Acid-base balance is a critical physiological state, and its derangement can be a life-threatening emergency. Pharmacists, especially in acute care settings, must be proficient in interpreting arterial blood gas (ABG) results, identifying the four primary acid-base disorders, and recommending appropriate pharmacotherapy. This quiz for PharmD students will test your knowledge of the fundamental principles of acid-base physiology, ABG analysis, and the management of acidosis and alkalosis.
1. The normal range for arterial blood pH in a human is:
- 7.25 – 7.35
- 7.35 – 7.45
- 7.45 – 7.55
- 7.00 – 7.20
Answer: 7.35 – 7.45
2. The primary buffer system that regulates pH in the extracellular fluid is the:
- Phosphate buffer system
- Protein buffer system
- Carbonic acid-bicarbonate buffer system
- Hemoglobin buffer system
Answer: Carbonic acid-bicarbonate buffer system
3. An arterial blood gas (ABG) report shows the following: pH 7.28, PCO₂ 60 mmHg, HCO₃ 25 mEq/L. This is consistent with which primary disorder?
- Metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Respiratory acidosis
4. An ABG report shows: pH 7.52, PCO₂ 28 mmHg, HCO₃ 24 mEq/L. This is consistent with which primary disorder?
- Metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Respiratory alkalosis
5. An ABG report shows: pH 7.25, PCO₂ 40 mmHg, HCO₃ 16 mEq/L. This is consistent with which primary disorder?
- Metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Metabolic acidosis
6. An ABG report shows: pH 7.55, PCO₂ 42 mmHg, HCO₃ 35 mEq/L. This is consistent with which primary disorder?
- Metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Metabolic alkalosis
7. The term “acidemia” refers to a state where the arterial blood pH is:
- Greater than 7.45
- Less than 7.35
- Exactly 7.40
- Within the normal range
Answer: Less than 7.35
8. Which of the following is a common cause of respiratory acidosis?
- Hyperventilation
- Anxiety or panic attack
- Hypoventilation due to opioid overdose or COPD exacerbation
- Aspirin overdose
Answer: Hypoventilation due to opioid overdose or COPD exacerbation
9. A patient experiencing a panic attack is breathing very rapidly. They are at risk for developing:
- Respiratory acidosis
- Respiratory alkalosis
- Metabolic acidosis
- Metabolic alkalosis
Answer: Respiratory alkalosis
10. Diabetic ketoacidosis (DKA) is a classic cause of which type of acid-base disorder?
- Respiratory acidosis
- Anion gap metabolic acidosis
- Non-anion gap metabolic acidosis
- Metabolic alkalosis
Answer: Anion gap metabolic acidosis
11. The anion gap is an important calculation used to differentiate the causes of:
- Respiratory acidosis
- Respiratory alkalosis
- Metabolic acidosis
- Metabolic alkalosis
Answer: Metabolic acidosis
12. The standard formula for calculating the anion gap is:
- Na⁺ – (Cl⁻ + PCO₂)
- Na⁺ + K⁺ – (Cl⁻ + HCO₃⁻)
- Na⁺ – (Cl⁻ + HCO₃⁻)
- (Na⁺ + K⁺) – (Cl⁻ + PCO₂)
Answer: Na⁺ – (Cl⁻ + HCO₃⁻)
13. A patient with severe diarrhea is losing large amounts of bicarbonate. This is a common cause of:
- Anion gap metabolic acidosis
- Non-anion gap metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
Answer: Non-anion gap metabolic acidosis
14. A patient with severe vomiting is losing large amounts of gastric acid. This is a common cause of:
- Anion gap metabolic acidosis
- Non-anion gap metabolic acidosis
- Metabolic alkalosis
- Respiratory alkalosis
Answer: Metabolic alkalosis
15. In the Henderson-Hasselbalch equation, the PCO₂ represents the ________ component, and the HCO₃ represents the ________ component of the acid-base balance.
- Metabolic; Renal
- Respiratory; Metabolic
- Renal; Respiratory
- Metabolic; Respiratory
Answer: Respiratory; Metabolic
16. When the body tries to correct an acid-base imbalance, it is called “compensation.” The primary organ system that compensates for a metabolic disorder is the:
- Liver
- Kidneys
- Lungs
- Heart
Answer: The Lungs
17. The primary organ system that compensates for a respiratory disorder is the:
- Lungs
- Liver
- Heart
- Kidneys
Answer: The Kidneys
18. A patient has metabolic acidosis. What would be the expected respiratory compensation?
- The patient will breathe slower (hypoventilation) to retain CO₂.
- The patient will breathe faster (hyperventilation) to blow off CO₂.
