Endocrine Disorders Flashcards
What is thyroid crisis (storm)?
- Book calls it Thyrotoxicosis
- An acute, severe, and rare condition that occurs when excessive amts. of thyroid hormones are released into circulation.
- Severe form of hyperthyroidism
- Physical or psychological stressors (possible cause)
Thyroid Crisis Etiology
- Thought to result from stressors (e.g., infection, trauma, surgery) in a patient w/ pre-existing hyperthyroidism (diagnosed or undiagnosed)
- Patients prone to thyroid crisis = those having thyroidectomy
- manipulation of hyperactive gland = increase in hormones released.
- Patients prone to thyroid crisis = those having thyroidectomy
Pathophysiology of Thyroid Crisis
- Unsure
- Massive release of Thyroid Hormone
- Low tissue tolerance to triiodothyronine (T3) and thyroxine (T4)
- Release leads to hypermetabolic state – stimulation of the sympathetic nervous system
Clinical Manifestation of Thyroid Crisis
- Sweating
- Heat intolerance
- Nervousness
- Tachycardia
- Wide Pulse Pressure
- Body Temp > 104o F without infection
- Seizure, Tremors
- Coma
Previous medical Hx most often associated w/ thyroid crisis
Grave’s Disease
Lab studies showing patient is in Thyroid Crisis?
- Elevated Total T4 and free T3 and T4
- Very low TSH
- Due to the elevated levels of thyroid hormoneo Decreased K+ and Mg+o Elevated Ca++
- LFTs (liver function test) may be elevated
- Hyperglycemia
- Insulin resistance and breakdown of stored glucose
Management of thyroid crisis
4 Fold:
-
Precipitating Factors
- Stress, Trauma, MI, Shock
- Controlling Excessive Thyroid Hormone release
-
Inhibiting Thyroid Biosynsthesis
- Conversion of TH to T3 and T4
- Treat peripheral effects
Drugs that Block Thyroid Synthesis
- Propyithiouracil (PTU)
- Methimazole
Drugs that Suppress release of TH
- Sodium Iodide
- Potassium iodide
- Saturated solution of potassium iodine (SSKI)
- Dexamethasone (Glucocorticoid Steroid)
- Inhibit thyroid hormone release
Beta Blocker used to treat Thyroid Crisis? How does it work?
- Propranolol (Inderal)
- Restore cardiac function
- Decreases catecholamine-mediated symptoms
Other drugs used in the treatment of Thyroid Crisis?
- Digoxin
- Dilitazem
- Lasix
- Tx’s CHF, tachydysrhythmias
- Decrease myocardial O2 consumption and heart rate
- Tx’s CHF, tachydysrhythmias
Emergency removal of excess circulation or hormone - How is it done?
- Plasmapherisis
- Dialysis
- Cholestyramine – oral
- Absorbs excessive hormone
Management goals of Thyroid Crisis?
- Reducing circulating thyroid hormone levels and clinical manifestations w/ appropriate drug therapy
- The ultimate goal is to avoid reoccurrence
- Identify triggers
- Life long medications to suppress thyroid hormone
- Thyroid Ablation
Thyroid Crisis Supportive Therapy
- Manage respiratory distress
- manage multi-system effect and responses to treatment -hourly!!
- Reduce fever
- Replace fluid
- Eliminate/manage initiating stressor
Thyroid Crisis - Managing Cardiovascular status
- HR – Rhythm – Heart sounds – BP
- D5NS to treat hypovolemia
Thyroid Crisis - managing body temperature
- Antipyretics
- Acetaminophen – Not ASA
- Increases free T3 and T4
- Tepid Baths
- Do not bring to shiver - ↑ Body temperature
Thyroid crisis- neurologic status
- Seizure precaution
- ↓ LOC may lead to obstructed airway
Thyroid Crisis - Radioiodine/RAI Therapy
- RAI therapy
- Definitive therapy
- Will make patient Hypothyroid
- Excreted in the urine - saliva
- Over a few dayso
- Do not share foods, drinkso
- Do not get close to children
- Definitive therapy
How long does the acute phase of thyroid crisis last?
24-48 hours
HYPOthyroidism Etiology
- Low levels of thyroid hormone
- Congenital – cretinism
- Detected at birth
- Primary thyroid failure
- Hashimoto’s disease
- Thyroiditis
- Low basal metabolic rate
What is Myxedema Coma?
