Fluids, Electrolytes, And Ph Imbalances

Front 1

Hypernatremia

Back 1

Excess sodium in the blood

Front 2

Two main causes of hypernatremia:

Back 2

1. Dehydration
2. Over-retention of sodium

Front 3

Clinical manifestations of hypernatremia:

Back 3

1. Hypovolemia (decreased blood volume from dehydration).
2. Tachycardia (increased HR) due to hypovolemia (need faster HR for blood to reach tissue).

3. Hypervolemia (increased blood volume).
4. Increased blood pressure due to hypervolemia.

Front 4

What happens to a cell with hypernatremia?

Back 4

Crenation (shrinking) of RBC

Front 5

Hyponatremia

Back 5

Decreased sodium in the blood

Front 6

Two causes of hyponatremia:

Back 6

1. DILUTIONAL HYPONATREMIA - Replacing body fluid with electrolyte-free fluid (i.e., H2O) or replacing with the wrong electrolytes.

2. SIADH (Syndrome of Inappropriate [Secretion of] ADH) - Loss of sodium through kidneys due to decreased aldosterone secretion.

Front 7

Clinical manifestations of hyponatremia:

Back 7

1. Hypervolemia due to over-hydration (from dilutional hyponatremia).
2. Hypovolemia due to under-retention of sodium (from SIADH).

Front 8

What happens to a cell with hyponatremia?

Back 8

Hemolysis (swelling leading to bursting)

Front 9

What happens to H+ when potassium leaves a cell?

Back 9

When potassium leaves a cell, H+ enters.

Front 10

How does insulin affect potassium levels?

Back 10

Insulin causes K+ uptake INTO cells. This causes decreased K+ in the extracellular fluid, which is HYPOKALEMIA.

Front 11

Hyperkalemia

Back 11

Increased potassium in the blood

Front 12

Four causes of hyperkalemia:

Back 12

1. Renal disease - Nephron causes too little potassium to leave the body, meaning there will be TOO MUCH potassium in the extracellular fluid.

2. Shift from intracellular to extracellular
- Burn injury causes cells to burst, releasing potassium into the extracellular fluid.
- Acidosis of the ECF causes K+ to leave the cell, and H+ to enter the cell. This relieves the original acidosis but causes hyperkalemia

3. Insulin deficit - insulin causes K+ uptake so if there is too little insulin, minimal K+ is taken up by cells, resulting in hyperkalemia of ECF.

4. Undersecretion of aldosterone (aldosterone causes secretion of K+ from the body into the urine, so if there isn't enough, not a lot of aldosterone will leave ECF).

Front 13

Hypokalemia

Back 13

Decreased potassium in the blood

Front 14

Four causes of hypokalemia:

Back 14

1. Diuretics
2. Alkalosis
3. Increased aldosterone secretion
4. Insulin excess

Front 15

Tetany

Back 15

Disorder marked by muscular twitching, cramps, and convulsions, and caused by hypocalcemia.

Front 16

Acidosis

Back 16

<7.35 pH

Front 17

Alkalosis

Back 17

>7.45 pH

Front 18

What is the main acid and base of the body?

Back 18

ACID - Hydrogen ions (H+)
BASE - Bicarbonate (HCO3-)

Front 19

Metabolic acidosis

Back 19

A condition occurring when the kidneys are not removing enough acid from the body, or when not enough bicarbonate is being produced. Marked by a pH of <7.35.

Front 20

Two causes of metabolic acidosis

Back 20

1. Increase in non-carbonic acid acids (i.e., metaboic acids such as ketones or lactic acid from anaerobic respiration)
2. Decrease in HCO3- in extracellular fluid (may be due to kidney problem)

Front 21

Effect of acidosis/alkalosis on the nervous system

Back 21

Low pH (acidosis) depresses the nervous system, while a high pH (alkalosis) stimulates the nervous system.

Front 22

Respiratory pH calculation

Back 22

CO2 + H2O <--> H2CO3 (carbonic acid) <--> H+ (very strong acid) + HCO3- (bicarbonate, weak base)

Front 23

How does hyperventilation affect the pH-respiratory system?

Back 23

1. Hyperventilate
2. Decreased CO2 (due to hyperventilation)
3. Decreased H2CO3 (due to less CO2 binding to H2O)
4. Decreased H+ ions (due to less H2CO3)
5. Increased ph (alkalosis due to less H+)

Front 24

How does acidosis affect the pH-respiratory system?

Back 24

1. Acidosis
2. Increased breathing (due to lungs wanting to fix acidosis)
3. Decreased CO2 (due to increased breathing)
4. Decreased H2CO3 (due to less CO2 binding to H2O)
5. Decreased H+ (due to less H2CO3)
6. Increased pH (alkalosis due to less H+)

Front 25

What systems regulate the balance of pH?

Back 25

The respiratory system regulates CO2 (acid) levels, while the excretory system regulates HCO3- (base) levels.
- Respiratory system utilizes the lungs.
- Excretory system utilizes the kidneys.

Front 26

Define "compensation"

Back 26

What is done to maintain the pH in response to disturbances

Front 27

Define "partially compensated"?

Back 27

When one of the systems (respiratory or excretory) is attempting to rectify the disturbance, but has not yet been successful, resulting in values for that system that are outside normal ranges.

Front 28

Define "fully compensated"?

Back 28

When pH levels are back within normal limits, but values for both systems are outside of normal limits.

Front 29

Define "corrected"

Back 29

When all values are within normal limits.

Front 30

Interprete these values:

pH 7.35
PaCO2 64 mmHg
PaO2 60 mmHg
HCO3- 33 mmol/L

Back 30

- pH is normal
- PaCO2 is too high, indicating that their breathing has decreased.
- PaCO2 is too low, indicating that the person has decreased breathing or problems with gas exchange.
- HCO3- is too high, indicating that their kidneys have increased bicarbonate to fix previous acidosis.

Fully compensated, respiratory acidosis.

Front 31

Interprete these values:

pH 7.32
PaCO2 32 mmHg
PaO2 86 mmHg
HCO3- 17 mmol/L

Back 31

- pH is too low, acidosis
- PaCO2 is too low to cause acidity, indicating that this is metabolic acidosis.
- PaO2 is normal, indicating that it is trying to fix metabolic acidosis.
- HCO3- is too low, confirming that it is metabolic acidosis.

Partially compensated, metabolic acidosis.

Front 32

Interprete these values:

pH 7.55
PaCO2 28 mmHg
PaO2 80 mmHg
HCO3- 24 mmol/L

Back 32

- pH is too high (alkalosis)
- PaCO2 is too low, meaning it is respiratory alkalosis
- PaO2 is normal.
- HCO3- is normal.

Since HCO3- value is normal, this respiratory alkalosis isn't even partially compensated.

Front 33

Interprete these values:

pH 7.33
PaCO2 55 mmHg
PaO2 57 mmHg
HCO3- 29 mmol/L

Back 33

- pH is too low (acidosis)
- PaCO2 is too high, indicating that it is respiratory acidosis.
- PaO2 is too low, confirming that it is respiratory acidosis. This person has decreased breathing.
- HCO3- is higher than normal, indicating that is trying to fix the respiratory acidosis.

Partially compensated respiratory acidosis.

Front 34

Interprete these values

pH 7.52
PaCO2 49 mmHg
PaO2 90 mmHg
HCO3- 40 mmol/L

Back 34

- pH is too high (alkalosis)
- PaCO2 is too high, indicating that it is trying to fix the low pH.
- PaO2 is normal.
- HCO3- is too high, indicating that this is metabolic alkalosis.

Partially compensated metabolic alkalosis.