Osmolality urine 测试

定义

The osmolality urine 测试 measures the concentration of chemicals in urine.

Osmolality can also be measured using a 血液测试.

How the Test is Performed

A clean-catch urine sample 是必要的. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly.

How to Prepare for the Test

Your provider may tell you that you need to limit your fluid intake 12 to 14 hours before the 测试.

Your provider will ask you to temporarily stop taking any medicines that may affect the 测试 results. Be sure to tell your provider about all the medicines you take, including dextran and sucrose. DO NOT stop taking any medicine before talking to your provider.

Other things can also affect the 测试 results. Tell your provider if you recently:

• Had any type of anesthesia for an operation.
• Received intravenous dye (contrast medium) for an imaging 测试 such as a CT or MRI scan.
• Used herbs or natural remedies, especially Chinese herbs.

How the Test will Feel

The 测试 involves normal urination. There is no discomfort.

Why the Test is Performed

This 测试 helps check your body's water balance and urine concentration.

Osmolality is a more exact measurement of urine concentration than the urine specific gravity 测试.

正常的结果

Normal values are as follows:

• Random specimen: 50 to 1200 mOsm/kg (50 to 1200 mmol/kg)
• 12 to 14 hour fluid restriction: Greater than 850 mOsm/kg (850 mmol/kg)

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or 测试 different samples. Talk to your provider about the meaning of your specific 测试 results.

What Abnormal Results Mean

Abnormal results are indicated as follows:

Higher than normal measurements may indicate:

• Adrenal glands do not produce enough hormones (艾迪生疾病 or other types of adrenal insufficiency)
• Glucose (a type of sugar) in the urine
• 心脏衰竭
• High sodium level in the blood
• Loss of body fluids (dehydration)
• Narrowing of the kidney artery (renal artery stenosis)
• 冲击
• Syndrome of inappropriate ADH secretion (SIADH)

Lower than normal measurements may indicate:

• Damage to kidney tubule cells (renal tubular necrosis)
• 尿崩症
• Drinking too much fluid
• 肾功能衰竭
• Low sodium level in the blood
• Severe kidney infection (pyelonephritis)

风险

There are no risks with this 测试.

参考文献

伯尔T，金沙JM. Disorders of water metabolism. In: Feehally J, Floege J, Tonelli M, Johnson RJ, eds. Comprehensive Clinical Nephrology. 6日艾德. Philadelphia, PA: Elsevier; 2019:chap 8.

Oh MS, Briefel G, Pincus MR. Evaluation of renal function, water, electrolytes, and acid-base balance. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24日艾德. Philadelphia, PA: Elsevier; 2022:chap 15.