Blood Stream Infections / Sepsis

Question 1

Means the presence of microorganisms in a normally sterile site

Answer 1

Infection

Question 2

Means the presence of microorganisms on an epithelial surface

Answer 2

Colonization

Question 3

Viable/cultivatable bacteria are in the bloodstream, often transiently

Answer 3

Bacteremia (not necessarily correlated with severe sepsis)

Question 4

Bacteremia + clinical manifestations

Answer 4

Septicemia

Question 5

Systemic inflammatory response syndrome (SIRS) requires at least 2 abnormalities from a list of 4 criteria. Name these criteria.

Answer 5

Temperature (high or low)
Heart rate (high)
Respiratory rate (high) or CO2 partial pressure (low)
WBCs (high or low or bands)

Question 6

Systemic response to infection; SIRS + infection

Answer 6

Sepsis

Question 7

SIRS + infection + organ(s) dysfunction / hypoperfusion / hypotension responsive to fluids

Answer 7

Severe sepsis (or sepsis syndrome)

Question 8

SIRS + infection + organ(s) dysfunction and hypotension unresponsive to fluids

Answer 8

Septic shock

Question 9

SIRS + infection + organ(s) dysfunction and hypotension unresponsive to fluids, lasts for more than 1 hour

Answer 9

Refractory septic shock

Question 10

Antigen that responds to the LPS of Gram(-) bacteria, causing endotoxic shock

Answer 10

TLR4 (toll-like receptor 4)

Question 11

Antigen that responds to peptidoglycan and lipoteichoic acid

Answer 11

TLR2 (toll-like receptor 2)

Question 12

TLR4 activation mainly releases what 3 proinflammatory mediators?

Answer 12

TNF-α, IL-1, IL-6

Question 13

Condition where blood clots form throughout the body’s small vasculature

Answer 13

DIC (disseminated intravascular coagulation)

Question 14

5 dysfunctions often seen in severe sepsis.

Answer 14

Hypotension, low platelets, renal damage, pulmonary damage, metabolic acidosis

Question 15

Bacteremia due to brushing teeth, dental procedures, biopsy, or catheterization; how long does it last?

Answer 15

Transient bacteremia; lasts <30 min

Question 16

Bacteremia associated with abscesses, UTI, cholangitis, and focal infections like pneumonia; how long does it last?

Answer 16

Intermittent bacteremia; lasts for hours but comes and goes

Question 17

Bacteremia associated with infectious endocarditis, other intravascular infections, and systemic bacterial infections like brucellosis; how long does it last?

Answer 17

Persistent (sustained/continuous) bacteremia; lasts for >8 hours continuously

Question 18

Distinguish between primary vs. secondary bacteremias

Answer 18

Primary = intravascular, secondary = extravascular

Question 19

Bacteremia due to infection of the surface of the heart, often by Staph aureus, Streptococci, Enterococci, and HACEK. Is it primary or secondary?

Answer 19

Infective endocarditis; primary

Question 20

Bacteremia due to damage of arterial endothelium, inflammatory damage and weakening of the arterial wall. Is it primary or secondary?

Answer 20

Mycotic aneurysm; primary

Question 21

Bacteremia due to damage of venous endothelium, causing clot formation and infection; often caused by an intravenous catheter or peripherally inserted central venous catheter (PICC line). Is it primary or secondary?

Answer 21

Suppurative thrombophlebitis; primary

Question 22

Are CABSI (catheter associated bloodstream infections) considered primary or secondary bacteremias?

Answer 22

Primary

Question 23

Is bacteremia due to a urinary tract infection considered primary or secondary?

Answer 23

Secondary

Question 24

Is bacteremia due to community-acquired and ventilator-associated pneumonia considered primary or secondary?

Answer 24

Secondary

Question 25

Is bacteremia due to HAI’s (hospital associated infections) like post-surgical wound infections considered primary or secondary?

Answer 25

Secondary

Question 26

Are most cases of clinically significant bacteremia primary or secondary cases?

Answer 26

Secondary

Question 27

Most sensitive method for detection of bacteremia / blood stream infections.

Answer 27

Blood cultures

Question 28

Ideally, how many blood culture sets should be taken from a patient over what amount of time to optimize likelihood of finding the organism?

Answer 28

3 sets in 24 hours (each set is 1 aerobic + 1 anaerobic bottle, 10 mL each)

Question 29

Do adults or kids usually have a higher bacteremic load?

Answer 29

Kids: have 10-100 times higher load than adults.