Blood Stream Infections

Question 1

Definition: Infection

Answer 1

Presence of microorganism in normally sterile site

Question 2

Definition: Bacteremia

Answer 2

Clutivatable bacteria in bloodstream

Question 3

Definition: Systemic Inflammatory Response Syndrome (SIRS)

Answer 3

Two or more of following: T > 38C or 90bpm, RR >20 or PaCO2 < 32 mmHg, WBC > 12,000 cells/mm3 or 4,000 cells/mm3 or > 10% immature band forms (leukocytosis/leukopenia)

Question 4

Definition Sepsis

Answer 4

Fulfilled SIRS criteria + confirmed infection with culture

Question 5

Definition: Hypostension

Answer 5

SBP < 90 mmHg, MAP < 70 mmHg

Question 6

Definition: Severe Sepsis

Answer 6

Sepsis + Organ fn. distant from site of infection, hypoperfusion or hypotension. Abnormalities may include lactic acidosis, oliguria, acute altered mental status, acute lung injury, thrombocytopenia in 3 days; To be considered SEVERE sepsis, hypotension must be reversible by administering fluids

Question 7

Definition: Septic Shock, Refractory Septic Shock

Answer 7

Sepsis + hypotension that despite fluid resuscitation requires vasopressor Tx. Includes perfusion abnormalities, lactic acidosis, oliguria, altered mental status, acute lung injury; RSS - SS lasting > 1hr and does not respond to vasopressor administration

Question 8

What is Toll-like receptor 4 and what role does it play in SIRS?

Answer 8

Transmits the LPS recognition of G(-) bacteria signal to the interior of the cell causing massive inflammatory response.

Question 9

Definition: Transient Bacteremia

Answer 9

Lasts for minutes, after procedures involving contaminated or colonized skin/mucosal surfaces

Question 10

Definition: Intermittent Bacteremia

Answer 10

Cycle of clearance and recurrence of bacteria associated with undrained closed-space infections such as intra-abdominal or soft-tissue abscesses

Question 11

Definition: Persistent (Continuous) Bacteremia

Answer 11

Characteristic of infective endocarditis and other intravascular infections

Question 12

Definition: Primary (Intravascular) Blood Stream Infection

Answer 12

BSI without a documented primary source of infection but the source is from an intravascular site such as infective endocarditis (S. aureus, Strep viridans, Enterococci), Mycotic aneurysm, Suppurative thrombophlebitis, Catheter Associated Bloodstream Infections (CABSI)

Question 13

Definition: Secondary (Extravascular) Blood Stream Infection

Answer 13

BSI in which there is documented portal of bacteria entry (skin infection, catheter, pneumonia, UTI) and/or known site of infection

Question 14

Dx of BSI’s

Answer 14

Blood cultures, before antimicrobial Tx, the more cultures the better, at least two sets of blood cultures should be taken from separate venipuncture sites. 3 blood culture sets over 24 hrs should be adequate