Electrolyte Balance

Question 1

Osmotic demyelinization syndrome/central pontine myelinolysis

Answer 1

Myelin sheath breaks down

Question 2

IV maintenance therapy

Answer 2

Replaces the normal ongoing losses of water and electrolytes under normal physiologic conditions via sensible vs insensible loss - for patients who are not eating or drinking but do NOT have volume depletion, hypotension

Question 3

IV replacement therapy

Answer 3

Increasing loss from mouth to anus (GI: vomiting, fistulas, ostomies, NG tubes, etc.), urinary, skin losses, or third spacing - intended to replace lost body fluids and electrolytes

Question 4

What are the primary regulators of electrolytes

Answer 4

Kidneys, endocrine, and GI systems

Question 5

Major intracellular cations

Answer 5

K+ (150 mEq/L), Mg++ (40 mEq/L), and Na+ (10 mEq)

Question 6

What does K+ do in the body

Answer 6

Important in conduction of nerve impulses to skeletal and cardiac muscles

Question 7

Primary hyperaldosteronism

Answer 7

Caused by an adrenal tumor - Na+ is reabsorbed and K+ is excreted leading to hypokalemia

Question 8

Secondary hyperaldosteronism

Answer 8

Disorder where the adrenal gland releases too much aldosterone in the blood - Na+ is reabsorbed and K+ is excreted leading to hypokalemia

Question 9

Normal K+

Answer 9

3.5 - 5 mEq/L

Question 10

Normal Na+

Answer 10

135 - 145 mEq/L

Question 11

Normal Mg++

Answer 11

1.4 - 2 mEq/L

Question 12

Severe hypokalemia levels

Answer 12

< 2.5 mEq/L

Question 13

Hypokalemia levels

Answer 13

< 3.5 mEq/L

Question 14

Hyperkalemia levels

Answer 14

> 5 mEq/L

Question 15

Iatrogenic

Answer 15

Relating to illness caused by medical examination or treatment

Question 16

K+ sparing diuretics

Answer 16

Blocks actions of aldosterone (keeps Na+ and water & excretes K+) on the kidneys
- Spironolactone

Question 17

Angiotensin receptor blockers (ARBs)

Answer 17

Inhibit the RAAS system

Question 18

Acidemia

Answer 18

The condition of blood having too many acids

Question 19

Tumor lysis syndrome

Answer 19

Intracellular K+ being released during chemotherapy

Question 20

Pseudohyperkalemia

Answer 20

Falsely elevated K+ levels due to disruption of cells during the collection or processing of the sample
- When cells are crushed, K+ is released

Question 21

How to calculate serum osmolality

Answer 21

Plasma osmolality (mOsm/kg) = 2 (serum NA+) + (Glucose / 18) + (BUN / 2.8)

Question 22

Mild hyponatremia

Answer 22

Na+ levels between 130-134 mEq/L

Question 23

Severe hyponatremia

Answer 23

Na+ < 120 mEq/L

Question 24

Dilutional hyponatremia

Answer 24

Too much water dilutes the blood

Question 25

Syndrom of innapropriate anti diuretic hormone (SIADH)

Answer 25

ADH is secreted excessively which causes water to be retained - Patients look euvolemic

Question 26

What is mannitol administration used for

Answer 26

To decrease fluid within the brain which then decreases brain mass and increased intracranial pressure (ICP)

Question 27

Diabetes insipidus (DI)

Answer 27

A defect related to ADH resulting in urine that is dilute, hypotonic, and tasteless (insipid)

Question 28

Central diabetes insipidus

Answer 28

Failure of ADH release from the posterior pituitary/hypothalamus

Question 29

Nephrogenic diabetes insipidus

Answer 29

The kidney doesn't respond to ADH - normal ADH secretion but varying degrees of renal resistance to the ADH