ATI CRITICAL ALTERATIONS IN GAS EXCHANGE: COMPREHENSIVE EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF 250

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
Rationale: In status asthmaticus, continuous nebulized beta-agonists are first-line to reverse
bronchoconstriction.

,7. In a patient with COPD and chronic hypercapnia, what is the primary stimulus for breathing?
A) Central chemoreceptors (PaCO₂)
B) Peripheral chemoreceptors (PaO₂)
C) Stretch receptors
D) Irritant receptors
Answer B: Peripheral chemoreceptors (PaO₂)
Rationale: In chronic hypercapnia, the central chemoreceptors are desensitized; the hypoxic drive (PaO₂)
becomes the primary stimulus for breathing.




8. Which of the following is a risk factor for the development of acute respiratory distress syndrome
(ARDS)?
A) Asthma
B) Sepsis
C) COPD
D) Hypertension
Answer B: Sepsis
Rationale: Sepsis is the most common risk factor for ARDS, triggering a systemic inflammatory response
that injures the alveolar-capillary membrane.




9. A patient with ARDS is placed in the prone position. What is the primary rationale for this
intervention?
A) Prevent pressure injuries
B) Improve oxygenation by matching ventilation and perfusion
C) Facilitate suctioning
D) Reduce ventilator-associated pneumonia
Answer B: Improve oxygenation by matching ventilation and perfusion
Rationale: Prone positioning redistributes ventilation to dorsal lung regions and improves V/Q matching,
enhancing oxygenation.




10. Which of the following is a sign of tension pneumothorax?
A) Decreased heart rate
B) Tracheal deviation away from the affected side
C) Equal breath sounds

, D) Hypertension
j




Answer B: Tracheal deviation away from the affected side
j j j j j j j j




Rationale: Tracheal deviation to the contralateral side indicates mediastinal shift, a late sign of tension
j j j j j j j j j j j j j j




j pneumothorax requiring immediate needle decompression. j j j j




11. A patient with COPD has a SpO₂ of 88% on 2 L/min via nasal cannula. What is the most appropriate
j j j j j j j j j j j j j j j j j j j j




j nursing action? j




A) Increase oxygen to 4 L/min
j j j j j




B) Administer oxygen at 2 L/min and assess for signs of respiratory distress
j j j j j j j j j j j j




C) Apply a non-rebreather mask
j j j j




D) Discontinue oxygen therapy
j j j




Answer B: Administer oxygen at 2 L/min and assess for signs of respiratory distress
j j j j j j j j j j j j j




Rationale: COPD patients with chronic hypercapnia are at risk for hypoxic drive; low-flow oxygen (1-2 L/min)
j j j j j j j j j j j j j j j




j is preferred with close monitoring.
j j j j




12. The nurse is assessing a patient with acute respiratory failure. Which of the following findings
j j j j j j j j j j j j j j j




j indicates impending respiratory arrest? j j j




A) Respiratory rate of 30 breaths/min
j j j j j




B) Agonal respirations
j j




C) SpO₂ of 92%
j j j




D) Mild retractions
j j




Answer B: Agonal respirations j j j




Rationale: Agonal respirations are irregular, gasping breaths indicating severe brainstem hypoxia and
j j j j j j j j j j j




j impending respiratory arrest. j j




13. A patient with ARDS is receiving positive end-expiratory pressure (PEEP). The nurse should monitor
j j j j j j j j j j j j j j




j for which complication?
j j




A) Increased cardiac output
j j j




B) Decreased venous return and hypotension
j j j j j




C) Increased urine output
j j j




D) Bradycardia
j




Answer B: Decreased venous return and hypotension
j j j j j j