17-4 -- obstruction/ischemic bowel disease Flashcards
What is the most common site of intestinal obstruction?
SI - due to narrow lumen
What are the 4 most common reasons for an intestinal obstruction?
Hernia - most common reason worldwide
Adhesion - most common in US
Volvulus
Intussusception
What are the 4 most common reasons for an intestinal obstruction?
Hernia
Adhesion
Volvulus
Intussesception
Defect in an abdominal wall that causes a protrusion of peritoneum and bowel
Hernia
If the neck of a hernia is constricted and venous stasis occurs, what will that cause to happen to the protruded bowel?
Hernia increases in size and edema occurs
What can cause Adhesions?
Surgery, infections, endometriosis
Volvulus
Bowel twists around its mesenteric attachment
If a volvulus occurs, the bowel segment is at risk for obstruction and?
Infarction
Intussusception
Segment of intestine telescopes into the segment of bowel immediately distal to it
- once trapped, peristalsis propels it along and it takes its mesentary with it
In what age group for intestinal obstructions is intussusception the most common etiology?
CHILDREN < 2 years old
If a child less than 2 years old presents with an intestinal obstruction, what should you consider that caused it?
Intussusception
What can cause Intussusception?
Idiopathic
Virus
Rotovirus vaccine
Intraluminal mass
Air/contrast enemas can treat?
Intussusception
Main symptoms of intestinal obstructions?
Abdominal pain and distention
Vomiting and constipation
Main symptoms of intestinal obstructions?
Abdominal pain and distention
Vomiting and constipation
Functional obstruction is usually?
Post-operative Ileus
What artery mainly supplies the right side of the colon?
Superior mesenteric
What artery mainly supplies the left side of the colon?
Inferior mesenteric
All of the ______ between the arteries make it possible for the intestines to withstand slow blood loss (chronic hypoperfusion)
Interconnections
Acute compromise of the arterial supply to the intestines usually causes infarction of?
Several meters of intestine (more severe)
What usually causes Acute obstruction of vascular supply to intestines?
Thrombosis/embolism
What usually causes slow Chronic hypoperfusion of intestines?
CHF, dehydration, shock, vasoconstricting drugs
Pathogenesis of Ischemic Bowel Disease
- Hypoxic injury
2. Reperfusion injury (restoration of blood flow)
What can cause the Reperfusion injury with Ischemic Bowel Disease?
Leakage of bacteria, infiltration of neutrophils and free radicals
Watershed zones
Intestinal segments at the end of arterial supplies
Watershed zones are more susceptible to ischemic bowel disease. What is an example of a zone?
Splenic flexure
Besides watershed zones, what else in the intestines is susceptible to ischemic bowel disease?
Epithelium
There will be worse outcomes if what artery is occluded with ischemic bowel disease?
Superior mesenteric
Symptoms of Acute obstruction causing ischemic bowel disease?
Sudden cramping, passage of bloody stool, shock, presents like other GI emergencies
Symptoms of Chronic hypoperfusion causing ischemic bowel disease?
Abdominal pain 30 mins after eating that improves after a few hours
Angiodysplasia
Malformed mucosal/submucosal blood vessels that are thin and dilated
Angiodysplasia
Malformed and mucosal/submucosal blood vessels taht are thin and dilated
Where is Angiodysplasia most common?
Cecum or right colon
What does Angiodysplasia look like?
Nests of torturous capillaries
Symptom range for Angiodysplasia?
Chronic, intermittent – Acute, massive hemorrhage
