What information should be included in the consent form for a computed tomography (CT) abdomen scan with intravenous (IV) and oral contrast?

From the Guidelines

A comprehensive consent form for a CT abdomen scan with IV and oral contrast should include several key elements, as outlined in the most recent guidelines 1. The form should clearly describe the procedure, explaining that it involves taking multiple X-ray images while the patient lies on a table that moves through a donut-shaped scanner. It should detail the contrast administration process, including that oral contrast (typically barium or iodine-based solutions like Gastrografin) will be consumed before the scan and IV contrast (usually iodinated agents like Omnipaque or Visipaque) will be injected during the procedure. The form must outline common side effects of contrast media, such as a warm sensation, metallic taste, and possible nausea, as well as rare but serious risks including allergic reactions and contrast-induced nephropathy. Radiation exposure risks should be mentioned, though contextualized as relatively low compared to the diagnostic benefit. The form should include specific contraindications, particularly asking about previous contrast reactions, kidney disease, metformin use, and pregnancy. Preparation instructions should be provided, typically including fasting for 4-6 hours before the scan while maintaining hydration with clear fluids. The consent form should also explain alternatives to the procedure and give patients the opportunity to ask questions before signing. This comprehensive information ensures patients can make an informed decision while understanding what to expect during the procedure, as supported by recent studies 1.

Some key points to consider when creating the consent form include:

• Clearly describing the procedure and its risks
• Outlining the benefits of the procedure
• Providing preparation instructions
• Explaining alternatives to the procedure
• Giving patients the opportunity to ask questions before signing
• Ensuring the patient understands the potential risks and benefits of the procedure, as recommended by guidelines 1.

By including these elements, the consent form can help ensure that patients are fully informed and able to make an informed decision about undergoing the CT abdomen scan with IV and oral contrast.

From the FDA Drug Label

Patients should receive the following information and instructions: This drug has been prescribed to perform an x-ray of the gastrointestinal tract. Inform the physician if pregnant or if allergic to iodine, any foods, or x-ray materials The iodine in diatrizoate salts may interfere with some thyroid tests if these are needed in the future. Patients should be well hydrated prior to and following ISOVUE (Iopamidol Injection) administration. The consent form for a computed tomography (CT) abdomen scan with intravenous (IV) and oral contrast should include:

• Information about the drug prescribed to perform the x-ray of the gastrointestinal tract
• Instructions to inform the physician if pregnant or if allergic to iodine, any foods, or x-ray materials
• A warning that the iodine in diatrizoate salts may interfere with some thyroid tests if these are needed in the future
• Advice to be well hydrated prior to and following IV contrast administration 2
• Possible side effects such as abdominal cramping, nausea, vomiting, diarrhea, skin rashes, itching, heartburn, dizziness, or headache
• Risks associated with radiation exposure to the fetus in pregnant women 3

From the Research

Information to be Included in the Consent Form

The consent form for a computed tomography (CT) abdomen scan with intravenous (IV) and oral contrast should include the following information:

• The risks associated with the intravascular application of contrast media, such as anaphylactoid reactions, nephropathy, and thyrotoxic crisis 4
• The potential advantages and disadvantages of using low-osmolar iodinated solutions as an oral contrast agent 5
• The types of contrast agents used, their risks, contraindications, and common clinical scenarios in which contrast-enhanced computed tomography is appropriate 6
• The possibility of alternative diagnostic tests or procedures that do not involve the use of contrast agents
• The importance of clear communication between the physician and radiologist to ensure that the most appropriate study is ordered at the lowest cost and risk to the patient 6

Patient Education and Understanding

The consent form should also take into account the patient's level of education and understanding of the risks associated with the procedure. Studies have shown that patients with higher education levels have a better understanding of the risks associated with contrast-enhanced CT scans 4. Therefore, the consent form should be adjusted to the educational status of the individual patient, using didactic aids or individualized information sheets if necessary.

Specific Considerations for IV and Oral Contrast

The consent form should also address the specific considerations for the use of IV and oral contrast in CT abdomen scans, including:

• The potential benefits and risks of using oral contrast agents, such as improved visualization of the appendix and diagnosis of appendicitis 7
• The possibility of using alternative oral contrast agents, such as low-osmolar iodinated solutions or neutral or negative oral contrast agents 5, 8
• The importance of following the instructions for taking the oral contrast agent to ensure optimal visualization of the abdominal structures 7