REF024 - Gastro-Intestinal Bleeding Scintigraphy

The purpose of this document is to assist clinicians in deciding on the appropriateness of the Nuclear Medicine procedure and to give guidance on the mechanism of referral.

The localisation of gastrointestinal bleeding is usually with endoscopy or radiographic procedures - CT or catheter angiography. In problematic cases, however, the use of technetium-99m labelled red blood cells may contribute to the management of a patient who is actively bleeding.

A site of active bleeding is localised by an accumulation of labelled red blood cells in the abdomen and the general configuration of radiopharmaceutical in the gut lumen can give some localisation. This can also assist in the choice of mesenteric vessel to catheterise first if angiography is to be performed afterwards.

A red blood cell study can be positive at bleeding rates of 0.5 ml per minute. In some cases, bleeding rates as low as 0.1 ml per minute may be detected. The study should be performed rapidly after bleeding is detected.

There is often a problem with the timing of this investigation, either because the bleeding is intermittent or because a patient admitted to hospital with a gastrointestinal haemorrhage is stabilised before examination by which time the bleeding has stopped.

The referrer may be any clinician holding a current valid medical qualification and currently employed in Secondary Care.

Referring clinicians are reminded of the requirement to avoid unnecessary exposure to ionising radiation. The investigation may already have been requested at this hospital or elsewhere and clinicians are asked to be particularly vigilant to ensure that their request is not a double request.

Requests will only be accepted if the diagnostic question fulfills one of the referral criteria below. Appropriate clinical information must be supplied to allow the investigation to be justified. It is not acceptable to simply request the investigation without appropriate clinical information.

Requests will be returned to the referrer if:

• The diagnostic question is unclear.
• The diagnostic question cannot be answered by the investigation.
• Insufficient clinical information is supplied to justify the investigation.

Requests should be submitted on the orange stripe NUCLEAR MEDICINE (ISOTOPE SCAN) request form. Patient details, Investigation required and Reason for Test/Diagnostic Question should be fully and appropriately completed and the form signed.

Note the requirement for Patient Preparation below

Sufficient clinical information must be provided to justify the investigation proceeding.

• If the patient is haemodynamically unstable they will need to be monitored by a doctor or nurse when in the department^[1]. Please note that the nuclear medicine department do not have staff who can monitor such patients.
• Breast feeding patients will need to stop breast feeding for 20 hours following this procedure and should consider expressing milk in advance of the procedure to be used for feeding during this period.