- Severe form of hypothyroidism
- Untreated hypothyroidism
Precipitation factors of Myxedema Coma?
- Drugs (esp. opioids, tranquilizers, & barbiturates)
- Extreme cold
- Sedatives
- Surgery
- Opioids
- Infection
- Trauma
Signs and Symptoms of Myxedema Coma
- Comatose
- Hypothermic
- Respiratory failure
- R/T muscle weakness
- Sleep apnea
- Cardiac failure
- R/T bradycardia
- Decreased stroke volume
Significance of slowed drug metabolism and Myxedema Coma?
- Potential drug toxicity
- Digoxin
Myxedema Coma Treatment
-
Supportive
- Ventilator
- Fluids
- Warming blankets – slowly
- Thyroid Hormones
- T3 and T4
-
Hydrocortisone – IV
- If patient also has adrenal insufficiency
Adrenal Gland - Medullary hormones
-
Dopamine
- Precursor of Norepinephrine (increase BP)
-
Norepinephrine
- ↑ PVR ( peripheral vascular resistance)
-
Epinephrine
- Fight of Flight (HR Increase, dilates eyes, gets body ready to go)
-
Opioid peptides
- Not exactly to sure how they work.
Cortical hormones
- Mineralocorticoids
- Kidney
- Glucocorticoids
- Metab of fat, charbohydrates, protein
Cushing’s Sydrome
- results from chronic exposure to excess corticosteroids, particularly glucocorticoids.
- Conditions causing CS: most common = iatrogenic adminstration of exogenous corticosteroids (e.g., prednisone)
- Excess circulation of glucocorticoids
-
Pituitary tumor 60%
- increased Adrenocorticotropic hormone (ACTH)
- Primary Adrenal neoplasm/hyperplasisa 25%
-
Ectopic ACTH or CRH (corticotropin-releasing hormone) 15%
- Pulmonary tumors
- Women > Men
Iatrogenic
of or relating to illness caused by medical examination or treatment.
Cushing’s Sydrome Diagnostic Tests
- 24 hour urine free cortisol
- Best for dx Cushing’s syndrome
- Day 1 collect second void and remaining voids
- Day 2 collect just AM void
- Normal: 10-100 mcg/24 hours
- Increased levels – Cushing’s
- Decreased levels – Addison’s
-
8 mg overnight dexamethasone (for borderline levels) suppression test
- Day 1 – 8 am cortisol level
- Take 8 mg dexamethasone at 11 pm
-
Day 2 – Collect blood at 8 am for cortisol level
- Pituitary Cushing’s 50% reduction of morning serum cortisol
Medications for Cushing’s Syndrome
- If patient fail surgical treatmen
-
Inhibit cortisol production in the adrenal glands
- Ketoconazole
- Metyrapone
- Aminoglutethemide
- Mitotane
- Must identify the cause first:
- Pituitary Cushing’s
- Transsphenoidal surgery
- Irradiation
- Gamma Knife
- Adrenal Tumor
- Adrenalectomy - increased risk for adrenal crisis
- Ectopic
- Surgery/radiation
- Pituitary Cushing’s
-
Inhibit cortisol production in the adrenal glands
Adrenal Insufficiency
hypodisfunction of adrenal cortex
Adrenal Insufficency - Primary vs. Secondary cause
Addison’s Disease
- West – autoimmune causes -adrenal tissue destroyed by abs agains pt’s own adrenal cortex
- All three classes of adrenal corticosteroids are reduced (gluco-, mineral-corticoids, and androgens)
- Gradual destruction of the adrenal glan
- World wide
- TB
- Destruction of the Adrenal gland
Secondary adrenal insufficiency
- Lack of ACTH secretion (corticosteroids and androgens are deficient, but mineral corticosteroids rarely are)
- Alteration in any step of the hypothalamic-pituitary-adrenal axis
- Can be temporary or permanent
Secondary causes of Adrenal Insufficiency
- Iatrogenic (induced by physician)
- Abrupt withdrawal of exogenous adrenocorticotropic hormones (ATCH)… or
- Complications of cortisol therapy
- qCortisol therapy → ↓ATCH secretion by disrupting the natural feedback loop → acute adrenal insufficiency.
