Small Intestine Flashcards
What comprises the small bowel?
Duodenum, jejunum, and ileum
How long is the duodenum?
12 inches
What marks the end of the duodenum and the start of the jejunum?
Ligament of Treitz
What is the length of the small bowel?
6 meters
What provides blood supply to the small bowel?
Branches of the SMA
What are the plicae circulares?
Circular folds of mucosa in small bowel lumen
What are the major structural differences between the jejunum and the ileum?
Jejunum: long vasa recta, large plicae circulares, thicker wall
Ileum: shorter vasa recta, smaller plicae circulares, thinner wall
What does the terminal ileum absorb?
B12, fatty acids, bile salts
What is an SBO?
Small Bowel Obstruction.
Mechanical obstruction to the passage of intraluminal contents.
What are the signs and symptoms of SBO?
Abdominal discomfort, cramping, nausea, abdominal distention, emesis, high-pitched bowel sounds
What lab tests are performed with SBO?
Electrolytes, CBC, T&S, UA
What are the classic electrolyte findings with proximal obstruction?
Hypovolemic, hypochloremic, hypokalemic alkalosis
What must be ruled out on PE in patients with SBO?
Incarcerated hernia
What major AXR findings are associated with SBO?
Distended loops of small bowel air-fluid levels on upright film
What is a complete SBO?
Complete obstruction of the lumen usually paucity or no colon gas
What is the danger of complete SBO?
Closed loop strangulation of the bowel leading to bowel necrosis
What is a partial SBO?
Incomplete SBO; some colon gas
What is the initial management of all patients with SBO?
NPO, NGT, IVF, Foley
What tests can differentiate partial from complete SBO?
CT with oral contrast, small bowel follow-through
What are the ABCs of SBO?
- Adhesions
- Bulge (hernias)
- Cancer and tumors
What are other causes (not ABCs) of SBO?
GIVES BAD CRAMPS:
Gallstone ileus, Intussusception, Volvulus, External compression, SMA syndrome, Bezoars, Bowel wall hematoma, Abscesses, Diverticulitis, Crohn’s disease, Radiation enteritis, Annular pancreas, Meckel’s diverticulum, Peritoneal adhesions, Stricture
What is SMA syndrome?
SMA compresses duodenum, causing obstruction.
Seen with weight loss.
What is the treatment of complete SBO?
Laparotomy and lysis of adhesions
What is LOA?
Lysis Of Adhesions
What is the treatment of partial SBO?
Initially, conservative treatment with close observation plus NGT decompression
Intra-operatively, how can the level of obstruction be determined in patients with SBO?
Transition from dilated bowel proximal to the decompressed bowel distal to the obstruction