NU373 Week 2 EAQ: Arterial Blood Gas (ABG)
Questions and Verified Answers
Which statement explains why metabolic acidosis develops with kidney failure?
o Inability of the renal tubules to secrete hydrogen ions and conserve bicarbonate
o Depressed respiratory rate due to metabolic wastes, causing carbon dioxide retention
o Inability of the renal tubules to reabsorb water to dilute the acid contents of blood
o Impaired glomerular filtration, causing retention of sodium and metabolic waste products Correct
Answer: o Inability of the renal tubules to secrete hydrogen ions and conserve bicarbonate
Bicarbonate buffering is limited, hydrogen ions accumulate, and acidosis results. The rate of respirations
increases in metabolic acidosis to compensate for a low pH. The fluid balance does not significantly alter
the pH. The retention of sodium ions is related to fluid retention and edema rather than to acidosis.
The laboratory data for a client with prolonged vomiting reveal arterial blood gases of pH 7.51, Pco2 of
45 mm Hg, HCO3 of 58 mEq/L (59 mmol/L), and a serum potassium level of 3.8 mEq/L (3.8 mmol/L).
The nurse concludes that the findings support which diagnosis?
o Hypocapnia
o Hyperkalemia
o Metabolic alkalosis
o Respiratory acidosis Correct Answer: o Metabolic alkalosis
Elevated plasma pH and elevated bicarbonate levels support metabolic alkalosis. The arterial carbon
dioxide level of 45 mm Hg is within the expected value of 35 mm Hg to 45 mm Hg; no hypocapnia is
present. The client’s serum potassium level is within the expected level of 3.5 mEq/L to 5 mEq/L (3.5–5
mmol/L). With respiratory acidosis the pH will be less than 7.35 and the Pco2 will be elevated.
An arterial blood gas report indicates that pH is 7.25, Pco2 is 60 mm Hg, and HCO3 is 26 mEq/L (26
mmol/L). Which client is most likely to exhibit these blood gas results?
o A client with pulmonary fibrosis
, o A client with uncontrolled type 1 diabetes
o A client who has been vomiting for 3 days
o A client who takes sodium bicarbonate for indigestion Correct Answer: o A client with pulmonary
fibrosis
The low pH and elevated Pco2 are consistent with respiratory acidosis, which can be caused by
pulmonary fibrosis, which impedes the exchange of oxygen and carbon dioxide in the lung.
A client with uncontrolled type 1 diabetes most likely will experience metabolic acidosis from excess
ketone bodies in the blood. A client who has been vomiting for 3 days most likely will experience
metabolic alkalosis from the loss of hydrochloric acid from vomiting. A client who takes sodium
bicarbonate for indigestion most likely will experience metabolic alkalosis from an excess of base
bicarbonate.
Which initial change in acid-base balance will the nurse expect when a client is in the progressive stage
of shock?
o Metabolic acidosis
o Metabolic alkalosis
o Respiratory acidosis
o Respiratory alkalosis Correct Answer: o Metabolic acidosis
Metabolic acidosis occurs during the progressive stage of shock as a result of accumulated lactic acid.
Metabolic alkalosis cannot occur with the buildup of lactic acid.
As shock progresses, eventually respiratory acidosis can result from decreased respiratory function in late
shock. Respiratory alkalosis may occur as a result of hyperventilation during early shock.
Which diagnosis is a client most likely to have who has an arterial blood gas report indicating that pH is
7.25, PCO2 is 35 mm Hg, and HCO3 is 20 mEq/L (20 mmol/L)?
o Panic attack
o Persistent vomiting
o Diabetic ketoacidosis
Questions and Verified Answers
Which statement explains why metabolic acidosis develops with kidney failure?
o Inability of the renal tubules to secrete hydrogen ions and conserve bicarbonate
o Depressed respiratory rate due to metabolic wastes, causing carbon dioxide retention
o Inability of the renal tubules to reabsorb water to dilute the acid contents of blood
o Impaired glomerular filtration, causing retention of sodium and metabolic waste products Correct
Answer: o Inability of the renal tubules to secrete hydrogen ions and conserve bicarbonate
Bicarbonate buffering is limited, hydrogen ions accumulate, and acidosis results. The rate of respirations
increases in metabolic acidosis to compensate for a low pH. The fluid balance does not significantly alter
the pH. The retention of sodium ions is related to fluid retention and edema rather than to acidosis.
The laboratory data for a client with prolonged vomiting reveal arterial blood gases of pH 7.51, Pco2 of
45 mm Hg, HCO3 of 58 mEq/L (59 mmol/L), and a serum potassium level of 3.8 mEq/L (3.8 mmol/L).
The nurse concludes that the findings support which diagnosis?
o Hypocapnia
o Hyperkalemia
o Metabolic alkalosis
o Respiratory acidosis Correct Answer: o Metabolic alkalosis
Elevated plasma pH and elevated bicarbonate levels support metabolic alkalosis. The arterial carbon
dioxide level of 45 mm Hg is within the expected value of 35 mm Hg to 45 mm Hg; no hypocapnia is
present. The client’s serum potassium level is within the expected level of 3.5 mEq/L to 5 mEq/L (3.5–5
mmol/L). With respiratory acidosis the pH will be less than 7.35 and the Pco2 will be elevated.
An arterial blood gas report indicates that pH is 7.25, Pco2 is 60 mm Hg, and HCO3 is 26 mEq/L (26
mmol/L). Which client is most likely to exhibit these blood gas results?
o A client with pulmonary fibrosis
, o A client with uncontrolled type 1 diabetes
o A client who has been vomiting for 3 days
o A client who takes sodium bicarbonate for indigestion Correct Answer: o A client with pulmonary
fibrosis
The low pH and elevated Pco2 are consistent with respiratory acidosis, which can be caused by
pulmonary fibrosis, which impedes the exchange of oxygen and carbon dioxide in the lung.
A client with uncontrolled type 1 diabetes most likely will experience metabolic acidosis from excess
ketone bodies in the blood. A client who has been vomiting for 3 days most likely will experience
metabolic alkalosis from the loss of hydrochloric acid from vomiting. A client who takes sodium
bicarbonate for indigestion most likely will experience metabolic alkalosis from an excess of base
bicarbonate.
Which initial change in acid-base balance will the nurse expect when a client is in the progressive stage
of shock?
o Metabolic acidosis
o Metabolic alkalosis
o Respiratory acidosis
o Respiratory alkalosis Correct Answer: o Metabolic acidosis
Metabolic acidosis occurs during the progressive stage of shock as a result of accumulated lactic acid.
Metabolic alkalosis cannot occur with the buildup of lactic acid.
As shock progresses, eventually respiratory acidosis can result from decreased respiratory function in late
shock. Respiratory alkalosis may occur as a result of hyperventilation during early shock.
Which diagnosis is a client most likely to have who has an arterial blood gas report indicating that pH is
7.25, PCO2 is 35 mm Hg, and HCO3 is 20 mEq/L (20 mmol/L)?
o Panic attack
o Persistent vomiting
o Diabetic ketoacidosis
