Clinical chemistry

1. Endocrine Disorders
Dr. C. C. Chemonges

2. Review
• Identify the role of the hypothalamus in
endocrine function.
• Describe the divisions of the pituitary gland
and identify hormones secreted by each
division.
• Discuss the difference between releasing
hormones, inhibiting hormones and
stimulating hormones.
• Describe the process of negative feedback.

3. Review
• Identify the function of the following hormones:
– Glucagon
– Aldosterone
– Oxytocin
– Somatotropin
– Vasopressin
– Calcitonin
– Prolactin
– Melatonin
– Parathormone
– Insulin

4. Four Classifications of Hormones
• Steroid
• Protein (peptide)
• Amine
• Fatty acid derivatives

5. Endocrine Dysfunction
Assessment
– ↓energy level/fatigue
– Intolerance to heat or cold
– Changes in sexual function
– Development of 2° sex
characteristics
– Changes in mood and ability
to concentrate
– Changes in memory and sleep
patterns
– Exophthalmos
– Hypotension or hypertension
Diagnostic Evaluation
• Common categories
– Blood tests
– Urine tests
– Stimulation and suppression
tests
Describe the procedure for 24
hour urine specimen
collection.

6. Pituitary Dysfunction
• Undersecretion or oversecretion
• Hypofunction: Hypopituitarism
– What will occur when there is a complete absence
of pituitary function?
• Anterior pituitary hyperfunction
– most commonly involves ACTH or GH
• Posterior pituitary hypofunction
– Most commonly deficient secretion of ADH

7. Pituitary Tumors
• Usually benign
• Three types:
– Eosinophilic (result in gigantism)
– Basophilic (cause Cushing’s Syndrome)
– Chromophobic (destroy pituitary)
• Diagnosed through careful assessment, visual
acuity and field testing, CT and MRI
• Medical management
• Surgical management

8. Diabetes Insipidus
• Posterior pituitary disorder
• ADH deficiency
• Key features: polydipsia and polyuria
• Can occur 2° to head trauma, brain tumor,
ablation of pituitary gland, CNS infections,
failure of kidney tubules to respond to ADH,
and systemic tumors
• Diagnosed by fluid deprivation test and trial of
desmopressin (DDAVP)

9. Diabetes Insipidus
Review Case Study
What are the goals of therapy for DI?
What is included in pharmacotherapy?
What is the role of the nurse in management?

10. Syndrome of Inappropriate ADH
Secretion
• Excess secretion of ADH even with subnormal
serum osmolality
• Can not excrete a dilute urine
• Retain fluids and develop dilutional hyponatremia
• Usually nonendocrine cause
• Typical interventions: treat underlying cause and
restrict fluids
• May use diuretics (furosemide) is severe ↓ Na

11. Nursing Managment
What are nursing interventions
associated with SIADH?

12. Thyroid Dysfunction
• Cretinism
• Hypothyroidism
• Hyperthyroidism

14. Diagnostics
• Labs
– Serum TSH (0.4 – 6.15 μU/mL)
– Serum Free T4 (0.9 – 1.7 ng/dL)
– Serum T3 (T3 70 – 220 ng/dL)
– Serum T4 (4.5 – 11.5 μg/dL)
– T3 Resin uptake test (25%-35%)
– Thyroid antibodies
– Serum thyroglobin
• Radioactive iodine uptake test
• Fine-needle bx
• Thyroid scan, radioscan, or scintiscan

15. Hypothyroid Management
• Hormone replacement
• Adjust insulin or anti-diabetic agents as needed
• Use sedatives/hypnotic cautiously
• Supportive therapy
• Assisting with ADLs
• Monitor VS + cognition
• Promote comfort
• Enhance coping

16. Hyperthyroid Management
• Treatment depends upon underlying cause
– Pharmacotherapy
– Surgery
• Encourage adequate nutrition and fluid
balance
• Enhance coping and Improve self-esteem
• Maintain normal body temperature
• Monitor and manage complications

17. Thyroidectomy
Preoperative Preparation
• Diet high in CHO + Protein
• High caloric intake
• Supplemental vitamins
• Avoid stimulants
• Teaching to include
demonstration of how to
support neck
Postoperative Care
• Assess dressing for drainage
• Note complaints of pressure
or fullness at incision site
• Tracheostomy tray at
bedside
• Manage pain
• Semi-Fowler’s with head
supported
• IV fluids → cold liquids,
ice→ high calorie diet
• Keep items within reach

18. Thyroidectomy: Potential
Complications
• Hemorrhage
• Hematoma formation
• Edema of glottis
• Injury to recurrent laryngeal nerve
• Injury to or removal of parathyroid glands
– Tetany

19. Parathyroid Glands
• Embedded in posterior aspect of thyroid gland
• Secrete parathromone
– Output regulated by ionized serum calcium levels
– Regulates calcium and phosphorus metabolism
– Actions are enhanced by vitamin D
• Increased serum calcium levels can be life
threatening

