Unit 4 Contrast Media + GI, Urinary, Biliary Exams

Soft tissue structures • GI • Urinary • Biliary System • Myelogram • Arthrogram • Vascular Studies (Angiogram)

• Radiopaque • Barium sulfate • Iodinated contrast media Appears white on images, Radiopaque

• Radiolucent • Air • Carbon Dioxide Appears black on images, Radiolucent

-Inert organic salt -Does not chemically react with the body -Usually no allergy Issues -Used exclusively for GI tract radiography -Enteric administration (oral, rectal, NG) -Packaged in many forms -Using the proper viscosity is important -Hygroscopic: Absorbs water, can solidify -Increase intake of fluids -May use laxative following exam -Cannot be absorbed if leaks into peritoneal cavity -Contraindicated for ruptures of GI system or if surgery likely -Alternatives: Gastrografin, Hypaque Oral, Nonionic LOCM should be used in cases of suspected esophageal trachea fistula

Diet: -Low residue or clear liquid diet -Fasting/NPO orders -Cathartics: Laxative -Suppositories: Medication inserted into rectum -Cleansing Enemas: filling colon with liquid -Tap water enema: 1000 mL tepid (105 degrees F) -Bag: 18 inches above the level of the table

-Esophagram: ulcers, foreign body, varices, GERD -Upper GI (stomach): ulcers, gastritis, hiatal hernia -Patient prep: -NPO 8-12 hours -No Smoking, no gum chewing -Double contrast study: Barium + Air

-Oral (Small bowel follow through) or Enteroclysis (via catheter) -Patient Prep: NPO, laxative and/or enema

-Patient Prep: NPO, Laxative and/or cleansing enema (The height of the bag of the barium should be 18 inches above the table for cleansing enema) -Contrast administration: -Patient is placed in SIMS position for enema tip insertion -Bag filled 1200-1500 mL -Bag suspended 24-30 inches above the table

• Barium sulfate may not be administered intravenously it is insoluble in blood • Patients should drink plenty of fluids following a barium study. • The sims position is the body position used when inserting the enema tip.

Iodine -Atomic number: 53 Administration -IV/IA -Oral -Direct injection Bolus: substantial IV dose -Characteristics affect clinical performance and whether patient has adverse reaction. -Iodine Concentration Viscosity -Toxicity -Osmolality Iodine contrast opacity is determined by iodine concentration

• Determines degree to which x-rays will be attenuated • Higher Concentration results in greater positive contrast but can be more side effects

• Measure of resistance of fluid to flow • High viscosity is “thick” • Low viscosity is “thin” • Can be reduced by warming contrast

• Potential to cause harm • Least toxic properties: nonionic, low osmolality, injected slowly -Excessive dose, failure to excrete media, interactions with some medications

• Number of particles in solution per kg of water • Human blood: 275- 295 • Contrast: 300-1000 • Primarily responsible for adverse effects (Higher osmolality produces adverse effects on pulmonary artery pressure, blood volume, and cardiac output) • HOCM: High osmolar contrast agent • LOCM: Low osmolar contrast agent • Isosmolar: osmolality equals human blood

-Precautions: Begin with taking patient history -Kidney disease Check lab work -BUN: 6-20 mg/dL -Creatinine: 0.6-1.5 mg/dL -GFR: 90-120 mL/min/1.73 m^2 Diabetes Check for metformin -Medications containing metformin may need to be withheld prior to and after contrast administration -Heart disease -Contrast causes vasodilation -Prior contrast study If so, which agent and dose? -Max dose for 24-36 hours is 250 mL -Allergies -Asthma -Previous reaction to CM Note current medications (beta-blockers, blood pressure meds)

-IVP or IVU -Functional study: images taken at set time periods following the administration of water-soluble nonionic contrast -Prep: Cleansing of bowel and NPO orders

-Bladder is filled through urinary catheter and examined using fluoroscopy and/or radiographs -Voiding Cystouerthrogram (VCUG): evaluates bladder and urethra, patient voids on exam

-Retrograde filling of the ureters by placing catheter into renal pelvis -Performed in OR setting

-After cholecystectomy (removal of gall bladder) T-tube is left in place -Contrast is injected to check for residual stones or patency before drain removal

-Performed with Endoscopy -Scope placed from mouth to duodenum -Catheter passed into biliary system -Contrast is used to evaluate for stones/structures

• Evaluates structures within the spinal canal -Herniated disks or impinged nerve roots • Lumbar puncture performed, injection of contrast • May include pressure measurements (manometer) and collection of CSF • Fluoro evaluation with additional images in CT • Head extended to keep contrast from flowing into cerebral region

-Contrast is injected into joints to evaluate for abnormalities within the joint capsule -Gas (Carbon dioxide) and/or water soluble contrast

• CNS is sensitive to increased ions in blood; can cause seizures, cardiac disfunction, allergic response • Ionic: molecules dissociate resulting in more particles • Nonionic: molecules remain intact • Ionic-higher osmolality