Page 1377 - Saunders Comprehensive Review For NCLEX-RN

8. The test is contraindicated in pregnancy.

F. Needle aspiration of thyroid tissue
1. Aspiration of thyroid tissue is done for cytological
examination.
2. No client preparation is necessary; NPO status may or
may not be prescribed.
3. Light pressure is applied to the aspiration site after the
procedure.

G. Glycosylated hemoglobin

1. HgbA1c is blood glucose bound to hemoglobin.
2. Hemoglobin A1c (glycosylated hemoglobin A;
HbA1c) is a reflection of how well blood glucose
levels have been controlled for the past 3 to 4 months.
3. Hyperglycemia in clients with diabetes is usually a
cause of an increase in HbA1c.
4. Fasting is not required before the test.
5. Normal reference intervals: <6% (adult without
diabetes)
6. HgbA1c and estimated average glucose (eAG)
reference intervals: Refer to Table 10-4 for these
reference intervals.

Poor glycemic control in a client with diabetes mellitus is

usually the cause of an increase in the HbA1c value.
H. 24-hour urine collection for vanillylmandelic acid (VMA)
1. Diagnostic tests for pheochromocytoma include a 24-
hour urine collection for VMA, a product of
catecholamine metabolism, metanephrine, and
catecholamines, all of which are elevated in the
presence of pheochromocytoma.
2. The normal range of urinary catecholamines:
a. Epinephrine: less than 20 mcg/day (less
than 109 nmol/day)
b. Norepinephrine: less than 100 mcg/day
(less than 590 nmol/day)
III. Pituitary Gland Problems (Box 46-6)
A. Hypopituitarism
1. Description: Hyposecretion of 1 or more of the
pituitary hormones caused by tumors, trauma,
encephalitis, autoimmunity, or stroke
2. Hormones most often affected are growth hormone
(GH) and gonadotropic hormones (luteinizing
hormone, follicle-stimulating hormone), but thyroid-
stimulating hormone (TSH), adrenocorticotropic

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