Endocrine Flashcards
Endocrine system
Includes pituitary gland, hypothalamus, adrenal glands, thyroid gland (and others).
Regulate growth, metabolism, sexual development.
Serum osmolality
275-295 mOsm/kg
(about double normal Na level)
Helps maintain fluid balance.
Measure of solute in relation to available fluid or plasma.
If >295, pt is volume depleted (high = dry)
…body will attempt to retain fluid by releasing ADH.
If <275, pt os volume overloaded and body doesn’t release ADH
SIADH
Too much ADH is released.
Pt retains water.
Oliguria (decreased output)
…will have high specific gravity (>1.030)
Dilutional hyponnatremia
Serum osmolality <270
Edema is NOT present
Neuro sx caused by cerebral edema
Pulmonary edema and dyspnea
Causes:
carcinoma of the lung
…produces a substance like ADH
Head problems
…trauma, tumors, CVA, meningitis
Hypoxemia
Nephrogenic causes
…anesthetics, narcotics, Tylenol, anticonvulsants
SIADH treatment
Fluid restriction
Consider hypertonic saline
…1-2mL/kg/hr until asymptomatic
Raise serum sodium 0.5mEq/L per hour
Can raise Na faster if the drop was faster
Consider lasix 1mg/kg
Avoid hypotonic solutions
Don’t use D5W
Diabetes Insipidus
Opposite of SIADH - not enough ADH
Constant urination (polyuria)
Low urine specific gravity (clear)
Dehydration
Elevated serum Na
Elevated serum osmolality
Causes:
head injury, infection, tumors, lithium, dilantin
Results in:
Hypovolemia, shock, electrolyte imbalances
Treatment of Diabetes Insipidus
Aggressive IV fluid replacement.
Raise sodium slowly
Consider vasopressin (synthetic ADH)
Monitor urine specific gravity and cardiac changes.
DKA
Not enough insulin, body breaks down fat
…Buildup of ketones
Leads to acidosis.
Characterized by hyperglycemia, dehydration, and acidosis.
Acidosis with elevated glucose is an indication of DKA rather than HHS
Symptoms:
Acidosis (elevated ketones)
Ketones can cause fruity breath
Kussmaul respirations (rapid, shallow to breath off CO2
Increased serum osmolality
Dilutional hyponatremia.
Potassium loss from inside cell to oudside cell (trying to offset hydrogen
…potassium may be elevated initially
Hypokalemia is most common cause of death
For every 100mg/dL glucose over 100, serum sodium decreases by 1.6 mEq/L
DKA treatment
Aggressive fluid: 100-150mL/kg
…1/2 in first 8-12 hrs and rest in 16-24hr
Switch to D5NS when glucose = 300
Insulin drives glucose, K, and H2O back into cells, so if they haven’t been hydrated they could go into circulatory collapse.
When managing DKA, focus on treating acidosis prior to administration of insulin.
…focus on improving acidosis, not glucose.
Prevent hypokalemia
Add 10-40 mEq/L/hr to fluids
Add insulin after hydrating and managing K
0.1 units/kg bolus. Same dose/hr drip
Don’t reduce glucose > 100mg/dL/hr
…glucose is a large molecule; water follows it easily which can cause fluid to third space back into the tissue, especially the brain…causing cerebral edema.
Bicarb will be low due to metabolic acidosis but not routinely given because when insulin is given, lactate and ketones will be metabolized into bicarb.
Corrected Sodium (DKA)
measured sodium + (serum glucose-100)0.016
Hyperosmolar Hyperglycemic State (HHS)
Similar to DKA but these pts still have some insulin…aren’t breaking down fatty acids
Acidosis NOT present
Blood sugar range 1000-2000
…Takes longer for sx to present themselves
Dehydration
HHS treatment
Aggressive fluid (1-2L in first 2 hrs)
Switch to 1/2NS once blood pressure and urine output stabilize.
Switch to D5NS when glucose = 300
Add insulin 0.1units/kg bolus, same dose/hr drip
Do not reduce glucose >100 mg/dL/hr
Prevent hypokalemia
…start K replacement at 5 or less because giving insulin will cause lower K.
