Bowel Obstruction Flashcards
(48 cards)
what happens to the bowel proximal to an obstruction
dilatation with air and fluid
how can an upper small bowel obstruction present
acutely, hours of onset, large volumes (of gastric, pancreatic and biliary secretions) vomited
how does a distal/ large bowel obstruction present
colicky abdominal pain and distention, vomiting (possibly faeculent)
what are the symptoms of intestinal obstruction
vomiting, pain (colicky), constipation, distention, complete/ incomplete obstruction
what determines when vomiting develops
hoe proximal the obstructions- the more proximal the earlier the vomiting
what causes vomiting when nothing is taken by mouth
GI secretions- saliva, gastric, pancreatic, bile, small intestine
what about the vomitus gives clues to the level of obstruction
nature of vomitus
vomitus: what does semi digested food eaten a day/ two before suggest
no bile, obstruction in gastric outlet
vomitus: what does copious bile stained fluid suggest
upper small bowel obstruction
vomitus: what does thicker, brown, foul-smelling vomitus suggest
faeculent vomiting, a more distal obstruction
what causes pain in bowel obstruction
distention of the bowel, intermittent episodes of colicky pain ( as peristalsis tries to overcome the obstruction)
what causes distention of the bowel
swallowed air and intestinal fluid secreted proximal to an obstruction
describe the onset of symptoms in large bowel obstructions
more gradually as large bowel has more capacity and absorptive capacity
what is prevented in large bowel obstruction if the ileocaecal valve is competent
backflow of accumulated contents
what is a closed loop obstruction and what can is cause
when thin walled caecum progressively distends and eventually may rupture
why is the caecum at most risk of rupturing
thin walls
what happens if the ileoceacal valve becomes incompetent
small bowel distends and the onset of symptoms is delayed
what are the symptoms of incomplete bowel obstruction
intermittent vomiting and erratic bowel habit
what does chronic incomplete obstruction leads to
gradual hypertrophy of the muscle of the bowel proximally- creates pain during peristalsis in this area
what are the physical signs of intestinal obstruction
dehydration, abdominal distention, visible peristalsis, relative lack of abdominal tenderness, possible palpable mass, resonant to percussion, possible hernia, high pitched- tinkling bowel sounds
what investigations should be done initially
supine abdo x ray- bowel proximal will be distended with gas
what do erect x rays show
air fluid levels- not done now
what does distended bowel look like on x ray
black with air, in anatomical position, has haustra coli
what is a CT used for
to look for cause and find transition site between distended bowel proximal and collapsed bowel distal
