Intra-abdominal Infection

Question 1

colonisation definition?

Answer 1

presence of microbe in human without inflammatory response (there but not causing issue)

Question 2

infection?

Answer 2

inflammation due to a microbe

Question 3

bacteraemia?

Answer 3

presence of viable bacteria in blood

Question 4

sepsis?

Answer 4

systemic inflammatory response to infection

life-threatening organ dysfunction caused by a dysregulated host response to infection

Question 5

septic shock?

Answer 5

subset of sepsis with circulatory and cellular/metabolic dysfunction associated with a higher risk of mortality

Question 6

what can cause an infection to become problematic?

Answer 6

unusual host response (age, immunosuppression, co-morbidity, drugs etc)
unusual microbe response (virulence expression latency, intracellular predilection for certain sites)
site of infection (worse if deep seated infection - cardio, bone, joints, occult)

Question 7

where can defence defects occur in the host?

Answer 7

surface mucosal barrier
complement
antibodies
B cells
macrophages
cytokines
T cells
NK cells
(area of defect depends on illness - eg alcoholism, malnutrition etc)

Question 8

what do phagocytes target?

Answer 8

bacteria

fungi

Question 9

what do T cells target?

Answer 9

viruses
fungi
protozoa

Question 10

what do B cells and antibodies target?

Answer 10

bacteria

viruses

Question 11

what do eosinophils target?

Answer 11

fungi
protozoa
worms

Question 12

what di mast cells target?

Answer 12

worms

Question 13

what does complement target?

Answer 13

bacteria

Question 14

what organisms are usually found in peritoneal cavity?

Answer 14

none
should be sterile
leakage of bowel contents etc results in peritonitis

Question 15

what can cause leakage of bowel contents?

Answer 15

perforated duodenal ulcer
perforated appendix
perforated diverticular
perforated tumour

Question 16

what is SOFA score?

Answer 16

sequential organ function assessment 
(sepsis related)
takes into account
- resp
- coagulation
- liver function
- cardio
- CNS
- renal
each scored from 0-4 (0=best, 4=worst)

Question 17

qSOFA?

Answer 17

shortened SOFA scoring
screens for outcome (not diagnosis)
- RR>22
- systolic BP < 100
- altered GCS
0/3 = <1% mortality
1/3 = 2-3% mortality
2+/3 = >10% mortality

Question 18

SIRS criteria?

Answer 18

when 2 or more of the following are present

• temp >38 or <36
• HR > 90
• RR >20 or PaCO2 < 32 (4.3kPa)
• WCC > 12000 (>12x10^9/L)

Question 19

how does infection severity progress?

Answer 19

colonisation > infection > SIRS > sepsis > severe sepsis > septic shock
(mortality increases)

Question 20

what is SIRS?

Answer 20

systemic inflammatory response syndrome
whole body inflammatory response
non-specific clinical response including >2 of the following
- temp >38 or <36
- HR >90
- RR >20
- WCC >12000 or <4000 or >10% immature neutrophils

Question 21

what can cause SIRS?

Answer 21

infection
trauma
burns
pancreatitis
other insults

Question 22

how is sepsis different to SIRS?

Answer 22

sepsis = SIRS with a presumed or confirmed infectious process

Question 23

what is septic shock?

Answer 23

sepsis + signs of at least 1 acute organ dysfunction

Question 24

what organisms generally cause community infection?

Answer 24

E coli (urine, abdomen)
strep pneumoniae (resp)
staph aureus (usually MSSA - skin)

Question 25

what organisms generally cause hospital infection?

Answer 25

``` E coli (catheter or abdomen) staph aureus (usually MRSA - line or wound related) CNS (line/prosthesis related) enterococci (urine, wound, line) klebsiella (urine, wound) pseudomonas ```

Question 26

supportive management in infection syndrome?

Answer 26

``` fluids analgesia VTE prophylaxis oxygen control electrolyte balance need for transfusion ```

Question 27

when might surgery be needed to support infection?

Answer 27

exploration | incision-excision and drainage etc

Question 28

what are coliforms?

Answer 28

E coli and similar bugs that inhibit large bowel e.g klebsiella, proteus, Enterobacter, serratia etc rod shaped gram -ve bacteria

Question 29

example of strict aerobe?

Answer 29

pseudomonas

Question 30

examples of aerobes?

Answer 30

staph strep enterococci coliforms (majority of human pathogens)

Question 31

examples of strict anaerobes?

Answer 31

clostridium bacteroides anaerobic cocci (Present in large numbers in large bowel)

Question 32

normal mouth flora?

Answer 32

``` strep viridans Neisseria (gram -ve cocci) anaerobes candida (few) staph ```

Question 33

normal stomach/duodenum flora?

Answer 33

usually sterile | can have a few candida and staph which may survive acidic environment

Question 34

normal flora of jejunum?

Answer 34

small numbers of coliforms and anaerobes

Question 35

normal flora of colon (faecal flora)?

Answer 35

large numbers of coliforms, anaerobes and enterococcus faecalis

Question 36

normal flora of bile ducts?

Answer 36

sterile

Question 37

how long are antibiotics given in sepsis?

Answer 37

usually 10-14 days | 4-6 weeks if complicated

Question 38

empirical treatment of intra-abdominal infections?

Answer 38

amoxicillin + gentamicin + metronidazole amox = strep and enterococcus gent = aerobic coliforms met = anaerobes

Question 39

how are abscesses managed?

Answer 39

large abscess has no blood supply so antibiotic wont reach it small abscesses can be treated with antibiotics but large ones need incision and drainage

Question 40

antibiotic for coliforms?

Answer 40

gentamicin

Question 41

antibiotics for anaerobes?

Answer 41

metronidazole

Question 42

antibiotic for enterococcus?

Answer 42

amoxicillin

Question 43

intra-abdominal infection empirical management if penicillin allergic?

Answer 43

cotrimoxazole + gentamicin + metronidaole

Question 44

what antibiotics are used for prophylaxis in GI/hepatobiliary surgery?

Answer 44

gentamicin + metronidazole

Question 45

what is the risk with gentamicin?

Answer 45

renal damage (nephrotoxic)

Question 46

how is nephrotoxicity risk managed in gentamicin use?

Answer 46

limit duration to 72 hrs after which ID/micro approval is needed limit duration to 24 hrs if concerns of renal function monitor renal function daily clear exclusion criteria also exists check levels twice a day

Question 47

dosing in gentamicin?

Answer 47

dose per weight? ensure correct dosing in overweight patients max dose = 600mg