NEUTROPENIC COLITIS
Williams N and Scott A D N.
BJS., 1997., 84, 1200-1205.
Neutropenic colitis is a clinicopathological condition characterised by a septic or inflammatory intra-abdominal process in patients with haematological malignancy or who are neutropenic for a variety of reasons.
Pathogenesis – The pathological process has a predilection for terminal ileum, caecum and appendix.
a) One mechanism is that Cytosine arabinoside used to treat leukaemia, leads on to ulceration of the leukemic deposits in the terminal ileum.
b) Second proposed mechanism is ischaemia secondary to decreased flow secondary to Hypotension.
c) Bacterial infection inducing damage to the mucosa.
The precise mechanism is unknown.
Blood cultures are often positive, the common pathogens are Chlostridium septicum, C.difficile, Escherichia coli, Pseudomonas aeroginosa, Klebsiella and Enterobacter sp. Less frequently Candida may be isolated.
Clinical presentation –
Affects adults and children, who are being treated with anti-Leukemic therapy.
Symptoms and signs: Nausea, vomiting, abdominal distention and discomfort with bloody diarrhoea.
Occurs 7-10 days after the onset of chemotherapy.
There is usually pyrexia, but this is a non-specific sign. Diarrhoea may be a side-effect of the chemotherapy.
RIF tenderness is present in 60-80% of patients. Later, there may be generalised peritonitis. There may be a mass palpable in the RIF, which usually represents a thickened dilated, fluid-filled caecum. It may also represent an ileo-caecal inflammatory mass.
Rapid progression may ensue to full blown septicaemia.
High index of suspicion. Abdo symptoms in a neutropenic patient should alert one to this possibility.
FBC – neutropenia and thrombocytopenia.
Blood cultures are positive in more than half of the cases.
No endoscopy for fear of inducing perforation.
Peritoneal lavage may be of help. Gram staining of the recovered fluid may reveal polymicrobial contamination.
Radiology:
Plain X-ray shows distal small bowel obstruction, thickening of the bowel wall, a right-sided soft tissue mass, or a gasless abdomen or right lower quadrant are all suggestive features.
Localised or diffuse ‘thumb-printing’ characteristic of mucosal oedema, may be noted and, in patients with enteric perforation, intraperitoneal free gas may be present.
Pneumatoses intestinalis may also be observed.
Ultrasound shows a round mass with dense central echoes and a wider hypoechoic periphery. Pseudopolypoid changes of the caecal mucosa and a pericolic fluid collection.
CT findings are more accurate and similar to USS.
Every case has to be decided on its own merits. There is a high morbidity and mortality with this procedure and hence, initial conservative management should be in the ITU and if the condition deteriorates, then surgery should be performed. Percutaneous drainage of any pericolic collection is a helpful.
Granulocyte colony-stimulating factor, is of definite help.