Ch 40.2 Fluids

Question 1

pH

Answer 1

reflects hydrogen ion concentration in body fluids. It tells us how acidic or alkaline the blood it.

Question 2

Partial pressure of arterial carbon dioxide (PaCO2) –

Answer 2

• tells us how well the lungs are functioning and excreting C02.
• Normal 35-45mm Hg.
• Lower than 35 indicates hyperventilation (increase in respiratory rate and depth decreases CO2 in the blood)
• Over 45mm Hg indicates there is too much CO2 in the blood (carbonic acid) and hypoventilation has occurred

Question 3

Partial pressure of arterial oxygen (PaO2)

Answer 3

• tells us how well the alveoli in the lungs are functioning.
• 80-100mm Hg.
• Value below normal indicates poor oxygenation of the blood.
• Lower than 60 can lead to metabolic acidosis due to anaerobic metabolism producing lactic acid.

Question 4

Oxygen saturation

Answer 4

• the percentage of hemoglobin that is carrying as much O2 as possible.
• Oxygen saturation can be affected by changes in temperature, pH, and PaCO2.
• The normal range is 95% to 99%. It drops rapidly when PaO2falls below 60 mm Hg (8 kPa).

Question 5

Base excess

Answer 5

serum pH is 7.4 and base excess reflects deviation from that. It is based on buffer systems and has a range of -2 to +2mmol/L. Negative indicates acidosis, higher indicates alkalosis

Question 6

Bicarbonate

Answer 6

• used by kidneys to regulate acid-base balance
• normal range is 22 to 26 mmol/L.
• Less than 22 mmol/L of bicarbonate usually indicates metabolic acidosis
• more than 26 mmol/L indicates metabolic alkalosis.

Question 7

Respiratory acidosis

Answer 7

Increased PaCO2, excess carbonic acid, and an increased H+ concentration
Occurs when respirations are not effective in excreting carbon dioxide

ncreased hydrogen ion concentration = decreased pH. CO2 crosses blood-brain barrier and can causes neurological changes and hypoxemia can intensify. May have hyperkalemia and hypercalcemia and renal system tries to compensate.
With chronic lung disease, pH may be close to normal, but shift in compensatory mechanisms

Question 8

Respiratory alkalosis

Answer 8

Decreased PaCO2 and increased pH

Occurs with hyperventilation

Question 9

Metabolic acidosis

Answer 9

Decrease in serum bicarbonate or the production of organic or fixed acids
Anion gap

Question 10

Metabolic alkalosis

Answer 10

Loss of acid from the body or through increase in levels of bicarbonate
Most common causes: vomiting and gastric suction, as well as potassium deficiency, hyperaldosteronism, and diuretic therapy

Question 11

anion gap

Answer 11

is the difference between the number of cations versus anions. An anion gap can be high, normal, or low (rare). A high anion gap indicates the presence of more anions than cations, or acidosis. When bicarbonate is used up to correct the acid-base balance, the gap widens
Compensation starts with increase in respiratory rate and depth to help rid CO2. If not quickly resolved, kidneys begin compensatory mechanisms to increase hydrogen excretion and to generate and release bicarbonate into ECF.

Question 12

Diabetic ketoacidosis

Answer 12

hyperglycemia, high ketones and metablic acidosis. Hyperglycemia can also cause metabolic acidosis.

Question 13

Assessing fluid intake and output

Answer 13

• Measure pts fluid intake and output over 24 hour period – records all intake oral, IV, and output including urine,
• Intake includes ice-cream, jello, soup juice water, enteral feedings, IV, blood transfusions
• Output: urine, diarrhea, emesis, gastric suction wound drainage.
• Daily intake should = output plus 500mls for insensible fluid loss

Question 14

1 cup icechips=

Answer 14

1/2 cup water

Question 15

Restriction of fluids

Answer 15

May be required for pts at risk of fluid volume excess (kidney disease) Good pt education important for understanding and compliance. May require increased mouth care due to oral dryness

Question 16

Colloids

Answer 16

a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. However, some definitions specify that the particles must be dispersed in a liquid, and others extend the definition to include substances like aerosols and gels.

type of IV fluid
contain proteins or starch, examples such as dextran, pentastarch, hetastarch, or blood derivatives such as albumin, plasma proteins or blood.

Question 17

Crystalloids

Answer 17

an aqueous solution composed of water and small solutes such as electrolytes and glucose (4, 5). Crystalloid solutions can be categorized based on whether they are hypotonic, isotonic, or hypertonic

type of IV fluid
used most commonly and include dextrose, sodium chloride and lactated Ringer’s solution

Question 18

Isotonic solution

Answer 18

is balanced

Question 19

Hypotonic solution

Answer 19

causes the cells to swell

Question 20

Hypertonic solution

Answer 20

causes the cells to shrink