Hazards of iohexol contrast agent

Iohexol contrast agent is a type of contrast agent. Proper use can make the examination results more accurate, but it will cause certain harm to the body during use. It may be a mild reaction, such as redness of the face, continuous sneezing, nausea, coughing, etc.; it may be a moderate reaction, such as chest tightness, diarrhea, conjunctival hemorrhage, etc.; severe reactions will cause confusion, low blood pressure, etc.

1. Mild reactions: facial flushing, increased eye and nasal secretions, sneezing, nausea, headache, dizziness, skin itching, fever and itching, conjunctival congestion, a few rashes, cough, nausea, mild vomiting, mild urticaria, etc. When such a reaction occurs, stop the injection, let the patient rest quietly, provide comfort and explanation, let the patient relax, take a deep breath, and observe the development of the reaction. Generally, no medication is required for treatment, and the symptoms can be relieved on their own. If treatment is required, 10 mg of dexamethasone can be injected intravenously. Rest quietly, breathe fresh air, drink plenty of water, take antihistamines, or intravenous injection of dexamethasone 10 mg, intramuscular injection of phenergan 25 mg, or intramuscular injection of diphenhydramine 25 mg. The patient can be released only after close observation for 30 minutes.

2. Moderate reaction: chest tightness, shortness of breath, severe vomiting, abdominal pain and diarrhea, large rash, and conjunctival hemorrhage. Symptoms include measles-like rash, edema of the eyes, face, ears, etc., chest tightness, shortness of breath, difficulty breathing, hoarseness, limb twitching, etc. Moderate vomiting, mild laryngeal edema and bronchospasm, etc., and a temporary drop in blood pressure. This type of reaction is more critical, so stop injecting the contrast agent immediately. Treatment: (1) Oxygen inhalation, keep the airway open, the patient lies flat and keeps fresh air, nasal cannula or mask oxygen. ⑵ Anti-allergic drugs: phenergan 25 mg intramuscular injection, dexamethasone 5-10 mg. ⑶ For patients without hypertension, heart disease, or hyperthyroidism, 0.25-0.5 mg of epinephrine can be injected subcutaneously or intramuscularly. In critical situations, it can be diluted and slowly injected intravenously. 10 mg of dexamethasone can be injected intravenously and the dose can be repeated. ⑷ When blood pressure drops and bradycardia (vasovagal reaction) occurs, rapidly drip 500-1000 ml of plasma substitute, 0.5-3.0 mg of atropine, intravenously; 0.25-0.5 mg of isoproterenol, slowly intravenously. ⑸ In case of dyspnea and spasmodic cough, 0.25g of aminophylline can be injected intravenously (0.25-0.5g/time, diluted with 20-40ml of 50% glucose solution and slowly injected intravenously, and the injection must not be completed in less than 5 minutes); 250-500mg of prednisolone, a glucocorticoid, can be injected intravenously. ⑹It will take effect after 5 to 10 minutes. If necessary, 10 mg of diazepam can be given intravenously for sedation. ⑺For laryngeal edema, use 5 mg of dexamethasone and 1 mg of epinephrine as laryngeal spray. ⑻ In case of respiratory depression, give respiratory stimulants, such as nikethamide (0.25-0.5g/time, subcutaneous, intramuscular, intermittent intravenous injection or caffeine.

3. Severe reactions: circulatory failure—drop in blood pressure, rapid and weak pulse, confusion, loss of consciousness, and cardiac arrest. Respiratory failure - laryngeal and bronchial spasm, difficulty breathing, and pulmonary edema will result in spitting up large amounts of foamy or pink sputum. Allergic reactions - pale complexion, cyanosis of limbs, chills, difficulty breathing, muscle cramps, decreased blood pressure, cardiac arrest, loss of consciousness, and possible convulsions. The occurrence of the above reactions is often life-threatening and must be promptly notified to the relevant departments and emergency physicians for on-site emergency treatment. ⑴ When shock occurs (bradycardia, sudden drop in blood pressure), immediately take a semi-sitting position and use a mask to breathe oxygen. ⑵ Establish an intravenous channel and quickly drip 1500-2000ml of plasma substitute or Ringer's solution. ⑶ Inject 0.25-1mg of epinephrine intravenously and check cardiac function every 10-15 minutes. The dosage depends on the treatment effect, and the maximum dose is 1mg.