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