Recognizing SBO Flashcards
abnormal bowel gas pattern 2 categories:
1) functional ileus 2) mechanical obstruction
2 varieties of functional ileus
1) localized (sentinel loops) 2) generalized / adynamic
2 varieties of mechanical obstruction
1) small bowel 2) large bowel
mechanical obstruction: how does the gut react?
1) loops proximal = dilated; 2) distal = evacuated
key finding in localized ileus (on KUB)
2-3 dilated loops of small bowel, w/ air in the rectosigmoid / underlying irritative process to next to loops
causes of sentinel loops
1) pancreatitis (LUQ) 2) cholecystitis (RUQ) 3) diverticulitis (LLQ) 4) appendicitis (RLQ)
generalized adynamic ileus findings
1) dilated loops of large / small bowel 2) gas in rectosigmoid 3) long air fluid levels
who develops generalized adynamic ileus?
post-op patients
mechanical small bowel obstruction
1) disproportionately dilated / fluid-filled loops of small bowel 2) LITTLE OR NO GAS IN RECTOSIGMOID
what is best at identifying cause / site of SBO?
CT
what is most common cause of SBO? other causes?
most common = adhesions; other causes: hernias, gallstone ileus, intusussusception, malignancy, IBD
closed loop obstruction
high risk of strangulation; enlarged bowel
volvulus def
closed loop obstruction of the large bowel
mechanical LBO, key findings
dilation of the colon; no gas in the rectum; no dilation of the small bowel if the ileocecal valve is competent (CT to diagnose)
causes of mechanical LBO
malignancy, hernia, diverticulitis, intussussception
