Maintaining acid-base balance is a critical physiological process, and disturbances can lead to life-threatening consequences. Pharmacists must be skilled in interpreting arterial blood gas (ABG) results to identify disorders, understand the underlying pathophysiology, and guide appropriate therapy. As a key topic within the Patient Care 4 curriculum’s renal system module, mastering acid-base balance is essential for providing comprehensive patient care in any clinical setting. This quiz will test your knowledge on the systematic approach to diagnosing and understanding the pathophysiology of the four primary acid-base disorders.
1. A normal arterial blood pH is tightly maintained between:
- a. 7.25 – 7.35
- b. 7.35 – 7.45
- c. 7.45 – 7.55
- d. 7.0 – 8.0
Answer: b. 7.35 – 7.45
2. In the context of acid-base balance, carbon dioxide (pCO₂) is considered the _____ component, regulated by the _____.
- a. metabolic, kidneys
- b. respiratory, lungs
- c. metabolic, lungs
- d. respiratory, kidneys
Answer: b. respiratory, lungs
3. Bicarbonate (HCO₃⁻) is considered the _____ component, regulated by the _____.
- a. metabolic, kidneys
- b. respiratory, lungs
- c. metabolic, lungs
- d. respiratory, kidneys
Answer: a. metabolic, kidneys
4. A patient’s ABG results show: pH 7.25, pCO₂ 60 mmHg, HCO₃⁻ 24 mEq/L. This represents:
- a. Respiratory Alkalosis
- b. Respiratory Acidosis
- c. Metabolic Alkalosis
- d. Metabolic Acidosis
Answer: b. Respiratory Acidosis
5. A patient with an opioid overdose is at high risk for which acid-base disorder due to hypoventilation?
- a. Respiratory Alkalosis
- b. Respiratory Acidosis
- c. Metabolic Alkalosis
- d. Metabolic Acidosis
Answer: b. Respiratory Acidosis
6. The “Acid-Base Balance” lecture is a specific topic within the Renal System module of which course?
- a. PHA5784C Patient Care 4
- b. PHA5104 Sterile Compounding
- c. PHA5703 Pharmacy Law and Ethics
- d. PHA5878C Patient Care 3
Answer: a. PHA5784C Patient Care 4
7. A patient having a panic attack and hyperventilating is most likely to develop:
- a. Respiratory Alkalosis
- b. Respiratory Acidosis
- c. Metabolic Alkalosis
- d. Metabolic Acidosis
Answer: a. Respiratory Alkalosis
8. The Anion Gap is calculated to help determine the cause of which acid-base disorder?
- a. Respiratory Alkalosis
- b. Respiratory Acidosis
- c. Metabolic Alkalosis
- d. Metabolic Acidosis
Answer: d. Metabolic Acidosis
9. Which of the following is a cause of high anion gap metabolic acidosis (HAGMA)?
- a. Diarrhea
- b. Renal tubular acidosis
- c. Diabetic ketoacidosis (DKA)
- d. Saline administration
Answer: c. Diabetic ketoacidosis (DKA)
10. How does the body compensate for metabolic acidosis?
- a. By increasing renal excretion of bicarbonate.
- b. By slowing down the respiratory rate to retain CO₂.
- c. By increasing the respiratory rate to blow off CO₂ (Kussmaul respirations).
- d. The body cannot compensate for metabolic acidosis.
Answer: c. By increasing the respiratory rate to blow off CO₂ (Kussmaul respirations).
11. The management of electrolyte abnormalities and acid-base balance are covered in the same course module.
- a. True
- b. False
Answer: a. True
12. Severe diarrhea can lead to which acid-base disorder due to loss of bicarbonate from the GI tract?
- a. High anion gap metabolic acidosis
- b. Normal anion gap metabolic acidosis
- c. Metabolic alkalosis
- d. Respiratory acidosis
Answer: b. Normal anion gap metabolic acidosis
13. A patient’s ABG results show: pH 7.55, pCO₂ 25 mmHg, HCO₃⁻ 23 mEq/L. This represents:
- a. Respiratory Alkalosis, uncompensated
- b. Respiratory Acidosis, compensated
- c. Metabolic Alkalosis, uncompensated
- d. Metabolic Acidosis, compensated
Answer: a. Respiratory Alkalosis, uncompensated
14. Prolonged vomiting or nasogastric suctioning can cause which acid-base disorder due to the loss of gastric acid (HCl)?