20. Hyperparathyroidism
• Manifestations:
– Apathy, fatigue, muscle weakness, nausea,
vomiting, constipation, HTN, cardiac dysrhythmias
• Dx: ↑ serum calcium and ↑ PTH concentrations
• Management:
– Surgical removal if symptoms
– Monitor and wait if no sx
– Avoid dehydration
– Measures to prevent complications of immobility

21. Acute Hypercalcemic Crisis
• Extreme serum calcium elevation
• > 15 mg/dL → neurologic, cardiovascular, and
renal symptoms that can be life threatening
• Treatment:
– Rehydration
– Diuretics
– Phosphate treatment
• Emergency treatment to lower calcium

22. Hypoparathyroidism
• Manifestations: Tetany
– Latent: numbness, tingling, cramps in extremities, stiff hands and feet
– Overt: bronchospasm, laryngeal spasm, carpopedal spasm, dysphagia,
seizures, photophobia, cardiac dysrhythmias
• Dx: Positive Chvostek’s and Trousseau’s sign
• In acute hypoparathyroidism IV parathormone
• Limit environmental stimuli
• Trach, mechanical ventilation and bronchodilators
• Chronic: diet high in calcium and low in phosphorus
• Oral Ca gluconate, aluminum carbonate, vitamin D

24. Adrenal Gland Dysfunction:
Pheochromocytoma
• Tumor of the adrenal gland
• Usually benign
• Peak incidence between 40 and 50
• Symptoms triad: headache, diaphoresis and
palpitations
• Hypertension and cardiac disturbances common
• Acute, unpredictible onset with gradual resolution of
symptoms

25. Adrenal Insufficiency
• Adrenal cortex function
is inadequate to meet
the needs for cortical
hormones
• Primary: Addison’s
• Secondary
• What is the most
common cause of Acute
Adrenal Insufficiency?

26. Adrenal Crisis

27. Adrenal Crisis
Medical Management
• Immediate
– Reverse shock
– Restore blood circulation
• Antibiotics if infection
• Identify cause
• Supplement glucocorticoids
during stressful procedures
or significant illness
Nursing Management
• Assess fluid balance
• Monitor VS closely
• Good skin assessment
• Limit activity
• Provide quiet, non-stressful
environment

28. Cushing’s Syndrome
• Excessive adrenocortical
activity
• Most often due to
corticosteroid use
• Overnight
dexamethasone
suppression test
• Indicators: ↑ Na+ ↑
glucose ↓ K+

29. Cushing’s Syndrome
Medical Management
• Pituitary tumor
– Surgical removal
– radiation
• Adrenalectomy
• Adrenal enzyme inhibitors
– Metyrapone, glutethimide,
ketoconzole
• attempt to reduce or taper
corticosteroid dose
Nursing Managment
• Prevent injury
• Increased protein, calcium
and vitamin D in diet
• Medical asepsis
• Monitor blood glucose
• FOBT
• Moderate activity with rest
periods
• Provide restful environment

30. Primary Aldosteronism
• Profound ↓ K+ and H+
ions, ↑pH and HCO3
• Near normal or ↑ Na
• Universal sign: HTN
• Dx:
– Measurement of aldosterone
excretion rate after salt
loading
– Renin-aldosterone
stimulation test and bilateral
adrenal venous sampling
• Symptoms:
– Muscle weakness
– Cramping
– Fatigue
– Nonacid urine
– Polyuria
– ↑ serum osmolality
– Polydypsia
– Arterial HTN

31. Primary Aldosteroninsm
Medical Management
• Surgical removal
• Spironalactone for
persisitent HTN
• Monitor for fluctuations in
adrenal hormones
– Corticosteroids, fluids, agents
to maintain BP and prevent
complications
• Maintain normal serum
glucose
Nursing Management
• Frequently monitor VS
• Explain all procedures and
treatment
• Maintain comfort
• Provide rest periods

32. Blood Glucose Tests
Random Blood Glucose:
Measurement of blood glucose levels with no
regard/reference to the last meal
Fasting Blood Glucose:
Measurement of blood glucose levels after an
overnight fast.
Oral Glucose Tolerance Test (OGTT):
Assessment of glucose tolerance after ingesting a
glucose solution.
2-Hour Post-Prandial Glucose:
Measurement of blood glucose levels 2 hours after a
meal.

33. Glycosylated Hemoglobin Assay
Function:
Measurement of HbA1c levels in the blood.
Clinical Significance:
Assessment of long-term glucose control in
diabetes.
Interpretation:
Higher HbA1c levels indicate poorer glucose control.

34. Serum and Urinary Ketones
Function:
Measurement of ketone levels in the blood or urine.
Clinical Significance:
Diagnosis and monitoring of diabetic ketoacidosis
(DKA).
Interpretation:
Elevated ketone levels indicate metabolic
derangement.

35. References
1. Carl A. Burtis, David E. Bruns (2023) Tietz
Fundamentals of Clinical Chemistry, 9th Ed.
2. Lawrence A. Kaplan, Amadeo J. Pesce (2009)
Clinical Chemistry:
Theory, Analysis,Correlation, 5 th Ed.
3. Robert L. Sunheimer (2010) Clinical
Laboratory Chemistry.