- There is no respiratory compensation for a metabolic disorder.
- The respiratory rate will not change.
Answer: The patient will breathe faster (hyperventilation) to blow off CO₂.
19. A patient has chronic respiratory acidosis due to COPD. What would be the expected metabolic (renal) compensation?
- The kidneys will excrete more bicarbonate.
- The kidneys will retain more bicarbonate, leading to an elevated serum HCO₃.
- The kidneys do not compensate for respiratory disorders.
- The kidneys will excrete more acid.
Answer: The kidneys will retain more bicarbonate, leading to an elevated serum HCO₃.
20. An ABG shows: pH 7.36, PCO₂ 60 mmHg, HCO₃ 34 mEq/L. This represents:
- Acute respiratory acidosis.
- Metabolic alkalosis.
- Respiratory acidosis with full metabolic compensation.
- A normal ABG.
Answer: Respiratory acidosis with full metabolic compensation.
21. A patient with an aspirin (salicylate) overdose often presents with which complex acid-base disorder?
- A pure metabolic acidosis.
- A pure respiratory alkalosis.
- A mixed respiratory alkalosis and anion gap metabolic acidosis.
- A mixed metabolic alkalosis and respiratory acidosis.
Answer: A mixed respiratory alkalosis and anion gap metabolic acidosis.
22. Which of the following substances would contribute to an elevated anion gap if ingested?
- Sodium chloride
- Potassium chloride
- Methanol or ethylene glycol
- Water
Answer: Methanol or ethylene glycol
23. The treatment for severe, life-threatening metabolic acidosis (e.g., pH < 7.1) may include the administration of:
- Intravenous sodium bicarbonate.
- Intravenous 0.9% NaCl.
- Intravenous potassium chloride.
- A loop diuretic.
Answer: Intravenous sodium bicarbonate.
24. A pharmacist’s role in managing acid-base disorders in the ICU includes:
- Interpreting ABG results.
- Recommending adjustments to ventilator settings to correct PCO₂.
- Calculating doses for bicarbonate infusions.
- All of the above.
Answer: All of the above.
25. In a patient with metabolic alkalosis, the compensatory response is:
- Hypoventilation to increase PCO₂.
- Hyperventilation to decrease PCO₂.
- Renal retention of bicarbonate.
- Renal excretion of acid.
Answer: Hypoventilation to increase PCO₂.
26. The normal range for arterial PCO₂ is:
- 22-26 mmHg
- 35-45 mmHg
- 50-60 mmHg
- 75-100 mmHg
Answer: 35-45 mmHg
27. The normal range for serum bicarbonate (HCO₃) is:
- 12-18 mEq/L
- 18-22 mEq/L
- 22-26 mEq/L
- 28-32 mEq/L
Answer: 22-26 mEq/L
28. Kussmaul respirations (deep, rapid breathing) are a clinical sign of the body’s attempt to compensate for:
- Respiratory acidosis
- Metabolic alkalosis
- Metabolic acidosis
- Respiratory alkalosis
Answer: Metabolic acidosis
29. The “MUDPILES” mnemonic is used to remember the causes of:
- Non-anion gap metabolic acidosis.
- Respiratory alkalosis.
- Anion gap metabolic acidosis.
- Metabolic alkalosis.
Answer: Anion gap metabolic acidosis.
30. The “L” in MUDPILES stands for:
- Lisinopril
- Lactate (lactic acidosis)
- Liver failure
- Loop diuretics
Answer: Lactate (lactic acidosis)
31. Respiratory compensation for a metabolic disorder is ________, while metabolic compensation for a respiratory disorder is ________.
- Slow; Rapid
- Rapid; Slow
- Ineffective; Effective
- Complete; Partial
Answer: Rapid; Slow
32. The primary treatment for any respiratory acid-base disorder is to:
- Administer intravenous bicarbonate.
- Administer a diuretic.
- Correct the underlying cause of the abnormal ventilation.
- Start renal replacement therapy.
Answer: Correct the underlying cause of the abnormal ventilation.
33. A patient receiving large volumes of 0.9% NaCl is at risk for developing which acid-base disorder?
- Anion gap metabolic acidosis
- Hyperchloremic, non-anion gap metabolic acidosis
- Metabolic alkalosis
- Respiratory acidosis
Answer: Hyperchloremic, non-anion gap metabolic acidosis
34. The pharmacist’s knowledge of __________ is critical for managing drug therapy in patients with acid-base disturbances, as pH can affect drug distribution and protein binding.
- Medicinal chemistry
- Pharmacokinetics
- Pharmacy law
- Marketing
Answer: Pharmacokinetics
35. A patient with an NG tube on continuous suction is losing gastric acid. What electrolyte abnormality often accompanies the resulting metabolic alkalosis?
