Bowel Obstruction Flashcards
Partial vs complete bowel obstruction
Partial- fluid or air continue to pass
Complete- cessation of passage of stool or flatus
Categories of bowel obstruction causes
Extrinsic/extra luminal (external to bowel)
Intrinsic (within wall of bowel)
Intraluminal (defect that prevents passage of GI contents)
What is happening in the bowel during an obstruction?
Bowel dilatation and retention of fluid within lumen proximal to obstruction while distal the bowel decompresses (swallowed air and gas from fermentation contribute to distention)
Why are pts with an obstruction usually dehydrated?
Edematous bowel leads to fluid sequestration so depletes volume
How do complications result from bowel obstructions?
Dilatation–poor vascular supply and perfusion–ischemia–necrosis–perforation–peritonitis
Most common obstruction
SBO
Most common causes of SBO
Adhesions MOSTLY (from prior abdominal/pelvic surgery) Hernia (abd wall/groin) Neoplasm (primary or metastatic tumor) Or intestinal inflammation/abscess, strictures, FB ingestion, intussusception, volvulus
What questions can be asked to determine if IBD associated with SBO?
N/v/d, constipation, hematochezia and length
Presentation of SBO
Maybe fevers/chills Abd pain (initially can be periumbilical, intermittent and crampy) and more focal can be peritonitis Bloating/distention, anorexia, n/v, hematochezia, obstipation (can't pass)
Red flags to indicate peritonitis on SBO exam
Shock vitals (tachycardia and hypotension)
Lying motionless
Hypoactive/absent bowel sounds (late phase)
Peritoneal signs (guarding, rigidity, rebound tenderness)
Diagnostics used in SBO
CBC/CMP Amylase/lipase UA (and elevated specific gravity) Lactate/LDH Plan abd films
Why is a CT scan helpful for SBO?
ID location, severity, etiology and complications
What is seen on a supine and upright abd x-rays for SBO?
Dilated loops of bowel with air fluid levels
Proximal bowel dilatation with distal bowel collapse
Look for free air consistent with perforation
What is seen on CT abd for SBO?
Dilated proximal bowel with distal collapsed loops
Bowel wall thickening > 3 cm
Submucosal edema
What other imaging can be used for SBO when xray and CT are contraindicated (pregnant, kidney function, allergy)?
Abd u/s
CT/MR enterography
UGI/SBFT