Clonidine test

The clonidine test is due to the inhibition of blood catecholamines in non-pheochromocytoma hypertensive patients after oral clonidine, while the release of tumor autonomic catecholamines in patients with pheochromocytoma cannot be inhibited, so blood catecholamine levels are unchanged. . METHODS: Blood catecholamine was taken under the condition of blood, and oral clonidine 0.3 mg was taken. Blood catecholamine was measured 2 to 3 hours before and after taking the drug. Clonidine inhibits the release of catecholamines caused by neurogenic factors and has no significant inhibitory effect on elevated catecholamines in patients with pheochromocytoma. The identification of hypertension caused by pheochromocytoma and hypertension caused by non-pheochromocytoma. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Tips: You should pay attention to the normal diet before the examination, pay attention to normal work and rest, and prevent endocrine disorders. Normal value The blood pressure is normal and there is no disease in the body. Clinical significance Abnormal results: 1. Clinical manifestations of pheochromocytoma vary widely from asymptomatic and physical 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 headache, dizziness, shortness of breath, fatigue, palpitations, tinnitus and other symptoms, but not necessarily related to blood pressure levels, and often only after the patient is known 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. Precautions Forbidden before examination: pay attention to normal diet, pay attention to normal work and rest, and prevent endocrine disorders. Requirements for inspection: Actively cooperate with the doctor's request. Inspection process METHODS: Blood catecholamine was taken under the condition of blood, and oral clonidine 0.3 mg was taken. Blood catecholamine was measured 2 to 3 hours before and after taking the drug. Clonidine inhibits the release of catecholamines caused by neurogenic factors and has no significant inhibitory effect on elevated catecholamines in patients with pheochromocytoma. The identification of hypertension caused by pheochromocytoma and hypertension caused by non-pheochromocytoma. Not suitable for the crowd Inappropriate crowd: temporarily unknown. Adverse reactions and risks No related complications or hazards.