- Hyperkalemia
- Hypokalemia
- Hypernatremia
- Hyperphosphatemia
Answer: Hypokalemia
36. A pharmacist’s assessment of a patient’s ABG results is part of which step in the Pharmacists’ Patient Care Process?
- Plan
- Implement
- Collect and Assess
- Follow-up
Answer: Collect and Assess
37. Which of the following is a potential cause of lactic acidosis?
- Severe infection (sepsis)
- Tissue hypoxia
- Certain medications like metformin (rarely)
- All of the above
Answer: All of the above
38. The treatment of chloride-responsive metabolic alkalosis involves:
- Administering intravenous bicarbonate.
- Administering fluids (like 0.9% NaCl) and repleting potassium.
- Restricting fluid intake.
- Starting a proton pump inhibitor.
Answer: Administering fluids (like 0.9% NaCl) and repleting potassium.
39. A key leadership role for a critical care pharmacist is to:
- Develop institutional protocols for the management of acid-base emergencies.
- Make all patient care decisions independently.
- Manage the nursing schedule.
- Order all laboratory tests.
Answer: Develop institutional protocols for the management of acid-base emergencies.
40. A patient’s acid-base status can influence electrolyte levels. For instance, acidemia tends to cause potassium to move:
- Out of the cells, leading to hyperkalemia.
- Into the cells, leading to hypokalemia.
- There is no effect on potassium levels.
- Both into and out of the cells equally.
Answer: Out of the cells, leading to hyperkalemia.
41. The use of a “smart pump” drug library for a sodium bicarbonate infusion is a safety technology designed to:
- Prevent dosing and infusion rate errors.
- Order the drug from the pharmacy.
- Bill for the infusion.
- Document the administration of the dose.
Answer: Prevent dosing and infusion rate errors.
42. A pharmacist’s role on ICU rounds is to apply their knowledge of acid-base principles to:
- Ensure the safe and effective use of medications in a critically ill patient.
- Remain silent and only observe.
- Take notes for the physician.
- Manage the ventilator settings.
Answer: Ensure the safe and effective use of medications in a critically ill patient.
43. A fully compensated acid-base disorder is characterized by a:
- pH that is severely abnormal.
- pH that has returned to the normal range, but the PCO₂ and HCO₃ are still abnormal.
- Normal PCO₂ and normal HCO₃.
- pH, PCO₂, and HCO₃ that are all abnormal.
Answer: pH that has returned to the normal range, but the PCO₂ and HCO₃ are still abnormal.
44. The use of acetazolamide, a carbonic anhydrase inhibitor, can cause which acid-base disorder?
- Metabolic alkalosis
- Non-anion gap metabolic acidosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Non-anion gap metabolic acidosis
45. Which of the following is a key step in a systematic interpretation of an ABG?
- Assess the pH to determine if it is acidemia or alkalemia.
- Determine if the primary disturbance is respiratory or metabolic.
- Check for compensation.
- All of the above.
Answer: All of the above.
46. A patient with end-stage renal disease who misses their dialysis sessions is at high risk for:
- Metabolic alkalosis
- Anion gap metabolic acidosis
- Respiratory alkalosis
- A normal acid-base status
Answer: Anion gap metabolic acidosis
47. An important part of a first response to a trauma patient is to assess their “ABCs.” The “B” (Breathing) is a direct assessment of:
- Their acid-base status.
- Their potential for a respiratory acid-base disorder.
- Their cardiac output.
- Their level of consciousness.
Answer: Their potential for a respiratory acid-base disorder.
48. An interprofessional team approach is critical for managing complex acid-base disorders because:
- It requires the coordinated expertise of physicians, nurses, respiratory therapists, and pharmacists.
- It is a requirement for hospital billing.
- It makes decision-making slower and less efficient.
- Each profession can work in isolation to achieve the best outcome.
Answer: It requires the coordinated expertise of physicians, nurses, respiratory therapists, and pharmacists.
49. Forging ahead in pharmacy practice means pharmacists in acute care settings will be increasingly involved in:
- The direct management of complex states like acid-base disorders.
- A purely dispensing role.
- Avoiding all patient care decisions.
- A reduction in their clinical responsibilities.
Answer: The direct management of complex states like acid-base disorders.
50. The ultimate goal of managing an acid-base disorder is to:
- Normalize the pH number on the lab report.
- Treat the underlying cause and restore normal physiological function.
- Use as many intravenous drips as possible.
- Discharge the patient as quickly as possible.
Answer: Treat the underlying cause and restore normal physiological function.
