Which laboratory value should the nurse review to determine ...

[natalie2426]

Which laboratory value should the nurse review to determine whether a patient's hypothyroidism is caused by a problem with the anterior pituitary gland or with the thyroid gland?
 
  a. Thyroxine (T4) level
  b. Triiodothyronine (T3) level
  c. Thyroid-stimulating hormone (TSH) level
  d. Thyrotropin-releasing hormone (TRH) level

Question 2

The nurse reviews a patient's glycosylated hemoglobin (Hb A1C) results to evaluate
 
  a. fasting preprandial glucose levels.
  b. glucose levels 2 hours after a meal.
  c. glucose control over the past 90 days.
  d. hypoglycemic episodes in the past 3 months.

[AmberC1996]

Answer to Question 1

ANS: C
A low TSH level indicates that the patient's hypothyroidism is caused by decreased anterior pituitary secretion of TSH. Low T3 and T4 levels are not diagnostic of the primary cause of the hypothyroidism. TRH levels indicate the function of the hypothalamus.

Answer to Question 2

ANS: C
Glycosylated hemoglobin testing measures glucose control over the last 3 months. Glucose testing before/after a meal or random testing may reveal impaired glucose tolerance and indicate prediabetes, but it is not done on patients who already have a diagnosis of diabetes. There is no test to evaluate for hypoglycemic episodes in the past.