Intra-abdominal Infections Flashcards Preview

Clinical Pathology > Intra-abdominal Infections > Flashcards

Flashcards in Intra-abdominal Infections Deck (26):
1

What are intra-abdominal Infections

Presence of microorganisms in normally sterile sites within the abdominal cavity

2

Name two normally sterile sites in the abdominal cavity

Peritoneum
Hepatobiliary tract
Stomach

NOT GASTROENTERITIS

3

Except for some anaerobes and candida species, the proximal intestine is relatively free from microorganisms. Why?

Bile inhibits growth

4

What organism reside in the large bowel?

95-99% anaerobes
Some aerobic bacteria - - enterobacteriaceae (coliforms)
- Gram negativecocci (enterococci)

5

What are the sources of a intraabdominal infection?

GI contents (lumen)
Blood
External e.g. surgery

6

What are the mechanisms pf intra abdominal infection?

Transaction of microorganism from GI tract lumen to peritoneal cavity e.g. inter peritoneal infection

Translocation of MO along a lumen e.g. hepatobiliary infection

Translocation of MO from extra-intestinal source e.g. haematogenous spread, penetrating trauma

7

What are the mechanisms by which infections translocate across a wall?

Perforation e.g. appendicitis, ulcer, diverticulum, cancer

Loss of integrity e.g. ischaemia, strangulation

Surgery e.g. seeding at operation, anastomotic leak

8

What are the mechanisms by which infection translocate across a lumen?

Blockage e.g. cholecystitis, hepatic abcess

Iatrogenic e.g. instrumentation (ERCP)

9

How does a perforated appendix cause peritonitis?

Obstruction of lumen of appendix (e.g. faecal matter/enlarged lymph)

Stagnation of luminal contents - bacterial growth

Increased luminal pressure - perforation into peritoneum

- peritonitis

10

What are the complications of diverticulum?

Diverticulitis
Perforation
Pericolic abcess

11

How is iscahemia cause in the GI?

strangulation
Arterial occlusion
Post operative e.g. aneurysm repair

12

What is cholecystitis?

Inflammation of gallbladder wall

13

What is cholecystitis associated with? What is this mainly caused by?

Obstructed cystic duct

Gallstones mainly, but can be malignancy, surgery, or parasitic worms

14

What is the presentation of cholecystitis?

Fever, upper right quadrant pain, jaundice

15

What is empyema of gallbladder and how does it present?

Frank pus in gallbladder

Same as cholecystitis but sepsis (severe pain, high fever, chills/rigor)

Requires removal

16

What is cholangitis?

Infection/inflammation of biliary tree (hepatic duct and common bile duct)

17

How is cholangitis caused? How does it present?

Obstruction of common bile duct

Fever, right upper quadrant pain, jaundice

18

What is a pyogenic liver abcess? What are the main routes by which it is caused?

Pus forming in liver

-Biliary obstruction
-Spread from other intra-abdominal obstruction
-haematogenous - from mesentery or systemic

19

What is an intra-peritoneal abcess?

Localised area of peritonitis with pus

20

What are the predisposing factors ofintraperitoneal abcess?

Perforation e.g. ulcer, appendix, diverticulum
Cholecystitis
Mesenteric bowel infarction
Pancreatitis/pancreatic necrosis
Postoperative anastomotic leak

21

What are the clinical presentations of an intraperitoneal abcess?

Nonspecific e.g. sweating, high swinging pyrexia, anorexia

Can show ipsilateral lung collapse with pleural effusion

22

What are the main causative bacterial organisms?

Aerobic gram - Enterbacteriacae (cloriforms) e.g E coli, Pseudonomas

Anaerobic gram -
Bacteriorides

Aerobic gram +
Enterococcus, Strep milleri

Anaerobic Gram +
Clostridium

23

Why are liver abcesses usually 'sterile'?

Polymicrobial - hard to grow anaerobes

24

What are liver accesses usually caused by?

Not GI flora
From haematogenous spread or trauma

25

What diagnostic imaging should you perform?

Chest X-ray - consolidation, pleural effusion adjacent to infected area

Ab ultrasound

Ab CT Scan

26

What is the antimicrobial therapy for these?

REMOVE abcess (drainage, resection)

Start smart
e.g. metronidazole and cefuroxime

Then focus
Narrowest spectrum based on culture results

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