Peritonitis Flashcards
What is the peritoneal space?
The space between both viscera’s - parietal peritoneum (lines cavities) & visceral peritoneum (lines organs)
What is the peritoneum made up of?
Mesothelial cells, macrophages, lymphocytes, mast cells, fenestrations, surfactant production
Which organs do we find in the retroperitoneum?
Kidney’s, ureters, adrenal glands, aorta, caudal vena cava, lumbar lymph nodes
Will intra-abdominal bleeding clot? Why?
Normal peritoneal fluid lacks fibrinogen = NO clot!
How do we classify peritonitis? Which conditions are associated?
Primary - the only example for this is with cats - feline infectious peritonitis (uncommon)
Secondary - either septic or aseptic
aseptic: most common is pancreatitis
septic: bacterial leakage into abdominal cavity
What causes an aseptic peritonitis? (mechanical/FB & chemical)
Whenever we do procedures like spays we technically induce a mild aseptic peritonitis
- Mechanical and FB: swabs, air, suture material, glove powder
- Chemical: uroperitoneum (leakage of urine into abdominal cavity), pancreatitis - most common (severe aseptic peritonitis)
What causes a septic peritonitis?
Any source of intra-abdominal bacterial contamination
- GIT
- Penetrating injury
- Ischaemic injury (torsion, strangulation)
- Ruptured abscess (pancreatic, prostatic, liver, intestinal, LN
- Uterus (ruptured pyometra)
- Rupture extrahepatic biliary system
What are the adjuvant substances that may also be within the abdominal cavity following a leakage that can make an infection worse?
- Gastric mucin: decreases macrophage phagocytic activity
- Bile: destroys mesothelial layer that inhibits neutrophils
- Haemoglobin: interferes with chemotaxis and phagocytic activity of neutrophils
- Foreign bodies: may introduce bacterial translocation from GIT
What is the diagnostic process for peritonitis?
- History & clinical signs
- Abdominal radiographs
- Abdominal ultrasound (AFAST)
- Abdominocentesis
- Blood count + Biochemistry
- Abdominal ultrasound (complete)
- CT
Which events in a history of a patient gives clues towards a possible peritonitis?
- Recent abdominal surgery (OVH, GI tract)
- Penetrating injury - bite wounds
- Spontaneous - perforation due to neoplasia?
- Dysuria/Pyuria: UTI, Prostatitis
- PU/PD - Pyometra
Whys is it important to do abdominal radiographs before doing an abdominocentesis?
Because some air may enter the abdominal cavity
What are the clinical signs with peritonitis?
Vague!
- peritoneal effusion (not always detectable on clinical exam)
- abdominal pain
- listen for gut sounds - ileus
- systemic signs: anorexia, vomiting, depression
- dehydration
What might we see on a radiograph that could indicate peritonitis?
- Loss of serosal detail especially with high amount of fluid in abdomen.
- Localised loss of serosal detail - commonly seen with pancreatitis
- Whenever there is free abdominal gas in the abdomen = indicative of septic peritonitis
How do we interpret an abdominocentesis sample?
- Gross examination: bloody? clear?
- Classification: normal, transudate, modified transudate, exudate
- EDTA: cytology
- Culture for antimicrobial selection
- Biochemistry
In house cytology:
- neutrophils (degenerative?)
- macrophages (active?)
- mesothelial cells (normal?)
- bacteria (try to identify intracellular bacteria - extracellular bacteria may be contamination of diff quick stain)
- Bilirubin: gall bladder rupture
not 100% diagnostic but on biochemistry: blood to fluid glucose difference & blood to fluid lactate difference
- bacteria uses up glucose in fluid and producing a lot of lactate - compared to blood. if there is a septic peritonitis, the glucose in peritoneal fluid will be less and lactate more.
Other biochemistry:
- If bilirubin is twice as much as in serum - indicative of bile peritonitis
- creatinine & potassium = uroperitoneum (sterile urine does not cause a septic peritonitis but an aseptic peritonitis, peritonitis from urine only if urine is already infected)
- triglycerides = usually indicative of a neoplastic process (chyloperitoneum)
What is a common reason for a spontaneous septic peritonitis?
Liver abscess rupture
