duration often 7-14 days dpeneidng on organisms

Approach to line infections: assess positive cultures - do organisms fit clinical picture?

CoNS >>> S. aureus >>> Enterococci > Candida spp. > GNR

Approach to line infections: initiate __________ antibiotics if clinically warranted, access the ________ of illness

- empiric (antibiotics)

- (access the) severity

Approach to line infections: Remove lines whenever possible

Culture the ____________ _____

- (Culture the) catheter tip

Approach to line infections: Remove lines ____________ ________

- (remove lines) whenever possible

Culture catheter tip

Approach to line infections: paired blood culture collection (____________ line + ________)

- suspected (line)

- peripheral

Approach to line infections

1. Paired blood culture collection (suspected line + peripheral)

2. Remove lines whenever possible

- Culture catheter tip

3. Initiate empiric antibiotics if clinically warranted

- Severity of illness

4. Assess positive cultures – do organisms fit clinical picture?

- CoNS >> S. aureus >> Enterococci > Candida spp. > GNR

5. Treat when appropriate – pathogen directed

- Gram-positive empiric coverage, pathogen-directed definitive therapy

- Duration often 7-14 days depending on organism

Line Infection: all of the other positive blood cultures require the _________ of the catheter with the EXCEPTION of __________-__________ __________________

- removal (of the catheter)

- (EXCEPTION of) coagulase-negative staphylococci

Infective endocarditis (IE): damaged endothelium allows for ______________ ___________

- (allows for) bacterial adherence

Infective endocarditis (IE): most common sites of IE

1. mitral valve

2. aortic valve

3. tricuspid valve

Infective endocarditis (IE): obstructs flow and function of the heart, can mimic __________ ___________

- (mimic) heart failure

HACEK group

Haemophilus

Actinobacillus

Cardiobacterium

Eikenella

Kingella

Organism consistent with IE

viridans Streptococci

S. bovis

S. aureus

E. faecalis

HACEK group

Modified Duke Criteria: Major Criteria for Diagnosis IE

1. Blood culture positive for IE

2. TTE / TEE positive for IE

- oscillating intracardiac mass on valve, abscess or new partial dehiscence of prosthetic valve

3. New valvular regurgitation

Modified Duke Criteria - Major Criteria for Diagnosis IE: Blood Culture

organism consistent with IE (viridans Streptococci, S. Boris, S. aureus, E. faecalis, HACEK group) in 2 separate blood cultures

OR

persistently positive blood cultures

- ≥ 2 positive blood cultures drawn > 12 h apart OR all 3 of a majority of ≥ 4 separate blood cultures (first and last ≥ 1 hour apart)

Single positive blood culture for Coxiella burnetii

Serious complications of IE

heart failure (30%)

embolic stroke (20%)

other emboli (> 20%)

- kidney

- splenic

- pulmonary

"Less" non-specific symptoms of IE

chills

anorexia

weight loss

myalgias / arthralgias

night sweats

Non-specific symptoms of IE

Fever (90%)

Malaise / fatigue

Dyspnea

Cough

Headache

Abdominal pain

Risk factors of IE

Men over the age of 60

IVDU

Poor dentition

Structural heart disease (valvular / congenital)

Prosthetic valves

History of IE

Hemodialysis

do not need to know, for reference

Infective endocarditis (IE): _________ flow and function of the heart

- obstructs (flow and function)

Infective endocarditis (IE): __________ endothelium allows for bacterial adherence

- damaged (endothelium allows)

Most commonly affects

1. mitral valve

2. aortic valve

3. tricuspid valve

Infective endocarditis (IE) pathophysiology: healthy host / immune system generally capable of preventing IE

Damaged endothelium allows for bacterial adherence

Most commonly affects

1. mitral valve

2. aortic valve

3. tricuspid valve

Obstructs flow and function

- can mimic heart failure

Tricuspid valve location

between right atrium and right ventricle

Tricuspid = right

MitraL = left

Modified Duke Criteria - Major Criteria for Diagnosis IE: Blood Culture - single positive blood culture for ____________ __________

- (culture for) Coxiella burnetii

Modified Duke Criteria - minor criteria for diagnosis IE: vascular

septic pulmonary infarcts

intracranial hemorrhage

conjunctival hemorrhage

Janeway's lesions

Modified Duke Criteria - minor criteria for diagnosis IE: fever

> 38°C

Modified Duke Criteria - minor criteria for Diagnosis IE

1. predisposing heart condition or IVDU

2. fever (> 38C)

3. vascular: septic pulmonary infarcts, intracranial hemorrhage, conjunctival hemorrhage, Janeway's lesions

4. immunologic: glomerulonephritis, Osler's nodes, Roth's spots, rheumatoid factor

5. microbiologic: positive blood culture not meeting major criteria

Modified Duke Criteria - minor criteria for diagnosis IE: predisposing _______ condition or ______

- heart (condition)

- (or) IVDU

IVDU will usually present with _______-______ heart failure

- (present with) right-sided (heart failure)

Intravenous goes into the venous system and into one of the vena cavas, thus, the right side of the heart

IVDU

intravenous drug user

Modified Duke Criteria - Major Criteria for Diagnosis IE: new ___________ __________

- (new) valvular regurgitation

Modified Duke Criteria - Major Criteria for Diagnosis IE: TTE / TEE positive for IE

Oscillating intracardiac mass on valve, abscess or new partial dehiscence of prosthetic valve

Modified Duke Criteria - Major Criteria for Diagnosis IE: _____ / ______ positive for IE

- TTE / TEE (positive)

Oscillating intracardiac mass on valve, abscess or new partial dehiscence of prosthetic valve

Modified Duke Criteria - Major Criteria for Diagnosis IE: Blood Culture - persistently positive blood cultures

≥ 2 positive blood cultures drawn > 12 hours apart

OR

all of 3 or a majority of ≥ 4 separate blood cultures (first and last ≥ 1 hour apart)

Osler's nodes

painful immune-complex depositions