Small Bowel Obstruction

Question 1

Small Bowel Obstruction What goes wrong?

Answer 1

Distal small bowel that collapses - preceding diarrhoea Transition point Proximal bowel dilation - secretion of fluid into lumen = dehydration Gram negative/ anaerobic microbes from the small intestine is released into the blood

Question 2

Bowel obstruction

Large vs small

Answer 2

Small = adhesions and hernias

Large = malignancy, strictures

Question 3

Small Bowel Obstruction Causes in children

Answer 3

Intussussception Pyloric Stenosis Congenital Atresia

Question 4

Small Bowel Obstruction Clinical Features 3 classic Then less specific

Answer 4

Central colicky abdominal pain Vomiting (and so dehydration) Absolute constipation - no faecal matter or flatus (perhaps preceded by diarrhoea) Less specific: Bloating Loss of appetite Fever

Question 5

Small Bowel Obstruction Questions to ask if suspecting malignancy

Answer 5

Weight Loss Change in Bowel Habit PR bleeding Previous Malignancy

Question 6

Small Bowel Obstruction Findings on examination

Answer 6

Guarding Rebound tenderness Percussion tenderness Tinkling bowel sounds Dehydration Distended abdomen

Question 7

Small Bowel Obstruction Investigations

Answer 7

Bloods: FBC CRP - elevated WCC + CRP could indicate perforation and sepsis U+ E - look for AKI due to dehydration LFTs Coag screen Amylase - exclude pancreatitis which is an important differential Group and Save - surgery ABG - lactate CXR - air under diaphragm AXR with gastrograffin ECG - could be an MI Urine Dip - BETA HCG in women

Question 8

Small Bowel Obstruction Cardinal Features on abdominal X ray

Answer 8

Small Bowel Dilatation Air fluid levels Absence of gas distally

Question 9

Small bowel obstruction Further Investigations

Answer 9

Gastrograffin follow through - instead of barium which is an irritant and can cause peritonitis Ultrasound CT - can look for cause and complications MRI - good at looking for cause but not easy to organise

Question 9

Small Bowel Obstruction Management Acute Conservative Medical Surgical

Answer 9

Acute: DRABCDE Conservative - Drip and suck = NG tube from which you aspirate until nothing comes out and then you attach a bag for free drainage AND IV fluids + catheter + fluid chart Medical - Anti-emetics - Analgesia - Buscopan Surgical +/- bowel obstruction +/- stoma - Depends on cause - Tumours: only option - Usually other causes surgery is only done when medical and conservative options fail - Other indications for surgery: if suspect ischaemia or strangulation

Question 10

Small Bowel Obstruction Complications

Answer 10

Perforation Electrolyte Disturbance Post-op complications including VTE