Computed Tomography, Various Sites(Abdomen, Angiography, Biliary Tract and Liver, Brain and Head, Cardiac Scoring, Chest, Colon, Kidneys, Pancreas, Pelvis, Pituitary, Spine, Spleen)

General

Synonym/Acronym:
Computed axial tomography (CAT), computed transaxial tomography (CTT), helical/spiral CT.

Rationale
To visualize and assess internal organs/structures for abnormal or absent anatomical features, abscess, aneurysm, cancer or other masses, infection, or presence of disease. Used as an evaluation tool for surgical, radiation, and medical therapeutic interventions.

Patient Preparation
There are no activity restrictions unless by medical direction. Instruct the patient to fast and restrict fluids, as ordered, for 2 to 4 hr prior to the procedure; CT studies performed without contrast usually do not require the patient to fast before the procedure (e.g., CTA). Fasting may be ordered as a precaution against aspiration related to possible nausea and vomiting. The American Society of Anesthesiologists has fasting guidelines for risk levels according to patient status. More information can be located at www.asahq.org.

Note: Protocols regarding the use of iodinated contrast medium in patients with impaired kidney function and who are receiving metformin or drugs containing metformin for type 2 diabetes may vary by facility; the drug may be discontinued on the day of the test and continue to be withheld for 48 hr after the test. Kidney function should be assessed per facility protocol before use of metformin is resumed (e.g., Cr, eGFR, hydration or clinical assessment).

Regarding the patient’s risk for bleeding, the patient should be instructed to avoid taking natural products and medications with known anticoagulant, antiplatelet, or thrombolytic properties or to reduce dosage, as ordered, prior to the procedure. Number of days to withhold medication is dependent on the type of anticoagulant. Note the last time and dose of medication taken. Protocols may vary among facilities.

Normal Findings

General

  • Normal structure, function, contour, and patency of organ and related vessels
  • Contrast medium normally circulates throughout area of inquiry, symmetrically and without interruption
  • No variations in number and size of vessels and organs; no evidence of infection, edema, obstruction, aneurysm, stenosis, malformations, trauma, cysts, polyps, or tumors

Cardiac Scoring

  • If the Agatston score is 100 or less, the probability of having significant CAD is minimal or is unlikely to be causing a narrowing at the time of the examination.

Critical Findings and Potential Interventions

General

  • Abscess
  • Aneurysm
  • Tumor with significant mass effect
  • Visceral injury; significant solid organ laceration

Abdomen

  • Acute GI bleed
  • Leaking aortic aneurysm
  • Aortic dissection
  • Appendicitis
  • Bowel perforation
  • Bowel obstruction
  • Mesenteric torsion

Angiography

  • Brain or spinal cord ischemia
  • Emboli
  • Hemorrhage
  • Occlusion

Brain and Head

  • Acute hemorrhage
  • Aneurysm
  • Infarction
  • Infection

Chest

  • Pneumothorax
  • Pulmonary embolism

Pelvis

  • Ectopic pregnancy

Spine

  • Cord compression
  • Fracture

Spleen

  • Hemorrhage
  • Laceration

Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.

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