Lecture 14-Abdominal Catastrophes

Question 1

Define referred pain

Answer 1

Pain perceived at a site distant from the site causing pain

Question 2

Define somatic referred pain

Answer 2

Pain caused by a stimulus to the proximal part of the somatic nerve that is perceived in the distal dermatome of the nerve

Question 3

Define visceral referred pain

Answer 3

CNS perceives visceral pain as coming from the somatic portion of the body supplied by the relevant spinal cord segments

Question 4

What can cause visceral pain?

Answer 4

Abnormally strong muscle contraction and stretch, inflammation and ischaemia

Question 5

True or false: patients with ureteric/renal colic roll around on the floor

Answer 5

TRUE

Question 6

How does peritonitis present?

Answer 6

• severe pain all over abdomen, may be referred to shoulder tips
• moving diaphragm and abdominal wall causes pain -> shallow, rapid breathing
• tender on examination, in early stages may have rebound tenderness

Question 7

How can obstruction of the small intestine cause dehydration?

Answer 7

Fluid loss due to accumulation of fluids, increased secretion and decreased reabsorption -> loss of isotonic salt water -> isotonic contraction of ECF volume -> dehydration

Question 8

What are common causes of bleeding into the gut?

Answer 8

• bleeding oesophageal varices
• bleeding peptic ulcer
• bleeding diverticular disease

Question 9

How do bleeding oesophageal varices and bleeding peptic ulcers present?

Answer 9

Haematemesis and melaena

Question 10

How does bleeding diverticular disease present?

Answer 10

Bright red bleeding from rectum (haematochezia)

Question 11

What is melaena?

Answer 11

Alteration of blood by digestive enzymes and intestinal bacteria -> black, tarry, smelly stool

Question 12

How can serum urea be used to diagnose upper GI tract bleeding?

Answer 12

Bleeding from stomach/oesophagus -> lots of protein to small intestine which is converted to urea by the liver. If serum creatinine is normal, increased urea with upper GI bleeding indicates the source of bleeding and the higher the serum urea, the larger the bleed

Question 13

What are the commonest causes of retroperitoneal bleeding?

Answer 13

Ruptured abdominal aortic aneurysm

Anticoagulants

Question 14

How does ruptured ectopic pregnancy present?

Answer 14

Lower abdo pain, vaginal bleeding, collapse and left shoulder tip pain when lying down

Question 15

What are the commonest viscus perforations?

Answer 15

Peptic ulcer

Diverticular disease

Question 16

What can a perforated peptic ulcer cause?

Answer 16

Chemical peritonitis

Question 17

What can perforated diverticular disease cause?

Answer 17

Peritoneal sepsis and septicaemia due to faecal peritonitis

Question 18

How does a ruptured abdominal aortic aneurysm present?

Answer 18

• sudden onset of severe abdo pain and back pain
• sudden collapse
• shock
• sudden death (50%)

Question 19

Why do fluid and electrolyte concentrations need to be corrected before anaesthesia?

Answer 19

Anaesthetics decrease sympathetic tone and have negative inotropic effect. In a dehydrated patient, SNS is maximally activated to maintain organ perfusion and if dehydration is not corrected before, patient may become hypotensive and die

Question 20

What are causes of small intestinal bowel obstruction?

Answer 20

• adhesions due to surgery
• femoral/inguinal hernias
• volvulus
• caecal carcinoma

Question 21

What are causes of large intestinal bowel obstruction?

Answer 21

• carcinoma
• sigmoid volvulus
• diverticular disease

Question 22

How can bowel obstruction lead to hypochloremic, hypokalaemic metabolic alkalosis?

Answer 22

• Vomiting -> loss of H+ and Cl- -> metabolic alkalosis

- kidney compensates by preserving H+ at the expense of K+ -> hypokalaemia

Question 23

What is the commonest cause of acute gut ischaemia?

Answer 23

Embolism (atrial fibrillation)

Question 24

How does acute gut ischaemia present?

Answer 24

Severe abdo pain and tenderness, toxic, hypotensive

Question 25

True or false: acute gut ischaemia increase WBC count

Answer 25

TRUE

Question 26

How can acute gut ischaemia be treated?

Answer 26

Laparotomy and resection of dead bowel