intra-abdominal infections Flashcards
source control
control where the pathogens are coming from
sequelae of intraabdominal infections
may cause peritonitis
systemic sepsis
liver abscesses
pyogenic - bacterial, most common
fungal - usually from haematogenous deposits of candida
helminthic - hydatid cyst, caused by echinococcus granulosus
protozoal - entamoeba histolytica in a return traveller
how to pathogens enter the liver
mostly the come from the bowel via the bile duct
sometimes they come through the portal vein
sometimes the hepatic artery bringing in blood from the systemic circulation brings pathogens
liver abscesses in S+E asian populations
klebsiella pneumoniae liver abscesses may be associated with underlying colorectal malignancy
fungal liver abscess
complication of disseminated candidiasis in the immunocompromised
via hepatic artery
multiple abscesses
helminthic liver abscess
Hyatid disease
- echinococcus granulosus - most common
- echinococcus multicularis - worse
- e. granulosus acquired by humans ingesting eggs in dog faces
- cysts develop in liver, lungs (brain, bone)
amoebic dystentery
entamoeba histolytica
amoebae may invade bowel wall and establish infection in liver
can rupture into pleural pace in into peritoneal space
splenic abscesses
bacterial infection uncommon
from microorganisms in systemic circulation
endocarditis the most common source
candida following candidaemia
pancreatitis
typically an inflammatory rather than infective process
blockage of pancreatic duct by gallstone or chronic alcohol abuse
pancreatic enzymes self digest organs, necrosis
may progress to systemic sepsis
cholangitis or ascending cholangitis
infection of biliary system due to blockage of the common bile duct, by gallstone (common), tumour or stricture
- biliary stasis, no flow of bile
- increased pressure of the biliary tree
- growth of bacteria ascending from duodenum
- may enter systemic circulation - sepsis syndrome
- serious and life threatening condition
cholecystitis
- obstruction of cystic duct by gallstone
- bile stasis
- inflammatory process, oedema of gall bladder
- enteric bacteria ascending from duodenum
- ranges from mild oedema and inflammation through to necrosis and perforation
diverticulitis
arises from diverticulosis, sac-like projections from colonic wall
up to 15% of those with diverticulosis develop diverticulitis
diverticulosis
sac-like projections from the colonic wall
diverticulosis is associated with western lifestyle
diverticulosis may be asymptomatic or may result in several pathological conditions, one of which is diverticulitis
cause of diverticulitis
increased pressure, abrasion from food
local erosion, inflammation, necrosis of mucosa
micro or macro perforation of diverticulum
leakage of bowel contents - enteric bacteria
may be contained by overlying fat, mesentery
small or large abscess
fistulas to adjacent organs may develop
significant risk of perforation and peritonitis
appendicitis pathogenesis
obstruction of the lumen - faeces, undigested food, swelling of lymphoid follicles luminal dilation, wall thickening bacterial overgrowth breakdown of mucosal barrier bacterial invasion of the wall inflammation, ischaemia gangrene perforation
infections due to leakage of gastrointestinal contents - intra-abdominal abscesses
develop when the leakage is contained by the mesentery, omentum, adjacent organs or within smaller parts of the peritoneal cavity
intra-abdominal abscesses occur due to
leakage of gastrointestinal contents
locations of intra-abdominal abscesses
subphrenic
sub hepatic
paracolic
mesenteric
peritonitis
inflammation of the peritoneal tissue
not exclusively infective - peritoneum can react to blood, gastric fluid, bile, urine
infection iss the most common cause
primary peritonitis
spontaneous bacterial peritonitis
- usually seen in patients with end stage liver disease
- CAPD peritonitis
primary periostitis in patients with end stage liver disease
fluid builds up in the peritoneal cavity and becomes infection
source of bacteria usually unknown
primary peritonitis - CAPD
continuous ambulatory peritoneal dialysis
a form of dialysis in renal failure patients
the peritoneum acts as an exchange membrane to remove wastes from the bloodstream
CAPD
putting a permanent catheter into the peritoneum
several times a day a solution of hypertonic dextrose is dripped into the peritoneum
the peritoneal membrane acts like a kidney, and the hypertonic solution pulls out toxins which can be drianed into a drainage bag
people on CAPD can periodically get infections indicated by pain and a cloudy drainage bag
