infections of the peritoneum Flashcards
(35 cards)
what is primary spontaneous peritonitis
It’s also called Spontaneous Bacterial Peritonitis (SBP) – infection of ascitic fluid without any bowel perforation.
What organisms commonly cause SBP?
> > E. Coli (most common), Klebsiella, Strept. Pneumoniae.
How is SBP diagnosed?
• Paracentesis (sampling ascitic fluid)
• WBC > 500 or PMN > 250 cells/mm³
• SAAG > 1.1 g/dL
• Culture (can be negative sometimes)
what is secondary peritonitis
Peritonitis due to a hole or leak in the abdominal organs, allowing infection to spread inside the abdomen.
In which patients does SBP usually occur?
In patients with ascites, especially due to liver failure or renal failure.
What is the mortality rate of SBP?
Around 20–30%, and it can lead to sepsis.
What are the clinical features of SBP?
Abdominal pain, fever, vomiting, rebound tenderness, and guarding.
What is the treatment for SBP?
• Start IV Cefotaxime (or other broad-spectrum antibiotic)
• Shift to specific antibiotics if an organism is identified
• Repeat paracentesis in 24–48 hours to check drop in PMN count
What organisms commonly cause Secondary Peritonitis?
• E. coli
• Anaerobes (e.g., Bacteroides)
• Streptococci, Pneumococci, Enterococci
What are the sources of infection in Secondary Peritonitis?
• Infected organs (appendicitis, diverticulitis, cholecystitis)
• Leaking organs (perforation, anastomotic leaks)
• Trauma wounds
• Hematogenous spread
What happens after a perforation?
• Paralytic ileus develops first (body trying to reduce spread)
• Omentum tries to contain infection
What are the two possible courses?
- Localization (forms abscess)
- Flaring up (causes generalized peritonitis)
Where does localized abscess usually form?
• At the original infection site (e.g., appendicitis)
• In dependent zones like pelvis, iliac fossa, pouch of Douglas
What are the risk factors for generalized peritonitis (flare-up)?
• Sudden perforations
• Persistent infections
• Immunosuppression
• Very young or elderly
• May lead to sepsis, shock, and multiple organ failure
What signs are typically found on examination?
• Patient looks unwell or toxic, lies still in bed
• May have altered mental status
• Unstable vitals: high fever, fast heart rate, low blood pressure
• Palpation: tenderness, rebound, guarding, rigidity
• Auscultation: Absent bowel sounds
What labs are done in acute abdomen?
• CBC, RFTs, LFTs, amylase, lipase, coagulation profile, glucose, β-hCG
What imaging can suggest a perforated viscus?
• Erect abdominal X-ray – shows air under diaphragm
What paracentesis finding supports peritonitis?
WBC count > 200 cells/μL in ascitic fluid
What are the basic steps in managing peritonitis?
- ABC stabilization + IV fluids
- NPO + Nasogastric tube (NGT) + Foley catheter
- IV analgesia
- IV broad-spectrum antibiotics (e.g. cephalosporins + metronidazole)
What is the surgical management once the patient is stable?
• Exploratory laparotomy (midline incision)
• Treat the underlying cause (e.g., patching perforation)
• Peritoneal lavage with saline
• Drain placement
What is the mortality rate of peritonitis?
Around 40%, higher if the cause is distal in the bowel
What is an intraperitoneal abscess?
It is a form of localized septic peritonitis.
Is a peritoneal abscess better than generalized peritonitis? Why?
Yes, because it means the body was able to localize the infection, often with help from the omentum.
What are the common locations of an intraperitoneal abscess?
• Primary site of the original infection
• Dependent peritoneal sites, including:
• Subphrenic area (e.g., Morrison’s pouch)
• Right iliac fossa (via right paracolic gutter)
• Pelvis (e.g., Douglas pouch/recto-vesical pouch)
