Acid-Base Metabolism/Blood Gases

Question 1

Blood gas ref ranges

Answer 1

pH = 7.35-7.45
Total CO2 = 22-26 mmol/L
PCO2 = 35-45 mmHg

Question 2

Metabolic acidosis

Answer 2

Bicarbonate deficient (decrease in CO2 content and pCO2), decrease in blood pH

Caused by diabetic ketoacidosis, lactic acidosis, renal failure, diarrhea, salicylate/ethylene glycol/methyl alcohol poisoning

Compensate by speeding up breathing

Question 3

Metabolic alkalosis

Answer 3

Bicarbonate excess, increase in blood pH

Caused by antacids, diuretics, vomiting, intestinal obstruction, Cushing syndrome, hyperaldosteronism

Compensate by slowing breathing

Question 4

Respiratory acidosis

Answer 4

Hypoventilation causes increase of PCO2 and CO2 content, decreased blood pH

Caused by COPD, bronchitis, emphysema, narcotics/barbiturates, meningitis

Compensate by kidneys retain bicarbonate

Question 5

Respiratory alkalosis

Answer 5

Hyperventilation reduces PCO2, increases blood pH

Caused by hypoxia, anxiety, pulmonary embolism, pneumonia, CHF, salicylate OD

Compensate by kidneys excreting bicarbonate

Question 6

Ratio of bicarbonate to carbonic acid is

Answer 6

20:1

Question 7

Blood gas sample on ice with bubble, what changes occur?

Answer 7

pO2 increased

HCO3 decreased

Question 8

Lab requirements for blood gas samples

Answer 8

On ice, no clots, no air bubbles