peritonitis

Question 1

intro

Answer 1

inflammation of the peritoneum (inner lining of abdo wall that covers internal organs)

Question 2

types

Answer 2

• primary - spontaneous bacterial peritonitis = infection of ascitic fluid without any source of infection
• secondary bacterial peritonitis = inflammation, perforation, gangrene of intra-abdominal / retroperitoneal structure from bacterial infection

Question 3

spontaneous bacterial peritonitis (primary) has peak incidence in

Answer 3

pt w/ ascites from liver cirrhosis

Question 4

peritonitis can be localised / generalised

Answer 4

always some localised peritonitis in inflammatory conditions w/ pain, tenderness
generalised when peritoneum irritated from infection or leakage of intestine contents

Question 5

peak incidence in

Answer 5

pt w/ cirrhosis and ascites

Question 6

risk factors

Answer 6

• low ascitic fluid protein concentration
• upper GI bleeding
• prior episodes of SBP

Question 7

pathophysiology for primary

Answer 7

bacterial translocation
- from intestinal lumen to mesenteric LN of abdomen
- spreads to systemic and portal circulation
- colonises so infection of ascitic fluid

peritoneal cavity gets inflamed,
- produces inflammatory exudate
- causes intestinal dilation and paralytic ileus

Question 8

pathophysiology for secondary peritonitis

Answer 8

• perforated duodenum/abdo wall (from peptic ulcer)
• translocated bacteria from abdo organ inflammation (eg. appendicitis, diverticulitis, pancreatitis)
• trauma, wounds
• iatrogenic (surgery, anastomosis insuff)
• non-bacterial cause (ectopic, ovarian cyst)

Question 9

LN of abdomen

Answer 9

• superior mesenteric LN - near SMA
• inferior mesenteric LN - near IMA
• intestinal trunk - formed from coeliac trunk, superior and inferior mesenteric LN

Question 10

factors causing portal hypertension and cirrhosis??

Answer 10

• intestinal dysmotility
• bacterial overgrowth
• altered intestinal permeability
• systemic IS dysfunction

Question 11

symptoms

Answer 11

• sudden onset abdo pain (abdo pain is less rapid when secondary peritonitis - due to underlying inflammatory disease)
• diffuse pain (spread)
• ascites
• fever and chills
• new onset or worsening encephalopathy
• collapse + shock = toxaemia
• GI upset - n,v,d,c (ileus has reduced/absent peristalsis)

Question 12

signs

Answer 12

• tenderness on palpation
• guarding
• rebound tenderness
• general malaise - unwell
• signs of infection - fever, tachy, hypotension, leukocytosis, sepsis, shock
• rigidity - pt lie still, knees flex to reduce abdo wall mvt

Question 13

investigation

Answer 13

• erect CXR (detects free air under diaphragm)
• serum amylase - excludes acute pancreatitis

Question 14

diagnosis

Answer 14

• US/CT scan or x-ray abdo for organ perforation
• peritoneal fluid analysis / paracentesis - increased neutrophils (>250)
• fluid culture - shows E.coli

Question 15

mgt for primary peritonitis

Answer 15

• IV cefotaxime (cefalosporin) as guided by bacteria culture
• prophylactic oral ciprofloxacin for cirrhosis + ascites pt
• abx prophylaxis given to pt if previous SBP and fluid protein

Question 16

mgt for secondary peritonitis

Answer 16

supportive care
* IV fluids
* IV broad spectrum abx
* electrolytes - insert NG tube
* analgesics
* antipyretics
* VTE prophylaxis

surgical
* emergency laparotomy to lavage abdo cavity and treat underlying condition

Question 17

complications

Answer 17

• toxiaemia and septicaemia
• causes multiorgan failure
• abscesses if still signs of infection (fever, high WCC, pain) - drain using US