Gastric emptying scanning is a nuclear study performed to determine the time it takes for the stomach to empty itself of foods or fluids. Normally, solids are emptied by reduction to allow passage through the pylorus by antral contractions, and liquids are emptied primarily by gravity. Thus, solids are more sensitive for use in the detection of abnormal gastric emptying. The radionuclide 99mTc as technetium Tc 99m sulfur colloid mixed with cooked liver made into a pâté or mixed with egg white (test meal of 300 g) or 111In as indium In 111 chloride mixed with orange juice is administered orally to the client. Scanning is performed after the meal, and an analysis of the delayed emptying curve (the percent of food retained compared with the time) provides the diagnostic information.⁴³

The study can include the administration of metoclopramide (Reglan) to evaluate the effect of the drug on gastric motility, providing that no obstruction is present.⁴⁴

• Normal gastric emptying of standard test meal; no abnormal gastric function or mechanical obstruction

• Inability of client to remain still during the procedure
• Food intake during the fasting period before the study, which would affect emptying time
• Medications such as anticholinergics or narcotics that affect motility

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Indications

• Determining the existence of mechanical obstruction caused by gastric tumor or ulcer disease revealed by delayed emptying time
• Evaluating gastric function or absence of function revealed by delayed emptying in diabetic neuropathy or gastroparesis
• Determining the cause, after surgery, of delayed gastric emptying caused by a nonfunctioning anastomosis
• Determining the cause of delayed gastric emptying in conditions such as anorexia, diabetes, scleroderma, or amyloidosis
• Evaluating the effects of medication regimens

Contraindications

• Pregnancy, unless the benefits of performing the procedure greatly outweigh the risks to the fetus

[Section Outline]

• Indications
• Contraindications

Nursing Care Before the Procedure

Client teaching and physical preparation are the same as for any nuclear scan study (see section under "Brain Scanning").

• Instruct the client to withhold food and medications that can decrease motility for 8 hours before the study; also specify whether fluid intake is allowed.
• Inform the client of the scanning schedule and explain that the study takes 1 hour or longer, depending on the time it takes the stomach to empty.
• History should include information about gastrointestinal status and known or suspected abnormal conditions, as well as results of associated diagnostic tests and procedures.

The client is requested to ingest the test meal containing the radiopharmaceutical as quickly as possible. Use of a standardized test meal allows accurate determination of gastric emptying because the rate of emptying varies with meal size and caloric content. The client is maintained in a sitting position; after the ingestion of the test meal, the images are obtained at 10- and 20-minute intervals in anterior and posterior views. Imaging is then performed over the stomach with the client in a supine position until the stomach empties (normally 1 to 1½ hours). Emptying time is calculated based on data obtained from the computer system as well as on the percentage of counts obtained, decay time of the radionuclide, and depth variables. An emptying curve is determined by calculating the percentage of retention versus the time. These results are interpreted by the nuclear medicine physician at the completion of the procedure. In general, a longer time indicates impaired gastric emptying and a shorter time indicates gastric hypermotility.

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any nuclear scan study (see section under "Brain Scanning").