Makindo Medical Notes.com

Related Subjects: Small Bowel Obstruction |Colonic (Large bowel) Obstruction |Caecal Volvulus |Small Bowel Ischaemia |Hartmann's procedure |Sigmoid Volvulus |Acute Colonic Pseudo-obstruction |

There is an increased incidence of SBO from adhesions, with a higher incidence of laparotomies. Causes are hernias, adhesions, Crohn's disease and intussusception. SBO is often diagnosed late or misdiagnosed, resulting in significant morbidity and mortality.

About

• Can result in an acute surgical admission
• Can be total or subtotal (partial)

Aetiology

• Obstruction will lead to more progressive bowel dilation
• Eventually untreated the bowel will perforate
• Usually at the site of maximal diameter

Causes

• Lumen: Tumour, Constipation, Foreign body, Gallstone, Bezoar
• Mural: Crohn's disease, Malignancy, Ischaemia, Radiation stricture, Pseudo-obstruction
• Extramural: Hernia, Volvulus, Intussusception, Adhesions, Tuberculosis, Malignancy (Ovarian and colonic malignancy)

Clinical

• Nausea and vomiting, Bilious vomiting
• Colicky Abdominal pain, Abdominal distension
• Failure of passage of flatus and stool PR
• Guarding, peritonism, perforation, sepsis and shock

Investigations

• FBC, U&E, ESR: Raised WCC, abnormal electrolytes
• Raised lactate suggests bowel ischaemia and sepsis
• ECG: may show MI or AF
• CXR: Free air if perforation has occurred
• AXR: Dilated bowel loops proximal to obstruction with fluid levels or a paucity of gas is observed.
• Double contrast CT: shows level and cause of obstruction and viability of bowel involved. May show evidence of metastases and other relevant pathology. Axial CT scan shows a disparity in calibre between distended proximal small bowel loops (diameter >3 cm) (dotted line) and collapsed distal small bowel loops. The transition point is determined by identifying a calibre change between the dilated proximal and collapsed distal small bowel loops

Example AVR

The valvulae conniventes are very well demonstrated. Distended central small bowel. Evidence of old surgical staples. The cause was adhesions

Comparison

Management

• Urgent resuscitation with fluids and correct electrolytes with Glucose/saline and potassium.
• Analgesia and antiemetic may be needed.
• NG tube on continuous drainage if vomiting. IV fluids, Catheter if needed
• Steroids may be considered for those with suspected Inflammatory bowel disease
• Those with signs of peritonitis or perforation or necrosis then emergency laparotomy and resection is done
• Antibiotics are used to cover gram-negative and anaerobic organisms
• In some cases Palliation is appropriate

References