Endocrine Nursing
Review diabetes mellitus, DKA, thyroid disorders, adrenal disorders, and pituitary disorders for NCLEX.
Endocrine Nursing
The endocrine system regulates metabolism, growth, reproduction, and homeostasis through hormonal signaling. NCLEX questions on endocrine disorders frequently test knowledge of diabetes management, thyroid emergencies, and hormonal imbalances. Mastery of these concepts is essential for the Physiological Integrity domain.
Diabetes Mellitus: Type 1 vs. Type 2
| Feature | Type 1 Diabetes | Type 2 Diabetes |
|---|---|---|
| Pathophysiology | Autoimmune destruction of pancreatic beta cells; absolute insulin deficiency | Insulin resistance with progressive beta cell dysfunction; relative insulin deficiency |
| Onset | Usually childhood/adolescence; can occur at any age | Usually adults over 40; increasingly seen in younger populations |
| Body habitus | Typically thin | Often overweight or obese |
| Treatment | Insulin is always required | Lifestyle modifications, oral hypoglycemics, may progress to insulin |
| Ketosis risk | High (prone to DKA) | Low (more prone to HHS) |
| C-peptide level | Low or absent | Normal or elevated initially |
Insulin Types and Administration
| Insulin Type | Onset | Peak | Duration | Examples |
|---|---|---|---|---|
| Rapid-acting | 10-15 min | 1-2 hours | 3-5 hours | Lispro (Humalog), Aspart (NovoLog) |
| Short-acting (Regular) | 30-60 min | 2-4 hours | 6-8 hours | Regular insulin (Humulin R, Novolin R) |
| Intermediate-acting | 1-2 hours | 6-12 hours | 18-24 hours | NPH (Humulin N, Novolin N) |
| Long-acting | 1-2 hours | No pronounced peak | 24+ hours | Glargine (Lantus), Detemir (Levemir) |
Key insulin administration points:
- Rotate injection sites within the same anatomic region to promote consistent absorption
- The abdomen provides the fastest and most consistent absorption
- When mixing insulins: draw up clear (Regular) before cloudy (NPH) -- remember "clear before cloudy"
- Never mix long-acting insulin (glargine, detemir) with any other insulin
- Regular insulin is the only type that can be given intravenously
- Store opened insulin vials at room temperature for up to 28 days; store unopened vials in the refrigerator
DKA vs. HHS
| Feature | Diabetic Ketoacidosis (DKA) | Hyperosmolar Hyperglycemic State (HHS) |
|---|---|---|
| Type of diabetes | Primarily Type 1 | Primarily Type 2 |
| Onset | Rapid (hours to days) | Gradual (days to weeks) |
| Blood glucose | Greater than 250 mg/dL | Greater than 600 mg/dL |
| Ketones | Present in blood and urine | Minimal or absent |
| pH | Less than 7.30 (metabolic acidosis) | Greater than 7.30 |
| Serum osmolality | Variable | Greater than 320 mOsm/kg |
| Breathing | Kussmaul respirations (deep, rapid), fruity breath odor | No Kussmaul respirations |
| Dehydration | Moderate | Severe |
| Mortality | Lower (less than 5%) | Higher (up to 20%) |
| Treatment priority | IV fluids, IV regular insulin drip, potassium replacement | Aggressive IV fluid resuscitation first, then insulin |
Critical DKA management points: Always check potassium before starting insulin. Insulin drives potassium into the cells; if the patient is hypokalemic, insulin could cause fatal cardiac arrhythmias. Replace potassium first when serum K+ is below 3.3 mEq/L. When blood glucose reaches 250 mg/dL, change IV fluids to dextrose-containing solutions to prevent hypoglycemia while continuing insulin to clear ketones.
Hypoglycemia vs. Hyperglycemia
Hypoglycemia (blood glucose less than 70 mg/dL): Signs include tremors, diaphoresis, tachycardia, confusion, irritability, hunger, and pallor. Treat conscious patients with 15-20 grams of fast-acting carbohydrates (4 oz juice, glucose tablets), recheck in 15 minutes, and repeat if still low (Rule of 15). For unconscious patients, administer IV dextrose 50% or IM glucagon. Hypoglycemia is more immediately dangerous than hyperglycemia.
Hyperglycemia (blood glucose greater than 250 mg/dL): Signs include polyuria, polydipsia, polyphagia, blurred vision, fatigue, and weight loss. This develops gradually compared to the rapid onset of hypoglycemia.
