Endocrine System & Hormones

• The endocrine system is comprised of glands that secrete hormones directly into the bloodstream.
• Hormone secretions and levels are directly related to bodily functions.
• Endocrine disorders are classified as:
  • Primary
  • Secondary
  • Tertiary
  • Quaternary

Endocrine Hormones Classifications

• Primary endocrine disorders involve dysfunction at the endocrine gland.
• Secondary endocrine disorders involve dysfunction of the anterior pituitary gland.
• Tertiary endocrine disorders involve dysfunction of the hypothalamus.
• Quaternary endocrine disorders include the inability of target tissues to respond to hormones.
• The endocrine system coordinates:
  • Sexual function
  • Blood glucose control
  • Metabolism
  • Growth and development
• Endocrine dysfunction often stems from the under or overproduction of select hormones.
• The endocrine system is linked to the nervous system through neuroendocrine regulation.
• Hormonal secretions are regulated through a negative feedback loop.
• The hypothalamus is located beneath the thalamus.
• Hypothalamic hormones work directly on other endocrine glands.

Pituitary Gland - Anterior

• The anterior pituitary is regulated by the hypothalamus
• Hormones secreted by the hypothalamus targets pituitary gland tissue
• The anterior pituitary gland secretes:
  • Two gonadotropin hormones
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Thyroid-stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Prolactin
  • Growth hormone (GH)
  • Melanocyte-stimulating hormone

Pituitary Gland - Posterior

• The posterior pituitary consists of nerve fibers.
• It's responsible for neuroendocrine reflexes.
• These reflexes cause hormone secretion in response to nervous system signals.
• The posterior pituitary secretes:
  • Antidiuretic hormone (ADH)
  • Oxytocin

Adrenal Glands

• Adrenal cortex makes up 90% of the adrenal gland.
• This gland secretes three types of hormones:
  • Mineralocorticoids (Aldosterone)
  • Glucocorticoids (Cortisol)
  • Androgens (Male sex hormones)
• The adrenal medulla is controlled by the sympathetic nervous system (SNS)
• It secretes: – Epinephrine – Norepinephrine
• Though epinephrine and norepinephrine are produced in the SNS, the adrenal medulla is not essential to life.

Thyroid Gland

• Located anteriorly, underneath the cricoid cartilage
• It produces three types of hormones: – Triiodothyronine (T3) – Thyroxine (T4) – Thyrocalcitonin (Calcitonin)
• T3 and T4 regulate: – Heart rate and contractility – Respiration rate and depth – Oxygen use – Glucose intake by cells – Glycolysis and enhanced gluconeogenesis – Protein synthesis and catabolism – Metabolization of fatty acids – Oxidation of free fatty lipids – Cholesterol and phospholipids

Parathyroid Gland

• Found partially embedded in the thyroid gland, possibly above the hyoid bone
• It secretes parathyroid hormone (PTH)
• PTH increases serum calcium through:
  • Bone reabsorption
  • Stimulates renal reabsorption of calcium
  • Stimulates activation of Vitamin D
• PTH decreases serum phosphate through:
  • Reabsorption of phosphate in the kidneys
  • Bone resorption
  • Small intestine absorption of phosphate

Gonads

• Sexual development and function depends on hormones secreted from sex organs.
• Testes
• Ovaries
• Sex organs are controlled by tropic hormones released from the anterior pituitary gland
• These hormones are based on gonadotropin-releasing hormone from the hypothalamus
• Males: FSH and LH = Testosterone
• Females: FSH and LH = Estrogen and Progesterone

Pancreas

• Located in the upper left quadrant of the abdomen and has both endocrine and exocrine functions.
• Islet cells control blood glucose through:
  • Insulin
  • Glucagon

Assessment

• History: – Comprehensive
• Includes family history and genetics.
• Physical assessment requires:
• Inspection (head to toe exam looking for specific manifestations)
• Auscultation (heart rate, rhythm, carotid and thyroid bruits)
• Palpation (thyroid and or testes noting size, shape, symmetry, nodules, and texture changes)
• Diagnostic studies include:
  • Lab studies to measure: – Serum hormone levels – TSH, T3, and T4 – Stimulation and suppression testing
  • Imaging includes: – CT – X-ray – MRI – Thyroid scan

Pituitary Gland Disorders

• Anterior:
  • Hypopituitarism
  • Hyperpituitarism
• Posterior:
  • Diabetes Insipidus (DI)
  • Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Hypopituitarism

• It involves the hyposecretion of hormones from the anterior pituitary gland.
• It may cause decreased body functions
• It's a rare disorder affecting less than 200,000 individuals in the U.S.
• Hypopituitarism is developed due to damage, compression, or inflammation of the pituitary, secondary to pituitary tumor, or damage to hypothalamus.

