Electrolytes, Minerals, & Gases

Question 1

Identify the major cation in extracellular fluid.

Answer 1

Sodium.

Question 2

What is the major function of sodium?

Answer 2

Maintains normal water distribution
Controls osmotic pressure of plasma

Question 3

Sodium regulation is controlled primarily by what?

Answer 3

The amount of water excreted (ADH regulation), amount of water ingested (thirst and osmolality) and blood volume status.

Question 4

Identify the major cation in intracellular fluid.

Answer 4

Potassium.

Question 5

What is the major function(s) of potassium?

Answer 5

Regulation of cellular function and neuromuscular excitation.
Major effect on the heart.

Question 6

How does increased or decreased potassium levels effect the heart?

Answer 6

May upset the potassium in cell/outside of cell ratio.
Leads to cardiac arrhythmias and muscle paralysis.

Question 7

What organ is responsible for potassium regulation?

Answer 7

Kidney.

Question 8

Describe the reabsorption process of potassium.

Answer 8

Reabsorbs in the proximal tubule
Secretes in the distal tubule and collecting ducts (Na/K exchange) under the influence of aldosterone.

Question 9

Identify the major anion in extracellular fluid.

Answer 9

Chloride.

Question 10

Describe the major functions of chloride.

Answer 10

Follows suit to that of sodium.
Maintenance of fluid balance and osmotic pressure.

Question 11

What electrode is used to measure sodium?

Answer 11

Lithium silicate gas electrode.

Question 12

What is the principle of sodium measurement?

Answer 12

Change in potential due to sodium activation.

Question 13

What electrode is used to measure potassium?

Answer 13

Ion selective electrode.
Valinomycin electrode.

Question 14

What electrode is used to measure CO₂?

Answer 14

pH electrode.

Question 15

What is the principle of CO₂ measurement?

Answer 15

CO₂ released from the sample and diffuses to membrane and lowers pH.

Question 16

What electrode is used to measure chloride?

Answer 16

2 phase Ag/AgCl ion selective electrode.

Question 17

What is the principle of chloride measurement?

Answer 17

Measures change in potential due to change in Ag/AgCl phase.

Question 18

Determine the reference interval for the following electrolyte:

Sodium

Answer 18

135 - 145 mmol/L.

Question 19

Determine the reference interval for the following electrolyte:

• *Potassium**
• *(Adult & Neonate)**

Answer 19

Adult: 3.6 - 5.5 mmol/L
Neonate: 3.7 - 5.9 mmol/L

Question 20

Determine the reference interval for the following electrolyte:

Chloride

Answer 20

98 - 108 mmol/L.

Question 21

Determine the reference interval for the following electrolyte:

CO₂

Answer 21

21.0 - 28.0 mmol/L.

Question 22

Determine the reference interval for the following electrolyte:

HCO₃

Answer 22

22 - 28.0 mmol/L.

Question 23

Determine the reference interval for the following electrolyte:

Anion Gap

Answer 23

8 - 16 mmol/L.

Question 24

Determine the reference interval for the following electrolyte:

Urine Sodium

Answer 24

40 - 220 mmol/L/24 hours

Question 25

Determine the reference interval for the following electrolyte:

Urine Potassium

Answer 25

25 - 125 mmol/L/24 hours

Question 26

Determine the reference interval for the following electrolyte:

Urine Calcium

Answer 26

100 - 300 mg/dL/24hr

Question 27

State the critical values for the following electrolyte:

• *Sodium**
• *(Adult & Newborn)**

Answer 27

Adult: <120 and >160
Newborn: <130 and >150

Question 28

State the critical values for the following electrolyte:

• *Potassium**
• *(Adult & Newborn)**

Answer 28

Adult: <2.5 and >6.5
Newborn: >7

Question 29

State the critical values for the following electrolyte:

CO₂

Answer 29

<20 & >70.

Question 30

Define hyponatremia.

Answer 30

Low sodium.

Question 31

Mild hyponatremia (125 - 130 mmol/L) may begin to produce what kinds of symptoms?

Answer 31

Gastrointestinal

(vomiting nausea, etc.)

Question 32

Moderate hyponatremia (115 - 125 mmol/L) may begin to produce what kinds of symptoms?

Answer 32

Neuropsychiatric

(headache, lethargy, ataxia, muscle weakness)

Question 33

Severe hyponatremia (<115 mmol/L) may begin to produce what kinds of symptoms?

Answer 33

Seizures, coma, respiratory depression, death.

Question 34

Define hypernatremia.

Answer 34

Elevated sodium.

Question 35

Hypernatremia (>145 mmol/L) may be the result of…

Answer 35

Due to excess water loss without sodium loss.

Diabetes insipidus, decreased water intake, increased sodium intake, loss of thirst mechanism, diarrhea, fever, burns.

Question 36

Hypernatremia (>145 mmol/L) may begin to produce what kinds of symptoms?

Answer 36

Nausea, vomiting, altered mental status, lethargy, irritability, seizures, death.

Question 37

Hypovolemic hyponatremia develops with sodium loss in excess of water loss; if urine sodium is >20 mmol/day, what may be the reason?

Answer 37

Due to increased excretion of sodium and water.

Causes: diuretics, aldosterone deficiency, potassium depletion, ketonuria.

Question 38

Hypovolemic hyponatremia develops with sodium loss in excess of water loss; if urine sodium is <20 mmol/day, what may be the reason?

Answer 38

External loss of sodium and water.

Causes: vomiting, diarrhea, burns, excessive sweating, metabolic acidosis.

Question 39

Normovolemic hyponatremia may be the result of…

Answer 39

Sodium depletion with normal body volume.

SIADH
Severe hyperlipidemia or hypoproteinemia
Excess water intake
Adrenal insufficiency w/ decreased cortisol and aldosterone
Pregnancy

Question 40

Hypervolemic hyponatremia develops with sodium loss in excess of water loss; if urine sodium is >20 mmol/day, what may be the reason?

Answer 40

Due to acute or chronic renal failure.

Question 41

Hypovolemic hyponatremia develops with sodium loss in excess of water loss; if urine sodium is <20 mmol/day, what may be the reason?

Answer 41

Due to cirrhosis, congestive heart failure, nephrotic syndrome.