Be sure to check before you get a CT scan, Tips to prevent CT contrast side effects

Cases of emergency situations such as loss of consciousness or drop in blood pressure after receiving contrast media used for CT scans are attracting attention. In fact, the number of reports of adverse reactions to contrast media has exceeded 21,000, and 33 patients have died in the past five years after receiving contrast media.

As a result, the Korea Institute for Medical Institution Evaluation and Accreditation has issued a patient safety warning regarding the administration of contrast media. This is because it was judged that the medical community's preventive measures and follow-up measures for contrast media side effects were insufficient.

Side effects of contrast media

What side effects can the contrast agent used in the test cause?

Iodized contrast agents are used in computed tomography or angiography. It can cause mild symptoms such as hives, itching, and nausea, as well as side effects such as kidney failure, anaphylactic shock, cardiac arrest, and death.

Gadolinium contrast used in MRI scans has a relatively low incidence of severe side effects compared to iodinated contrast agents, but it may be dangerous for kidney patients. This is because normal kidney function causes the contrast agent to be excreted in the urine, but if kidney function is impaired, neogenic systemic fibrosis (NSF) can occur. Neogenic systemic fibrosis is an itchy, thick, and severe debilitating condition of the skin that can also affect the heart and lungs.

Prevention and Response to Contrast Mediums Accidents

In order to prevent contrast hypersensitivity reactions, hospitals should first equip the laboratory with emergency medications and medical equipment, and thoroughly check the patient's contrast agent hypersensitivity before conducting the examination. For patients who have had hypersensitivity to contrast media in the past, it is recommended to have a pre-skin examination* or treatment with medications such as prednisolone. In order for the patient to breathe well in the event of sudden shock, it is also necessary to prepare an emergency kit containing an airway securing device and medications such as epinephrine and steroids.

*Pre-skin examination: A test that can assess the degree of hypersensitivity of the patient before the administration of contrast medium.

However, even if there are no abnormalities in the pre-skin examination, side effects may appear if a large amount of contrast medium is added. If contrast media is used to control pain, the amount is small and there is almost no chance of side effects, but it is important to note that the amount used may vary depending on your weight, age, and type of examination. For example, a CT contrast agent is administered in a dose of about 100~150cc per examination.

Precautions before contrast test

First, patients who are about to undergo a CT scan should inform their healthcare provider in advance of their hypersensitivity reactions, allergy history, and whether they are taking diabetes medications, anti-cancer drugs, or blood pressure medications.

In particular, if you have an allergic disease such as asthma or have already experienced a hypersensitivity reaction to contrast media in the past, you are very likely to have a hypersensitivity reaction. Patients with impaired kidney function or diabetes or high blood pressure are at risk of developing nephrotoxicity when tests including contrast are performed.

Second, even after the test including contrast medium is completed, you should stay in the hospital for 30 minutes ~ 1 hour for observation. If you have a cough, shortness of breath, or itching all over your body, we recommend that you notify your healthcare provider as soon as possible.