Electrolytes

Question 1

What is the major extracellular fluid ion?

Answer 1

Sodium

Question 2

How is sodium eliminated from cells?

Answer 2

Sodium pump

Question 3

What is a major influence on osmolality?

Answer 3

Sodium

Question 4

How is sodium regulated?

Answer 4

Through adequate intake
Renal tubular absorption
Intestinal absorption
Osmoreceptors that secrete ADH

Question 5

What affects plasma volume of sodium?

Answer 5

Urine
GI Tract
Sweat

Question 6

What are the 2 related and interdependent systems of sodium balance?

Answer 6

Osmoregulation

Volume regulation

Question 7

What control osmoregulation of sodium?

Answer 7

Osmoreceptors in the hypothalamus sense increased osmolality and secrete ADH

Question 8

What controls volume regulation of sodium?

Answer 8

Stretch receptors sense volume changes

Question 9

What does ADH respond to?

Answer 9

Increases osmolality

Decreased Plasma volume

Question 10

Where does ADH act?

Answer 10

on the collecting ducts to maximize water reabsorption

Question 11

What system is the main regulator of sodium balance?

Answer 11

Renin-Angiotensin - Aldosterone system

Question 12

What is Aldosterone secreted in response to?

Answer 12

Angiotensin
Hyperkalemia
ACTH

Question 13

What does Aldosterone increase the secretion of?

Answer 13

Potassium

Question 14

What are the four causes of Hyponatremia?

Answer 14

Loss of Sodium
Increase in extracellular water
decreased intake of sodium
shifts in plasma osmolality not due to sodium

Question 15

What is the most common cause of Hyponatremia?

Answer 15

Excess sodium loss

Question 16

What are the 4 causes of Excess sodium loss?

Answer 16

through the GI tract: Vomiting, diarrhea, and salive
Renal loss
Cutaneous: sweating and burns
3rd space: sequestration of fluid

Question 17

What are examples of extracellular fluid sequestration?

Answer 17

Peritonitis
Ascites
Uroabdomen
Chylothorax
GI sequestration

Question 18

What is a common cause of sodium osmotic shift from Intracellular to extracellular fluid?

Answer 18

Hyperglycemia

Mannitol adminstration

Question 19

What are the three causes of increased extracellular water and hyponatremia?

Answer 19

Primary polydipsia
Excessive administration of sodium poor IVF
Edematous conditions

Question 20

What is the most common cause of Hypernatremia?

Answer 20

Dehydration due to lack of intake or pure water loss

Question 21

What is the less common cause of Hypernatremia?

Answer 21

Excess intake or retention through ingestion, IV administration, or increased aldosterone

Question 22

What is the major extracellular fluid anion?

Answer 22

Chloride

Question 23

What is chloride involved in?

Answer 23

transport of electrolytes and water

Acid base metabolism

Question 24

If the changes in sodium and chloride are proportional consider …

Answer 24

abnormalities in sodium

Question 25

If changes in chloride concentrations are greater than sodium consider...

Answer 25

acid-base abnormalities

Question 26

When evaluating chloride look at....

Answer 26

Sodium concentrations | Total CO2

Question 27

What regulates chloride?

Answer 27

electrochemical gradients | active transport of sodium

Question 28

What interferes with chloride transport?

Answer 28

Furosemide | GI entertoxins

Question 29

What is the most common cause of hypochloremia?

Answer 29

Hypochloremic metabolic alkalosis

Question 30

What are the other causes of Hypochloremia?

Answer 30

``` All causes of hyponatremia Vomiting in monogastrics Abomasal disorders High GI obstructions Sweating in horses ```

Question 31

Paradoxical aciduria requires what 2 things?

Answer 31

Volume depletion | Chloride depletion

Question 32

What does the kidney do to compensate for Hypochloremia and Paradoxical aciduria?

Answer 32

Reabsorbs sodium to correct dehydration | Resorbs HCO3- instead of chloride (electroneutrality)

Question 33

What is the cause of Hyperchloremia?

Answer 33

Parallels sodium increased Hyperchloremic Metabolic acidosis: GI tract loss of Bicarb or Proximal and distal renal tubular acidoses Alkalemia/Bicarb excess

Question 34

What are the major functions of Potassium?

Answer 34

Major intracellular cation Resting cell membrane potential Carbohydrate metabolism Electron transport

Question 35

What is the major intracellular cation?

Answer 35

Potassium

Question 36

How is potassium regulated?

Answer 36

Adequate intake Renal excretion Sweat GI loss

Question 37

What hormone promotes renal excretion of potassium?

Answer 37

Aldosterone

Question 38

What is the most common cause of Hyperkalemia?

Answer 38

Failure of Renal Excretion

Question 39

What are the causes of Hyperkalemia?

Answer 39

Failure of renal excretion Redistribution Increased intake through parenteral administration

Question 40

What causes of Hyperkalemia pertain to the urinary system?

Answer 40

Oliguria/Anuria Urethral obstruction Rupture urinary bladder

Question 41

What disease causes Hyperkalemia?

Answer 41

Hypoadrenocorticism (Addison's) - decreased aldosterone

Question 42

What diuretics cause Hyperkalemia?

Answer 42

Potassium sparing Diuretics - Spirolactone

Question 43

What is the magic number for Sodium:Potassium ratio??

Answer 43

27

Question 44

What is a major mechanism for Hyperkalemia?

Answer 44

Redistribution: Inorganic Acidosis Insulin deficiency Severe muscle trauma: Rhabdomyolysis or Seizures

Question 45

What causes Pseudohyperkalemia?

Answer 45

Generally in vivo: Marked Thrombocytosis: leakage of intracellular potassium Hemolysis

Question 46

What is characteristic of EDTA contamination?

Answer 46

Low levels of calcium | High levels of potassium

Question 47

What are causes of Hypokalemia?

Answer 47

Decreased intake or low Potassium IV fluids Loss Horse Sweat Redistribution: Alkalemia or Insulin injection

Question 48

What are the consequences of Potassium

Answer 48

Weakness Neurologic signs EKG abnormalities