Download Case Studies Directions: Read the following cases and provide

Case Studies
Directions: Read the following cases and provide answers for the questions
that follow.
Case 1
Thomas L. a 28-year-old male, complained of abrupt polydipsia and polyuria. Blood and
urine analyses provided the following results:
Fasting blood glucose 93 mg/dL
Serum sodium 145 mEq/L
Serum potassium 2.8 mEq/L
Urine osmolarity <200 mOsm/L
Urine volume 15 L/day
Urine glucose 0
Water deprivation and hypertonic saline infusion did not cause a significant reduction in
the polyuria and concentration of urine. Complete water-deprivation resulted in the
following: Urine osmolarity 225 mOsm/L. However, there was a significant concentration
of the urine and a decrease in urinary output following administration of ADH.
1. Define polydipsia and polyuria.
2. To maintain a steady state, about how much fluid must Thomas drink per day?
3. Why was a water deprivation and hypertonic saline infusion ordered? How would a
normal healthy person respond to these tests. Interpret the results of Thomas L.’s tests.
4. Why did the water deprivation and hypertonic saline infusion not result in a
concentrated urine?
5. Are Thomas's kidneys capable of responding to ADH? What is the evidence?
6. What is the name of this endocrine disorder?
7. Is there a defective endocrine gland? If so, which is it?
8. Thomas L. was given a nasal spray containing a synthetic substance to self-administer
to treat this condition. What type of compound was present in the nasal spray?
9. Why was this compound given as a nasal spray? Why not have Thomas take it in tablet
form?
10. Diagram the hypothalamic-pituitary-target organ pathway for this individual and
indicate the normal and pathophysiological conditions involved.
11. The symptoms appeared abruptly. What could have been the cause of this endocrine
disorder?
11. What is the long-term prognosis for Thomas L? Must he take the nasal spray for the
rest of his life? Why or why not?
Case 2
Hazel C. a 30-year-old female demonstrated a subtle onset of the following symptoms:
dull facial expression; droopy eyelids; puffiness of the face and periorbital swelling;
sparse, dry hair; dry, scaly skin; evidence of intellectual impairment; lethargy; a change of
personality; bradycardia (60 b/min); a blood pressure of 90/70; constipation, and
hypothermia. Plasma concentrations of total and free T4 and T3 follow:
Total
T4
3 ug/dL (normal = 4-12 ug/dL)
T3
0.14 ng/dL (normal = 75-195 ng/dL)
Free
0.6 ng/dL
0.01 ng/dL
Radioimmunoassay (RIA) of peripheral blood indicated elevated TSH levels. A TSH
stimulation test did not increase the output of thyroid hormones from the thyroid gland.
1. Why does Hazel have a lower-than-normal body temperature?
2. How do Hazel's levels of T3 and T4 compare to normal?
3. What do Hazel's elevated levels of TSH reveal about the function of her anterior
pituitary? about her thyroid glands?
4. What is a TSH stimulation test and how are the results interpreted?
5. Is this a primary or secondary disorder? How is this determined?
6. Name the endocrine disorder in this case.
7. Diagram the feedback loop involved.
8. What is a palpable goiter and would you expect to find a palpable goiter in this case?
Explain your answer.
9. If a person has bradycardia and hypotension, which of the following hormones would
most immediately restore heart rate and blood pressure to normal: TH or EPI?
11. What is the most likely explanation for the bradycardia and low blood pressure?
12. What is the most likely explanation for the constipation?
13. Describe a suitable treatment for Hazel. Would this treatment require injections or
capsules?
14. Why would it be unnecessary to treat Hazel with supplemental EPI?
15. Is this treatment expected to return blood pressure and heart rate to normal? Why or
why not?
Case 3
Oscar T. a 45-year-old male from the Midwest presented with the following symptoms
during February: weakness, fatigue, orthostatic hypotension, weight loss, dehydration,
and decreased cold tolerance. His blood chemistry values follow:
Serum sodium 128 mEq/L
Serum potassium 6.3 mEq/L
Fasting blood glucose 65 mg/dL
Hematology tests resulted in these values: Hematocrit 50%; Leukocytes 5000/cu mm
Oscar also noticed increased pigmentation (tanning) of both exposed and nonexposed
portions of the body and back. A plasma cortisol determination indicated a low cortisol
level. Following administration of ACTH, plasma cortisol did not rise significantly after
sixty and ninety minutes. Endogenous circulating levels of ACTH were later determined to
be significantly elevated.
1. What is orthostatic hypotension?
2. What hormone from which organ is most likely involved with Oscar's serum electrolyte
imbalance?
3. Is Oscar anemic? Which of the test results answers this question?
4. Does Oscar have an infection? Which of the test results answers this question?
5. Which hormone is most likely associated with the symptoms of weaknesss, fatigue,
weight loss and decreased cold tolerance?
6. What endocrine organ is the site of the malfunction? What hormones are normally
secreted from this gland? Is more than one hormone deficient in Oscar?
7. What is the name of this disorder?
8. Is this a primary or secondary disturbance? Explain your answer.
9. In a normal person, how would plasma cortisol levels be affected following
administration of ACTH? What do Oscar's ACTH test results imply?
10. Why is Oscar's endogenous circulating level of ACTH significantly elevated?
11. What is the cause of Oscar's hyperpigmentation? How is this related to his high levels
of ACTH?
12. What type of replacement therapy would be required for Oscar? Will the replacement
of one hormone suffice to treat all his symptoms?
13. Diagram the feedback loops for this endocrine disorder.
14. What is the long-term outlook for Oscar? Might one expect Oscar's abnormal
pigmentation to resolve once his treatment has begun? Explain.
Case 4
A 50-year-old male (Horace C.) had a total thyroidectomy followed by thyroid hormonereplacement therapy. Thirty-six hours later he developed laryngeal spasms, a mild tetany,
and cramps in the muscles of the hands and arms. The following tests were performed:
Plasma calcium 7.0 mg/dL
Plasma phosphorus 5.0 mg/dL
Plasma chloride 99 mEq/L
1. Of the plasma electrolytes, which is most seriously disturbed?
2. What hormone(s) regulate plasma calcium?
3. What gland is the source of those hormone(s)?
4. What has happened to those glands in Horace?
5. What endocrine disorder is present in Horace? Could this have been avoided?
6. What caused Horace's tetany and laryngeal spasms?
As a follow-up, calcium gluconate and vitamin D (calcitriol) were given orally each day
and the tetany and laryngeal spasms were alleviated.
7. During the treatment phase, what is the purpose of vitamin D administration with
supplemental calcium?
8. Diagram the negative feedback loop for the hormone(s) involved and be sure to
identify the effectors.
9. Is hormone replacement therapy necessary for Horace or could his case be managed
by supplements and vitamins?