Abdominal Catastrophes

Question 1

Outline the nerve supply of the peritoneum

Answer 1

Parietal = supplied by nerves that supply skin of abdo – localised pain

Visceral = supplied by autonomic nervous system – referred pain

Question 2

What is the nerve supply to the diaphragm?

Answer 2

Phrenic nerve = C3/4/5

Question 3

Irritation of the parietal peritoneum below the diaphragm can refer pain to where?

Answer 3

Tip of the shoulder

Question 4

Define referred pain

Answer 4

Pain perceived at a site distant from the site causing the pain

Question 5

Define somatic referred pain

Answer 5

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

E.g. = shingles casing RIF pain, R lower lobe pneumonia causing RIF pain

Question 6

Define visceral referred pain

Answer 6

Thorax/abdo = visceral afferent pain fibres follow sympathetic fibres back to the same spinal cord segment that gave rise to the preganglionic sympathetic fibres

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

= poorly localised

Question 7

What causes visceral pain?

Answer 7

Abnormally strong muscle contraction

Inflam

Ischaemia

Question 8

Outline visceral pain location in regards to the gut

Answer 8

Foregut = epigastric

Midgut = periumbilical

Hindgut = suprapubic

Question 9

Where is gastric and duodenal pain felt?

Answer 9

Foregut = epigastric

Question 10

Where is gallbladder pain felt?

Answer 10

Mixed

Foregut = epigastric

Can irritate the parietal peritoneum on adjacent chest wall

Can irritate peritoneum underneath the diaphragm = referred should tip pain

Tip of the scapula

Question 11

Where is splenic pain felt?

Answer 11

Over the spleen

Question 12

Where is acute appendicitis pain felt?

Answer 12

Early = visceral peritoneum = midgut = periumbilical

Late = parietal peritoneum = localised = RIF

Question 13

Where is pancreatic and abdo aortic pain felt?

Answer 13

Midgut = periumbilical

Retroperitoneal = pain felt all the way through to the back

Question 14

Where is small bowel colic felt?

Answer 14

Midgut = periumbilical

Pain every 90 secs

Question 15

Where is large bowel colic felt?

Answer 15

Hindgut = suprapubic

Pain every 4-5mins

Question 16

Where is renal/ureteric colic felt?

Answer 16

Felt in the groin and flank

Often described as one of the strongest pain sensations known

Pts rolls around on the floor

Question 17

Where is peritonitis felt?

Answer 17

Severe pain all over the abdo

Referred to the shoulder tip

Diaphragmatic/abdo all movement increase pain = ridge abdo and shallow rapid breathing

Question 18

Why is a bowel obstruction so lethal?

Answer 18

Normally secrete 7-9L fluids a day into upper intestinal tract

Fluid loss due to = accumulation of fluids, increased secretion, decreased reabsorption

= loss of isotonic salt water = isotonic contraction of ECF vol

= dehydration and increased hematocrit

Question 19

What happens to hematocrit when a pt is dehydrated?

Answer 19

It raises

Question 20

What are the common causes of bleeding into the gut?

Answer 20

Bleeding oesophageal varices

Bleeding peptic ulcer

Bleeding diverticular disease

Question 21

Where is a duodenal ulcer most likely to be located?

Answer 21

Posterior – that has eroded into the gastroduodenal artery

Question 22

Describe a bleeding oesophageal varices

Answer 22

Increased pressure in portal vein = devel of large swollen veins within the oesophagus and stomach

These can easily rupture and bleed = large amount of blood loss

Question 23

What is melaena

Answer 23

Dark sticky faeces containing partially digested blood
Most common cause = bleeding oesophageal varices or bleeding peptic ulcer

Bleeding = large protein meal for SI = protein converted to urea = raised levels

Question 24

Define haematemesis

Answer 24

Vomiting blood

Question 25

What is diverticular disease?

Answer 25

Muscle spasms in the LI in the presence of an abnormal sac = abdo pain and disturbance of bowel function without inflam

Question 26

Outline the possible causes of retroperitoneal bleeding

Answer 26

Ruptured AAA

Anticoagulated pts may bleed from torn retroperitoneal veins

Question 27

How does a ruptured AAA present?

Answer 27

Sudden death = 50%

Severe sudden abdo/back/loin pain

Sudden collapse

Presents to emergency department with shock

Question 28

How does rupture ectopic pregnancy present?

Answer 28

L/R iliac fossa pain

Vaginal bleeding

Collapse

Left shoulder tip pain on lying down

Question 29

What can result from a gastric ulcer?

Answer 29

Posterior perforation = contents into the lesser sac = fluid then tracks to the greater sac via epiploic foramen

Question 30

What does pneumoperitoneum usually indicate?

Answer 30

Perforated organ

Question 31

Define volvulus

Answer 31

When a loop of intestine twists around itself and the mesentery that supports it = bowel obstruction

Question 32

Name the causes of small bowel obstruction

Answer 32

Adhesions due to previous surgery

Femoral/inguinal hernia

Volvulus

Carcinoma of the caecum

Question 33

Name the causes of large bowel obstruction

Answer 33

Carcinoma, particularly left-sided

Sigmoid volvulus

Diverticular disease

Question 34

What results from a bowel obstruction?

Answer 34

Isotonic hypovolaemia

Vomiting = loss of H and Cl = metabolic alkalosis = renal compensation to preserve H at the expense of K = hypokalaemia

Question 35

What is acute pancreatitis, its cause and treatment?

Answer 35

Auto-digestion by inappropriatly activated proteases (trypsin)

Cause = alcohol, gallstones

No treatment

Management = supportive

Question 36

What is the most common cause of acute gut ischaemia and how does it present?

Answer 36

Embolism (AF)

Sever abdo pain, on exam tender over ischaemic gut

Question 37

What is acute cholangitis and its most common cause?

Answer 37

Infection in the bile ducts

Cause = gallstone obstruction leading to jaundice and biliary stasis = e.coli infect

Question 38

How does acute cholangitis present?

Answer 38

Charcots triad =

1) jaundice
2) RUQ pain
3) fever

Pts often have rigors, confusion and septic shock

Question 39

Prior to anaesthetic is it very important to do what?

Answer 39

Correct hypovolaemia and serum K abnormalities