Peritonitis Flashcards
How may bacteria enter the peritoneal cavity?
Bacteria may enter via four portals:
- Exterior: penetrating wound, infection at laparotomy, peritoneal dialysis
- Intra-abdominal viscera:
- a) Gangrene of a viscus: e.g. acute appendicitis, acute cholecystitis, diverticulutis, ischaemic colitis
- b) Perforation of a viscus: e.g. perforated duodenal ulcer, perforated appendicitis, rupture of intestine from trauma
- c) post op leakage of intestinal suture line
- Blood stream: as part of septicaemia (pneumococcal, streptococcal or staphylococcal).
- Female genital tract: acute salpingitis, puerperal infection.
What are the common bacteria of peritonitis of bowel origin?
Mixed faecal flora:
- Escherichia coli
- Strep faecalis
- Pseudomonas
- Klebsiella
- Proteus
- Clostridium
- Bacteroides
What are the common bacteria of peritonitis of gynaecological origin?
Chlamydial, gonococcal or streptococcal.
What are the pathological effects of peritonitis?
- Absorption of toxins from large inflammed surface
- Paralytic ileus leading to:
- loss of fluid
- loss of electrolytes
- loss of protein
- Gross abdo distension –> elevation of diagphram –> liability to lung collapse and pneumonia.
What are the clinical features of peritonitis?
Secondary to some precipitating lesion (e.g. appendicitis, diverticulitis). Will have its own signs.
Early peritonitis:
- severe pain -pt lies still; local or generalised tenderness (+ rebound tenderness)
- diaphragmatic irrititation > shoulder tip pain
- Vomiting
- Elevated temp, tachycardia
- No bowel sounds
Advanced: abdo distended and tympanitic, signs of free fluid, rapid (feeble) pulse, faeculent vomit, skin is moist, cold and cyanosed.
Investigations in peritonitis?
Limited value: diagnosis = clinical fx.
- FBE: leukocytosis
- Serum lipase: exclude pancreatitis and prevent surgery
- CXR: free gas under diaphragm (perforated viscus). Exclude pulmonary infection.
- AXR: free gas, other cause.
- CT: free gas. Cause of peritonitis.
DDx of peritonitis?
Intestinal obstruction, ureteric/biliary colic (in all patient tends to be restless).
Also: basal pneumonia, MI, intraperitoneal haemorrhage and leakage AAA.
What are the principles of managing peritonitis?
- Treat cause!
- Pain relief: opiates e.g. IV morphine
- Gastric aspiration: place NGT to prevent aspiration, further distension
- IV fluid and electrolytes, +/- blood and blood products
- ABx: broad bowel cover (penicillin+gentamicin, cephalosporin+metronidazole)
- Surgery: if source can be removed
How is peritoneal dialysis peritonitis diagnosed and treated?
Abdo pain and turbid dialysate.
Single organism: IV and intraperitoneal ABx
Multi organism: suggest perforation. Laparotmy + ABx
What is pneumococcal peritonitis?
May be secondary to septicaemia from lung infection or ascending PV infection in girls 4-10y.
Clinical fx: sudden onset peritonitis with severe toxaemia and fever. Leukocytosis (20+).
Why is bile peritonitis only rare in acute cholecystitis?
- unlike the appendix which rapidly gangrenes with inflammation, gallbladder thickens and is walled of by adhesions
- gallbladder has vascular supply from liver bed therefore frank gangrene unusual (unlike end artery supply by ileocolic to appendix).
What is a complication following peritonitis?
Pus may collect in subphrenic spaces of in the pelvis.
Describe the anatomy of the subphrenic region.
- Lies between the diaphgram above and the transverse colon + mesocolon below
- Right and left subphrenic spaces lie between the diaphgram and the liver separated by falciform ligament
- Right and left subhepatic spaces below the liver,
- the right forms Morrison’s pouch
- the left is the lesser sac; communicates with the right via foramen of Winslow.
What is the aetiology of a subphrenic pus collection?
- Following generalised peritonitis (e.g. upper abdo surgery)
- Rare: from haematogenous spread, direct spread from primary lesion (e.g. empyema)
What are the clinical features of a subphrenic collection?
- Usually follows generalised peritonitis by 10 - 21 days
- Symptoms: malaise, nausea, loss of weight, anaemia, pyrexia
- Common = swinging temp beginning ~10d after initial illness
- Localising: pain in upper abdo/lower chest, +/- referred to shoulder tip
