furosemide challenge test

The furosemide challenge test is carried out by the following principle. Furosemide inhibits the reabsorption of Na+ and Cl- by the ascending branch of the renal tubule, interferes with the concentration process of urine, and increases the urine volume. At the same time, a large amount of Na+ reaches the far curve. The tubules and manifolds increase the K+-Na+ exchange. The net effect is a decrease in blood Na+, a decrease in blood volume, stimulation of the secretion of renin by the juxtaglomerular apparatus, and an increase in levels, thereby stimulating the synthesis and secretion of aldosterone. Therefore, under the action of a certain dose of furosemide, the secretion reaction of RAS can better reflect the increased release of aldosterone than the hormone assay in the basic state. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Tips: Pay attention to the normal diet, pay attention to normal work and rest, and prevent endocrine disorders. Normal value Under normal circumstances, blood aldosterone increased significantly after the furosemide challenge test; blood aldosterone did not increase significantly in primary aldosteronism. Clinical significance Abnormal results There are three types of clinical symptoms of aldosteronism: 1. Hypertensive patients have high blood pressure, and appear earlier, often appear in about 4 years before the onset of hypokalemia. Generally, it is moderately elevated, and the increase in diastolic blood pressure is more obvious. 2. Neuromuscular dysfunction. (1) Neuromuscular weakness and paralysis Generally speaking, the lower the blood potassium, the heavier the myopathy. Tiredness, coldness, tension, diarrhea, sweating, and loss of potassium-diuretic diuretics (such as hydrochlorothiazide, furosemide) can be induced. It is often found that the lower limbs cannot move autonomously when they wake up in the morning. The severity of the attack varies, and the severe one can affect the upper limbs, sometimes involving the respiratory muscles. Cranial nerve innervation muscles are generally unaffected. Bilateral flaccid convulsions at the time of onset. (2) Paroxysmal hand, foot and ankle and muscle spasm were found in about 1/3 of patients, with beam arm compression sign (Trousseau sign) and facial nerve attack sign (Chvostek sign). It can last for days to weeks. Can appear alternately with paroxysmal paralysis. 3. Loss of potassium nephropathy and pyelonephritis. People who need to be examined: patients with hypertension, neuromuscular dysfunction, potassium-deficient nephropathy and pyelonephritis. 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 [Method] The patient was supine overnight, and the blood was collected in the morning position to measure aldosterone, 40 mg of intramuscular injection of furosemide, and the maximum 50 mg remained in the standing position for 2 hours. The aldosterone was measured again by blood sampling. [Results] If the patient's basal blood aldosterone level was significantly increased, serum renin, angiotensin II and aldosterone did not increase significantly after the expedited urinary priming test, suggesting that the abnormal secretion of aldosterone increased, supporting the primary aldosteronism. diagnosis. Not suitable for the crowd Inappropriate crowd: temporarily unknown. Adverse reactions and risks No related complications or hazards.

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