Gastrointestinal Blood Loss Scan

Gastrointestinal Blood Loss Scan

Synonym/acronym: Gastrointestinal bleed localization study, GI scintigram, GI bleed scintigraphy, lower GI blood loss scan.

Common use

To detect areas of active gastrointestinal bleeding or hemorrhage to facilitate surgical intervention or medical treatment. Usefulness is limited in emergency situations because of time constraints in performing the scan.

Area of application

Abdomen.

Contrast

IV radioactive technetium-99m-labeled red blood cells.

Description

Gastrointestinal (GI) blood loss scan is a nuclear medicine study that assists in detecting and localizing active GI tract bleeding (2 or 3 mL/min) for the purpose of better directing endoscopic or angiographic studies. This procedure can detect bleeding if the rate is greater than 0.5 mL/min, but it is not specific for site localization or cause of bleeding. Endoscopy is the procedure of choice for diagnosing upper GI bleeding. After injection of technetium-99m-labeled red blood cells, immediate and delayed images of various views of the abdomen are obtained. The radionuclide remains in the circulation long enough to extravasate and accumulate within the bowel lumen at the site of active bleeding. This procedure is valuable for the detection and localization of recent non-GI intra-abdominal hemorrhage. Images may be taken over an extended period to show intermittent bleeding.

Pediatrics An upper GI series is usually done in the pediatric population to diagnose the cause of recurrent GI signs (bleeding) and symptoms. The etiology is often related to age. In infants, recurrent symptoms such as vomiting after feeding, poor feeding, poor weight gain, and abdominal pain (evidenced by frequent crying during or after a feeding) may trigger an investigation. The most common causes of upper or lower GI bleeding in infants up to 1 mo include allergies to milk proteins, anorectal fissures, bacterial enteritis, coagulopathy, esophagitis, Hirschsprung’s disease, intussuseption, peptic ulcer, stenosis, varices, or Meckel’s diverticulum. Children between 2 to 23 months are most commonly diagnosed with allergies to milk proteins, anorectal fissures, esophagitis caused by gastroesophageal reflux (GER), gastritis, intussusception, Meckel’s diverticulum, NSAID-induced ulcer, and ingested foreign body. Pediatric patients 24 mo and older are most commonly diagnosed with esophageal varices, Mallory Weiss tears, peptic ulcer, related to Helicobacter pylori infection or peptic ulcer secondary to some other type of systemic disease (e.g., Crohn or inflammatory bowel disease [IBD]). Other abnormal findings in this age group include IBD, polyps, malignancy, sepsis, and Meckel’s diverticulum.

This procedure is contraindicated for

  • high alert Patients who are pregnant or suspected of being pregnant, unless the potential benefits of a procedure using radiation far outweigh the risk of radiation exposure to the fetus and mother.

Indications

  • Diagnose unexplained abdominal pain and GI bleeding

Potential diagnosis

Normal findings

  • Normal distribution of radionuclide in the large vessels with no extravascular activity

Abnormal findings related to

  • Angiodysplasia
  • Aortoduodenal fistula
  • Diverticulosis
  • GI bleeding
  • Inflammatory bowel disease
  • Polyps
  • Tumor
  • Ulcer

Critical findings

  • Acute GI bleed

  • It is essential that a critical finding be communicated immediately to the requesting health-care provider (HCP). A listing of these findings varies among facilities.

  • Timely notification of a critical finding for lab or diagnostic studies is a role expectation of the professional nurse. Notification processes will vary among facilities. Upon receipt of the critical value the information should be read back to the caller to verify accuracy. Most policies require immediate notification of the primary HCP, Hospitalist, or on-call HCP. Reported information includes the patient’s name, unique identifiers, critical value, name of the person giving the report, and name of the person receiving the report. Documentation of notification should be made in the medical record with the name of the HCP notified, time and date of notification, and any orders received. Any delay in a timely report of a critical finding may require completion of a notification form with review by Risk Management.

Interfering factors

  • Factors that may impair clear imaging

    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status.
    • Retained barium from a previous radiological procedure.
    • Metallic objects (e.g., jewelry, body rings) within the examination field, which may inhibit organ visualization and cause unclear images.
    • Other nuclear scans done within the previous 24 to 48 hr.
    • Inaccurate timing of imaging after the radionuclide injection.

  • Other considerations

    • The examination detects only active or intermittent bleeding.
    • The procedure is of little value in patients with chronic anemia or slowly decreasing hematocrit.
    • The scan is less accurate for localization of bleeding sites in the upper GI tract.
    • Improper injection of the radionuclide allows the tracer to seep deep into the muscle tissue, producing erroneous hot spots.
    • The test is not specific, does not indicate the exact pathological condition causing the bleeding, and may miss small sites of bleeding (less than 0.5 mL/min) caused by diverticular disease or angiodysplasia.
    • Physiologically unstable patients may be unable to be scanned over long periods or may need to go to surgery before the procedure is complete.
    • Consultation with an HCP should occur before the procedure for radiation safety concerns regarding younger patients or patients who are lactating. Pediatric & Geriatric Imaging Children and geriatric patients are at risk for receiving a higher radiation dose than necessary if settings are not adjusted for their small size. Pediatric Imaging Information on the Image Gently Campaign can be found at the Alliance for Radiation Safety in Pediatric Imaging (www.pedrad.org/associations/5364/ig/).
    • Risks associated with radiation overexposure can result from frequent x-ray or radionuclide procedures. Personnel working in the examination area should wear badges to record their level of radiation exposure.

