Abdominal Catastrophes

Question 1

Describe the presentation of peritonitis

Answer 1

• Peritonitis has severe pain all over abdomen which may be referred to the shoulder tips
• Diaphragmatic and abdominal wall movement cause pain - shallow breathing
• Very tender on examination of the abdomen
• Inflamed peritoneal cavity can exclude litres of fluid

Question 2

How does bowel obstruction cause fluid loss

Answer 2

• In small intestinal obstruction, fluid loss occurs due to: accumulation of fluids, increased secretion, decreased reabsorption
• Leads to loss of isotonic salt water resulting in isotonic contraction of ECF volume
• When vomiting, the fluid lost into the intestines is deposited, causing more water to be lost
  
  • Hypovolaemic shock
• Leads to dehydration and increased haematocrit

Question 3

What are the common causes of bleeding into the gut, retroperitoneum and peritoneal cavity

Answer 3

• Bleeding varices, ulcers and diverticular disease bleed into the gut
• Abdominal aortic aneurysm bleed into the retroperitoneum
• Ruptured ectopic pregnancy bleeds into the peritoneal cavity

Question 4

Describe the presentation of AAA

Answer 4

• Most common cause of retroperitoneal bleeding
• Sudden onset of severe abdominal pain, collapse
• Patient in hypovolaemic shock
• Many patients die of multi-organ failure on the ITU

Question 5

Decsribe the consequences of bowel perforation

Answer 5

• Posterior perforation of gastric ulcer initially allows gastric contents to enter the lesser sac
  
  • Fluid can tract into the greater sac via the epiploic foramen
• Perforated peptic ulceration leads to a chemical peritonitis
• Perforated diverticular disease leads to peritoneal sepsis and septicemia

Question 6

Why are anaesthetic agents potentially damaging to dehydrated patients

Answer 6

• Anaesthetic agents dramatically reduce sympathetic tone and have negative inotropic effects
• If a patient is dehydrated, the sympathetic nervous system is maximally activated to maintain vital organ perfusion
• If dehydration not corrected before anaesthesia, then patient may become hypotensive and die

Question 7

Describe the presentation of acute pancreatitis

Answer 7

• Autodigestion by proteases of the retroperitoneum
• Commonly due to alcohol and gallstones
• Patients can present with significant dehydration - vomiting and fluid loss into retroperitoneum
• Raised serum amylase

Question 8

Describe the presentation of acute gut ischaemia

Answer 8

• Commonest cause is embolism
• Present with severe abdominal pain and tenderness
  
  • Rapidly become unwell and hypotensive
• Very high white cell count
• Treatment is urgent laparotomy

Question 9

Describe the presentation and treatment of acute cholangitis

Answer 9

• Infection in the bile ducts
• Commonest cause is gallstone obstruction in the common bile duct
  
  • If bile flow is blocked, bacteria from the duodenum can ascend into the liver
• Commonest organism is E.coli
  
  • E.coli in bile duct within the liver can build up the bile flow and spread into the portal vein
• Symptoms - right upper quadrant pain, fever, jaundice
  
  • Septic shock if bacteria enters the liver and into the portal vein
• Treatment is to remove the gallstone through ERCP
  
  • Wire inserted into duodenum and into the common bile duct
    
    • Stone-retrieval balloon removes the gallstone

Question 10

Describe the presentations of causes of blood loss into the gut

Answer 10

• Bleeding oesophageal varices leads to hematemesis (vomit blood) and melaena (black stools)
• Bleeding peptic ulcer leads to hematemesis and melaena
  
  • Commonly due to posterior duodenal ulcer eroding into the gastroduodenal artery
• Bleeding diverticular disease leads to bright red bleeding from rectum into stools (hematochezia)
  
  • Come out of polyp and erode into artery

Question 11

Describe the investigations of blood loss into the gut

Answer 11

• Melaena
  
  • Due to alteration of blood by digestive enzymes and intestinal bacteria
  • Have a strong distinct smell
• Blood is protein rich and can be converted by the liver into urea
  
  • Leads to a rise in blood urea
    
    • If serum creatinine normal and blood urea raised, then source of bleeding and largeness of bleed identified

Question 12

Describe the consequences of bowel perforation in the small intestine

Answer 12

• Adhesions due to previous surgery
• Femoral/inguinal hernia
• Volvulus - twisting of bowel
• Carcinoma of the caecum

Question 13

Describe the consequences of bowel perforation in the large intestine

Answer 13

• Carcinoma, particularly left-sided
• Sigmoid volvulus
• Diverticular disease

Question 14

Describe the consequences of vomiting

Answer 14

• Vomiting leads to loss of HCl ions which leads to metabolic alkalosis
• Renal compensation preserves H+ ions at the expense of potassium, leading to hypokalaemia
• Bowel obstruction leads to hypochloremic, hypokalaemic metabolic alkalosis