Exam 2: Acid-Base Balance

Question 1

How does pH effect body processes?

Answer 1

organs function at the correct pH environment, so when it goes outside of that 7.35-7.45 range different compensatory systems kick in (resp & renal

Question 2

What are the normal values for pH, PaCO2, and HCO3

Answer 2

pH: 7.35-7.45
PaCO2: 35-45 mmHg
HCO3: 22-26 mEq/L

Question 3

What are the ABG values for metabolic acidosis?

Answer 3

pH = <7.35
PaCO2: WNL
HCO3: <22

DIARRHEA

Question 4

What are the causes for metabolic acidosis?

Answer 4

pH low due to base loss (low bicarb) in body fluids or accumulation of acid (other than carbonic acid)

Ketones produced during DKA, Lactic acid & diarrhea = loss of base

Kidneys attempt to preserve Na+ (H+ into ICF, K+ into ECF)
RR increase -> “blow off” CO2 -> Kussmaul’s respirations

Question 5

What are the ABG values for metabolic alkalosis?

Answer 5

pH = >7.45
PaCO2: WNL
HCO3: >26

EMESIS

Question 6

What are the causes for metabolic alkalosis?

Answer 6

pH high due to loss of acid or gain in base (elevated bicarb)

Vomiting: loss of stomach acid, prolonged suctioning
Gain in base: ingestion of baking soda, IV sodium bicarb

RR decrease -> to compensate and retain CO2

Question 7

What are the ABG values for respiratory acidosis?

Answer 7

pH = <7.35
PaCO2: >45
HCO3: WNL

HYPOVENTILATION

Question 8

What are the causes for respiratory acidosis?

Answer 8

Hypoventilation - COPD, sedative OD, atelectasis, etc.

pH low due to elevated CO2

Kidney compensation can take up to 24hrs; bicarb will be normal but will increase in time

Question 9

What are the ABG values for respiratory alkalosis?

Answer 9

pH = >7.45
PaCO2: <35
HCO3: WNL

HYPERVENTILATION

Question 10

What are the causes for respiratory alkalosis?

Answer 10

Hyperventilation - Anxiety, pain, exercise, brain injury, pregnancy, septicemia
Decreased lung compliance: pneumonia, asthma, PE

pH increased due to decreased CO2