- a. Respiratory Acidosis
- b. Metabolic Acidosis
- c. Respiratory Alkalosis
- d. Metabolic Alkalosis
Answer: d. Metabolic Alkalosis
15. What is the formula for calculating the anion gap?
- a. Na⁺ + K⁺ + Cl⁻
- b. Na⁺ – (Cl⁻ + HCO₃⁻)
- c. (Na⁺ + K⁺) – (Cl⁻ + HCO₃⁻)
- d. HCO₃⁻ / (0.03 * pCO₂)
Answer: b. Na⁺ – (Cl⁻ + HCO₃⁻)
16. The ROME mnemonic is a helpful tool for interpreting ABGs. What does it stand for?
- a. Renal Opposite, Metabolic Equal
- b. Respiratory Opposite, Metabolic Equal
- c. Respiratory Opposite, Metabolic Elevated
- d. Renal Opposite, Metabolic Opposite
Answer: b. Respiratory Opposite, Metabolic Equal
17. An active learning session on acid-base balance is part of the Patient Care 4 curriculum.
- a. True
- b. False
Answer: a. True
18. Which compensatory mechanism is faster?
- a. Renal compensation for a respiratory disorder.
- b. Respiratory compensation for a metabolic disorder.
- c. Both are equally fast.
- d. Compensation does not occur.
Answer: b. Respiratory compensation for a metabolic disorder.
19. A patient’s ABG results show: pH 7.20, pCO₂ 40 mmHg, HCO₃⁻ 15 mEq/L. This represents:
- a. Respiratory Alkalosis
- b. Respiratory Acidosis
- c. Metabolic Alkalosis
- d. Metabolic Acidosis
Answer: d. Metabolic Acidosis
20. The Henderson-Hasselbalch equation describes the relationship between pH, pKa, and:
- a. The ratio of an acid to its conjugate base.
- b. The anion gap.
- c. The patient’s creatinine clearance.
- d. The serum osmolality.
Answer: a. The ratio of an acid to its conjugate base.
21. A patient with end-stage renal disease (ESRD) is unable to excrete metabolic acids, leading to:
- a. Chronic metabolic alkalosis
- b. Chronic respiratory acidosis
- c. Chronic metabolic acidosis
- d. A normal acid-base status
Answer: c. Chronic metabolic acidosis
22. Which of the following is NOT a cause of high anion gap metabolic acidosis? (Hint: MUDPILES)
- a. Methanol
- b. Uremia
- c. Diarrhea
- d. Salicylates
Answer: c. Diarrhea
23. How does the kidney compensate for respiratory acidosis?
- a. By increasing the excretion of bicarbonate.
- b. By increasing the reabsorption/generation of bicarbonate.
- c. By increasing the excretion of CO₂.
- d. By decreasing the excretion of potassium.
Answer: b. By increasing the reabsorption/generation of bicarbonate.
24. The “Renal System” module in Patient Care 4 covers acid-base balance.
- a. True
- b. False
Answer: a. True
25. A patient’s ABG shows: pH 7.50, pCO₂ 48 mmHg, HCO₃⁻ 35 mEq/L. This represents:
- a. Respiratory Alkalosis, compensated
- b. Respiratory Acidosis, uncompensated
- c. Metabolic Alkalosis, with respiratory compensation
- d. Metabolic Acidosis, uncompensated
Answer: c. Metabolic Alkalosis, with respiratory compensation
26. The administration of large volumes of 0.9% NaCl can cause what type of acid-base disorder?
- a. High anion gap metabolic acidosis
- b. Normal anion gap (hyperchloremic) metabolic acidosis
- c. Metabolic alkalosis
- d. Respiratory alkalosis
Answer: b. Normal anion gap (hyperchloremic) metabolic acidosis
27. What is the role of the bicarbonate buffer system?
- a. To generate energy for the cell.
- b. To immediately resist changes in pH.
- c. To transport oxygen in the blood.
- d. To regulate body temperature.
Answer: b. To immediately resist changes in pH.
28. An active learning session on acid-base is part of which course?
- a. PHA5784C Patient Care 4
- b. PHA5163L Professional Skills Lab 3
- c. PHA5781 Patient Care I
- d. PHA5782C Patient care 2
Answer: a. PHA5784C Patient Care 4
29. The term “acidemia” refers to:
- a. A blood pH < 7.35
- b. A process that lowers the blood pH.
- c. A blood pH > 7.45
- d. A process that raises the blood pH.
Answer: a. A blood pH < 7.35
30. A patient with COPD is likely to have which chronic acid-base disorder?
- a. Respiratory alkalosis
- b. Metabolic alkalosis
- c. Respiratory acidosis
- d. Metabolic acidosis
Answer: c. Respiratory acidosis
31. Winter’s formula (Expected pCO₂ = 1.5 * HCO₃⁻ + 8 ± 2) is used to assess the appropriateness of respiratory compensation in which disorder?
