S9.2 GI Emergencies Flashcards
What is peritonitis?
Inflammation of the serosal membrane that lines the abdominal cavity.
Outline the pathophysiology of peritonitis
Can occur spontaneously (primary), or from breakdown of peritoneal membranes leading to foreign substances entering (secondary).
What are the symptoms and treatments of peritonitis?
Abdominal pain
Surgery
What is primary peritonitis and in which disease does it occur?
Aka spontaneous bacterial peritonitis
Commonly occurs in patients with cirrhosis, this is an infection of ascitic fluid (in cirrhosis, ascites is fluid in the peritoneal cavity)
What is secondary peritonitis?
An inflammatory process in the peritoneal cavity secondary to perforation of an intra-abdominal structure, which allows bacteria to enter
What are some causes of secondary peritonitis?
Peptic ulcer, appendicitis, diverticulitis, surgery, ovarian cyst
What are some causes of bowel obstruction in children and adults?
Children: Intussusception, Intestinal atresia
Adults: Adhesions, Incarcerated hernias
What is intussusception?
When one part of the gut tube telescopes (moves) into an adjacent section.
Can be from a motility issue or a mass
What are the symptoms and treatment of intussusception?
Abdominal pain, vomiting, haematochezia
Air enema, surgery
Describe the main features and symptoms of small bowel obstruction
More common in younger people
Colicky abdominal pain (3-4 min)
Early vomiting
Late constipation
Describe the main features and symptoms of large bowel obstruction
More common in elderly
Colicky abdominal pain (10-15 min)
Late vomiting
Early constipation
How do you differentiate between small and large bowel obstruction on an X-ray?
Small bowel: should be able to see plicae circulares
Large bowel: should be able to see haustra
Name 3 causes of small bowel obstruction
Intra-abdominal adhesions
Hernias
IBD
What are intra-abdominal adhesions?
Fibrous band which connect organs/tissues
Commonly arise after surgery
How do hernias cause small bowel obstruction?
Narrow the lumen of the bowel
How can IBD cause small bowel obstruction?
In Crohn’s repeated inflammation/healing causes narrowing of the bowel
Name some causes of large bowel obstruction
Colon cancer, diverticular disease, volvulus
What is a volvulus?
Part of the colon twists around its mesentery, most common in sigmoid, but also in caecum.
Caused by overloaded sigmoid (constipation).
What is acute mesenteric ischaemia?
Symptomatic reduction in blood supply to the GI tract
Describe the 3 types of acute mesenteric ischaemia
Acute occlusion - Arterial embolism in SMA
Non occlusive mesenteric ischaemia - Low cardiac output
Mesenteric venous thrombosis - malignancy
What are the symptoms of acute mesenteric ischaemia?
Abdominal pain 30 min after eating, vomiting, left sided pain
What are the investigation and treatments of acute mesenteric ischaemia?
Investigations: bloods, CXR, CT angiography
Treatment: surgery, angioplasty
Give two causes of major upper GI bleeds
Peptic ulceration
Oesophageal varices
What are the two most common sites for peptic ulcers, and what arteries are affected?
Duodenal ulcer (gastro-duodenal artery) Gastric (splenic artery)
Why do varices occur at the oesophagus?
As the oesophagus has venous drainage through portal vein and systemic veins, allowing Porto-systemic anastomosis to occur in it
Outline the portal and systemic drainage of the oesophagus
Portal drainage - Oesophageal veins drain into left gastric vein then portal vein
Systemic drainage - Oesophageal veins drain into azygous vein then SVC
What is the treatment for oesophageal varices?
Banding
TIPS
What is an abdominal aortic aneurysm?
A permanent pathological dilation of the aorta with a diameter >1.5x the norm
What causes AAA?
Caused by degradation of the elastin and collagen in tunica media.
Which region is most common for AAA to occur?
Infrarenal
What are the symptoms of AAA?
First asymptomatic, but when ruptured causes abdo + back pain, pulsatile abdo mass, hypotension, cardiovascular collapse
How do you diagnose AAA?
Presence of a pulsatile mass
CT
X-ray
What is the treatment for AAA?
Surgery if >5.5cm
Endovascular repair
Stop smoking
