Diseases of GI Tract - Intra-Abdominal Infections (25)

Question 1

Intra-abdominal infection

Answer 1

Presence of micro-organisms in normally-sterile sites within abdominal cavity (peritoneal/hepatobiliary tree) not gastroenteritis

Question 2

Why not gastroenteritis?

Answer 2

Bowel lumen is non-sterile

Question 3

Normal flora of stomach

Answer 3

Sterile

Question 4

Normal flora of proximal S.I

Answer 4

Relatively free of micro-organism, growth inhibited by bile (few aerobic bacteria, candida)

Question 5

Normal flora of distal S.I

Answer 5

Similar to L.I

Question 6

Normal flora of large intestine

Answer 6

Anaerobic bacteria (95-99%), aerobic bacteria (enterobacteriaeceae - enteric gram-neg bacilli, coliforms, gram-positive cocci)

Question 7

Sources of intra-abdominal infection

Answer 7

Blood, GI contents, external (post-op if skin no properly sterilised)

Question 8

Perforated appendix (TAAW) common seen in

Answer 8

Children and young adults

Question 9

Perforated appendix (TAAW) caused by

Answer 9

Obstruction of lumen of vermiform appendix, build up of intra-luminal pressure

Question 10

Peritonitis

Answer 10

Escape of luminal contents into peritoneal cavity

Question 11

Why do you get obstruction of lumen of vermiform appendix?

Answer 11

Lymphoid hyperplasia, faecal obstruction > stagnation of luminal contents, bact growth and increase inflammatory cells

Question 12

Perforated appendix clinic

Answer 12

Severe, generalised pain, shock, ‘appendix mass’

Question 13

What is an appendix mass?

Answer 13

Inflamed appendix with adherent covering of omentum and small bowel

Question 14

Treatment of perforated appendix

Answer 14

Appendicectomy, cefuroxime and metronidazole (5 days)

Question 15

Perforated diverticulum (TAAW) caused by

Answer 15

Herniations of mucosa/submucosa through muscular layer (sigmoid and descending)

Question 16

Complications of diverticula

Answer 16

Diverticulitis, perforation, peri-colic abscess

Question 17

Symptoms bowel malignancy

Answer 17

Weight loss, alteration of bowel habit, blood in stool

Question 18

Complication of bowel malignancy

Answer 18

Intraperitoneal/bloodstream infection (C.septicum/Strep gallolyticus)

Question 19

Causes of ischaemic bowel

Answer 19

Interruption of blood supply - strangulation, arterial occlusion, post-op (aneurysm repair)

Question 20

Ischaemia and translocation

Answer 20

Gut wall loses structural integrity, allowing it

Question 21

Post-op infection

Answer 21

Seeding, anastomotic leak, acute infection (ab pain, tenderness, shock), intra-peritoneal abscess

Question 22

Translocation along a lumen

Answer 22

Hepatobiliary infections

Question 23

What is cholecystitis?

Answer 23

Inflammation of gallbladder (chemical inflammation/bacterial infection)

Question 24

What is cholecystitis associated with?

Answer 24

Obstruction of cystic duct (gallstones, malignancy, surgery, parasitic worms)

Question 25

Cholecystitis clinical presentation

Answer 25

Fever, RUQ pain, mild jaundice (Murphy’s sign)

Question 26

Emphysematous cholecystitis

Answer 26

Intramural gas in gallbladder wall

Question 27

Empyema of the gallbladder

Answer 27

Complication of cholecystitis, frank pus in gallbladder

Question 28

Presentation of empyema of gallbladder

Answer 28

Severe pain, high fever, chills and riggers (septic presentation of cholecystitis)

Question 29

Cholangitis

Answer 29

Inflammation of biliary tree (hepatic and common bile ducts)

Question 30

Causes of cholangitis

Answer 30

Obstruction of common bile duct, can follow instrumentation (e.g. endoscopic retrograde cholangio-pancretography)

Question 31

Presentation of Cholangitis

Answer 31

Fever (rigors), jaundice, RUQ pain (Charcot’s triad)

Question 32

Pyogenic liver abscess routes of infection

Answer 32

Biliary obstruction, direct spread from other intra-abdominal infections, Haematogenous, Penetrating trauma, Idiopathic

Question 33

Haematogenous spread of liver abscess

Answer 33

• From mesenteric infection via hepatic portal vein

- From systemic intravascular infection via hepatic artery

Question 34

Intra-peritoneal abscess

Answer 34

Localised area of peritonitis with build-up of pus (subphrenic, sub hepatic, paracolic, pelvic)

Question 35

Predisposing factors for intra-peritoneal abscess

Answer 35

Perforation (peptic ulcer, perforated appendix, perforated diverticulum), cholecystitis, mesenteric iscahemia/bowel infarct, pancreatitis/pancreatic necrosis, penetrating trauma, post-op anastomotic leak

Question 36

Presentation of intra-peritoneal abscess

Answer 36

Sweating, anorexia, wasting, high swinging pyrexia

Question 37

Subphrenic abscess presentation

Answer 37

Pain in shoulder on affected side, persistent hiccup, intercostal tenderness, apparent hepatomegaly

Question 38

Apparent hepatomegaly in Subphrenic abscess

Answer 38

Liver displaced downwards, ipsilateral lung collapse with pleural effusion

Question 39

Pelvic abscess presentation

Answer 39

Urinary frequency, tenesmus (frequency to poo)

Question 40

Other conditions

Answer 40

• Spontaneous bacterial peritonitis (SBP)
• Pancreatic and splenic abscesses
• Ameobic abscess
• Hydatid cyst
• Ileo-caecal TB

Question 41

Microbiology of liver abscess

Answer 41

Usually polymicrobial, sterile (contain hard-to-grow anaerobes), associated abscesses (brain), secondary to haeomtagoneous spread/involve lower GI flora

Question 42

Blood tests

Answer 42

FBC - neutrophilia/neutropenia
CRP - raised
LFTs - abnormal in hepatobiliary disease

Question 43

Imaging

Answer 43

Chest x-ray (consolidation, pleural effusion)

Abd ultrasound (masses, free fluid, dilate bile ducts)

Abd CT scan (higher definition)