Untitled Deck

Question 1

What does pH reflect in blood?

Answer 1

pH reflects the power of hydrogen (H⁺) in blood.

Question 2

What happens to pH with more H⁺?

Answer 2

More H⁺ → lower pH → acidosis

Question 3

What happens to pH with less H⁺?

Answer 3

Less H⁺ → higher pH → alkalosis

Question 4

What is the goal of homeostasis in acid-base balance?

Answer 4

Homeostasis is the goal. Two systems push pH back toward normal.

Question 5

Which system regulates PaCO₂?

Answer 5

Respiratory system (lungs) → regulates PaCO₂ (an acid). Fast response (minutes).

Question 6

Which system regulates HCO₃⁻?

Answer 6

Metabolic system (kidneys) → regulates HCO₃⁻ (a base). Slow response (~48–72 hr to move meaningfully).

Question 7

What is the normal reference range for pH?

Answer 7

pH: 7.35–7.45 (midpoint 7.40 helps you decide acid vs alk)

Question 8

What is the normal reference range for PaCO₂?

Answer 8

PaCO₂: 35–45 mmHg (think acid: higher = more acid)

Question 9

What is the normal reference range for HCO₃⁻?

Answer 9

HCO₃⁻: 22–26 mEq/L (think base: lower = more acid)

Question 10

What does PaO₂ indicate?

Answer 10

PaO₂: oxygenation only (helpful clinically, not required to name acid–base status)

Question 11

What is the first step in naming the ABG?

Answer 11

Look at pH first

Question 12

What does a pH < 7.40 indicate?

Answer 12

< 7.40 → trending acidic

Question 13

What does a pH of 7.40 indicate?

Answer 13

7.40 → trending alkalotic

Question 14

How does the respiratory system behave in relation to pH?

Answer 14

Respiratory (PaCO₂) behaves opposite to pH: ↑PaCO₂ → ↓pH (acid) | ↓PaCO₂ → ↑pH (alk)

Question 15

How does the metabolic system behave in relation to pH?

Answer 15

Metabolic (HCO₃⁻) behaves same as pH: ↑HCO₃⁻ → ↑pH (alk) | ↓HCO₃⁻ → ↓pH (acid)

Question 16

What does uncompensated mean?

Answer 16

Uncompensated: the other system is still normal.

Question 17

What does partially compensated mean?

Answer 17

Partially compensated: other system moved out of normal, but pH not yet normal.

Question 18

What does fully compensated mean?

Answer 18

Fully compensated: pH back in normal (7.35–7.45), but one/both components are out of range.

Question 19

What is the key rhythm in acid-base balance?

Answer 19

The system that caused the problem is the name; the other system tries to fix it.

Question 20

What is the example of respiratory acidosis, uncompensated?

Answer 20

A. Respiratory acidosis, uncompensated: pH 7.25, PaCO₂ 60, HCO₃⁻ 24

Question 21

What indicates respiratory acidosis in the example?

Answer 21

pH <7.40 → acidic; PaCO₂ high (acid) → matches pH → Respiratory acidosis

Question 22

What is the bedside observation for respiratory acidosis?

Answer 22

↑ work of breathing (WOB), often faster rate, shallow breaths; CO₂ retention.

Question 23

Why does respiratory acidosis matter?

Answer 23

CO₂ narcosis risk, declining mental status, acidosis depresses myocardium if severe.

Question 24

What is the treatment for respiratory acidosis?

Answer 24

Improve ventilation (move CO₂ out) by reducing WOB and increasing effective Vₜ.

Question 25

What is the example of metabolic acidosis, uncompensated?

Answer 25

B. Metabolic acidosis, uncompensated: pH 7.28, PaCO₂ 40, HCO₃⁻ 16

Question 26

What indicates metabolic acidosis in the example?

Answer 26

pH acidic; HCO₃⁻ low → Metabolic acidosis

Question 27

What should the body response be in metabolic acidosis?

Answer 27

Lungs should hyperventilate (↓PaCO₂) to raise pH (respiratory compensation is fast).

Question 28

What is the example of metabolic acidosis, partially compensated?

Answer 28

C. Metabolic acidosis, partially compensated: pH 7.32, PaCO₂ 30, HCO₃⁻ 16

Question 29

What indicates partial compensation in metabolic acidosis?

Answer 29

PaCO₂ low (lungs blowing off CO₂) → compensation underway; pH still out of range.

Question 30

What is the example of fully compensated respiratory acidosis?

Answer 30

D. Fully compensated: pH 7.38, PaCO₂ 60, HCO₃⁻ 34

Question 31

What indicates fully compensated respiratory acidosis?

Answer 31

pH normal (slightly <7.40 → acid side of normal); PaCO₂ high; HCO₃⁻ high.

Question 32

What is the definition of hyperventilation?

Answer 32

Hyperventilation = excess alveolar ventilation → ↓PaCO₂ (alkalosis tendency).

Question 33

What is the definition of hypoventilation?

Answer 33

Hypoventilation = inadequate alveolar ventilation → ↑PaCO₂ (acidosis tendency).

Question 34

What is a bedside clue for rising PaCO₂?

Answer 34

↑WOB, rapid shallow pattern, accessory muscles, drowsiness/headache (CO₂ effects).

Question 35

What is the formula for patient inspiratory flow need?

Answer 35

Need (L/min) = VT(L)÷TI(s)×60

Question 36

What is the importance of patient inspiratory flow need?

Answer 36

If the device’s delivered total flow is below this number, the patient will entrain room air.

Question 37

How to calculate delivered flow from a device?

Answer 37

Delivered flow (L/min) = total parts × flowmeter setting.

Question 38

What is the rule regarding FiO₂ and total flow?

Answer 38

Higher FiO₂ = smaller air ports → lower total flow; lower FiO₂ = more air entrainment → higher total flow.

Question 39

What is the quick estimate for physiologic dead space?

Answer 39

Physiologic dead space (quick bedside est.) ≈ 1 mL/lb IBW.

Question 40

What is the formula for alveolar minute ventilation?

Answer 40

V˙A=(VT−VD)×f

Question 41

What is a common pre-analytic error for ABG?

Answer 41

Air bubbles/contamination change PaO₂/PaCO₂ → bad analysis.

Question 42

What should you provide when asked about a device?

Answer 42

They want delivered total flow (ratio × L/min), not patient need or FiO₂ percent.

Question 43

What should you not do with wheeze sounds?

Answer 43

You don’t suction out wheeze (treat bronchospasm).

Question 44

What is the difference between ventilation and oxygenation?

Answer 44

PaCO₂ problem = ventilation; PaO₂/SpO₂ problem = oxygenation.