B&l: 24. Dugan : Bacteremia And Blood Cultures

Front 1

define Bacteremia

Back 1

bacteria in blood

Front 2

define SIRS

Back 2

- systemic inflammatory response syndrome: 2 or more of the following
Temp >38oC
Heart rate >90 beats/min
Respirations >20 breaths/min
WBC >12,000/cmm or with >10% bands (left shift)

Front 3

define Sepsis

Back 3

- SIRS due to infection

Front 4

define Severe Sepsis

Back 4

sepsis associated with organ dysfunction, hypoperfusion, or hypotension

Front 5

What is a Left shift?

Back 5

increase in PMNs

shows bacterial infection

Front 6

Septic Shock

Back 6

persistent hypotension and perfusion abnormalities despite adequate fluid resuscitation

Front 7

Multiple Organ Dysfunction Syndrome (MODS)

Back 7

altered organ function in acutely ill patient such that homeostasis cannot be maintained without intervention

Front 8

starting with a bacterial infection, how do you get to shock and organ failure

Back 8

bacterial infection

Bacteremia

host inflammatory response

increased inflammation and coag/decreased fibrinolysis

changes in endothelium, microvasculature, BP

Shock and Organ failure

Front 9

what is the leading cause of death in noncardiac critically ill pts?

Back 9

Sepsis progressing to septic shock

Front 10

what is the pathophysiology of bactermia?

***

Back 10

Infection goes into LYMPHATICS

these lymphatics eventually dump into the vascular system leading to bactermia

Front 11

Intravascular devices can lead to what

Back 11

bacteremia

Front 12

Leading cause of bacteremia?

**

Back 12

UTI

Front 13

There are 3 clinical patterns of Bacteremia... one of them is Transient. Please describe it

Back 13

Common - organisms are cleared quickly
Teeth brushing, defecation, instrumentation, etc.

Front 14

There are 3 clinical patterns of Bacteremia... one of them is Intermittent. Please describe it

Back 14

Subacute endocarditis, some abscesses, etc.

Front 15

There are 3 clinical patterns of Bacteremia... one of them is Continuous. Please describe it

Back 15

continuously have organisms in the blood stream

examples: Acute endocarditis, deep seated infections, etc.

Front 16

Infants and elderly
Alteration in host defenses, eg, loss of spleen
Severe underlying illnesses: diabetes, malignancy, etc
Major surgery
Presence of foreign bodies
Renal failure requiring dialysis
Obstructive processes
Treatment with cytotoxic or antimetabolites
Loss of normal skin barrier

are all what?

Back 16

Factors that predispose to sepsis and septic shock

Front 17

there are 3 difficulties associated with diagnosis of infection in septic pts... what are they?

Back 17

Establish infection as the primary cause of systemic inflammatory response syndrome (SIRS)

Localization of infection

Interpret the microbiological findings

Front 18

What bug is causing shock more than any other?

***

Back 18

Staph Aureus

Front 19

For acute sepsis, how many cultures must you take and how far apart?

*

Back 19

2-3 blood cultures 30 min apart

Front 20

For subacute sepsis, how many cultures must you take and how far apart?

*

Back 20

3 or more cultures over 1-2 days

Front 21

how much blood should you take when you draw for sepsis (not sure how important this is, but interesting)

Back 21

10-20 mL of blood for each set (aerobic and anareobic)

have to take that much becauseless than 1 organism per mL is normally seen

Front 22

he went over all these different types of culture systems... which one did he seem to like best?

Back 22

Continuous Monitoring Blood Culture Systems

Front 23

Bacillus, Coag neg Staph, Propionibacterium and Corynebacterium can often be seen in culture. What is going on?

***

Back 23

They are false positives

like 80-90% of the time they are contaminants

Front 24

When you are interpreting a culture, you must consider patterns of positivity.. what is meant by this?

**

Back 24

you want to Repeatedly isolate organism from subsequent blood cultures...to make sure it is not contaminate

Front 25

Contamination rate should be what?

Back 25

<3%

Front 26

Lamy, et al. found that blood for 6 culture bottles (35-42 ml) preferably drawn _____ is best (1 stick)!

Back 26

AT ONE TIME

few institutions do this

Front 27

Suspect endocarditits
Temp >39.4oC (103oF)
Indwelling vascular catheter

are what?

Back 27

Major criteria for people who need a blood culture...

only one is needed

Front 28

Temp 38.3-39.3oC
Age >65 years
Chills
Vomiting
Hypotension (systolic BP <90 mm Hg
WBC >18,000 cells/mm3
Bands >5%
Platelets <150,000 cells/mm3
Creatinine >2 mg/dL

are what?

Back 28

Minor criteria for people who need a blood culture...

2 are needed

Front 29

treatment slide:

just read

Back 29

Empiric treatment
Aminoglycoside + 3rd generation cephalosporin
Organism isolated → specific therapy
S. aureus (meth sens) - nafcillin + gentamicin
S. aureus (meth res) - vanco + gentamicin
E. coli - 3rd generation cephalosporin
P. aeruginosa - aminoglycoside + extended spectrum penicillin (tobramycin + ticarcillin)
Antibiotic delivered by IV
Often over longer period of time

Front 30

Advanced age
Nosocomial bacteremia
Enterococcal, Gram negative or fungal etiology
Underlying problems, i.e. diabetes, cancer, etc.
Presence of septic shock
Lack of febrile response

are factors that

Back 30

lead to poor prognosis

(mortality 20-30%)

Front 31

Weinstein's take home points (from reading)

**

Back 31

blood culture contamination is common

the identify of the organism isolated can help tell if the culture is contaminated

number of blood cultures that yield a particular organism can help predict future infections