Preparation and Examination of the Gastrointestinal Tract

1
Preparation and Examination of the
Gastrointestinal Tract

• Chapter 9

Happy Thanksgiving
2
Classification of Contrast Media

• Barium Sulfate
• Water-soluble iodinated
• Oily iodine
• gases

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Scheduling and Sequencing

• Proper scheduling of GI exams requires
  COMMUNICATION (between doctors and nurses, nurses
  and the department, etc.)
• Considerations must be made as to all the
  procedures that are going to be performed on the
  patient so that the correct sequence can be
  followed

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Guide to Sequencing Order for Diagnostic Studies

• All exams not requiring contrast media and any
  lab studies for iodine uptake
• Exams of the urinary tract (IVP)
• Radiographic exams of the biliary system
  (gallbladder)
• Lower GI series (BE)
• Upper GI series

5
Ensuring Compliance with Preps

• Nurses are responsible for inpatient preps
• Radiographer is usually responsible for
  explaining preps to outpatients or those
  scheduling outpatient procedures
• Scout films are taken to evaluate patient prep

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Preparation for Examination

• Most common reason for prep is for cleansing
  purposes
• Cleansing of the bowel usually requires several
  steps diet, cathartics, suppositories or
  enemas. May utilize several or all of these
  methods.

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Diet

• Patients may be placed on a low-residue diet for
  several days prior to the exam
• Liquid intake is encouraged or forced
• For 24 hours before exam, patient may be
  restricted to clear liquids (water, broths,
  gelatin, tea)
• Fasting may be employed (NPO 8-12 hours)

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Cathartics

• Laxative preparations that aid in cleansing the
  bowel
• Fluid intake increases the effectiveness of
  cathartics
• Bisacodyl or Dulcolax tablets or magnesium
  citrate (carbonated beverage) are common
  cathartics
• Heavy doses of cathartics may cause painful bowel
  spasms patients may have persistant diarrhea.
• Patients should always be told what to expect
  from their bowel preparation

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Suppositories

• Rectal suppository is a semi-solid nugget of
  medication that is inserted into the rectum to
  stimulate peristaltic action in the colon to
  cause evacuation of the distal portion of lower
  bowel
• Suppository should remain for at least 30 minutes
  before evacuation

10
Cleansing Enema

• Procedure to dislodge and flush out any fecal
  contents
• This is usually carried out at the patients home
  or by their nurse (if they are an inpatient)
• Occasionally, this duty may be assigned to the
  radiographer
• Items needed enema bag with tubing, disposable
  rectal catheter, iv pole
• Mix a soapsuds enema of 1000 ml of tap water and
  30 ml of castile soap (dont use any other kind
  as it may be an irritant to the bowel)
• Run the liquid through the tubing to eliminate
  air, lubricate the tip, explain the procedure,
  place patient in Sims position, hand enema bag
  approx. 18 in above the table (too high can cause
  to rapid a flow), insert tip

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Inserting the Tip

• The insertion of the tip will remain the same for
  any type of enema however, there will be several
  differences from a cleansing enema to a BE

12
Barium Sulfate

• Inert, organic salt, packaged in many forms, may
  be given oral or rectal, forms a colloidal
  suspension.
• No flavor (unless flavored for drinking), but
  hard to swallow because of its chalky
  consistency easier to drink really cold and with
  a straw (keeps it from coating the mouth)
• Although a warm solution of barium for lower GI
  studies would seem more comforting, cold barium
  is less likely to cause bowel spasms
• The proper viscosity or thickness is important in
  GI exams- much variation from doc to doc

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More about Barium

• Being an inert compound, it does not react
  chemically with the body to any appreciable
  extent- allergies are almost never a problem and
  few side effects occur
• Barium is hygroscopic (has a tendency to absorb
  water) this nature can cause a barium impaction-
  to decrease the risk, patients should be
  instructed to drink lots and lots of fluids and a
  laxative may be recommended.
• Always check with patients about latex allergies
  a few cases of allergy to the enema tip have been
  reported

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Iodinated Media

• Used when barium is contraindicated or if
  abdominal surgery is likely in the immediate
  future
• Also used when there is a high risk of impaction
  and occasionally for neonatal studies
• More expensive than barium, produce less
  contrast, can cause dehydration and are hazardous
  if aspirated
• Radiologist will guide you as far as what media
  to use

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Air

• Negative contrast
• Can be produced from crystals or room air

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Glucagon

• drug used to treat hypoglycemia
• Causes relaxation of smooth muscles in the GI
  tract
• Slows peristalsis
• Prevents cramping
• Can be administered IM or IV

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Routine BE

• Scout film to ensure cleansing has occurred
• Prepare a bag of 1200-1500 ml (compared to about
  1000 ml in a cleansing enema)
• Enema bag is suspended at a height of 24-30
  inches (compared to 18 in for cleansing enema)
  This is due to the viscosity of the barium
  requires greater hydrostatic pressure to maintain
  a proper flow rate
• Larger rectal catheter is used than in a
  cleansing enema has a cuff to inflate a balloon
  to help hold in place

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BE Considerations

• Patients with unusual conditions may require
  special care when undergoing a BE
• Enlarged Colon like congenital megacolon or
  Hirschsprungs Disease distal colon where no
  peristalsis occurs- results in chronic
  constipation and extremely large colon
• When colon is enlarged, more water absorption can
  occur, increasing the chances of developing a
  barium impaction If this condition is known
  ahead of time, water soluble contrast may be
  used if not, follow up care is necessary to
  insure the patient avoid an impaction
• Colon enlargement can also cause hypervolemia or
  fluid overload the colon absorbs so much water
  that it changes the concentration of fluid in the
  blood. This can lead to CHF and in extreme cases
  lead to total physical collapse.
• If it is of concern, water absorption can be
  minimized by mixing barium with normal saline
• Potential colon perforation if this is
  suspected, do not use barium. Use a water
  soluble contrast. If barium is extravasated into
  the peritoneal cavity, it can cause a condition
  known as barium peritonitis.
• ostomies

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UGI

• NPO 8 hours prior
• No smoking or gum chewing (increases gastric
  secretion)
• Valsalva maneuver for hiatal hernia or reflux
• Pylorospasm stomach does not empty into the
  duodenum because of constriction of the sphincter
  muscle between the stomach and duodenum patient
  will be asked to lie in the RAO position which
  allows gravity to assist in the normal flow of
  gastric contents

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Double Contrast UGI

• Shows mucosal surface
• Utilizes the crystals

21
Hypotonic Duodenography

• Used for the detection of lesions in the duodenum
  distal to the duodenal bulb and also for the
  diagnosis of pancreatic disease
• This study is declining and being replaced by US,
  double contrast GI, CT and ERCP