Bacteremia Flashcards
what is bacteremia?
presence of bacteria in blood
irrespective of fever and symptoms
why isn’t fever a good marker of bacteremia?
non specific
elderly people don’t tend to get fevers
what is best practice for injections/IVs/needles?
- palpate
- clean
- poke
what is sepsis?
syndrome with systemic inflammatory response criteria
INNATE immune response to infection (non-specific)
what is the pathogenesis of sepsis?
- bacteria enters blood
- blood vessels leak
- organ dysfunction
primary bacteremia
no clear source of infection
only source of infection is in the blood
intravascular devices
- catheters
- IVs
endocarditis
secondary bacteremia
originates from infection elsewhere in body –> enters blood
UTI - urosepsis
pneumonia - bacteremic pneumonia
TRANSIENT bacteremia
bacteria enters bloodstream, but is quickly cleared by immune system
asymptomatic
what are the causes of TRANSIENT bacteremia?
teeth brushing
eating
what is a risk associated with TRANSIENT bacteremia?
endocarditis
INTERMITTENT bacteremia
extravascular source of infection
bacteria periodically enter blood
what are some causes of INTERMITTENT bacteremia?
pneumonia
UTIs
abscesses
CONTINUOUS bacteremia
intravascular source of infection
bacteria continuously present in blood
what are the causes of CONTINUOUS bacteremia?
IV catheters
intravascular infections (endocarditis)
what organisms cause CONTINUOUS bacteremia?
present on skin
- S. aureus
- S. epidermis
If S. aureus is ever found in the blood __________________
ALWAYS treat
never considered a contaminant
how is bacteremia diagnosed?
blood cultures
what volume of blood should be collected for culture?
32-40 mL
8-10 mL/bottle
what sites should be cultured?
TWO!
2x from one site
2x from another site
why do we take cultures from two different sites?
to differentiate between contaminated vs pathogen
prevents complications if aseptic technique was not followed
if organism grows in both culture sites = bacteremia
if organism only grows in one = contaminant
how many bottles should be collected?
4x total
site 1: 1x aerobic + 1x anaerobic
site 2: 1x aerobic + 1x anaerobic
the should blood cultures be samples?
BEFORE antibiotics
how much blood should be collected for pediatric patients?
2x bottles
1-3 mL/bottle
how do we diagnose LINE INFECTIONS?
1) peripheral blood culture
2) blood from the line
if they correlate –> culture tip of line
> 15 colonies = colonized
< 15 colonies = skin contaminant
contaminant or pathogen?
CONTAMINANT
- not virulent
- only grew in one bottle
PATHOGEN
- virulent
- grew in > 1 bottles
what 3 organisms are ALWAYS pathogens in blood (ie. NEVER contaminants in blood)
- gram negatives
- S. aureus
- group A strep pyogenes
