L8 - Heart & Circulatory system

Question 1

Definition of Bacteraemia?

Answer 1

mere PRESENCE of bacteria in the blood

Question 2

Definition of Septicaemia?

Answer 2

Presence of bacteria in the blood that causes CLINICAL SYMPTOMS

Question 3

What were the main causative bacteria of Septicaemia before WWII?

Answer 3

pyogenic cocci - strep, staph

Question 4

What were the main causative bacteria of septicaemia after introducing antibiotics?

Answer 4

Gram-neg rods

Question 5

What are the main causative bacteria of septicaemia today?

Answer 5

Gram-pos, Gram-neg

Candida albicans

Question 6

Why is it that streptocci do not cause septicaemia as much but staphylocci still do?

Answer 6

Strep are susceptible to antibiotics still

Question 7

How can septicaemia occur?

Answer 7

haemotogenous spread - infection at other site

intraluminal spread - through CVC

extraluminal spread - break in skin

Question 8

What is the Plague caused by?

Answer 8

Yersinia pestis

gram-neg bacillus

Question 9

How is the Plague transmitted?

Answer 9

Droplets
contact
faecal-oral
vector

BLACK RATS

Question 10

2 diff. types of plagye?

Answer 10

bubonic

pneumonic

Question 11

What bacteria are newborn babies vulnerable to that can cause septicaemia?

Answer 11

L. monocytogenes

Group b streptococcus

Question 12

What bacteria are immunosuppressed people vulnerable to that can cause septicaemia?

Answer 12

P. aeruginose
Stenotrophomonas maltophilia
Acinetobacter spp.

Question 13

What is endotoxic shock?

Answer 13

Lipid A - vasodilation - hypotension ‘warm shock’

vessels constrict - ‘cold shock’

disseminated intravascular coagulation (DIC)

Question 14

What bacteria is endotoxic shock caused by?

Answer 14

Gram-neg bacteria that cause septicaemia

Question 15

what is toxic shock syndrome caused by?

Answer 15

TSST-1 toxin of S.aureus

Question 16

What happens during TSS?

Answer 16

non-specific binding of MHC II with T cell receptors for TSST-1

cytokine storm

Question 17

How is septicaemia diagnosed in the lab?

Answer 17

BacT/ALERT system

blood cultures - 3 draws from diff. sites

colourimetric detection

Question 18

what is the antimicrobial treatment of septicaemia?

Answer 18

empirical therapy - aminoglycoside * B-lactam + metronidazole

Question 19

What is infective endocarditis?

Answer 19

infection of endocardial surface of the heart

golden ‘vegetation’ lumps

Question 20

What are vegetations (endocarditis)?

Answer 20

damaged valves = disturbance in blood flow

microcolonies deposit fibrin

growing vegetations = friable - break off and block other vessels

Question 21

What is ‘early’ prosthetic valve endocarditis?

Answer 21

<1 after valve replacement

contamination

S. aureus
diptheroids
coag-neg staph

Question 22

What is ‘late’ prosthetic valve endocarditis?

Answer 22

> 1 after valve replacement

endogenous infections

‘viridans streptococci’
Enterococci
coag-neg staph

Question 23

What is native valve endocarditis?

Answer 23

rare

seen in i.v. drug users

tricuspid valve infected

Question 24

How is endocarditis diagnosed?

Answer 24

Modified Duke critera

Question 25

What are the ‘major’ requirements for the Duke criteria?

Answer 25

2x blood cultures positive for organisms known to cause IE

Echocardiogram positive for IE

Question 26

What are the ‘minor’ requirements for the Duke criteria?

Answer 26

predisposing factors

fever

vascular phenomena (Janeway lesions)

immunologic phenomena (Roth’s spots)

microbial evidence

Question 27

What are the 3 allowed criteria for the Duke criteria?

Answer 27

2 major
1 major, 3 minor
5 minor

Question 28

What is a mycotic aneurysm?

Answer 28

damage of arterial wall

bulging

Question 29

What is suppurative thrombophlebitis?

Answer 29

inflammation of vein wall

clots

common with IV catheter