- Other secondary causes
- Metastatic carcinomas
- Lung
- Breast
- Pituitary infarct
- Surgery
- CNS Disturbances
- Basilar Skull Fracture
- Meningitis
- Metastatic carcinomas
Chronic Adrenal Insufficiency Treatment
Chronic Adrenal Insufficiency
- Hydrocortisone
- Usually 2/3 in AM
- 1/3 in PM
- Mimics the natural body
- Mineralocorticoid
- Fludrocortisone (Florinef)
Adrenal crisis (aka addisonian crisis or acute adrenal insufficiency)
- Rare – Life threatening emergency caused by insufficient adrencorticol hormone or a sudden sharp decrease in the hormones
- Dysfunction of the adrenal cortex
- Hypoadrenalism
- Hypocorticism
- Primary vs Secondary
- Primary – involves the adrenal gland
- Secondary – related to some other cause
- Hypothalmic-pituitary disease
Initial symptoms of Adrenal Crisis?
- Initially
- N/V/D
- Weakness
- Fatigue
- Anorexia
- Abdominal Pain
- Initial Symptoms
- Non-specific until linked with past history of AI or recent use of corticosteroid
- > 20 mg hydrocortisone for 7 – 10 days
- Suppression of hypothalmic-pituitary-adrenal feedback
Signs of Adrenal Crisis
Severe Dehydration
- Weight Loss
- Orthostatic hypotension
Dehydration is related to nephrons inability to reabsorb sodium and water
Other S/S of Adrenal crisis
- Tachycardia
- Orthostatic HTN
- Headache
- EKG changes associated with ↑K+
- Hyperpigmentation
Lab findings of Adrenal Crisis
Aldosterone Deficiency
- Hyperkalemia
- >5mEq/L
- Hyponatremia
- <130mEq/L
- Hypovolemia
- Elevated BUN/CR
Cortisol Deficiency (milder):
- Hypoglycemia
- Decreased gastric motility
- Decreased vascular tone
- Hypercalcemia
prim & sec? = anemia and leukocytosis - eosonophils?
ATCH levels
Elevated -= primary adrenal insufficiency,
norm/low = secondary
Other Tests - Adrenal Insufficiency
CT of Head & CT of Adrenals
Adrenal Crisis Management Goals
- Administer needed Hormones
- Restore fluid and electrolyte balance
- Hormone Replacement
- Hydrocortisone
- 100 mg IV q 6 – 8 hours for 24 hours
- Glucocorticosteroids (prednisone & decadron) cause further loss of sodium….
- DO NOT USE
- Hydrocortisone
- Fluid Replacement
- Normal Saline
- Dextrose
- Vasopressors
- To use or not to use???
- Are not effective until the patient is adequately hydrated.
- To use or not to use???
Pituitary Tumors
- Also called adenomas
- Hyperfunction
- Anterior Pituitary Gland
- May involve 1 or more hormones
Pituitary Tumor Classification
- Size
- Macroadenomas - > 10 mm in diameter
- Microadenomas - <10 mm in diameter
- Hormone Production
- Prolactin – 60%
- Growth Hormone – 20%
- ACTH – 10%
- Others – 10%
Prolactin Hypersecretion associated with Pituitary Tumors
- Decreased testosterone
- Loss of Libido; ED
- decreased sperm count
- Gynecomastia – rare galactorrhea
- Decreased Estradiol -
- Irregular menses
- Infertility
- Galctorrhea
- Ectopic Causes
- Dopamine antagonists
- Chronic Renal Failure
- Decreased clearance
- Neurogenic secretion
- Chest trauma, thoracotomy, herpes zoster
- Hypothyroidism
- Medications• Page 1062 Box 38-1
Growth Hormone (Acromegaly)
- Macroadenomas -> Ha = headaches
- Facial Features
- Coarsening of features
- Increased size of nose, lips, and skin foldso
- Coarsening of features
- Increase size of hands and feet
- Deepening voice
- Increase vertebral bodies -> kyphosis
Diagnosis –Prolactin Hypersecretion
- Based on History
- Galactorrhea
- Irregular menstrual cycle
- Infertility
- Gonadal Dysfunction
- Prolactin Levels
- Normal – 20 ng/ml
- Medication - <150 ng/ml
- Tumor - >150 ng/ml
Diagnosis of GH Hypersecretion
Clinically obvious
Confirmed by GH levels
