NP235 ABG QUESTIONS AND ANSWERS
WITH VERIFIED SOLUTIONS 2024
ABG Interpretation - ANSWER •The level of the CO2 is controlled by breathing so any abnormal values in
carbon dioxide levels are considered to be a respiratory problem
•The level of HCO3 in the blood is controlled by the renal system so any abnormal values in the
Bicarbonate levels are considered to be a metabolic problem
pH - ANSWER •The relative concentration of hydrogen in arterial blood
❖The chief component of acid-base balance
❖Normal Range is 7.35-7.45
(Acidosis) 7.35 7.40 7.45 (Alkalosis)
PaCO2 - ANSWER •Partial pressure of carbon dioxide
⮚CO2 functions as acid reserve
⮚Normal range is 35- 45 mmHg
⮚CO2 levels typically stimulate respiration
⮚pCO2 (Alkalosis) 35 40 45 (acidosis)
Bicarbonate (HCO3) - ANSWER •Indicator for the base reserve
•Reflects the kidneys and/ or metabolic function
•HCO3 (Acidosis) 22 24 26 (Alkalosis)
PaO2 - ANSWER •Partial pressure of oxygen
▪Does not play an active role in acid/base balance
, ▪Normal for adults < 60 years is 80-100mmHg
▪After the age of 60, normal PaO2 levels are slightly lower due to decreasing lung compliance
Normal 80-100mmHg
Mild 60-80mmHg
Moderate 40-60mmHg
Severe <40mmHg
Oxygen Saturation (SaO2) - ANSWER •Percent of hemoglobin which is bound to oxygen
•Normal is 94-100%
Normal Values - ANSWER Low End. High End
•pH (< acidic) 7.35. 7.45 (>alkalotic)
•pCO2 (<alkalotic)35 45 (>acidic)
•pO2 80mmHg 100 mmHg
•HCO3 (< acidic) 22 26 (>alkalotic)
Is is Metabolic or Respiratory? - ANSWER •For Metabolic disorders remember the Ph changes in the
same direction as the HC03
•For Respiratory disorders remember the Ph changes in the opposite direction as the Co2.
Metabolic Acidosis: Serum pH/Serum HC03 decreased ; the PaCo2 decreases to compensate.
Metabolic Alkalosis: Serum pH/Serum HC03 increased ; the PaCo2 increases to compensate.
Respiratory Acidosis: Serum pH decreased / PaCo2 increased ; the HC03 increases to compensate
WITH VERIFIED SOLUTIONS 2024
ABG Interpretation - ANSWER •The level of the CO2 is controlled by breathing so any abnormal values in
carbon dioxide levels are considered to be a respiratory problem
•The level of HCO3 in the blood is controlled by the renal system so any abnormal values in the
Bicarbonate levels are considered to be a metabolic problem
pH - ANSWER •The relative concentration of hydrogen in arterial blood
❖The chief component of acid-base balance
❖Normal Range is 7.35-7.45
(Acidosis) 7.35 7.40 7.45 (Alkalosis)
PaCO2 - ANSWER •Partial pressure of carbon dioxide
⮚CO2 functions as acid reserve
⮚Normal range is 35- 45 mmHg
⮚CO2 levels typically stimulate respiration
⮚pCO2 (Alkalosis) 35 40 45 (acidosis)
Bicarbonate (HCO3) - ANSWER •Indicator for the base reserve
•Reflects the kidneys and/ or metabolic function
•HCO3 (Acidosis) 22 24 26 (Alkalosis)
PaO2 - ANSWER •Partial pressure of oxygen
▪Does not play an active role in acid/base balance
, ▪Normal for adults < 60 years is 80-100mmHg
▪After the age of 60, normal PaO2 levels are slightly lower due to decreasing lung compliance
Normal 80-100mmHg
Mild 60-80mmHg
Moderate 40-60mmHg
Severe <40mmHg
Oxygen Saturation (SaO2) - ANSWER •Percent of hemoglobin which is bound to oxygen
•Normal is 94-100%
Normal Values - ANSWER Low End. High End
•pH (< acidic) 7.35. 7.45 (>alkalotic)
•pCO2 (<alkalotic)35 45 (>acidic)
•pO2 80mmHg 100 mmHg
•HCO3 (< acidic) 22 26 (>alkalotic)
Is is Metabolic or Respiratory? - ANSWER •For Metabolic disorders remember the Ph changes in the
same direction as the HC03
•For Respiratory disorders remember the Ph changes in the opposite direction as the Co2.
Metabolic Acidosis: Serum pH/Serum HC03 decreased ; the PaCo2 decreases to compensate.
Metabolic Alkalosis: Serum pH/Serum HC03 increased ; the PaCo2 increases to compensate.
Respiratory Acidosis: Serum pH decreased / PaCo2 increased ; the HC03 increases to compensate