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in evaluating for stomach and intestinal bleeding.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex, anesthetics, sedatives, or radionuclides.
  • Obtain a history of the patient’s gastrointestinal system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Note any recent procedures that can interfere with test results, including examinations using barium- or iodine-based contrast medium.
  • Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Address concerns about pain related to the procedure and explain that some pain may be experienced during the test, or there may be moments of discomfort. Reassure the patient that the radionuclide poses no radioactive hazard and rarely produces side effects. Inform the patient that the procedure is performed in a nuclear medicine department by an HCP specializing in this procedure, with support staff, and takes approximately 60 min to complete, with additional images taken periodically over 24 hr.
  • Explain that an IV line may be inserted to allow infusion of IV fluids such as normal saline, anesthetics, sedatives, radionuclides, medications used in the procedure, or emergency medications.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Instruct the patient to remove jewelry and other metallic objects from the area to be examined.
  • Note that there are no food or fluid restrictions unless by medical direction.
  • Make sure a written and informed consent has been signed prior to the procedure and before administering any medications.

Intratest

  • Potential complications:

  • Although it is rare, there is the possibility of allergic reaction to the radionuclide. Have emergency equipment and medications readily available. If the patient has a history of allergic reactions to any substance or drug, administer ordered prophylactic steroids or antihistamines before the procedure.

  • Establishing an IV site and injection of radionuclides is an invasive procedure. Complications are rare but do include bleeding from the puncture site related to a bleeding disorder, or the effects of natural products and medications known to act as blood thinners, hematoma related to blood leakage into the tissue following needle insertion, infection that might occur if bacteria from the skin surface is introduced at the puncture site, or nerve injury that might occur if the needle strikes a nerve.

  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure that the patient has removed all external metallic objects from the area to be examined prior to the procedure.
  • Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided.
  • Record baseline vital signs and assess neurological status. Protocols may vary among facilities.
  • Establish an IV fluid line for the injection of saline, anesthetics, sedatives, radionuclides, or emergency medications.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Have emergency equipment readily available.
  • Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
  • Administer a sedative to a child or to an uncooperative adult, as ordered.
  • Place the patient in a supine position on a flat table with foam wedges to help maintain position and immobilization.
  • The radionuclide is administered IV, and images are recorded immediately and every 5 min over a period of 60 min in various positions.
  • The needle or catheter is removed, and a pressure dressing is applied over the puncture site.
  • Observe/assess the needle/catheter insertion site for bleeding, inflammation, or hematoma formation.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • Advise the patient to drink increased amounts of fluids for 24 to 48 hr to eliminate the radionuclide from the body, unless contraindicated. Tell the patient that radionuclide is eliminated from the body within 6 to 24 hr.
  • Monitor vital signs and neurological status every 15 min for 1 hr, then every 2 hr for 4 hr, and then as ordered by the HCP. Monitor intake and output at least every 8 hr. Compare with baseline values. Protocols may vary among facilities.
  • No other radionuclide tests should be scheduled for 24 to 48 hr after this procedure.
  • Instruct the patient to resume usual diet, fluids, medication, and activity, as directed by the HCP.
  • Instruct the patient in the care and assessment of the injection site.
  • If a woman who is breastfeeding must have a nuclear scan, she should not breastfeed the infant until the radionuclide has been eliminated. This could take as long as 3 days. She should be instructed to express the milk and discard it during the 3-day period to prevent cessation of milk production.
  • Instruct the patient to immediately flush the toilet and to meticulously wash hands with soap and water after each voiding for 24 hr after the procedure.
  • Instruct all caregivers to wear gloves when discarding urine for 24 hr after the procedure. Wash gloved hands with soap and water before removing gloves. Then wash hands after the gloves are removed.
  • Nutritional Considerations: A low-fat, low-cholesterol, and low-sodium diet should be consumed to reduce current disease processes. High fat consumption increases the amount of bile acids in the colon and should be avoided.
  • Recognize anxiety related to test results, and be supportive of perceived loss of independent function. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include antibodies antineutrophilic cytoplasmic, angiography abdomen, barium enema, barium swallow, cancer antigens, capsule endoscopy, colonoscopy, CBC, CBC hematocrit, CBC hemoglobin, CT abdomen, EGD, fecal analysis, IgA, MRI abdomen, Meckel’s diverticulum scan, proctosigmoidoscopy, upper GI series, and WBC scan.
  • Refer to the Gastrointestinal System table at the end of the book for related tests by body system.