Bowel Obstruction + Ischaemia Flashcards

1
Q

what is a simple bowel obstruction

A

occlusiion of bowel without vascular compromise

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2
Q

what is a strangulated obstruction

A

occlusion of bowel with vascular compromise

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3
Q

most common cause of small bowel obstruction

A

adhesions

strangulated hernias also common

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4
Q

what needs to be ruled out in large bowel obstruction

A

Colorectal cancer

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5
Q

other causes of bowel obstruction

A

luminal:

  • foreign body , impacted faeces, intussusception, gallstones

intramural:

-tumours, strictures, crohns, diverticulitis

extrinsic:

  • adhesions, volvulus, hernia, tumour compression
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6
Q

cardinal symptoms of bowel obstruction

A

colikcy abdominal pain

vomiting

absolute constipation

abdominal distention

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7
Q

signs of bowel obstruction on examination

A

abdominal tenderness

tympanic percussion

tinkling bowel sounds

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8
Q

imaging choice for bowel obstruction

A

CT now 1st line

supine CXR still frequently done

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9
Q

Difference between large + small bowel obstruction on XRAY

A

small:

  • central, valvulae conniventes transverse entire thickness of the bowel

large:

  • peripheral, haustra partially cross thickness of the bowel
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10
Q

what type of bowel obstruction is this

A

large

  • haustra
  • peripheral
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11
Q

what type of bowel obstruction is this

A

small

  • central
  • valvulae conniventes cross entire bowel width
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12
Q

what other imaging may be required in bowel obstruction

A

erect CXR if perforation suspected- shows air under diaphragm if perforated

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13
Q

management of bowel obstruction

A

Trial of ‘Drip + suck’: NG tube, nil by mouth, IV fluids.

analgesia.

Surgery: laparotomy. absolute indications if:

  • peritonitis
  • perforation
  • irreducible hernia
  • caecal volvulus
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14
Q

what is paralytic ileus

A

reduced small bowel motility in the absence of obstruction

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15
Q

what usually causes paralytic ileus

A

post abdo surgery

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16
Q

what are bowel sounds like in paralytic ileus compared to obstruction

A

ileus = silent

obstruction = tinkling

17
Q

management of paralytic ilieus

A

IV fluids, NG tube if vomiting, mobilise to stimulate peristalsis

18
Q

what is a pseudo-obstruction

A

reduced motility of the large bowel in the absence of obstruction

19
Q

what causes pseudo-obstruction

A

increased sympathetic tone

20
Q

what is a volvulus

A

twisting of a loop of intestine around its mesenteric attachment

  • results in bowel obstruction
  • affected loop can become ischaemic due to compromised blood supply
21
Q

most common sites for volvulus

A

sigmoid colon

  • counterclockwise twisting

caecum (2nd)

  • clockwise twisting
22
Q

coffee bean sign

A

sigmoid volvulus

23
Q

management of sigmoid volvulus

A

decompression by sigmoidoscope + flatus tube insertion

24
Q

management of a caecal volvulus

A

laparotomy with ileocaecal resection

25
Q

what structures make up the foregut?

what is the blood supply?

A

stomach, biliary system, liver, pancreas

Celiac artery

26
Q

what structures make up the midgut?

what is the blood supply?

A

duodenum to first half of transverse colon

-superior mesenteric artery

27
Q

what structures make up the hindgut?

what is the blood supply?

A

2nd half of transverse colon to rectum

- inferior mesenteric artery

28
Q

what is acute mesenteric ischaemia

A

acute reduction in blood flow through the superior mesenteric artery (most commonly) or coelic artery, injuring the small bowel

29
Q

risk factors for acute mesenteric ishaemia

A

Atrial fibrillation

Post MI

Atherosclerosis

Coagulation Disorders

30
Q

what is chronic mesenteric ichaemia due to

A

atherosclerosis of the superior mesenteric artery / inferior mesenteric artery / coeliac artery

aka intestinal angina

31
Q

presentation of acute mesenteric ischaemia

A

sudden onset abdominal pain disproportionate to exam findings

progressess to peritonism

32
Q

how is mesenteric ishaemia diagnosed

A

CT angiogram

33
Q

blood gas in mesenteric ishaemia

A

metabolic acidosis

high lactate

34
Q

management of acute mesenteric ischaemia

A

IV fluids + Abx

Papaverine - opiod antispasmodic which causes vasodilation

Thrombolysis

In perforation/peritonitis: urgent laparoscopy/laparotom for embolectomy and resection of any infarcted bowel

35
Q

management of chronic mesenteric ishaemia

A

systemic mesenteric bypass

  • percutaneous angioplasty if unfit for open surgery
36
Q

what is ishaemic colitis

A

large bowel ishaemia, typically transient, leading to inflammation

  • usually due to atherosclerosis
  • splenic flexure most commonly affected
37
Q

what is fulminant ishaemic colitis

A

ishaemic colitis with necrosis, perforation and sepsis

38
Q

presentation of ishaemic colitis

A

abdominal pain, onset over hours, tenderness over affected area

PR bleeding + diarrhoea

39
Q

diagnostic test for ischaemic colitis

A

colonoscopy

  • sloughing, friability, ulceration