Acid-Base Balance

Question 1

PaO2 Levels

Answer 1

97mmHg

80-100mmHg

Question 2

HCO3- Levels

Answer 2

-24 mEq/L

22-26 mEq/L

Question 3

O2 Sat Levels

Answer 3

-97%

95+

Question 4

pH Levels

Answer 4

7. 4

7. 35-7.45

Question 5

PaCO2 Levels

Answer 5

40mmHg

35-45mmHg

Question 6

HCO3- : CO2

Answer 6

20:1

Question 7

3 Mechanisms to maintain acid-base balance

Answer 7

• buffers
• respiratory
• kidneys

Question 8

Arterial Blood used because:

Answer 8

• better well-mixed sample
• how well lungs are oxygenating
• Vv reflect more what body tissues are doing

Question 9

Kidneys

Answer 9

• adjusts bicarb levels
• hours to days
• reg by excreting acidic or basic urine
• incr H+–>acidic urine
• decr H+–>excrete more bicarb

Question 10

Base Excess Levels

Answer 10

• 0

-2 to +2

Question 11

w/x/y/z

Answer 11

pH/PaCO2/PaO2/HCO3-

7.4/40/98/24

Question 12

Buffers

Answer 12

• chemicals present in plasma & RBC

- very rapid H2CO3 H+ + HCO3-

Question 13

Respiratory

Answer 13

• adjusts CO2
• 1-3 min
• incr ventilation due to incr H=, incr CO2, decr pH

Question 14

PaO2 Normal values on room air

Answer 14

• Adults: 80-100 mmHg

- New Born: 40-70 mmHg

Question 15

Hypoxia with increased A-a O2 gradient =

Answer 15

• indicates decreased O2 in arterial blood as compared to O2 content in alveolus & suggests LUNG PATHOLOGY
• (V/Q mismatch)

Question 16

A-a O2 Gradient

Answer 16

-used to determine cause of hypoxemia

Question 17

Hypoxia with normal A-a O2 Gradient

Answer 17

-normal A-a in presence of hypoxemia is due to HYPOVENTILATION not a lung disorder