CP 23 - Intra-abdominal infection

Question 1

what is intra-abdominal infection

Answer 1

Presence of micro-organisms in normally-sterile sites within the abdominal cavity -Excludes gastroenteritis
(Bowel lumen is a non-sterile site)

Question 2

which micro-organism is present in the proximal small intestine

Answer 2

a few aerobic bacteria and Candida spp.

Question 3

what are the source of intra-abdominal infection

Answer 3

gi contents, blood, external

Question 4

what is the 3 main mechanism of intra-abdominal infection?

Answer 4

• Translocation of micro-organisms from gastrointestinal tract lumen to peritoneal cavity (intraperitoneal infection)
• Translocation of micro-organisms along a lumen (biliary tract/ hepatobiliary infection)
• Translocation of micro-organisms from an extra-intestinal source
  (penetrating trauma, haematogenous spread)

Question 5

which type of mechanism of cause is perforated appendix

Answer 5

translocation across a wall - perforation - perforated appendix - obstruction of lumen of appendix (severe, generalised pain, shock, may localise to form ‘appendix mass’)

Question 6

what is treatment for appendicitis

Answer 6

appendicectomy, antibiotics - cefuroxime & metronidazole for 5 days.

Question 7

which type of mechanism of cause is perforated diverticulum

Answer 7

translocation across a wall - herniations of mucosa & submucosa through muscular layer

Question 8

what organisms can cause appendix

Answer 8

E.Coli & Bacteriodes Fragilis

Question 9

what are some of the complication for perforated diverticulum

Answer 9

diverticulitis, perforation, pericolic abscess

Question 10

what is a complication for bowel cancer

Answer 10

Intraperitoneal and/or bloodstream infection due to loss of bowel wall integrity and following syndrome

• clostridium speticum and streptococcus gallolyticus

Question 11

how can ischaemia cause infection?

Answer 11

gut wall loses structural integrity - allow translocation of luminal contents

Question 12

what mechanism of causation of hepatobiliary infections

Answer 12

translocation along a lumen

Question 13

what is cholecystitis

Answer 13

inflammation of gallbladder wall

Question 14

what can be the cause of cholecystitis?

Answer 14

obstruction of the cystic duct - gallstone 90%

Question 15

what are some of the symptoms of cholecystits

Answer 15

fever, right upper quadrant abdo pain, mild jaundice

Question 16

what is a complication for cholecystitis

Answer 16

empyema of the gallbladder (collection of pus) - presentatio is the same for cholecystitis but septic (severe)

Question 17

what is cholangitis

Answer 17

inflammation/infection of biliary tree (hepatic and common bile ducts)

Question 18

what are the causes for cholangitit

Answer 18

same causes as cholecystitis - mainly obstruction of common bile duct

Question 19

what is the presentation of cholangitis

Answer 19

rigor (fever), jaundice and right upper quadrant pain

Question 20

what is the route of infection for pyogenic liver abscess?

Answer 20

• Biliary obstruction
• Direct spread from other intra-abdominal infections
• Haematogenous
• penetrating trauma
• idopoathic

Question 21

what is intra-peritoneal abscess

Answer 21

Localised area of peritonitis with build-up of pus

Question 22

what are some of the clinical presentation of intra-peritoneal abscess

Answer 22

• Nonspecific presentation
• localising features - subphrenic abscess - pain in shoulder on affected side, persistent hicup, intercostal enderness aprrarent hepatomegaly

Question 23

what are some of the post-operative intra-peritoneal infection?

Answer 23

seeding at operation, anastomotic leak, acute infection, intraperitoneal abscess

Question 24

what are some of the examples of intra-peritoneal abscess?

Answer 24

subphrenic, subhepatic, paracolic, pelvic

Question 25

what is some clinical presentation for pelvic intra-peritoneal abscess

Answer 25

urinary frequency, tenesmus (a continual or recurrent inclination to evacuate the bowels)

Question 26

what are some of the organisms which can cause abdominal infection

Answer 26

• aerobic gram -ve bacilli
  enterobacteriaceae (coliforms) - predominantly E.Coli
  pseudomonas spp.
• anaerobic gram -ve bacilli
  bacteroides spp, prevotella spp
• aerobic gram +ve cocci
  enterococcus spp.
• anaerobic gram +ve bacilli
  clostridium spp.

Question 27

what are some of the organisms which can cause liver abscess

Answer 27

infection secondary to haematogenous spread or trauma may not involved normal GI flora

hepatobiliary tract infections usually involve lower GI flora, despite duodenal origin

Question 28

what diagnosis skills can be used to investigate intra-abdominal disease

Answer 28

full blood count - neutrophilia/neutropenia

C-reactive protein - raised

liver function test - abnormal in hepatobiliary disease

Question 29

what sort of imaging technique can be used to investigate intra-abdominal disease

Answer 29

Chest X-ray (consolidation, pleural effusion adjacent to infected area) , abdominal ultrasound, abdominal CT

Question 30

what microbiological investigations

Answer 30

sample to test - blood, peritoneal fluid, USC, Microscopy, culture and sensitivity testing

Question 31

what are the general principle for antimicrobial therapy

Answer 31

start smart - empirical antibiotics then narrow down to the possible spectrum based on culture results then oral switch