Clinical Chemistries: Electrolytes

Question 1

What are electrolytes?

Answer 1

Ions

• anions (-)
• cations (+)

Question 2

What are the major functions of electrolytes?

Answer 2

Maintain water balance, fluid osmotic pressure, normal muscle, and nerve function, and acid-base regulation

Question 3

What are the commonly run in-house electrolytes tests?

Answer 3

Sodium
Potassium
Chloride

Question 4

What are the commonly run send-out electrolytes tests?

Answer 4

Calcium
Phosphorus
Magnesium

Question 5

What is bicarbonate?

Answer 5

not a true electrolyte

it is a blood buffer that maintains pH

Question 6

What does Acid-Base Balance refer to?

Answer 6

The steady-state of the pH of the body

Question 7

What is the normal pH?

Answer 7

7.35 to 7.45

Question 8

Below 7.3=

Answer 8

Acidosis (excess H+)

Question 9

Above 7.5=

Answer 9

Alkalosis (low H+)

Question 10

What two systems work to regulate the pH in acid-base imbalance?

Answer 10

Respiratory and renal systems

Question 11

Hypercapnia

Answer 11

Increases in CO2 in the body

Question 12

What happens if the respiratory rate decreases?

Answer 12

Less CO2 is eliminated

Question 13

What does an increase in partial pressure cause?

Answer 13

Acidosis

Question 14

Hypocapnia

Answer 14

Decrease of CO2 in body

Question 15

Decrease in PCO2 causes what?

Answer 15

Alkalosis

Question 16

Metabolic acidosis or alkalosis

Answer 16

All other causes besides the respiratory system
Ketosis (acidosis)
Vomiting (Alkalosis)

Question 17

Cations

Answer 17

Na+
K+
Ca++
Mg++
H+

Question 18

Anions

Answer 18

Cl-
HCO3-
PO4

Question 19

What important role does sodium play?

Answer 19

Water distribution and body fluid osmotic pressure maintenance

Question 20

What tube do you not use when running sodium?

Answer 20

Heparin

Question 21

Conditions associated with hypernatremia

Answer 21

Water deprivation
Hyperventilation
Osmotic diuresis

Question 22

Conditions associated with hyponatremia

Answer 22

GI disorders
Ketonuria
Hypoadrenocorticism
Congestive Heart Failure

Question 23

Potassium

Answer 23

Major intracellular cation

Question 24

What is potassium important in?

Answer 24

Normal muscular function
Respiration 
Cardiac function
Nerve impulse transmission
Carbohydrate metabolism

Question 25

What is preferred when running potassium?

Answer 25

Plasma | Potassium may be released during the clotting

Question 26

What do you avoid when collecting blood for potassium?

Answer 26

Hemolysis | Releases Potassium

Question 27

Conditions associated with hyperkalemia

Answer 27

Metabolic acidosis Urinary tract infection Renal Insufficiency

Question 28

Conditions associated with hypokalemia

Answer 28

Anorexia Ketonuria Diuresis

Question 29

Chloride

Answer 29

Predominant extracellular anion

Question 30

What does chloride play an important role in?

Answer 30

Maintenance of water distribution Osmotic pressure normal anion/cation ratio

Question 31

Hyperchloremia

Answer 31

Elevated chloride levels

Question 32

Hypochloremia

Answer 32

Decreased chloride levels

Question 33

What interferes with the results of chloride?

Answer 33

Hemolysis and prolonged storage

Question 34

Bicarbonate (HCO3)

Answer 34

The second most common anion of plasma

Question 35

What does bicarbonate help maintain?

Answer 35

Acid-base (pH) balance

Question 36

What helps regulate bicarbonate levels?

Answer 36

The Kidney

Question 37

What is bicarbonate levels frequently estimated from

Answer 37

CO2 levels

Question 38

What percent of bicarbonate levels are from the total CO2 levels measured?

Answer 38

95%

Question 39

What is found in more than 50% of bones?

Answer 39

Magnesium

Question 40

What can result from the imbalance of the Mg/Ca ratio?

Answer 40

Muscular tetany from the release of acetylcholine

Question 41

What are the two species that show clinical signs of hypomagnesemia?

Answer 41

Cattle and Sheep

Question 42

What may decrease magnesium results?

Answer 42

Anticoagulants other than heparin

Question 43

What is found in 99% of bones?

Answer 43

Calcium

Question 44

What are the functions of the remaining 1% of the calcium in the body?

Answer 44

Maintenance of neuromuscular excitability and tone Activity of enzymes Inorganic ion transfer across cell membranes Facilitates blood coagulation

Question 45

The concentrations of calcium are inversely related to what concentrations?

Answer 45

Inorganic phosphorus

Question 46

When collected a blood sample for calcium levels what should you not use?

Answer 46

EDTA | Oxalate or citrate anticoagulants

Question 47

More than 80% of inorganic phosphorus is found where?

Answer 47

In the bones

Question 48

What are the functions of the remaining 20% inorganic phosphorus?

Answer 48

Energy storage, release, and transfer | Involvement in the carbohydrate metabolism

Question 49

What is inorganic phosphorus needed to make?

Answer 49

Nearly every type of protein in the body

Question 50

Inorganic PO4 in plasma or serum becomes what in red blood cells?

Answer 50

Organic PO4

Question 51

What will falsely elevate inorganic phosphorus levels?

Answer 51

Hemolysis

Question 52

Anion Gap: Normal circumstances

Answer 52

The same number of cations and anions | Any difference is called the anion gap

Question 53

What is the Anion Gap calculated from?

Answer 53

Measured electrolyte values

Question 54

What is the formula to calculate Anion Gap

Answer 54

(Na+ + K+) - (Cl- + HCO3)

Question 55

In what cases will you see an increase in the anion gap?

Answer 55

Lactic acidosis Renal failure Diabetic ketoacidosis

Question 56

In what cases will you see a decrease in the anion gap?

Answer 56

Hypoalbuminemia