Abdominal Catastrophes Flashcards
Outline the nerve supply of the peritoneum
Parietal = supplied by nerves that supply skin of abdo – localised pain
Visceral = supplied by autonomic nervous system – referred pain
What is the nerve supply to the diaphragm?
Phrenic nerve = C3/4/5
Irritation of the parietal peritoneum below the diaphragm can refer pain to where?
Tip of the shoulder
Define referred pain
Pain perceived at a site distant from the site causing the pain
Define somatic referred pain
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
Define visceral referred pain
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
What causes visceral pain?
Abnormally strong muscle contraction
Inflam
Ischaemia
Outline visceral pain location in regards to the gut
Foregut = epigastric
Midgut = periumbilical
Hindgut = suprapubic
Where is gastric and duodenal pain felt?
Foregut = epigastric
Where is gallbladder pain felt?
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
Where is splenic pain felt?
Over the spleen
Where is acute appendicitis pain felt?
Early = visceral peritoneum = midgut = periumbilical
Late = parietal peritoneum = localised = RIF
Where is pancreatic and abdo aortic pain felt?
Midgut = periumbilical
Retroperitoneal = pain felt all the way through to the back
Where is small bowel colic felt?
Midgut = periumbilical
Pain every 90 secs
Where is large bowel colic felt?
Hindgut = suprapubic
Pain every 4-5mins
Where is renal/ureteric colic felt?
Felt in the groin and flank
Often described as one of the strongest pain sensations known
Pts rolls around on the floor
Where is peritonitis felt?
Severe pain all over the abdo
Referred to the shoulder tip
Diaphragmatic/abdo all movement increase pain = ridge abdo and shallow rapid breathing
Why is a bowel obstruction so lethal?
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
What happens to hematocrit when a pt is dehydrated?
It raises
What are the common causes of bleeding into the gut?
Bleeding oesophageal varices
Bleeding peptic ulcer
Bleeding diverticular disease
Where is a duodenal ulcer most likely to be located?
Posterior – that has eroded into the gastroduodenal artery
Describe a bleeding oesophageal varices
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
What is melaena
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
Define haematemesis
Vomiting blood
What is diverticular disease?
Muscle spasms in the LI in the presence of an abnormal sac = abdo pain and disturbance of bowel function without inflam
Outline the possible causes of retroperitoneal bleeding
Ruptured AAA
Anticoagulated pts may bleed from torn retroperitoneal veins
How does a ruptured AAA present?
Sudden death = 50%
Severe sudden abdo/back/loin pain
Sudden collapse
Presents to emergency department with shock
How does rupture ectopic pregnancy present?
L/R iliac fossa pain
Vaginal bleeding
Collapse
Left shoulder tip pain on lying down
What can result from a gastric ulcer?
Posterior perforation = contents into the lesser sac = fluid then tracks to the greater sac via epiploic foramen
What does pneumoperitoneum usually indicate?
Perforated organ
Define volvulus
When a loop of intestine twists around itself and the mesentery that supports it = bowel obstruction
Name the causes of small bowel obstruction
Adhesions due to previous surgery
Femoral/inguinal hernia
Volvulus
Carcinoma of the caecum
Name the causes of large bowel obstruction
Carcinoma, particularly left-sided
Sigmoid volvulus
Diverticular disease
What results from a bowel obstruction?
Isotonic hypovolaemia
Vomiting = loss of H and Cl = metabolic alkalosis = renal compensation to preserve H at the expense of K = hypokalaemia
What is acute pancreatitis, its cause and treatment?
Auto-digestion by inappropriatly activated proteases (trypsin)
Cause = alcohol, gallstones
No treatment
Management = supportive
What is the most common cause of acute gut ischaemia and how does it present?
Embolism (AF)
Sever abdo pain, on exam tender over ischaemic gut
What is acute cholangitis and its most common cause?
Infection in the bile ducts
Cause = gallstone obstruction leading to jaundice and biliary stasis = e.coli infect
How does acute cholangitis present?
Charcots triad =
1) jaundice
2) RUQ pain
3) fever
Pts often have rigors, confusion and septic shock
Prior to anaesthetic is it very important to do what?
Correct hypovolaemia and serum K abnormalities
