From the Guidelines
Premedication for asthmatic patients undergoing contrast studies is not supported by recent evidence, and its use should be individualized based on the patient's history of reactions to contrast media. According to the most recent study 1, very low-certainty evidence suggests that glucocorticoid and/or antihistamine premedication does not provide a clear benefit in preventing hypersensitivity reactions to contrast media. However, for patients with a history of anaphylactoid reactions to contrast media, the 2011 ACCF/AHA/SCAI guideline 1 recommends appropriate steroid and antihistamine prophylaxis before repeat contrast administration.
Some key points to consider when deciding on premedication for asthmatic patients undergoing contrast studies include:
- The patient's history of reactions to contrast media
- The severity of their asthma
- The potential benefits and risks of premedication
- The availability of emergency treatments, such as bronchodilators and rescue inhalers
In general, patients with asthma should continue using their regular asthma medications throughout the period of contrast media administration and bring rescue inhalers to the procedure. The radiology team should be informed of the patient's asthma history, and emergency bronchodilators should be readily available during the procedure. After contrast administration, patients should be monitored for at least 30 minutes for any delayed reactions.
It is essential to weigh the potential benefits of premedication against the potential risks and to individualize treatment based on the patient's specific needs and medical history. The most recent evidence 1 suggests that premedication may not be necessary for all patients, but it may still be beneficial for those with a history of severe reactions to contrast media.
From the Research
Asthma Contrast Premedication
- The risk of bronchospasm in asthmatic patients undergoing general anesthesia or administration of radiographic contrast media can be reduced with a stepwise preventive pharmacological approach 2.
- Premedication with corticosteroids, such as methylprednisolone, can help attenuate the severity of an unpredictable reaction, although it may not completely prevent a severe event 3.
- The use of oral corticosteroids, such as prednisolone and dexamethasone, is recommended for acute asthma exacerbations, but the optimal dosing regimen is still unclear 4.
- A stratified premedication strategy based on the severity of previous hypersensitivity reactions to iodinated contrast media can help reduce the risk of breakthrough reactions 5.
- The choice of intravenous corticosteroids, such as methylprednisolone, dexamethasone, or hydrocortisone, may not significantly affect the outcome of acute severe pediatric asthma treatment 6.
Premedication Strategies
- A therapeutic approach based on the degree of asthma control, as assessed by clinical and functional criteria, can help reduce the risk of bronchospasm in asthmatic patients undergoing general anesthesia or administration of radiographic contrast media 2.
- The use of alternative products, such as different types of contrast media, can also help reduce the risk of hypersensitivity reactions 5.
- Premedication with antihistamines, such as chlorpheniramine, may also be effective in reducing the risk of mild reactions 5.
Corticosteroid Use
- The use of corticosteroids, such as methylprednisolone and dexamethasone, is a common practice in the prevention and treatment of asthma exacerbations and hypersensitivity reactions 3, 4, 5, 6.
- The optimal dosing regimen for corticosteroids in acute asthma exacerbations is still unclear, and further studies are needed to determine the most effective approach 4.