Vitamin levels

Question 1

hypokalemia

Answer 1

serum potassium <3.4 mEq/L
causes: abnormal kidney or GI losses, medications, metabolic alkalosis, hyperaldosteronism, hypomagnesemia, catecholamines, and inadequate intake
signs and symptoms: muscle weakness, cramping, dysrhythmias, paralysis, muscle necrosis, and death

Question 2

hypercalcemia

Answer 2

serum or plasma total Ca > 11 mg/dL or ionized Ca > 5.6 mg/dL
most often seen in patients with hyperparathyroidism or cancer with bone metasteses
Can also occur with toxic serum concentrations of vit A or D, chronic consumption of calcium carbonate in the setting of kidney insufficiency, immobility, tuberculosis, and medications

Question 3

Calcium

Answer 3

controlled by parathyroid gland
decreased serum Ca -> PTH secretion stimulated, which increases bone resorption, augments renal Ca conservation and activated Vit D, which in turn increases Ca absorption from the GI tract

Question 4

hypocalcemia

Answer 4

total serum calcium concentration < 8.8 mg/dL
hypotension, decreased myocardial contractility, prolonged QT interval, paresthesia, muscle cramps, tetany, and seizures
Causes include Vit D def or inability to activate Vit D, hyperphosphatemia, sepsis, rhabdomyolysis, massive blood transfusion

Question 5

phosphorous ranges

Answer 5

new born: 4.5-9 mg/dL
10days to 2 yo: 4.6-6.7 mg/dL
2-12 yo: 4.5-5.5 mg/dL
>12 yo: 2.7 -4.5 mg/dL

Question 6

hyperphosphatemia

Answer 6

> 4.5-9 mg/dL depending on age
usually asymptomatic
biggest concern is soft tissue & vascular calcification from elevated serum calcium and phosphorous concentrations

Question 7

hypophosphatemia

Answer 7

<2.7-4.5 mg/dL depending on age
common in critical illness, malnutrition, alkalosis, and it patients receiving phosphate binders
primary causes: inadequate intake or administration of large amounts of dextrose solution in malnourished (refeeding syndrome)

Question 8

Sodium

Answer 8

predominant extracellular osmotic agent
preterm: 130-140 meq/L
term: 133-146 meq/L
children/adolescents: 135-145 meq/L

Question 9

Calcium

Answer 9

in circulation 50% is ionized, and the rest is bound to albumin or complexed to small anions
90% of Ca is absorbed through the small intestine and <10% is absorbed through the large intestine
Ca citrate better absorbed than calcium carbonate in individuals with decreased gastric acid

Question 10

hypermagnesemia

Answer 10

usually well tolerated except when concentration exceeds 3mg/dL
central nervous system depression, hyproreflexia, electrocardiographic abnormalities, respiratory depression, coma, cardiac arrest

Question 11

hypernatremia

Answer 11

> 145 meq/L

lack of oral hydration, dairrhea, vomitting, overzealous, diuresis, fever, and the inability to express a need for water

Question 12

potassium

Answer 12

intracellular osmotic agent

newborns: 3.7-5.9 meq/L
infants: 4.1-5.3 meq/L
children: 3.4 -4.7 meq/L

Question 13

magnesium

Answer 13

1.6-2.3 mg/dL (all age groups)

absorbed throughout the entire intestinal tract with maximal absorption at the distal jejunum and ileum

Question 14

hypomagnesemia

Answer 14

commonly seen in hospitalized patients - apathy, deprression, psychosis, confusion, leg cramps , hyperactive tendon reflexes, anorexia, nausea, vomiting

Question 15

hyerkalemia

Answer 15

> 4.5 meq/L
one of the most dangerous electrolyte imbalances for premature infants
related to immature kidneys

Question 16

hypovolemia

Answer 16

serum osmolarity increase and blood volume decreases - release of ADH increasing permeability of water in the collecting tubule where water is then reabsorbed -more concentrated urine
signs and symptoms- thirst, altered mental status, weakness, fatigue, neuromuscular irritability, agitation, seizures, coma

Question 17

hyponatremia

Answer 17

serum na concentration <135 mEq/L

headache, nausea, vomiting, muscle cramps, lethargy, restlessness, disorientation, depressed reflexes