| A | B |
|---|
| Thyroid-stimulating hormone (TSH) | 0.35–5.5 mcg/mL This is the most sensitive test to evaluate thyroid function by measuring pituitary TSH secretion. No fluid restriction is required.Avoid shellfish several days before test. |
| T3 | 80–200 ng/dL, Measures triiodothyronine (T3) and thyroxine (T4) to evaluate thyroid function.Increased level indicates hyperthyroidism and decreased reflects hypothyroidism. |
| T4 | 4.5–11.5 mcg/dL Measures triiodothyronine (T3) and thyroxine (T4) to evaluate thyroid function.Increased level indicates hyperthyroidism and decreased reflects hypothyroidism. |
| Serum calcium | 9–11 mg/dL This test evaluates parathyroid function and calcium metabolism. Fasting not required; however,is part of a chemistry panel in which fasting is required. |
| Serum phosphate | 2.5–4.5 mg/dL It measures serum phosphate.Increased levels in both tests indicate hyper- parathyroidism; decreased levels indicate hypoparathyroidism. |
| Cortisol | 8 to 10 am 5–23 mcg/dL 4 to 6 pm 3–13 mcg/dL This test measures total serum cortisol, which evaluates adrenal cortex function. Levels are increased in Cushing’s syndrome and decreased in Addison’s disease. Advise client to rest in bed 2 hours before blood is drawn.Explain that two blood samples are drawn—one at 8:00 to 10 am,the other at 4 to 6:00 pm. |
| Aldosterone | 4–30 ng/dL sitting position Less than 16 ng/dL supine position Levels are drawn to diagnose hyperaldosteronism. Ask client to be in supine position for 1 hour before test is drawn. |
| Urinary 17- ketosteroids | 5–15 mg/24 hours men 5–25 mg/24 hours women 17-KS are metabolites of testosterone, which are released from adrenal cortex. Teach client about 24-hour urine collection, which must be iced or refrigerated during collection.Levels increase with Cushing’s syndrome and decrease in Addison’s disease. |
| Glycosylated hemoglobin (Hb A1c) | 5.5%–7% Test used to measure glucose control during the previous 3 months.Levels are increased in newly diagnosed or poorly controlled diabetic.It is not used to diag- nose diabetes mellitus. No fasting is required. |
| Fasting blood glucose 70–110 mg/dL | This test measures circulating blood glu- cose level.Increases are seen in diabetes mellitus,acute pancreatitis; decreased level is seen in Addison’s disease. This test is done fasting. |
| Two-hour oral glucose tolerance test (OGTT) | Less than 125 mg/dL Determines the level of glucose 2 hours after drinking 75 g of glucose.Glucose level should return to premeal levels, but in diabetics,the level is higher than 200 mg/dL. Client is NPO for 12 hours before test. Then client must drink entire 100 g of glucose and not eat anything else until blood is drawn. |
| Urine glucose | Negative Estimates the amount of glucose in urine, which should be negative. Collect a fresh urine sample; stagnant urine may alter test results. |
| Urine ketones | Negative Measures ketones excreted in urine from incomplete fat metabolism.Positive result means lack of insulin or diabetic ketoacidosis. Some drugs may interfere with both test results. |
| Urine test for microalbumin | 0.2–1.9 mg/dL is the earliest indicator for development of diabetic nephropathy. Elevated microalbumin levels increase the risk for end-stage renal disease. Collect a fresh urine sample and send to laboratory for analysis. |
| Magnetic resonance imaging (MRI) MRI | uses a super magnet and radiofrequency signals to elicit a response from hydrogen nuclei.As a result,tumors of the pituitary gland and hypothalamus can be identified. Assess for presence of metallic implants,because clients with metal implants cannot have an MRI.Inform client of the need to lie motionless during the test.Be sure all metal objects are removed because the magnetic field can be injurious to anyone within the field. |
| Computed tomography (CT) scan | Specialized radiographic procedures that produce com- puter-generated images with significantly more detail than standard x-rays allow.May be done with or without contrast media.Abdominal CT is used to detect tumors of the adrenal gland and pancreas. If contrast dye used,ask about allergies to iodine and seafood.Client must lie still during the procedure. |
| Thyroid scan | Iodine-125 is injected IV.A scanner passes over the thyroid making a graph of the radiation emitted.“Cold spots,” which do not take up the I-125,indicate malignancy. Ask about allergies to iodine and seafood.Client may need to withhold thyroid drugs or medications containing iodine for weeks before the study.No fasting is needed. |
| Radioactive iodine (RAI) uptake test | Iodine-131 or I-125 (capsule or liquid form) is given,then the thyroid is scanned three times.Increased uptake indicates Graves’disease; decreased uptake means hypothyroidism. Client fasts for 8 hours before the test but can eat 1 hour after radioiodine capsule or liquid has been taken. Thyroid drugs or medications containing iodine are held for weeks before the study. |
| Growth hormone (GH) | Less than 5 ng/mL for men Less than 10 ng/mL for women Used to evaluate growth hormone excess or deficiency.Increased values indicate acromegaly. The client must be fasting,well rested, and not physically or emotionally stressed. |
