Intra-Abdominal Infections Flashcards
Define: Intra-adbominal infection
Microorganisms presence in usually sterile abdominal cavity.
Where do intra-abdominal infections usually occur?
> Heptatobiliary tree
> Peritoneal cavity
What disease is not an intra-abdominal infection and why?
Gastroenteritis because it occurs in the bowel lumen which is not sterile.
What are the sources of intra-abdominal infections?
> GI contents
Blood
External
What is an Intraperitoneal infection mechanism?
Microorganisms translocate from GI lumen to peritoneal cavity
What is a Hepatobiliary/ biliary tract infection mechanism?
Microorganisms translocate along a lumen
What is a penetrating trauma/haematogenous infection mechanism?
Microorganisms from an external source
What are the mechanisms of translocation across a wall?
> PERFORATION - Appendix, Ulcer, Diverticulum, Malignancy
INTEGRITY LOSS - Ischaemia, Strangulation
SURGERY - Seeding, anastomosis leakage
In whom does a perforated appendix occur?
Children and young adults
What is the pathogenesis of a perforated appendix?
> Blocked vermiform appendix
Stagnation of bacteria, inflammatory cells
Build up of pressure may –> Perforation
Lumen contents into peritoneal cavity –> Peritonitis
What are the symptoms of a perforated Appendix?
> Severe, general pain
Shock
May feel an “Appendix Mass”
What is the treatment for a perforated Appendix?
> Cefuroxamine
> Metrondiazole
What is a diverticulum?
When a submucosa/mucosa herniation through muscular layer
What are the complications of a diverticulum?
> Diverticulitis
Perforation
Peri-colic abscess.
What two types of intra-abdominal infections can Bowel cancer be?
> Intra-peritonea
> Haematogenous
What bacteria are assoc with Bowel cancer?
> Clostridium Septicum
> Streptococcus Gallolyticus
What is the pathology of Bowel cancer leading to integrity loss?
Abnormal malignant tissue has less bowel wall integrity
What are the symptoms of bowel cancer?
> Weight loss
Altered bowel habit
Blood in stool etc
How does Ischaemia cause gut wall integrity loss?
> Strangulation
Ischaemia
Post-op aneurysm repair
How can surgery cause an intra-peritoneal infection?
> Anastomosis Leak
Acute infection - Shock and acute pain
Seeding - Reduce chance with prophylaxis
Intra-peritoneal abscess
What are the mechanisms of hepatobiliary/ biliary tract infections?
Blockage - Cholecystitis, Cholangitis, Hepatic Abscess
Iatrogenic - Instrumentation
What is Cholecystitis? What are its cause/results? How does it present?
= Chemical inflammation of the gallbladder wall
Cause/Result = Bacterial infection. Assc with gallstones, surgical, malignancy and parasitic worms
Presentation = Fever, Right UQ pain, Mild Jaundice
What is Emphysematous Cholecystitis?
Gas in the gallbladder wall
What is a complication of Cholecystitis?
Empyema of Gallbladder = Pus in gallbladder wall. Same presentation as Cholecystitis but with septic infection.
What is Cholangitis?
Inflammation/infection of the biliary tree
What is the only cause of Cholangitis that is different from Cholecystitis?
Can occur following endoscopy.
How can Cholangitis present?
Fever, R UQ pain, Jaundice (Same as Cholecystitis)
What are the infection routes for a pyogenic liver abscess?
> Biliary obstruction
Direct spread from other intra-abdominal infections
Haematogenous - from mesenteric or systemic infection
Penetrating trauma
Idiopathic
What is a intra-peritoneal abscess?
A localised collection of pus build-up.
Where are intra-peritoneal abscess usually located?
> Subphrenic
Subhepatic
Paracolic
Pelvic
What are the pre disposing factors to an intra-peritoneal abscess?
> Perforation - ulcer, diverticulum, appendix > Pancreatitis > Bowel ischaemia > Penetrating trauma > Cholecystitis > Post op anastomotic leak
What is the presentation of intra-peritoneal abscess?
NON SEPCIFIC > Anorexia > Wasting > Sweating > High swinging pyrexia
What are the symptoms of a Subphrenic Abscess?
> Persistant hiccups
Pain in affected shoulder side
Intercostal pain
Apparent hepatomegaly
What are the symptoms of a Pelvic Abscess?
> Urinary frequency
> Tenesmus - want to empty bowels loads
What is spontaneous bacterial peritonitis?
Infected ascitic fluid (peritoneal fluid more than 25ml)
What bacteria causes Amoebic abscesses?
E. Histolytica
What bacteria causes a Hytaid cyst?
E. Granulosus
What causes Ileocaecal TB?
M. Tuberculosis
