Bacteraemic infections

Question 1

Why is septicemia/bacteraemia not a diagnosis?

Answer 1

bacteria in the blood have to come from a source (e.g. infected heart valve, urinary tract, abscess, gut)

Question 2

What are some examples of precipitating agents?

Answer 2

endotoxin
toxic shock syndrome toxin (s aureus)
erythrogenic toxin (group a streptococcus)
cell wall of game +ve bacteria

Question 3

Where do endocarditic vegetations localise from high velocity regurgitant blood flow?

Answer 3

ventricular surface of valve
chordae tendinae of anterior mitral leaflet
atrial wall
atrial surface of mitral valve

Question 4

What are the common organisms recovered from bacteraemia in the oral cavity?

Answer 4

streptococci, diphtheroids, s. epidermis

Question 5

What are the common organisms recovered from bacteraemia in the airway?

Answer 5

streptococci, haemophilus, diphtheroids, streptococci, s. epidermidis, aerobic gram -ve rods

Question 6

What are the common organisms recovered from bacteraemia in the GIT?

Answer 6

streptococci, s epidermidis, diphtheroids, neisseria, aerobic gram -ve rods, bateroides,

Question 7

What are the common organisms recovered from bacteraemia in the urinary tract?

Answer 7

aerobic gram -ve rods, diphtheroids, streptococci

Question 8

What are the common organisms recovered from bacteraemia in the genital tract?

Answer 8

aerobic gram -ve rods, streptococci

Question 9

What is diagnostic of infective endocarditis in terms of blood culture?

Answer 9

increasing vol of blood cultured between 2 and 20ml - increasing relative yield of positive blood cultures

Question 10

Which bacteria are more likely to cause hospital acquired bacteraemia compared to community acquired?

Answer 10

staph aureus, klensiella, pseudomonas aeruginosa, coagulase negative staphylococci

Question 11

What are the symptoms of infective endocarditis?

Answer 11

fever, weakness, sweats, anorexia, weight loss, malaise, myalgia-arthralgia, back pain, confusion

Question 12

What are the signs of infective endocarditis?

Answer 12

pyrexia, murmur, embolic event, peripheral manifestations (osier’s nodes, petechiae, laneway lesions), retinal lesion, stroke, splenomegaly, septic complications

Question 13

How is clinically significant bacteraemia managed?

Answer 13

supportive therapy 
- fluids = IV colloids, saline
- inotropes = dobutamine
- organ support = ventilation, haemofiltration 
removal of infected focus 
- surgery to drain abscess
- removal of infected intravascular catheter
- wound debridement
antibiotics 
- IV at least initially
- broad spectrum - if etiology unknown 
- narrow spectrum when etiology known 
immunotherapy
- ?corticosteroids - no current evidence base
- ? monoclonal antibodies