NBRC TMC/CRT/RRT Version 3 Exam Practice Question Bank — 300 Questions with Answers and Rationales

NBRC TMC/CRT/RRT Version 3 Exam Practice Question Bank — 300 Questions with Answers and Rationales 1. A 58-year-old male with COPD is brought to the ED with worsening dyspnea. ABG on 2 L/min nasal cannula: pH 7.31, PaCO₂ 68, PaO₂ 55, HCO₃⁻ 32. What is the primary acid-base disorder? A) Acute respiratory acidosis B) Chronic respiratory acidosis C) Acute on chronic respiratory acidosis D) Metabolic alkalosis Answer: C Rationale: PaCO₂ 45 = respiratory acidosis. Elevated HCO₃⁻ (32) indicates renal compensation. pH 7.31 (7.35) shows an acute component. 2. A 34-year-old asthmatic has peak flow 180 L/min (predicted 450). After 3 albuterol nebulizers, peak flow is 210 L/min. What is the percent improvement? A) 12% B) 14% C) 16.7% D) 20% Answer: C Rationale: (210−180)/180 × 100 = 30/180 × 100 = 16.7%. 12% indicates poor response; 16.7% is minimal but positive. 3. Which of the following is the BEST indicator of hypoventilation in a spontaneously breathing patient? A) PaO₂ 60 mmHg B) PaCO₂ 55 mmHg C) SaO₂ 88% D) pH 7.32 Answer: B Rationale: PaCO₂ directly measures alveolar ventilation. 45 mmHg = hypoventilation regardless of O₂. 4. A patient post-cardiac arrest has ETCO₂ 22 mmHg on capnography. What is the most likely interpretation? A) Hyperventilation B) Hypoventilation C) Normal ventilation D) Pulmonary embolism Answer: A Rationale: Normal ETCO₂ 35–45 mmHg. 35 = hyperventilation or low cardiac output. Here, hyperventilation is most likely. 5. A 72-year-old female with pneumonia has a P/F ratio of 180. This indicates: A) Mild ARDS B) Moderate ARDS C) Severe ARDS D) No ARDS Answer: B Rationale: Berlin criteria: Mild 200–300, Moderate 100–200, Severe 100. P/F 180 = moderate ARDS. 6. You auscultate bronchial breath sounds over the right lower lobe. This suggests: A) Normal lung B) Consolidation C) Pleural effusion D) Pneumothorax Answer: B Rationale: Bronchial breath sounds normally heard over trachea. Over peripheral lung = consolidation (transmitted from central airways). 7. A patient has a pH of 7.28, PaCO₂ of 50 mmHg, and HCO₃⁻ of 24 mEq/L. What is the primary acid-base disorder? A) Respiratory acidosis B) Respiratory alkalosis C) Metabolic acidosis D) Metabolic alkalosis Answer: A Rationale: Low pH with elevated PaCO₂ indicates acute respiratory acidosis. 8. A patient has a pH of 7.48, PaCO₂ of 32 mmHg, and HCO₃⁻ of 23 mEq/L. What is the primary acid-base disorder? A) Respiratory acidosis B) Respiratory alkalosis C) Metabolic acidosis D) Metabolic alkalosis Answer: B Rationale: Elevated pH with low PaCO₂ indicates respiratory alkalosis. 9. A patient has a pH of 7.30, PaCO₂ of 38 mmHg, and HCO₃⁻ of 18 mEq/L. What is the primary acid-base disorder? A) Respiratory acidosis B) Respiratory alkalosis C) Metabolic acidosis D) Metabolic alkalosis Answer: C Rationale: Low pH with low HCO₃⁻ and normal PaCO₂ indicates metabolic acidosis. 10. A patient has a pH of 7.46, PaCO₂ of 42 mmHg, and HCO₃⁻ of 30 mEq/L. What is the primary acid-base disorder? A) Respiratory acidosis B) Respiratory alkalosis C) Metabolic acidosis D) Metabolic alkalosis Answer: D Rationale: Elevated pH with elevated HCO₃⁻ indicates metabolic alkalosis. 11. A COPD patient has a baseline HCO₃⁻ of 34 mEq/L. This indicates: A) Acute respiratory acidosis B) Chronic respiratory acidosis with renal compensation C) Metabolic alkalosis D) Normal acid-base status Answer: B Rationale: Chronic CO₂ retention triggers renal HCO₃⁻ retention to compens