Endocrine

HPA Axis

hypothalamus secretes releasing hormones that stimulate pituitary to release potent hormones that cause glands (adrenals) to function

Adrenals

medulla releases epinephrine and norepinephrine; cortex secretes mineralocorticoids and glucocorticoids

T3 and T4

thyroid gland hormones that increase metabolic rate, oxygen consumption, glucose consumption, body temp, over growth + development

Calcitonin

thyroid gland hormone that controls concentration of calcium in the blood and increases effects of SNS

PTH

controls plasma calcium levels

Mineralocorticoids

Adrenal gland hormone that maintains fluid balance and increases sodium reabsorption in the kidneys

Glucocorticoids

adrenal hormones that regulate metabolism and resist effects of stress in multiple tissues

Catecholamines (epinephrine and norepinephrine)

adrenal hormones that control SNS response

Somatostatin

pancreas hormone that inhibits release of growth hormone in multiple tissues

Diabetes Insipidus

can result from decreased tubular response to ADH/pituitary tumor; leads to increased UO, dehydration, increased thirst

Tx of DI

hormone replacement therapy with Desmopressin

SIADH

Posterior pituitary gland dysfunction and overproduction of antidiuretic hormone [ADH] into the central circulation causing excess water retention and low Na+; water intoxication and hyponatremia can cause cerebral edema, seizures, and death

SIADH causes

certain malignant tumors, pancreatic cancer, lymphoma, prostate cancer; diagnosis includes UA that shows high specific gravity

SIADH Treatment

remove any suspect medications, fluid restrictions, close monitoring of electrolytes; pt is given IV hypertonic saline if Na is not raised

Thyroid Hormone Negative Feedback

• low levels of T3/T4 or BMR = stimulus

• hypothalamus releases TRH

• TRH stimulates thyroid to release T3 and T4

• levels of T3 and T4 shut off hypothalamus and anterior pituitary

Hypothyroidism RF

insufficient iodine intake, exposure to high levels of radiation, certain medications

Hypothyroidism

presents w fatigue, weight gain, constipation, fertility issues, dry hair, edema around eyes, enlarged tongue, goiter, hypothermia

Hypothyroidism Assessment

elevated TSH and decreased free T4; management includes replacement of thyroid hormone and usually use Levothyroxine

Hyperthyroidism

overproduction of thyroid hormones - can be caused by Grave’s disease or toxic nodules

Hyperthyroidism S+S

tremors, palpitations, insomnia, weight loss, weakness; goter/thyroid bruit, warm/moist skin; labs reveal decreased TSH and increased free T4

Hypoparathyroidism symptoms

positive Chvostek’s and Trousseau sign; ridged fingernails, hoarseness; low Calcium and low PTH and elevated PO4

Addison’s Disease

decrease cortisol and mineralocorticoids usually from autoimmune dysfunction of the tissues of the adrenal glands; pt presents with poor activity intolerance, weakness, fatigue, anorexia, N/V, cold intolerance, craving for salt

Addisons’s Disease Physical Exam

pt appears dehydrated, weight loss, weak pulses, hyperpigmentation of skin, loss of pubic hair; decreased cortisol levels, elevated K and low NA, hypoglycemia, elevated ACTH

Hypercortisolism —- Cushing’s Disease

increased production of steroid hormone usually from overabundance of ACTH or cortisol or mineralcoritcoids

Cushing’s Disease Physical Exam

truncal obesity with thin extremities, moon face, thin fragile skin, reddish straie, edema of BLE, elevated BP; diagnosed is 24 hour urine for free cortisol, elevated cortisol, low K and CT of pituitary and Arenal glands

Cushing’s Disease tx

lifelong necessity hormone replacement

Adrenal Crisis

can occur from rapid withdrawal of steroid hormones from surgical intervention or aggressive medication; pt develops low BP, tachycardia, decreased LOC

Pheochromocytoma

usually benign tumor that is catecholamine secreting and can trigger life threatening HTN, hyperglycemia, HF, renal damage, stroke

Type 2 Diabetes

insulin resistance with insulin excess; more common in adults and increases with age + assciated with obesity and genetics

Type 1 Diabetes

primary beta cell destruction leads to absolute insulin deficiency; pt will die without insulin injections

Diabetes Risk Factors

obesity, alcoholism, genetics, sedentary

DM symptoms

weight loss, fatigue, vision changes, inconitencne, non-healing wounds, polydipsia (excessive thirst), polyuria, polyphagia (excessive hunger)

Hgb A1C

measures average blood sugar levels over past 2 months; 5.7 - 6.4 % is pre-diabetic

Sulfonulureas for Type 2 DM

stimulates pancreatic B cells to secrete more insulin

Biguanides for Type 2 DM

decreases overproduction of glucose by liver

Thiazolidndiones for Type 2 DM

reduces insulin resistance and increases insulin receptors on cell membranes

Rapid Acting Insulins

Lispro, Aspart, Glassine; onset is 5-15 minutes and 3-4 duration; better control of postprandial and less risk of nighttime hypoglycemia; can use within 5-15 min of meals

Short Acting/Regular Insulin

30-60 min onset and 6-8 duration

Intermediate Insulin

NPH; 2-4 onset and 10-16 hour duration; can be mixed with rapid acting

Insulin Pump Advantages

eliminates individual insulin injections and delivers more accurately, fewer large swings in glucose levels, improves quality of life, allows more flexibility with meals

Insulin Disadvantages

pricey, can cause weight gain, can cause DKA, hospital stay for training

Complications of Diabetes

blindness from changes in blood flow and ischemia to retina, renal failure from prolonged hyperglycemia, neuropathy ; HTN, CAD, stroke (from atherosclerosis and alterations in circulation); higher risk for infection and slower wound healing

Lifestyle Modifications for Diabetes

healthy weight, maintain blood glucose, follow diabetic diet, track carbs, routine Hgb A1C, monitor BP, reduce stress, quit smoking, reduce alcohol

A1C levels

<5.7% normal, 5.7-6.4% pre diabetic, above 6.5 % is diabetic; goal for most diabetics is <7 %

DKA

insufficient insulin present for cells to attain sufficient glucose + body attempts to obtain energy by breaking down fat stores and releasing fatty acids that are converted into ketone bodies for energy; ketone bodies have a low pH = metabolic acidosis, causing severe hyperglycemia

Causes of DKA

not taking insulin, not taking enough, new diagnosis of type 1

DKA Presentation

polyuria, polydipsia, polyphagia, fruity breath, dehydration, hypotension, N/V, lethargy

Diagnosis and Treatment of DKA

BG > 250, ketonuria, serum pH < 7.3, bicarb <15, positive anion gap; treat w insulin, fluid replacement (0.9% NS), correct electrolyte imbalances