NSG 840 Actual Exam: Oxygenation and
Mechanical Ventilation of Surgical Patients
Questions And Answers With Verified
Rationales | 2026/27 Digital Pdf Download
1. A postoperative patient suddenly develops tachypnea, restlessness,
and oxygen saturation of 86% on room air. What is the nurse’s priority
action?
A. Administer IV fluids
B. Place the patient in Trendelenburg position
C. Apply supplemental oxygen
D. Call respiratory therapy immediately
Answer: C. Apply supplemental oxygen
Rationale: Hypoxemia following surgery requires immediate correction to
improve tissue oxygenation. Supplemental oxygen is the priority intervention
before additional assessments and collaborative actions are initiated.
2. Which assessment finding is the earliest indicator of hypoxia in a
surgical patient?
A. Cyanosis
B. Bradycardia
C. Restlessness
D. Hypotension
Answer: C. Restlessness
,Rationale: Restlessness and anxiety are early neurological signs of inadequate
oxygenation. Cyanosis and hemodynamic instability are late findings.
3. A patient receiving mechanical ventilation has an arterial blood gas
(ABG) showing PaCO₂ of 52 mmHg. Which condition does this indicate?
A. Respiratory alkalosis
B. Hyperventilation
C. Respiratory acidosis
D. Metabolic acidosis
Answer: C. Respiratory acidosis
Rationale: Elevated PaCO₂ indicates carbon dioxide retention caused by
inadequate ventilation, resulting in respiratory acidosis.
4. Which ventilator mode delivers a preset tidal volume at a preset rate?
A. SIMV
B. CPAP
C. Assist-Control (AC)
D. Pressure support ventilation
Answer: C. Assist-Control (AC)
Rationale: Assist-control ventilation guarantees delivery of a preset tidal
volume and respiratory rate, making it useful for critically ill surgical
patients.
,5. A nurse notes high-pressure alarms on a ventilator. What is the most
likely cause?
A. Disconnection in tubing
B. Patient coughing
C. Low oxygen supply
D. Circuit leak
Answer: B. Patient coughing
Rationale: High-pressure alarms commonly occur from airway resistance
caused by coughing, secretions, biting the tube, or bronchospasm.
6. What is the normal range for arterial oxygen saturation (SpO₂)?
A. 75%–80%
B. 82%–88%
C. 90%–92%
D. 95%–100%
Answer: D. 95%–100%
Rationale: Normal oxygen saturation reflects adequate hemoglobin
oxygenation and tissue perfusion.
7. Which postoperative patient is at highest risk for pulmonary
embolism?
A. Ambulating after surgery
B. Receiving prophylactic anticoagulants
, C. Immobile after orthopedic surgery
D. Using incentive spirometry hourly
Answer: C. Immobile after orthopedic surgery
Rationale: Immobility and orthopedic surgery significantly increase venous
thromboembolism risk due to venous stasis and hypercoagulability.
8. Positive end-expiratory pressure (PEEP) is primarily used to:
A. Decrease oxygenation
B. Prevent alveolar collapse
C. Increase carbon dioxide retention
D. Lower intrathoracic pressure
Answer: B. Prevent alveolar collapse
Rationale: PEEP maintains alveolar expansion during expiration, improving
oxygenation and preventing atelectasis.
9. A patient on mechanical ventilation suddenly becomes agitated and
the oxygen saturation falls rapidly. What should the nurse assess first?
A. Medication history
B. Nutritional intake
C. Airway patency
D. Family support
Answer: C. Airway patency
Mechanical Ventilation of Surgical Patients
Questions And Answers With Verified
Rationales | 2026/27 Digital Pdf Download
1. A postoperative patient suddenly develops tachypnea, restlessness,
and oxygen saturation of 86% on room air. What is the nurse’s priority
action?
A. Administer IV fluids
B. Place the patient in Trendelenburg position
C. Apply supplemental oxygen
D. Call respiratory therapy immediately
Answer: C. Apply supplemental oxygen
Rationale: Hypoxemia following surgery requires immediate correction to
improve tissue oxygenation. Supplemental oxygen is the priority intervention
before additional assessments and collaborative actions are initiated.
2. Which assessment finding is the earliest indicator of hypoxia in a
surgical patient?
A. Cyanosis
B. Bradycardia
C. Restlessness
D. Hypotension
Answer: C. Restlessness
,Rationale: Restlessness and anxiety are early neurological signs of inadequate
oxygenation. Cyanosis and hemodynamic instability are late findings.
3. A patient receiving mechanical ventilation has an arterial blood gas
(ABG) showing PaCO₂ of 52 mmHg. Which condition does this indicate?
A. Respiratory alkalosis
B. Hyperventilation
C. Respiratory acidosis
D. Metabolic acidosis
Answer: C. Respiratory acidosis
Rationale: Elevated PaCO₂ indicates carbon dioxide retention caused by
inadequate ventilation, resulting in respiratory acidosis.
4. Which ventilator mode delivers a preset tidal volume at a preset rate?
A. SIMV
B. CPAP
C. Assist-Control (AC)
D. Pressure support ventilation
Answer: C. Assist-Control (AC)
Rationale: Assist-control ventilation guarantees delivery of a preset tidal
volume and respiratory rate, making it useful for critically ill surgical
patients.
,5. A nurse notes high-pressure alarms on a ventilator. What is the most
likely cause?
A. Disconnection in tubing
B. Patient coughing
C. Low oxygen supply
D. Circuit leak
Answer: B. Patient coughing
Rationale: High-pressure alarms commonly occur from airway resistance
caused by coughing, secretions, biting the tube, or bronchospasm.
6. What is the normal range for arterial oxygen saturation (SpO₂)?
A. 75%–80%
B. 82%–88%
C. 90%–92%
D. 95%–100%
Answer: D. 95%–100%
Rationale: Normal oxygen saturation reflects adequate hemoglobin
oxygenation and tissue perfusion.
7. Which postoperative patient is at highest risk for pulmonary
embolism?
A. Ambulating after surgery
B. Receiving prophylactic anticoagulants
, C. Immobile after orthopedic surgery
D. Using incentive spirometry hourly
Answer: C. Immobile after orthopedic surgery
Rationale: Immobility and orthopedic surgery significantly increase venous
thromboembolism risk due to venous stasis and hypercoagulability.
8. Positive end-expiratory pressure (PEEP) is primarily used to:
A. Decrease oxygenation
B. Prevent alveolar collapse
C. Increase carbon dioxide retention
D. Lower intrathoracic pressure
Answer: B. Prevent alveolar collapse
Rationale: PEEP maintains alveolar expansion during expiration, improving
oxygenation and preventing atelectasis.
9. A patient on mechanical ventilation suddenly becomes agitated and
the oxygen saturation falls rapidly. What should the nurse assess first?
A. Medication history
B. Nutritional intake
C. Airway patency
D. Family support
Answer: C. Airway patency
