Bowel Obstruction Flashcards
function of small bowel?
function of large bowel?
nutrient absorption
water absorption
four main clinical features of bowel obstruction
distension
constipation
vomiting
abdominal pain
vomiting more profuse in small or large bowel obstructio?
small bowel
is the pain sudden or gradual?
character of pain ?
location?
sudden onset of pain
colicky/constant
central
what sort of bowel sounds do you get as obstruction progresses leading to abdominal distension
tinkling BS
how can you determine if it is small or large bowel obstruction?
small bowel
- vomiting occurs early
- less distension
- pain higher in abdomen and colicky
large bowel
- pain is more constant
small bowel obstruction on AXR?
centrally dilated + see in dilated bowel section there is valvulae conniventes (cross the lumen)
large bowel obstruction on AXR:
peripheral gas shadows and and see large bowel haustra that don’t cross the lumen.
how can you tell if it is a functional/ileus or a mechanical bowel obstruction?
functional = reduced bowel motility - absent BS + NO PAIN
mechanical = pain + tinkling BS
difference between simple/closed loop/strangulated bowel obstruction?
which one of the three presents with a more sharp constant pain?
simple = one obstructing point + no vascular compromise
closed loop = obstruction at two points + vascular compromise, at risk of perforation due to forming a loop of distended bowel
strangulated bowel obstruction = blood supply is compromised, sharp + constant pain - more localised with peritonism
where does closed loop bowel obstruction normally occur?
caecum
is sigmoid volvulus simple, closed loop or strangulated obstruction
closed loop but at risk of becoming strangulated
common causes of small bowel obstruction?
adhesion
neoplasms
hernias
what is an adhesion
fibrous band that forms as a result of injury during surgery - internal scar tissue
common causes of large bowel obstruction
colon cancer
diverticular stricture
volvulus (often sigmoid or caecal)
where are diverticular strictures most commonly found
sigmoid
what is sigmoid volvulus?
commonly occurs in which patients?
how is it managed if no signs of avascular necrosis?
how is it managed if there is gangrenous tissue?
when bowel twists on its mesentery producing severe obstruction -
occurs in elderly, constipated patient.
insertion of flatus tube or sigmoidoscopy
sigmoid colectomy
what % of large bowel obstructions are due to cancer or diverticular stricture?
90%
Management of strangulation and large bowel obstruction?
Surgery
Management of ileus and small bowel obstruction?
can be managed conservatively initially
Management of bowel obstruction is of ‘Drip and Suck’ lines similarly to pancreatitis
what is the initial Tx of bowel obstruction
o NBM
o IV fluids to rehydrate and correct electrolyte imbalance (vomit).
o Insert NGT (Ryle’s tube) to relieve gastric distension (to stop vomiting, + blockage partially improves as you rest the bowel as half the problem with bowel obstruction is the swelling/oedema around the obstruction).
o IV Analgesia, catheterize to monitor fluid balance.
what % of bowel obstructions will be relieved by NBM, fluids, NGT + analgesia?
70%
Some large bowel obstructions can be relieved by flexible sigmoidoscopy to unkink colon but risk of what?
Perforation
what imaging do you do to identify cause and location of obstruction?
what can be given prior to this which may actually have mild therapeutic action?
CT Abdo
gastrografin
what type of obstruction is a surgical emergency?
strangulation/closed loop
what would indicate an immediate laparatomy?
if signs of peritonitis
OR
if caecum dilated >10
complications?
where does perforation commonly occur?
perforation
abdominal abscess
peritonitis
caecum (as it’s the thinnest)