Thyroid Disorders
| Feature | Hypothyroidism | Hyperthyroidism |
|---|---|---|
| Metabolism | Decreased | Increased |
| Weight | Gain | Loss |
| Heart rate | Bradycardia | Tachycardia, atrial fibrillation |
| Temperature tolerance | Cold intolerance | Heat intolerance |
| Skin | Dry, coarse, cool | Warm, moist, smooth |
| GI function | Constipation | Diarrhea |
| Energy level | Fatigue, lethargy | Restlessness, insomnia |
| Treatment | Levothyroxine (Synthroid) | Methimazole, propylthiouracil (PTU), radioactive iodine, surgery |
Thyroid storm is a life-threatening exacerbation of hyperthyroidism triggered by infection, surgery, or trauma. Signs include severe tachycardia, high fever (greater than 104 degrees F), delirium, and cardiovascular collapse. Treatment includes PTU, beta-blockers, corticosteroids, cooling measures, and supportive care. This is a medical emergency.
Myxedema coma is the severe, decompensated form of hypothyroidism. Signs include hypothermia, bradycardia, hypoventilation, hypotension, and altered mental status. Treatment includes IV levothyroxine, IV corticosteroids, rewarming, and hemodynamic support.
Post-thyroidectomy nursing care: Assess for hemorrhage (check behind the neck for pooling blood), respiratory distress (laryngeal edema or nerve damage), hypocalcemia (Trousseau's and Chvostek's signs due to accidental parathyroid removal), and keep a tracheostomy tray and calcium gluconate at the bedside.
Adrenal Disorders
| Feature | Cushing's Syndrome (Excess Cortisol) | Addison's Disease (Cortisol Deficiency) |
|---|---|---|
| Appearance | Moon face, buffalo hump, truncal obesity, thin extremities, striae | Weight loss, hyperpigmentation (bronze skin) |
| Blood pressure | Hypertension | Hypotension (orthostatic) |
| Blood glucose | Hyperglycemia | Hypoglycemia |
| Sodium | Hypernatremia | Hyponatremia |
| Potassium | Hypokalemia | Hyperkalemia |
| Immunity | Immunosuppression, increased infection risk | Normal immune function |
| Treatment | Reduce or discontinue exogenous steroids, surgical removal of tumor | Lifelong corticosteroid replacement (hydrocortisone), mineralocorticoid (fludrocortisone) |
Addisonian crisis is an acute, life-threatening adrenal insufficiency triggered by stress, infection, or abrupt steroid withdrawal. Presents with severe hypotension, dehydration, hyperkalemia, and hyponatremia. Emergency treatment includes IV hydrocortisone and aggressive fluid resuscitation. Teach patients to never abruptly discontinue corticosteroids and to increase doses during illness or stress.
Pituitary Disorders: SIADH vs. DI
| Feature | SIADH (Excess ADH) | Diabetes Insipidus (Deficient ADH) |
|---|---|---|
| Fluid status | Fluid retention (dilutional) | Massive fluid loss |
| Urine output | Decreased, concentrated | Increased (up to 20 L/day), very dilute |
| Serum sodium | Hyponatremia (dilutional) | Hypernatremia (dehydration) |
| Serum osmolality | Decreased | Increased |
| Urine specific gravity | Greater than 1.030 | Less than 1.005 |
| Treatment | Fluid restriction, hypertonic saline (3%) for severe cases, demeclocycline | Desmopressin (DDAVP), fluid replacement |
Remember: SIADH = Saturated (fluid overload), DI = Dry (dehydrated).
Sick Day Rules for Diabetes
- Never omit insulin, even if unable to eat (the body produces more glucose during illness)
- Monitor blood glucose every 2-4 hours
- Test urine for ketones (Type 1) if blood glucose is greater than 240 mg/dL
- Maintain adequate fluid intake
- Contact the healthcare provider if blood glucose remains above 240 mg/dL, ketones are present, or if unable to keep fluids down
NCLEX Endocrine Focus Points
- Check potassium before starting an insulin drip for DKA
- Hypoglycemia is more immediately dangerous than hyperglycemia -- treat first, then investigate the cause
- Thyroid storm and myxedema coma are medical emergencies with opposite presentations
- Cushing's and Addison's have opposite lab values -- create a comparison chart
- Never stop corticosteroids abruptly; taper gradually
Review the Endocrine Nursing Cheat Sheet for rapid reference, and quiz yourself with Physiological Integrity flashcards.