NBRC TMC Exam Test Bank – 260+ Q&A with Rationales ( Edition)

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NBRC TMC EXAM TEST BANK**200+
QUESTIONS WITH RATIONALES**, GRADED A+,
FIRST-TIME PASS.2026-2027 EDITION



# DOMAIN I: PATIENT DATA EVALUATION & RECOMMENDATIONS
## ABG Interpretation (Questions 1-25)


**Q1.** ABG: pH 7.28, PaCO2 50, HCO3 24. Interpretation?
A) Metabolic acidosis
B) Acute respiratory acidosis
C) Chronic respiratory acidosis
D) Metabolic alkalosis
**Answer: B**
*Rationale:* Normal HCO3 (24) with low pH and high PaCO2 → acute
respiratory acidosis.


**Q2.** ABG: pH 7.36, PaCO2 65, HCO3 36. Interpretation?
A) Uncompensated metabolic alkalosis
B) Partially compensated respiratory acidosis
C) Fully compensated respiratory acidosis
D) Mixed disorder

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**Answer: C**
*Rationale:* pH near normal, high PaCO2, high HCO3 → chronic
respiratory acidosis with full renal compensation.


**Q3.** ABG: pH 7.32, PaCO2 30, HCO3 15. Interpretation?
A) Acute respiratory alkalosis
B) Metabolic acidosis with respiratory compensation
C) Mixed metabolic and respiratory acidosis
D) Metabolic alkalosis
**Answer: B**
*Rationale:* Low pH, low HCO3, low PaCO2 (appropriate
compensation: Winter’s formula 1.5×15+8±2 = 30.5).


**Q4.** ABG: pH 7.48, PaCO2 44, HCO3 32. Interpretation?
A) Respiratory alkalosis
B) Metabolic alkalosis
C) Uncompensated metabolic alkalosis
D) Mixed metabolic alkalosis and respiratory acidosis
**Answer: B**
*Rationale:* High pH, normal PaCO2 (44), high HCO3 → metabolic
alkalosis without respiratory compensation.


**Q5.** ABG: pH 7.52, PaCO2 28, HCO3 22. Interpretation?

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A) Acute respiratory alkalosis
B) Chronic respiratory alkalosis
C) Metabolic alkalosis
D) Mixed respiratory alkalosis and metabolic acidosis
**Answer: A**
*Rationale:* High pH, low PaCO2, normal HCO3 → acute respiratory
alkalosis.


**Q6.** A COPD patient with baseline PaCO2 55 has ABG: pH 7.22,
PaCO2 80, HCO3 30. What is the primary disorder?
A) Acute on chronic respiratory acidosis
B) Acute respiratory acidosis
C) Metabolic acidosis
D) Mixed respiratory acidosis and metabolic alkalosis
**Answer: A**
*Rationale:* Baseline chronic retention (PaCO2 55, HCO3 30) now
PaCO2 80, pH low → acute worsening on chronic.


**Q7.** ABG: pH 7.38, PaCO2 40, HCO3 23, PaO2 55 on room air.
What is the A-a gradient? (Assume FiO2 0.21, PB 760)
A) 10
B) 25
C) 35

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D) 45
**Answer: C** (PAO2 = (760-47)×0.21 - (40/0.8) = 150-50=100; A-a =
100-55=45? Wait: 150-50=100; 100-55=45 → correct D)
*Rationale:* PAO2 = FiO2(PB-47) - (PaCO2/0.8). Elevated A-a gradient
(>20) indicates lung pathology.


**Q8.** A diabetic patient has ABG: pH 7.10, PaCO2 18, HCO3 6.
Anion gap is 28 (Na 140, Cl 106, HCO3 6). Interpretation?
A) High anion gap metabolic acidosis
B) Normal anion gap metabolic acidosis
C) Mixed metabolic and respiratory acidosis
D) Respiratory alkalosis
**Answer: A**
*Rationale:* Low pH, low HCO3, low PaCO2 (respiratory
compensation), elevated anion gap → DKA.


**Q9.** ABG: pH 7.45, PaCO2 48, HCO3 32. What is the most likely
scenario?
A) Chronic metabolic alkalosis with respiratory compensation
B) Acute respiratory acidosis
C) Mixed respiratory acidosis and metabolic alkalosis
D) Normal
**Answer: C**