Lecture 14-Abdominal Catastrophes Flashcards
(26 cards)
Define referred pain
Pain perceived at a site distant from the site causing pain
Define somatic referred pain
Pain caused by a stimulus to the proximal part of the somatic nerve that is perceived in the distal dermatome of the nerve
Define visceral referred pain
CNS perceives visceral pain as coming from the somatic portion of the body supplied by the relevant spinal cord segments
What can cause visceral pain?
Abnormally strong muscle contraction and stretch, inflammation and ischaemia
True or false: patients with ureteric/renal colic roll around on the floor
TRUE
How does peritonitis present?
- 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
How can obstruction of the small intestine cause dehydration?
Fluid loss due to accumulation of fluids, increased secretion and decreased reabsorption -> loss of isotonic salt water -> isotonic contraction of ECF volume -> dehydration
What are common causes of bleeding into the gut?
- bleeding oesophageal varices
- bleeding peptic ulcer
- bleeding diverticular disease
How do bleeding oesophageal varices and bleeding peptic ulcers present?
Haematemesis and melaena
How does bleeding diverticular disease present?
Bright red bleeding from rectum (haematochezia)
What is melaena?
Alteration of blood by digestive enzymes and intestinal bacteria -> black, tarry, smelly stool
How can serum urea be used to diagnose upper GI tract bleeding?
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
What are the commonest causes of retroperitoneal bleeding?
Ruptured abdominal aortic aneurysm
Anticoagulants
How does ruptured ectopic pregnancy present?
Lower abdo pain, vaginal bleeding, collapse and left shoulder tip pain when lying down
What are the commonest viscus perforations?
Peptic ulcer
Diverticular disease
What can a perforated peptic ulcer cause?
Chemical peritonitis
What can perforated diverticular disease cause?
Peritoneal sepsis and septicaemia due to faecal peritonitis
How does a ruptured abdominal aortic aneurysm present?
- sudden onset of severe abdo pain and back pain
- sudden collapse
- shock
- sudden death (50%)
Why do fluid and electrolyte concentrations need to be corrected before anaesthesia?
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
What are causes of small intestinal bowel obstruction?
- adhesions due to surgery
- femoral/inguinal hernias
- volvulus
- caecal carcinoma
What are causes of large intestinal bowel obstruction?
- carcinoma
- sigmoid volvulus
- diverticular disease
How can bowel obstruction lead to hypochloremic, hypokalaemic metabolic alkalosis?
- Vomiting -> loss of H+ and Cl- -> metabolic alkalosis
- kidney compensates by preserving H+ at the expense of K+ -> hypokalaemia
What is the commonest cause of acute gut ischaemia?
Embolism (atrial fibrillation)
How does acute gut ischaemia present?
Severe abdo pain and tenderness, toxic, hypotensive