Pathophysiology

• Hormone deficiency of the anterior pituitary causes changes in metabolic or sexual function.
• The pathology depends on which hormone is deficient.
• Hormone deficiencies include:
  • Adrenocorticotropic hormone (ACTH) and decreased aldosterone and cortisol release.
  • Thyroid stimulating hormone (TSH) and decreased thyroid hormone.
  • Luteinizing hormone (LH) and growth hormone (GH) causing changes in sexual and reproductive functioning.
• Diagnostics include:
  • Suspected missing hormones
  • Hormonal studies and ACTH stimulation tests with TSH, FSH, LH, prolactin, and GH levels – CT or MRI to rule out tumor of brain or pituitary. – Blood testing for other causes of weakness.
• Medication and management includes:
  • Restoring hormone levels to normal, hormone replacement with corticosteroids, thyroid hormones, testosterone, or estrogen.
  • Supportive therapies like electrolyte replacement, Vitamin D, and Calcium.
• Complications:
• Panhypopituitarism or hyposecretion of all hormones from the hypothalamus.
• Lack of ACTH causing inability to maintain fluid volume and circulatory collapse.
• Lack of TSH causing decreased metabolism.
• Women with hormone replacement therapy with estrogen have risk for hypertension and DVT.
• Deficient anterior pituitary hormones can result in hypotension and circulatory issues related to ACTH causing decreased aldosterone production causing sodium and water loss through the kidneys.
• Nursing management involves:
  • Assessment and analysis of hormone deficiency
  • Nursing diagnoses and potential problems include:
    • Fluid volume deficit
    • Risk for injury
    • Impaired mobility
    • Hypoglycemia
    • Hyponatremia
    • Hyperkalemia
    • Osteoporosis
• Nursing interventions encompass:
  • Assessments of vital signs, serum glucose levels, fertility changes, and signs of decreased bone density .
  • Nursing actions/teaching involve safety measures, increased Vitamin D and Calcium, hormone replacement, physical therapy, dietitian consultation, teaching clinical manifestations for acute adrenal insufficiency, and teaching to emphasize taking supplements in the morning.

Hyperpituitarism

• It involves hypersecretion of hormones and often relates to hypersecreting tumors.
• Higher incidences are more likely in women and can occur in both children and adults, there may be a genetic link.
• Secondary to hypersecretion of hormone leading to specific dysfunction, this will be dependent upon the increased hormone.
• Diagnostics will focus on the hormone or target cells affected by the increased hormone:
  • ACTH Stimulation test
  • Measurement of: TSH, FSH, LH, Prolactin and GH – Head CT or MRI to check for a possible tumor? – Serum studies – Assess increased size of hands, feet, and broadening of facial bones.
• Medications can treat symptoms, reduce hormone secretion, and target glands with cell hyperfunction.
• Other Medications:
  • Dopamine agonists like Bromocriptine mesylate inhibit release of anterior pituitary hormones.
  • Growth hormone receptor blockers and somatostatin analogs inhibit GH release.
• If a tumor is present, medication can reduce size prior to removal.
• Surgical management options include: – Transsphenoidal hypophysectomy using sublabel transeptal approach or endoscopic approach – Stereotactic radiosurgery
• Potential complications include:
  • Increased ACTH, which causes, hyperglycemia, hypertension, and acromegaly.
  • Increased GH that triggers organ overgrowth in the heart, thyroid, liver, and kidneys.
  • Nerve entrapment, pain, changes in sensations, and surgical-related complications.
• Nursing management includes: – Patient assessment of specific hormones through table 41.3, along with neurological and vision assessment – Diagnoses depend on the increased hormone Symptoms: fluid volume excess, body image disturbance, pain, acromegaly, hyperglycemia, and hypertension Interventions: assessing vital signs, intake and output, daily weight, serum electrolytes
  • Teach importance of medications/treatments – Meds: dopamine agonists, somatostatin analogs, and hormone supplements, along with their process.

Post Transsphenoidal Hypophysectomy

• Post-Operative surgical management involves assessing through:
• Vital signs
• Neurological status
• Intake and Output
• Mucous membranes & mouth
• Urine Specific Gravity
• Serum Sodium and osmolality
• It is important take action through:
• Administering humidified oxygen
• Maintain IV access/administer IV Solutions
• Administer desmopressin or vasopressin as ordered
• Maintain HOB at 45-60 degrees
• Provide adequate oral fluids by providing mouth care
• Teaching includes:
• Signs of meningitis, Diabetes Insipidus, Use of a soft toothbrush, report any increased drainage from nose of clear fluid and avoiding certain activities.

