Electrolytes

Question 1

Potassium range and daily intake

Answer 1

3.5-5mEq/L. 4200mg/day

Question 2

Potassium natural sources

Answer 2

Citrus, meat, bananas, potatoes, broccoli, prunes, beans, milk, nuts, salt substitute, fish.

Question 3

What happens to K with acidosis?

Answer 3

It comes out of the cell

Question 4

What causes K loss?

Answer 4

Aldosterone, black licorice, hypomagnesemia, polyuria increase renal excretion of K+

Question 5

Calcium range and daily intake

Answer 5

8.5-11mg/L. 1000mg/day. 1200mg if >50yr old

Question 6

Calcium natural sources

Answer 6

Dairy, broccoli, oranges, canned fish. (Vitamin D improves absorption, undigested fat prevents absorption.)

Question 7

Calcium albumin relationship

Answer 7

Low albumin leads to low calcium

Question 8

Calcium loss factors

Answer 8

Thiazide diuretics decrease renal excretion of Ca. Chronic diarrhea & undigested fat increase excretion of Ca. Balance controlled by PTH, calcitonin and vitamin D.

Question 9

Calcium functions

Answer 9

Influences excitability of nerve and muscle cells; necessary for muscle contraction, bone health, activation of clotting mechanism.

Question 10

Magnesium range and daily intake

Answer 10

1.3-2.1mg/dl. 320-420mg/day. (we start replacing at 1.8)

Question 11

Mg natural sources

Answer 11

Dark green leafy veggies, whole grains, milk, nuts (Undigested fat prevents absorption.)

Question 12

Mg loss factors

Answer 12

High blood ethanol increases & oliguria decreases renal excretion of Mg. Chronic diarrhea & undigested fat increase fecal excretion.

Question 13

Mg functions

Answer 13

Sedative effect on neuromuscular junctions (inhibits acetylcholine and diminishes muscle excitability); nerve conduction, DNA synthesis

Question 14

Phosphate range and daily intake

Answer 14

2.4-4.4mg/dl. 20-40mmol/day

Question 15

Phosphate natural sources

Answer 15

Milk, poultry, fish, beans, nuts, processed foods. Aluminum antacids prevent absorption. Need vitamin D for intestinal absorption

Question 16

Phosphate loss factors

Answer 16

Oliguria decreases renal excretion of PO. PTH stimulates renal tubes to excrete phosphorous. Kidneys are major route of phosphate excretion.

Question 17

Phosphate functions

Answer 17

Necessary for production of ATP (energy source for cellular metabolism). Muscle, RBCs, bone, teeth, CNS function. PTH stimulates secretion of phosphorus via kidneys

Question 18

Isotonic fluids

Answer 18

NS, D5W, LR,

Question 19

Hypotonic fluids

Answer 19

1/4, 1/2 NS

Question 20

Hypertonic fluids

Answer 20

3,5% NS, D5+electrolytes, D10 and higher,

Question 21

ECV deficit s/sx

Answer 21

Sudden weight loss, orthostatic hypotension, tachycardia, thready pulse, flat or collapsing neck veins when supine, slow vein filling, oliguria, concentrated urine, dry mucous membranes, skin turgor, absence of sweat/tears, tongue furrows, thirst, restlessness, confusion, hypotension, cold, clammy skin, hypovolemic shock.
Labs: Elevated Hct, BUN > 25 mg, urine specific gravity > 1.030.

Question 22

ECV excess s/sx

Answer 22

Sudden weight gain, edema in dependent areas, full neck veins when upright, crackles, pulmonary edema, bounding pulse.
Labs: BUN

Question 23

Hypernatremia s/sx

Answer 23

Extreme thirst, dry/flushed skin, postural hypotension, fever, restlessness, oliguria, N/V, confusion, agitation, coma, seizures.
Nx: Treat underlying cause, gradual water replacement (5DW), diuretics.
Labs: Na > 145 mEq & serum osmolality > 295 mOsm/kg, urine specific gravity 1.030, alkalosis