DCBE Flashcards
what does DCBE stand for?
double contrast barium enema
what can be examined in a DCBE?
the colon, rectum and caecum - the large bowel
what its the first line diagnostic test?
what is an alternative method?
Virtual colonoscopy for visualisation of colon disease
CT colonography
what is involved in double contrast?
barium and gas
what is the aim of the double contrast
to image the entire large bowel - the barium coats the wall and the gas helps distend the bowel facilitating a fine coat of barium on the bowel mucosa and acts in extreme contrast with the dense barium suspension
what is the patient preparation for a DCBE
what are the side effects?
cleaning of the bowel with a low residue diet and laxatives 48 and/or 24 hrs before
the laxative (Picolax) has a osmotic (dehydrating) effect on the patient making faeces ‘watery’ to pass rapidly but this is dangerous and fluid intake should be encouraged - also as a result patients may experience headaches, tiredness and abdominal pain
this ensures no faecal remnants mask any pathology or are misleading presenting similar to a pathology
what are the contraindications for the use of a laxative agent? - 4 points
acute surgical conditions
severe dehydration
toxic megacolon
ulcerative colitis
what 2 things should be discontinued before a DCBE?
iron tablets - may cause constipation
bran supplements - remain within GIT preventing optimum cleansing of the bowel
what additional patient prep is carried out? - 6 points
ID check
change into gown and fully explain procedure
remove any artefacts
check patient history and medication
LMP
safety checklist - effectiveness of bowel prep, use of bucopan, allergies etc.
what can be given to reduce bowel spasms
when is it contraindicated
what is given instead
a muscle relaxant = Buscopan
intravenously injected in the median cubital fossa
patients with known close-angled glaucoma and cardiac disease (heart or eye problems)
Glucagon
what is the positive contrast agent used
barium sulphate suspension - a measure amount of warm water (to decrease risk of bowel spasm and patient discomfort) is added to the barium powder to ensure a high density and low viscosity suspension
additional equipment for a DCBE - 10 points
funnel to fill enema bag with water (unless using a pre-mixed kit) rectal catheter with gas insufflation bag drip stand for barium bag gas insufflation device (hand balloon) lubricating jelly gauze swabs adhesive tape (for positioning catheter) gloves muscle relaxant needle and syringe
what are the clinical indications for a DCBE? - 7 points
rectal bleeding altered bowel habit tenesmus palpable abdominal mass left iliac fossa pain iron deficiency anaemia polyp/tumour noted during colonoscopy
what are the contraindications for DCBE? - 9 points
pregnancy
recent rectal biopsy (bowel wall will be compromised and there is potential for perforation)
colitis (bowel wall = inflamed and barium could irritate and worsen symptoms)
acute gastrointestinal bleeding
severe rectal inflammation
complete LBO
suspected perf (water soluble agent used)
buscopan contraindications (glaucoma, tachycardia, megacolon)
incomplete bowel prep
what are the side effects of DCBE? - 3 points
bloating & digestive discomfort
constipation
dehydration
What are rare side effects of DCBE? - 4 points
bowel perforation (incorrect catheter placement) barium impaction (causes LBO) allergic reaction (to latex balloon) blurred vision (Buscopan)
Describe a DCBE procedure introducing positive contrast agent - 7 points
patient lies on left side with knees and hips flexed
lubricated catheter is inserted into rectum and secured in place
Buscopan (or Glucagon) administrated at this point or prior to negative contrast agent
barium sulphate solution administered from enema kit held on drip stand - run into patient’s colon via rectum and bowel is screened with fluoroscope
table (initially horizontal) can be angled into Trendelenburg position to allow coating of mucosa
when barium solution reaches splenic flexure/mid transverse colon, barium clamped and patient moved into different positions to coat mucosal linings
barium drained back into bag and negative contrast agent introduced
describe a DCBE procedure introducing negative contrast agent 5 points
introduced through insufflator - helps bowel to distend and ‘push’s barium coating further round the bowel as far as the ileo-caecal valve
varius ‘spot images’ captured to ensure all anatomy is demonstrated (rectum, sigmoid, descending/transverse/ascending colon, splenic/hepatic flexure, caecum)
table may be moved into vertical position for erect oblique images of both flexures - care so patient doesn’t fall or injure whilst table is moving
over-couch projections may be taken using over-couch tube to ensure complete visualisation of the region - lateral rectum, lateral decubitus abdomen (PA and/or AP), prone abdomen (30-35% caudal angulation to demonstrate sigmoid colon)
once required images taken, enema tube removed, patient escorted to the toilet to evacuate remaining barium and air - approx 20 mins
what is the aftercare for DCBE - 4 points
ensure patient doesn’t leave until blurring of vision is resolved (due to Buscopan on smooth muscle fibres affecting vision) - usually lasts no longer than an hour
aware of possible ‘white stools’
resumes normal diet but encourage drinking plenty of fluids and eat high fibre foods (to avoid constipation)
aware how to access examination results
