Blood stream infections

Question 1

5 factors that help contribute to sepsis?

Answer 1

1. Chemo and radiation
2. Corticosteroids and immunosuppressants
3. People are getting older
4. Invasive devices like catheters and surgical prostheses
5. Certain antimicrobials for non-bacterial infections that allow for potential resistance

Question 2

Compare bacteremia vs. septicemia:

Answer 2

Bacteremia: viable bacteria within liquid component of the blood
Septicemia: same as bacteremia but implies presentation of CLINICAL MANIFESTATIONS associated with bacteria in bloodstream

Question 3

Order of bloodstream infections (1-4); what is the timing of this?

Answer 3

1. Bacteremia
2. Sepsis: infection with a systemic response
3. Severe sepsis: maybe renal failure, hypotension, DIC, confusion
4. Septic shock: body shuts down and you have ORGAN HYPOPERFUSION and lactic acidosis;
   could be 4 hours!!

Question 4

SIRS is; what is sepsis equal to?

Answer 4

an inflamm state of the whole body without proven source of infection;
SIRS and proof of BSI

Question 5

SIRS can lead to; besides BSI, what can cause SIRS?

Answer 5

MODS;

1. severe trauma
2. Complication of surgery
3. Burns
4. Acute pancreatitis
5. Immunodeficiency

Question 6

Some clinical features of sepsis include; what three things can lead to acute organ dysfunction?

Answer 6

fever, rapid pulse and breathing, nausea, diarrhea, confusion;

1. systemic inflammation
2. coagulation
3. impaired fibrinolysis

Question 7

_____ plays most critical role in mediating SIRS; this can lead to what being released?

Answer 7

TLR-4; release of proinflamm mediators like TNF-alpha, IL1, IL6

Question 8

What can serve as the initial trigger for excessive release of cytokines in endotoxic shock? Consequence?

Answer 8

LPS of gram neg bacteria;

DIC (microthrombi that can reduce blood flow and damage body’s organs) and defective clotting

Question 9

Cascade of inflamm and coag during sepsis can be blocked by what?

Answer 9

Activated protein C; recombinant form has been approved to treat sepsis

Question 10

Types of bacteremia (TIC):

Answer 10

Transient (chewing, brushing teeth, surgery involving non-sterile sites, aka procedures involving contaminated or colonized skin and/or mucosal surfaces and at onset of acute bacterial infections);
Intermittent (extravascular infection which provides portal of entry for bacteria; think of abscesses, cholangitis, pneumonia, osteomyelitis, meningitis or pyogenic arthritis);
Continuous: bacterial endo and other endovascular infections (low numbers of bacteria)

Question 11

Examples of intravascular infections include

Answer 11

1. Infective endocarditis (acute means death in several days to less than six weeks; subacute is 6 weeks to 3 months; chronic is later than 3 months)
2. Mycotic aneurysm (endo cells lining arteries lead to seeding of the organism, think staph, strep, salmonella)
3. Thrombophlebitis (damage to endo cells lining a vein; results in clot formation and seeding of clot by organisms, think catheter)

Question 12

Steps of infective endocarditis

Answer 12

1. Damage to cardiac endothelium
2. Deposition of platelets and fibrin
3. Organisms in bloodstream can stick
4. Another layer of 2
5. Bacterial multiplication
6. Vegetation formation

Question 13

CRBSI is

Answer 13

due to catheters and it being used for too long, moved around, contaminated, poor aseptic technique, location

Question 14

Five sources for CRBSI

Answer 14

1. Insertion site
2. Catheter hub
3. Hematogenous seeding of catheter
4. Contamination of infusate
5. Hands of health care personnel

Question 15

One main organism causing catheter-related infections:

Answer 15

Coagulase-neg staphylococci

Question 16

Two organisms associated with neoplasms include:

Answer 16

1. Clostridium septicum
2. Streptococcus bovis
   (maybe campylobacter, aeromonas hydrophilia, plesiomonas shigelloides)

Question 17

What is most commonly used to dtect BSI’s?

Answer 17

Blood cultures (slow)

Question 18

Number of blood culture sets corresponds with

Answer 18

x2 the number of bottles (ie two sets = four bottles); aerobic bottle and anaerobic bottle in the set, and three sets means 99% bacteremia detected (80, 90 with 1 and 2 sets)

Question 19

For a blood culture, what must be done after you give iodine?

Answer 19

Ideally, let it dry and then perform venipuncture to get your sample

Question 20

What helps with differentiating infectious SIRS from noninfectious SIRS? What is this stimulated by?

Answer 20

Procalcitonin level;

bacterial products like endotoxins/LPS, and cytokines (IL1, IL2, IL6, TNF-alpha)

Question 21

Intravascular infections are; extravascular infections are

Answer 21

within the cardiovascular system; bacteria that enter the bloodstream through the lymphatic system from another site of infection

Question 22

SIRS manifested by at least two of the following four:

Answer 22

1. Hyperthermia or hypothermia
2. Tachycard
3. Tachypnea/hyperventilation
4. Leukocytosis or leukopenia

Question 23

Sever sepsis is defined as sepsis plus what?

Answer 23

1. Cardiovascular (hypotensive for at least one hour despite volume resuscitation)
2. Renal (low urine output for hour despite volume resus)
3. Pulmonary
4. Hematologic: platelet count below 80 or decreased by 50% in 3 days
5. Metabolic: pH < 7.3 and plasma lactate >1.5 x upper normal

Question 24

Secondary or extravascular BSI is

Answer 24

documented portal of bacterial entry and/or a known associated site of infection (pneumonia in lung, UTI, post-surgical wounds)