Histamine challenge test

The histamine challenge test is the use of histamine for the induction of challenge in patients with paroxysmal hypertension without seizures or low blood pressure. Before the test, the sedative drug should be stopped for 3 days, and the antihypertensive drug should be stopped for 2 weeks. If the blood pressure is >21.3/14.6 kPa (160/110 mmHg), it is not suitable for this test. Phentolamine should be provided during the test so that it can be used when blood pressure is too high. Those with allergies and asthma should not be tested. This test has the risk of causing an extremely high blood pressure and must be taken with great care. Basic Information Specialist classification: maternity check check classification: blood test Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: Negative results are generally normal. Positive: Positive test results are common in allergies and other diseases. Reminder: All antihypertensive drugs were stopped within one week before the test, and sedative drugs were discontinued the first two days. Normal value In normal people and patients with essential hypertension, blood pressure can be decreased after injection, and facial flushing, headache, nausea, etc. are negative. Clinical significance (1) For pheochromocytoma, further examination of hypertension during non-onset period. (2) After intravenous injection, the blood pressure increased by 8.0/4.0 kPa before intravenous injection or the highest blood pressure of cold blood pressure test was 2.5/1.5 kPa or more. Positive result. Abnormal result 1. The clinical manifestations of pheochromocytoma vary widely from nodules and signs to sudden onset of malignant hypertension, heart failure or cerebral hemorrhage. PHEO is "about 10% rule", that is, about 10% is outside the adrenal gland, 10% is malignant, 10% is familial, 10% is in children, 10% is bilateral, and 10% is multiple. Clinical signs and symptoms are associated with excessive secretion of catecholamines, the so-called "6H performance" hypertension (hypertension), headache (headache), heart consciousness (hypertension), hypermetabolism (hypermetabolism), hyperglycemia (hyperglycemia), hyperhidrosis (hyperhidrosis) . 2. Essential hypertension. Hypertensive patients may have headaches, dizziness, shortness of breath, fatigue, palpitations, tinnitus and other symptoms, but not necessarily related to blood pressure levels, and often noticed after the patient learns to have high blood pressure. During the physical examination, the aortic valve second heart sound hyperthyroidism, the aortic valve area systolic murmur or the contraction early click sound can be heard. Precipitating persistent hypertension can have left ventricular hypertrophy and can smell the fourth heart sound. The clinical manifestations of hypertension in the late stage are often associated with heart, brain, kidney dysfunction or organ complications. People who need to be examined: those with suspected symptoms such as essential hypertension and hypertension caused by pheochromocytoma can also be used to distinguish between hypertension with different causes. Positive results may be diseases: skin allergies, urticaria, urticaria type drug eruption, pollen allergic asthma precautions Inappropriate population: those with myocardial infarction, cerebral hemorrhage, history of heart failure, history of asthma or allergic disease, older age or high blood pressure (>23/13 kPa). Contraindications before the test: All antihypertensive drugs were stopped within one week before the test, and the sedative drugs were stopped for the first two days. Requirements for examination: Establish an intravenous infusion channel before the start of the test, and slowly drip with 5% dextrose solution for drug administration. This test has certain risks. Benzyl oxazoline should be prepared during the test so that it can be used when blood pressure is too high. The false positive of this test is about 10%, and attention should be paid to the identification. Inspection process method: 1 first cold compression test, blood pressure measurement before and after cold press, until the blood pressure returned to the level before cold pressurization. 2 0.07-0.14mg of phosphoric acid histamine (corresponding to histamine matrix 0.025 ~ 0.05mg) was added to 2ml / saline quickly intravenously (usually 0.01mg first) can also be stimulated with glucagon 0.5 ~ 1mg test). 3 The blood pressure of the ipsilateral upper wall was measured 5 times per minute after the injection, and then measured every 2 minutes and the basal blood pressure was restored. Not suitable for the crowd 1. Patients who have taken contraceptives, thyroid hormones, steroid hormones, etc., may affect the results of the examination and prohibit patients who have recently taken the drug history. 2, special diseases: patients with hematopoietic function to reduce disease, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.