Diabetes Insipidus (DI)

• DI Epidemiology
• It is a condition with Approx 30% of cases are Idiopathic and Approx 25% are secondary to brain tumors
• DI may occur after inter cranial, especially with Central DI
• Central Diabetes Insipidus is caused by decreased secretion of ADH.

Pathophysiology

• Minimal to no ADH production in hypothalamus
• Water reabsorption for circulation
• ADH decreases permeability therefore, increased excretion from kidneys via fluid volume and diluted urine

Clinical Manifestations

• Weight Loss, Polyuria, Polydipsia, Nocturia, and Hemoconcentration (Increased serum Sodium serum AND Hematocrit).
• Hypovolemia
• Hypotension Tachycardia
• Fluid volume deficit
• Thirst
• Skin Turgor
• Fatigue
• Diagnosis
• Serum Sodium(Na+) Electrolyte, decreased Urine
• Blood Serum Electrolyte, due to increased urine, due to hemoconcentration therefore, increased
• Urine osmolality greater than 200, and Urine specific gravity greater than 1.005
• Treatment
• Serum Electrolytes
• A and O x4 oral/ fluid replacement
• Unconscious pt emergency IV fluid
• Hypotonic Fluids such as Dextrose in water an and 45% NS, and with this the monitoring of hyperglycemia, volume overload, hypernatremia and volume status
• Vasopressin may cause an increased action, so frequent monitoring of fluid status and urine electrolytes is key to determining severity
• DDVAP Primary choice Q subq, Intranasal

Nursing Diagnosis & Action

• Assessment
• Assessment of fluid loss in Pt.
• Assess lab for decreased BP.
• Assess levels- low due to volume elevated for compensation and polyuria.
• Assess levels- low due to volume elevated for compensation & polyuria
• Diagnoses:
• Hypernatremia and Ineffective Volume deficit & Decreased Volume.
• Actions:
• Assess IV assess with prescribed fluids, and the the use desmopressin with Vasopressin
• Patient teaching to the the importance of their medications, weights etc for early interventions
• Assess Pt and lab for changes

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

• Epidemiology: related to an increased ADH which is causes CNS disorders ( tumors in brain or neck), Medications side effects (NSAIDS), Psychotropic meds, and bronchogenic carcinoma.
• Pathophysiology: ADH=Overload of Water causing hemodilution (Hyponatremia and hypo-osmolality).

Clinical Manifestations

• Hyponatremia-Sodium < 120 mEq/L can cause confusion and headache & Seizures leading to come & increase Intercranial pressure:

Diagnosis

• Electrolytes: assess levels
• Fluid excess, headache, confusion, and irritation
• Assessment: monitor oliguria S/S and monitor any S/S Hyponatremia

Actions

• Restrict fluid, diuretics, and 3% sodium as ordered

Hypothyroidism

• TSH is controlled by the anterior pituitary gland and hypothalamus
• Can be associated with: – Autoimmune disease
  • Hashimoto's thyroiditis – Thyroid surgery – Radioactive iodine therapy for hyperthyroidism – Iodine and Tyrosine deficiencies - Not typical due to Iodized salt in the US

Pathophysiology

• Hallmark Sign: Decreased Metabolism
• Developments due to disorder of the thyroid and anterior pituitary gland

Clinical Manifestations

• Energy
• Sleep
• Hair & Skin changes ( loss & brittle)
• Susceptibility to cold

Key Diagnosis/Treatments

• Labs- low levels of T3 & T4
• Hashimotos testing- increased TSH
• Medical management includes: – Secondary and Tertiary Hypothyroidism that requires the regulation of TSH levels and may require the increased the use of hormone treatments like Levothyroxin and monitoring any anginas and CHF.

Complications

• Myexedema Coma with decreased cardiac function
• Hypothermia leading to a Hypoglycemia and Pt is very sensitive. This require Analgesics, Anesthetics, and supportive treatment from medical team
• Assess: symptoms and any non putting edema and any tone with difficulty.
• Actions include: assessment, and the treatment like – Oxygen saturation and the constant patient monitoring with turning and skin prep

Hyperthyroidism

Key Points

• High instances in all women aged 20-40 y/o and grave disease is also common
• caused by several issues (thyroid disease
• and TSH issues: Key Actions include: High T3/4: Goal: Control function body
• Beta Check with HR and Palpations in high hyper, as well as control stress.
• Medical management includes: – Monitoring the T3/T4 levels/ TSH
• Thyroid/Surgery the scan Monitor what medication to give while assessing patient and reporting
• Monitor symptoms; especially respiratory complication