- a. Metabolic alkalosis
- b. Respiratory acidosis
- c. Respiratory alkalosis
- d. Metabolic acidosis
Answer: d. Metabolic acidosis
32. Excessive use of loop or thiazide diuretics can lead to:
- a. Metabolic acidosis
- b. Metabolic alkalosis
- c. Respiratory acidosis
- d. Respiratory alkalosis
Answer: b. Metabolic alkalosis
33. In respiratory alkalosis, the primary disturbance is a:
- a. Low pCO₂
- b. High pCO₂
- c. Low HCO₃⁻
- d. High HCO₃⁻
Answer: a. Low pCO₂
34. A patient’s ABG shows: pH 7.36, pCO₂ 65 mmHg, HCO₃⁻ 38 mEq/L. This represents:
- a. Normal acid-base status.
- b. Acute respiratory acidosis.
- c. Chronic respiratory acidosis (fully compensated).
- d. Decompensated metabolic alkalosis.
Answer: c. Chronic respiratory acidosis (fully compensated).
35. A patient is given sodium bicarbonate. What is the intended therapeutic effect in the setting of severe acidosis?
- a. To act as a base to buffer excess acid and increase the pH.
- b. To cause a shift of potassium into the cells.
- c. To act as a diuretic.
- d. To decrease the respiratory rate.
Answer: a. To act as a base to buffer excess acid and increase the pH.
36. A key role for the pharmacist in managing acid-base disorders is:
- a. Performing the arterial blood gas draw.
- b. Identifying and managing drug-induced acid-base disorders.
- c. Intubating the patient.
- d. Adjusting the ventilator settings.
Answer: b. Identifying and managing drug-induced acid-base disorders.
37. In metabolic alkalosis, how does the body compensate?
- a. By increasing the respiratory rate.
- b. By decreasing the respiratory rate to retain CO₂.
- c. By increasing bicarbonate excretion.
- d. By decreasing bicarbonate reabsorption.
Answer: b. By decreasing the respiratory rate to retain CO₂.
38. The management of DKA, a cause of metabolic acidosis, is a topic in the Patient Care 5 curriculum.
- a. True
- b. False
Answer: a. True
39. The normal range for arterial pCO₂ is:
- a. 22-26 mmHg
- b. 35-45 mmHg
- c. 55-65 mmHg
- d. 75-100 mmHg
Answer: b. 35-45 mmHg
40. The normal range for serum bicarbonate (HCO₃⁻) is:
- a. 12-18 mEq/L
- b. 18-22 mEq/L
- c. 22-26 mEq/L
- d. 28-32 mEq/L
Answer: c. 22-26 mEq/L
41. The first step in analyzing an ABG is to:
- a. Calculate the anion gap.
- b. Assess the pCO₂.
- c. Assess the pH.
- d. Assess the HCO₃⁻.
Answer: c. Assess the pH.
42. Which of the following can cause a high anion gap metabolic acidosis?
- a. Lactic acidosis
- b. Ketoacidosis
- c. Ethylene glycol ingestion
- d. All of the above
Answer: d. All of the above
43. A patient with a mixed acid-base disorder would show:
- a. A completely normal ABG.
- b. Two or more primary acid-base disturbances occurring simultaneously.
- c. A disorder with no compensation.
- d. A disorder with full compensation.
Answer: b. Two or more primary acid-base disturbances occurring simultaneously.
44. If a patient has a pH of 7.30 and a pCO₂ of 25 mmHg, the primary disorder is metabolic acidosis. What does the low pCO₂ represent?
- a. A second primary disorder.
- b. A laboratory error.
- c. Respiratory compensation.
- d. A lack of compensation.
Answer: c. Respiratory compensation.
45. Which of the following is NOT part of the MUDPILES mnemonic for HAGMA?
- a. Methanol
- b. Uremia
- c. Diarrhea
- d. Iron
Answer: c. Diarrhea
46. A patient taking acetazolamide is at risk for what acid-base disorder?
- a. Metabolic alkalosis
- b. Normal anion gap metabolic acidosis
- c. Respiratory acidosis
- d. Respiratory alkalosis
Answer: b. Normal anion gap metabolic acidosis
47. A patient with severe anxiety is hyperventilating. Their ABG would likely show a pH that is ____ and a pCO₂ that is ____.
- a. low, high
- b. high, low
- c. low, low
- d. high, high
Answer: b. high, low
48. The active learning session on the renal system covers acid-base balance.
- a. True
- b. False
Answer: a. True
49. The kidneys’ response to a primary respiratory disorder takes _____ to become fully effective.
- a. minutes
- b. hours
- c. days
- d. weeks
Answer: c. days
50. The ultimate goal of understanding acid-base pathophysiology is to:
- a. Correctly identify the underlying disorder to guide appropriate and life-saving therapy.
- b. Be able to recite the Henderson-Hasselbalch equation from memory.
- c. Pass the Patient Care 4 exam.
- d. Impress your preceptors on rounds.
Answer: a. Correctly identify the underlying disorder to guide appropriate and life-saving therapy.