Abdominal castrophies, pain and imaging

Question 1

Describe the sensory innervation to parietal and visceral peritoneum

Answer 1

Parietal is supplied by the same nerve that supplies the skin above it (somatic innervation). Visceral pain is sensed by the sympathetic fibres

Question 2

In what circumstances can somatic pain be referred?

Answer 2

When the stimulus is in the proximal part of the somatic nerve, the pain will be referred to the distal dermatome of that nerve

Question 3

Give two examples of somatic referred pain

Answer 3

• In SHINGLES, when the virus reactivates it irritates the proximal nerve, and so pain is referred to whatever root is affected. It is often mistaken for appendicitis, as it may start at umbellical region of T10 and then move to RIF as the shingles spreads and then the rash doesnt appear till later - In RIGHT LOWER LOBE PNEUMONIA the pain can initially be felt in the right illiac fossa

Question 4

Explain why visceral pain is referred

Answer 4

The visceral afferent pain fibres follow sympathetics back to their spinal cord roots. The CNS therefor perceives the pain as coming from the somatic portion of the body supplied by that spinal segment (dermatome). You therefor get a generalised pain around the region of that dermatome

Question 5

What can cause visceral pain?

Answer 5

Stretching Abnormally strong contraction Inflammation Ischaemia

Question 6

Where can lung and diaphragm pain be refered to? and why?

Answer 6

The shoulder/ neck- because its pain afferents travel on the splanchnic nerve (C3,4,5) and pain is mistaken for coming from somatics innervating C3 and 4- the neck region

Question 7

Describe gall bladder pain

Answer 7

sharp, fast onset Starts centrally (epigastric), then irritates parietal peritoneum and so is localised to the right, then irritates diaphragm and so may radiate to shoulder

Question 8

Describe the difference between large bowel colic pain and small bowel colic pain

Answer 8

Small bowel more painful and frequent- every 90 s. Large bowel waves of pain every 4/5 mins.

Question 9

Where can kidney/ ureteric pain be felt

Answer 9

Anywhere in lower abdomen as well as down lateral theigh and scrotum. It is very severe theyll probably be rolling around on the floor.

Question 10

Describe the pain of peritonitis

Answer 10

Severe pain all over abdomen, if the diaphragm is affected it will radiate to shoulder tip. The pain is worse on moving the diaphragm so breathing tends to be shallow. It will be tender to touch. In the early stages they may only have rebound tenderness

Question 11

What are the 4 main categories of abdominal catastrophies

Answer 11

Blood loss Perforation of a viscus Autodigestion of a viscera/ the peritoneum Gut ischeamia (Acute cholangitis doesnt really fit a class tho)

Question 12

What could cause bleeding into the gut? (3)

Answer 12

Bleeding oesphageal varices Bleeding peptic ulcers Bleeding diverticular disease

Question 13

What are the 3 biggest signs of GI bleeding?

Answer 13

Haematemesis- vomiting blood (upper GI bleed) Malaena- metabolised blood in stools making then dark and smelly (Bleed can be anywhere above caecum) Haematochezia- red blood in stools (rectal/ colon bleeding)

Question 14

What artery is commonly eroded and the source of bleeding for duodenal ulcers

Answer 14

The gastroduodenal artery (erodes through posterior wall)

Question 15

Why may a pts serum urea be high if they have an upper GI bleed?

Answer 15

Large protein meal is presented to stomach, protein converted to urea by liver, so urea increases. The higher the urea the greater the bleed. If serum creatinine is high, its probably due to kidney failure instead.

Question 16

What is the most common cause of retroperitoneal bleeding?

Answer 16

Ruptured abdominal aeortic aneurysms. If on anticoagulants it may be due to torn retroperitoneal veins

Question 17

If someone with a ruptured AAA doesnt die suddenly, how will they present?

Answer 17

severe back/ central pain Shock sudden collapse

Question 18

What may cause bleeding into the peritoneum?

Answer 18

Ruptured ectopic pregancy.

Question 19

Describe the presentation of someone with a ruptured ectopic pregnancy

Answer 19

• Reproductive age - Lower abdo pain - Vaginal bleeding - Collapse/ shock - left shoulder tip pain when lying down

Question 20

What is pointed at in the image shown?

Answer 20

Diverticular

Question 21

What are the two most common cause of a perforated viscus?

Answer 21

Peptic ulcers

Perforated diverticular disease

Question 22

What are the consequences of a perforated peptic ulcer and a perforated diverticular?

Answer 22

ulcer- gastric contents enter peritoneal-> chemical peritonitis (10% mortality)

Diverticular- bacteria and gut contents enter peritoneum rapidly leading to sepsis (50% mortality)

Question 23

What investigation can be done which can indicate a perforated viscus?

Answer 23

Erect CXR- see gas under diaphragm

Question 24

What are the general signs of a perforated viscus?

Answer 24

Severe generalised abdo pain

shallow breathing

hypovolaemic

septic

Question 25

Give common causes of small and large bowel obstruction (3 each)

Answer 25

Small= adhesions, hernias, volvulus, carcinomas

Large= carcinomas, volvulus, diverticular disease

Question 26

What is the commonest cause of acute gut ischaemia?

Answer 26

Embolism from A. Fib

Question 27

How may acute gut ischaemia present?

Answer 27

severe abdo pain and tenderness, toxic, hypertensive, very high WBC

Question 28

How is ischaemic bowel treated?

Answer 28

Urgent laparotomy to remove dead bowel. It carries a 90% mortality rate.

Question 29

When is an abdominal x ray implicated? (4)

Answer 29

• suspected bowel obstruction
• flare ups of IBD
• Forgein bodies
• Suspected calcification

Question 30

What features of an AXR suggest small bowel obstructiona and what suggests large bowel obstruction?

Answer 30

Small bowel- presence of valvulae conniventes and diametes of >3cm, central location

large bowel- diametes of >6 cm/ >9cm at caecum and presence of haustra, peripheral location

Question 31

What is shown in the image

Answer 31

Small bowel obstruction

Question 32

What is in the image shown

Answer 32

Large bowl obstruction

Question 33

What is in the image shown

Answer 33

Sigmoid volvulus- coffebean sign

Question 34

Where is the most common place for an intestinal volulus and why

Answer 34

sigmoid colon, it has a long mesentary which can easily become twisted on itself

Question 35

What is toxic megacolon

Answer 35

Breakdown of the colon wall, with impingment on the myenteric plexus, resulting in loss of the smooth muscle tone, dilation and pressure build up. It is usually secondary to UC, or rarely crohns or C. Diff.

Question 36

What is shown in the image?

Answer 36

Toxic megacolon- this person aslo has lead pipe colon due to their UC

Question 37

What calcifications can be seen in an AXR?

Answer 37

Renal caliculi

vascular calcification

pancreatic calcification following chronic inflammation

Question 38

How can swallowing mechanisms, strictures ect be imaged?

Answer 38

Barium swallows, barium enemas

Question 39

What is a virtual colonoscopy?

Answer 39

Where indivulal images from CT scanners are used to create a 3D virtual image of the colon. This saves the pt having to have a colonoscopy for cancer- 95% of which are negative

Question 40

What are the Avd and DisAdv of MRI?

Answer 40

No radiation

High resolution

Takes long time

Clostrophobia