ATI CRITICAL ALTERATIONS IN GAS EXCHANGE: COMPREHENSIVE
EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A
Questions 1–250
1. A patient with ARDS is on mechanical ventilation. The nurse
notes a sudden drop in oxygen saturation and increased peak
airway pressures. Which complication should the nurse suspect?
A) Pulmonary edema
B) Pneumothorax
C) Atelectasis
D) Mucus plug
Answer B: Pneumothorax
,Rationale: Sudden drop in SpO₂ with increased peak airway pressures
and decreased breath sounds on the affected side suggests
pneumothorax, a common complication of positive-pressure
ventilation.
2. A patient with COPD has an arterial blood gas (ABG) showing pH
7.32, PaCO₂ 58 mmHg, HCO₃ 28 mEq/L. Which acid-base disorder is
present?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis with metabolic compensation
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer B: Chronic respiratory acidosis with metabolic
compensation
Rationale: Elevated PaCO₂ with low pH indicates respiratory acidosis;
the elevated HCO₃ indicates renal compensation, suggesting
chronicity.
,3. Which ABG finding is most characteristic of acute respiratory
distress syndrome (ARDS) in the early phase?
A) pH 7.48, PaCO₂ 30, PaO₂ 60, HCO₃ 22
B) pH 7.30, PaCO₂ 35, PaO₂ 55, HCO₃ 20
C) pH 7.35, PaCO₂ 40, PaO₂ 90, HCO₃ 24
D) pH 7.40, PaCO₂ 45, PaO₂ 80, HCO₃ 25
Answer B: pH 7.30, PaCO₂ 35, PaO₂ 55, HCO₃ 20
Rationale: ARDS presents with refractory hypoxemia, low PaCO₂
(respiratory alkalosis), and metabolic acidosis from tissue hypoxia.
4. The nurse is caring for a patient with acute respiratory failure.
Which assessment finding indicates the need for immediate
intubation?
A) Respiratory rate of 28 breaths/min
B) GCS score of 8
C) SpO₂ of 90% on 4 L/min
D) Use of accessory muscles
Answer B: GCS score of 8
Rationale: GCS ≤8 indicates compromised airway protection and is an
indication for intubation.
, 5. A patient is receiving oxygen via a Venturi mask at 40% FiO₂.
Which is the correct flow rate for this setting?
A) 2 L/min
B) 4 L/min
C) 6-8 L/min
D) 10-15 L/min
Answer C: 6-8 L/min
Rationale: Venturi masks use specific flow rates to deliver precise
FiO₂; 40% typically requires 6-8 L/min.
6. A patient with asthma is experiencing status asthmaticus. Which
medication should the nurse prepare to administer first?
A) Continuous albuterol nebulization
B) IV methylprednisolone
C) Magnesium sulfate
D) Heliox therapy
Answer A: Continuous albuterol nebulization
EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A
Questions 1–250
1. A patient with ARDS is on mechanical ventilation. The nurse
notes a sudden drop in oxygen saturation and increased peak
airway pressures. Which complication should the nurse suspect?
A) Pulmonary edema
B) Pneumothorax
C) Atelectasis
D) Mucus plug
Answer B: Pneumothorax
,Rationale: Sudden drop in SpO₂ with increased peak airway pressures
and decreased breath sounds on the affected side suggests
pneumothorax, a common complication of positive-pressure
ventilation.
2. A patient with COPD has an arterial blood gas (ABG) showing pH
7.32, PaCO₂ 58 mmHg, HCO₃ 28 mEq/L. Which acid-base disorder is
present?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis with metabolic compensation
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer B: Chronic respiratory acidosis with metabolic
compensation
Rationale: Elevated PaCO₂ with low pH indicates respiratory acidosis;
the elevated HCO₃ indicates renal compensation, suggesting
chronicity.
,3. Which ABG finding is most characteristic of acute respiratory
distress syndrome (ARDS) in the early phase?
A) pH 7.48, PaCO₂ 30, PaO₂ 60, HCO₃ 22
B) pH 7.30, PaCO₂ 35, PaO₂ 55, HCO₃ 20
C) pH 7.35, PaCO₂ 40, PaO₂ 90, HCO₃ 24
D) pH 7.40, PaCO₂ 45, PaO₂ 80, HCO₃ 25
Answer B: pH 7.30, PaCO₂ 35, PaO₂ 55, HCO₃ 20
Rationale: ARDS presents with refractory hypoxemia, low PaCO₂
(respiratory alkalosis), and metabolic acidosis from tissue hypoxia.
4. The nurse is caring for a patient with acute respiratory failure.
Which assessment finding indicates the need for immediate
intubation?
A) Respiratory rate of 28 breaths/min
B) GCS score of 8
C) SpO₂ of 90% on 4 L/min
D) Use of accessory muscles
Answer B: GCS score of 8
Rationale: GCS ≤8 indicates compromised airway protection and is an
indication for intubation.
, 5. A patient is receiving oxygen via a Venturi mask at 40% FiO₂.
Which is the correct flow rate for this setting?
A) 2 L/min
B) 4 L/min
C) 6-8 L/min
D) 10-15 L/min
Answer C: 6-8 L/min
Rationale: Venturi masks use specific flow rates to deliver precise
FiO₂; 40% typically requires 6-8 L/min.
6. A patient with asthma is experiencing status asthmaticus. Which
medication should the nurse prepare to administer first?
A) Continuous albuterol nebulization
B) IV methylprednisolone
C) Magnesium sulfate
D) Heliox therapy
Answer A: Continuous albuterol nebulization
