- Inflammation of the peritoneum and peritoneal cavity to bacteria, endotoxin, bile or gastric juice
- Transudation of fluid occurs in response to inflammation
- Normal volume of the peritoneum is 100ml
- This increases rapidly with passage of transudate which is rich in polymorphonuclear leukocyte
Primary peritonitis
- Diffuse bacterial infection without apparent intra-abdominal source of infection
- Most common in young girls between 3-9 years old
- In children, most common pathogens are pneumococcus, streptococcus
- Spread of infection
- From genitals through to fallopian tubes
- From upper respiratory tract
- From middle ear (more common in males)
- It can also occur in adults with cirrhosis, ascites or indwelling catheter for peritoneal dialysis
- The most common pathogen is E.coli
Secondary peritonitis
- From a known source – occurs secondary to bowel/visceral pathology
- E.g. perforation, appendicitis, pancreatitis, cholangitis
- Other causes
- Chemical/iatrogenic – from barium contrast
- Traumatic
- Drug induced
- Granulomatous
Teritiary peritonitis
- Persistent or recurrent intra-abdominal infection after adequate treatment for primary or secondary peritonitis
- Usually occurs after 48 hours
- More common in immunosuppressed patients
- Common pathogens – E. faecalis, S. epidermidis, P. aeruginosa, C. albicans
- Treatment is by aggressive antibiotic therapy, maintenance of haemodynamic stability, exploration of abdomen, transfusions
- ICU care is often needed
- Mortality rate is >50%
Classification
Pathoanatomical classification
- Fibrinous – clear fluid
- Serofibrinous
- Purulent – exudate is thin, greenish yellow or opaque white
- Putrid – thin, green, gangrenous
- Haemorrhage
Surgical classification
- Local – inflammation localised in 1 anatomic region
- Diffuse – inflammation spreads in over 2 area but only 2/3 abdominal floors (upper, middle, lower)
- Total – inflammation spreads through all abdominal space including subdiaphragmatic space
Stages of peritonitis
- Initial (reactive) stage – up to 24hrs
- Toxic stage – 24-72hrs
- Terminal stage – >72hrs
Clinical features
- Abdominal pain – abrupt onset, initially local then more diffuse
- Abdominal tenderness and distension
- Nausea and vomiting – first gastric contents, then duodenal, then intestinal
- Abdominal guarding (AKA ‘defence musculaire’) – tensing of anterior abdominal wall muscles to guard inflamed peritoneum
- Fever and tachycardia
- positive Blumberg sign – perform slow deep palpation and observe rebound tenderness
Investigations
- Medical history – gall stones, peptic ulcer disease, previous operations
- Physical exam – heart rate, blood pressure, respiration
- Start abdominal exam from mid femur
- Palpation – Blumberg
- Bloods – ↑WCC and CRP
- XR – shows gas under diaphragm
- USS, CT
- Laparoscopy, diagnostic laparotomy
Management
- NG tube
- Fluid resuscitation
- Insert urine catheter to assess urine output
- Antibiotics and analgesics
- Only give when diagnosis has been confirmed as they can mask clinical picture of peritonitis
- Patient can show false signs of improvement before suddenly deteriorating