NUR 113 EXAM 1 PRACTICE QUESTIONS WITH
DETAILED EXPLANATIONS 2026
◉ What happens to pH when hydrogen ion concentration increases?
Answer: The pH decreases (becomes more acidic).
◉ What is the significance of acid-base balance?
Answer: It is crucial for normal physiological function.
◉ What are the two systems that regulate acid-base balance?
Answer: The respiratory system and the renal system.
◉ What is the role of the respiratory system in acid-base balance?
Answer: It regulates carbon dioxide (CO2) excretion.
◉ What is the normal range for PaCO2 in arterial blood?
Answer: 35 - 45 mmHg
◉ What does a pH level below 7.35 indicate?
Answer: Acidosis.
,◉ What does a pH level above 7.45 indicate?
Answer: Alkalosis.
◉ What is the normal range for HCO3 in arterial blood?
Answer: 22 - 26 mEq/L
◉ What is the primary indicator of metabolic acid-base
disturbances?
Answer: Bicarbonate (HCO3).
◉ What is respiratory acidosis characterized by?
Answer: Increased PaCO2 and decreased pH.
◉ What is metabolic alkalosis characterized by?
Answer: Increased HCO3 and increased pH.
◉ What is the formula for carbonic acid formation?
Answer: CO2 + H2O = Carbonic Acid.
◉ What is the role of kidneys in acid-base balance?
Answer: They control sodium bicarbonate and excrete acids or
regenerate bases.
,◉ What is the normal range for PaO2 in arterial blood?
Answer: 80 - 100 mmHg
◉ What does SaO2 measure?
Answer: The percentage of oxygen bound to hemoglobin.
◉ What is the first step in interpreting arterial blood gases (ABGs)?
Answer: Check the pH to determine if it is normal.
◉ What indicates hypoxemia in terms of PaO2 levels?
Answer: PaO2 levels below 80 mmHg.
◉ What is the compensation mechanism for acidosis?
Answer: The respiratory system increases ventilation to decrease
CO2.
◉ What is the compensation mechanism for alkalosis?
Answer: The respiratory system decreases ventilation to increase
CO2.
, ◉ What is the relationship between pH and HCO3 in metabolic
acidosis?
Answer: pH decreases and HCO3 decreases.
◉ What is the relationship between pH and PaCO2 in respiratory
alkalosis?
Answer: pH increases and PaCO2 decreases.
◉ What indicates respiratory acidosis in ABG results?
Answer: Low pH < 7.35 and elevated CO2 levels PaCO2 > 45.
◉ What is the normal range for PaO2?
Answer: 80-100 mmHg.
◉ What does a PaO2 below 80 indicate?
Answer: Hypoxemia.
◉ What is the normal range for oxygen saturation (SaO2)?
Answer: 95-100%.
◉ What does the acronym R*O*M*E stand for in ABG interpretation?
Answer: Respiratory Opposite / Metabolic Equal.
DETAILED EXPLANATIONS 2026
◉ What happens to pH when hydrogen ion concentration increases?
Answer: The pH decreases (becomes more acidic).
◉ What is the significance of acid-base balance?
Answer: It is crucial for normal physiological function.
◉ What are the two systems that regulate acid-base balance?
Answer: The respiratory system and the renal system.
◉ What is the role of the respiratory system in acid-base balance?
Answer: It regulates carbon dioxide (CO2) excretion.
◉ What is the normal range for PaCO2 in arterial blood?
Answer: 35 - 45 mmHg
◉ What does a pH level below 7.35 indicate?
Answer: Acidosis.
,◉ What does a pH level above 7.45 indicate?
Answer: Alkalosis.
◉ What is the normal range for HCO3 in arterial blood?
Answer: 22 - 26 mEq/L
◉ What is the primary indicator of metabolic acid-base
disturbances?
Answer: Bicarbonate (HCO3).
◉ What is respiratory acidosis characterized by?
Answer: Increased PaCO2 and decreased pH.
◉ What is metabolic alkalosis characterized by?
Answer: Increased HCO3 and increased pH.
◉ What is the formula for carbonic acid formation?
Answer: CO2 + H2O = Carbonic Acid.
◉ What is the role of kidneys in acid-base balance?
Answer: They control sodium bicarbonate and excrete acids or
regenerate bases.
,◉ What is the normal range for PaO2 in arterial blood?
Answer: 80 - 100 mmHg
◉ What does SaO2 measure?
Answer: The percentage of oxygen bound to hemoglobin.
◉ What is the first step in interpreting arterial blood gases (ABGs)?
Answer: Check the pH to determine if it is normal.
◉ What indicates hypoxemia in terms of PaO2 levels?
Answer: PaO2 levels below 80 mmHg.
◉ What is the compensation mechanism for acidosis?
Answer: The respiratory system increases ventilation to decrease
CO2.
◉ What is the compensation mechanism for alkalosis?
Answer: The respiratory system decreases ventilation to increase
CO2.
, ◉ What is the relationship between pH and HCO3 in metabolic
acidosis?
Answer: pH decreases and HCO3 decreases.
◉ What is the relationship between pH and PaCO2 in respiratory
alkalosis?
Answer: pH increases and PaCO2 decreases.
◉ What indicates respiratory acidosis in ABG results?
Answer: Low pH < 7.35 and elevated CO2 levels PaCO2 > 45.
◉ What is the normal range for PaO2?
Answer: 80-100 mmHg.
◉ What does a PaO2 below 80 indicate?
Answer: Hypoxemia.
◉ What is the normal range for oxygen saturation (SaO2)?
Answer: 95-100%.
◉ What does the acronym R*O*M*E stand for in ABG interpretation?
Answer: Respiratory Opposite / Metabolic Equal.
