Bowel obstruction Flashcards
how can you classify bowel obstruction
mechanical bowel obstruction
paralytic ileus
mechanical bowel obstruction classification
intraluminal
intramural
extramural
sites of bowel obstruction
SBO
LBO
degrees of bowel obstruction
partial
complete
closed loop - at 2 points, segment in middle is building up pressure
progression of BO
simple
strangulated
Causes of SBO
- adhesions
- hernias
gallstone ileus
Meckel’s diverticulum
strictures - Crohn’s
Malignancy
Paed:
congenital atresia
intussusception
Causes of LBO
- tumours
- volvulus
adhesions
strictures
faecal impaction
Paed:
Hirschprung disease
meconium ileus
rectal atresia
bacterial translocation in bowel obstruction
bacteria from bowel goes into bloodstream and peritoneum
4 cardinal symptoms of bowel obstruction
abdominal pain - colicky
vomiting
constipation
abdominal distension
aspects of history you should ask in bowel obstruction for the following: adhesions obstructed hernia CRC bowel ischaemia perforation
adhesions - previous surgery, recurrent episodes (structural band)
obstructed hernia - irreducible lump
CRC - elderly, CIBH, weight loss, FH, polyps
bowel ischaemia - change in pain character, becomes sharp
perforation - dramatic change in pain, worse with movement, very unwell
clinical findings in bowel obstruction
dehydration abdominal distension - 3rd space losses abdominal inspection abdominal tenderness septic - perforation tympanic percussion high pitched tinkling sounds or absent later on collapsed empty rectum on DRE
explain tinkling bowel sounds
fluid in bowel moves from one point to another, trickling
always examine for a hernia, true or false
true, bowel obstruction might be from strangulated hernia
complications of bowel obstruction
perforation
infection
lab tests for BO
loss of acid and electrolytes, alkalosis in vomiting
high lactate, urea and creatinine
lactic acidosis in bowel strangulation
raised WCC - bacterial translocation
radiological investigations for BO
plain supine AXR
CT abdo pelvis
AXR features for SBO
step laddering
valvulae coniventes
centrally in the abdomen
AXR features for LBO
haustrations
peripherally located
what does a coffee bean shape on AXR indicate
volvulus
very high risk of perforation
what does gas in the bowel wall mean
sign of ischaemic bowel
management of bowel obstruction
ABCDE - urgent resuscitation
‘DRIP’ - IV fluids, electrolyte correction
‘SUCK’ - NG tube for gastric decompression
Bowel rest
IV analgesia and antiemetics
why would you not operate on a patient with bowel obstruction
not: likely adhesions, no signs of ischaemia/necrosis/perforation
need active monitoring for 3-5 days
would you give prokinetics in BO?
No, Prokinetics are CONTRAINDICATED
when would you operate on bowel obstruction
ischaemia necrosis perforation tumour hernia closed loop obstruction when it can't be managed conservatively
adhesional BO is managed operatively/conservatively
conservatively
what must you ensure before operating
optimise the patient a couple of hours prior to theatre
rehydrate, correct electrolytes, acidosis
Don’t just rush to surgery
what do you do in theatre if you are unsure that the bowel is dead
wrap bowel in warm towels and wait
declares itself
either resect or leave it in
how does an ileostomy look on the skin
spouts out of skin
like a smaller rose
how does a colostomy look on the skin
smaller spout
most common cause of paralytic ileus
- post operative
others:
hypokalaemia
peritonitis and inflammation
parturition
pelvic fractures
neuropathy
would you do an abdominal CT to rule out mechanical obstruction, true or false
true
what is mechanical bowel obstruction
interruption to the normal passage of bowel contents due to a structural abnormality
what is a paralytic ileus
temporary impairment of peristalsis in the absence of mechanical obstruction
what is a general rule for differentiating between small and large bowel obstruction from the history
small: early, large volume, bilious vomiting
late constipation
large: late onset, bilious then faeculent vomiting
early constipation
abdominal distension
