Flashcards in Intestinal obstruction Deck (33)
twist/rotation of segment of bowel
always at part of bowel with mesentery
narrow base + wide lumen
telescoping of one hollow structure into its distal hollow structure
absence of opening or failure of development of hollow structure
which is more common, SBO or LBO?
SBO: 70% of cases
RFs for SBO in adults
adhesions - previous surgery
RFs for SBO in children
hypertrophic pyloric stenosis
age + race dependent
what makes up the majority of LBOs?
colorectal malignancies, distal to the transverse colon
Classification of BO
extent of luminal obstruction
pathology e.g. simple, closed loop, strangulation
SBO pathology of obstruction
increased secretions + distension
untreated obstruction --> ischamia --> necrosis --> perforation
LBO pathology of obstruction
colon prox to obstruction dilates
increase in colonic pressure
decreased mesenteric BF
atrial supply compromised
full thickness necrosis
colic occurs early
active 'tinkling' bowel sounds
Why faceulent vomiting?
fermentation of intestinal contents in established obstruction
What would a digital rectal exam of LBO show?
what would sudden onset, pain, localised tenderness and distension in large bowel be?
does vomiting follow or precede pain in SBO?
resonance if theres gas and resonance if theres fluid?
tympanic - gas
dull - fluid
Plain X-ray partial SBO
gas throughout abd
in LBO what does contrast enema provide info on?
level, degree & type of obstruction
analgesia + antiemetic
a dynamic obstruction
**failure of peristalsis**
no mechanical cause
differences in presentation of SBO and LBO
SBO: vom occurs earlier, distention is less and pain higher in the abdomen
central gas shadows and no gas in large bowel
pain is more constant, peripheral gas shadows proximal to blockage, but not in rectum
(unless you've done a PR examination!)
functional obstruction from reduced bowel motility
no pain + bowel sounds are absent
1 obstructing point
no vascular compromise
closed loop obstruction
obstruction at 2 points
loop of grossly distended bowel at risk of perforation
blood supply is compromised
peritonism is the cardinal sign
other signs of mesenteric ischamia