24 Intra-abdominal infections Flashcards
Define intra-abdominal infection.
Presence of micro-organisms in normally sterile sites within the abdominal cavity e.g. peritoneal cavity/hepatobiliary tree.
Excludes gastroenteritis.
What are the three mechanisms of intra-abdominal infection?
Translocation from GU lumen to peritoneal cavity.
Translocation along a lumen.
Translocation of extra-intestinal source.
Describe how a perforated appendix might form.
Presentation?
Obstructed lumen to vermiform appendix, stagnation, bacterial growth, pressure build up bursts.
Severe, generalised pain and shock.
What are the complications of a perforated diverticulum? (3)
Diverticulitis.
Perforation.
Pericolic abscess.
How might bowel cancer cause intraperitoneal infection?
Associated with which bloodstream infections?
Loss of bowel wall integrity.
Clostridium septicum.
Streptococcus gallolyticus.
How do intra-abdominal post-operative infections occur?
Seeding at operation (reduced by prophylactic antibiotics).
Anastomotic leak.
What is cholecystitis?
Presentation?
Inflammation of gallbladder wall associated with cystic duct obstruction (gallstones, malignancy, worms).
Fever, URQ pain, mild jaundice.
What is empyema of the gallbladder?
Presentation?
Complication of cholecystitis - frank pus in gall bladder.
Severe pain, high fever, chills and rigors.
What is cholangitis?
Inflammation/infection of upper biliary tree (hepatic and common bile ducts).
What are the routes infection for a pyogenic liver abscess? (4)
Biliary obstruction.
Direct spread.
Haematogenous via mesenteric in hepatic portal vein or systemic via hepatic artery.
Penetrating trauma.
What are the predisposing factors for an intra-peritoneal abscess? (6)
Perforation: ulcer/ appendix/ diverticulum. Cholecystitis. Infarction. Necrosis. Trauma. Postoperative anastomotic leak.
What is the presentation of an intra-peritoneal abscess?
Sweating, anorexia, wasting, high swinging pyrexia.
Subphrenic: shoulder pain, hiccup, apparent hepatomegaly, ipsilateral lung collapse + pleural effusion.
Pelvic: urinary frequency and tenesmus.
What are hydatid cysts caused by?
Echinococcus granulosus.
Which organisms cause intrabdominal infections? (7)
Enterobacteriaceae: E.coli. Pseudomonas. Bacteroides spp. Prevotella spp. Enterococcus. Streptococci. Clostridium.
What is the empirical therapy for intestinal source intra-abdominal infection?
Cefuroxime + metronidazole.
Piperacillin/tazobactam is over 65.
And pus drainage if intraperitoneal abscess.
