NORCET Nursing Foundation – Oxygen Therapy

Test 01 • 50 MCQs • 50 Marks • 30 Minutes

Conceptual + Clinical + Scenario-Based Questions

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Q1. What is the primary purpose of oxygen therapy?

A. To increase blood pressure B. To correct or prevent hypoxemia C. To decrease body temperature D. To increase blood glucose

Answer: B. To correct or prevent hypoxemia
Oxygen therapy is administered to increase the availability of oxygen to tissues when oxygenation is inadequate or when clinically indicated.

Q2. Which parameter is most directly used to estimate peripheral arterial oxygen saturation?

A. Pulse oximetry B. Blood pressure C. ECG D. Temperature

Answer: A. Pulse oximetry
Pulse oximetry provides a non-invasive estimate of peripheral oxygen saturation (SpO₂). Clinical assessment should always be interpreted along with the patient's condition.

Q3. Which oxygen delivery device is generally appropriate for a patient who needs a low-flow supplemental oxygen concentration and is breathing spontaneously?

A. Nasal cannula B. Non-rebreather mask C. Venturi mask at maximum setting D. Bag-valve-mask without indication

Answer: A. Nasal cannula
A nasal cannula is commonly used for low-flow oxygen supplementation in spontaneously breathing patients.

Q4. A patient is receiving oxygen through a nasal cannula at 2 L/min. Which statement is correct?

A. It is a low-flow oxygen delivery method B. It delivers a fixed 100% FiO₂ C. It requires a reservoir bag D. It is used only during mechanical ventilation

Answer: A. It is a low-flow oxygen delivery method
Nasal cannula is a low-flow device. The actual inspired oxygen concentration varies with respiratory pattern and minute ventilation.

Q5. Which oxygen delivery device provides a more predictable fixed FiO₂?

A. Nasal cannula B. Simple face mask C. Venturi mask D. Standard nasal catheter

Answer: C. Venturi mask
A Venturi mask uses controlled air entrainment to deliver a relatively precise, predetermined oxygen concentration, making it useful when controlled FiO₂ is required.

Q6. A patient with chronic respiratory disease requires carefully controlled oxygen concentration. Which device is particularly useful?

A. Venturi mask B. Simple mask at an arbitrary flow C. Room air only D. Oxygen hood

Answer: A. Venturi mask
The Venturi system allows controlled oxygen concentration and is commonly used when precise oxygen delivery is desirable.

Q7. Which oxygen device is commonly used when a patient requires a high concentration of oxygen while still breathing spontaneously?

A. Non-rebreather mask B. Nasal cannula at 1 L/min C. Simple mask at minimum flow D. Room air

Answer: A. Non-rebreather mask
A non-rebreather mask can provide a high concentration of oxygen when properly fitted and supplied with adequate flow, and is often used in acute hypoxemia.

Q8. A patient is placed on a non-rebreather mask. What should the nurse check before relying on the device?

A. That the reservoir bag remains adequately inflated during inspiration B. That the oxygen source is turned off C. That the mask is completely loose D. That the reservoir bag is removed

Answer: A. That the reservoir bag remains adequately inflated during inspiration
The reservoir bag should remain sufficiently inflated so that the patient receives the intended oxygen concentration. The oxygen flow must be adequate.

Q9. Why should a simple face mask generally not be operated at very low oxygen flow rates?

A. It may allow carbon dioxide rebreathing B. It always causes hypothermia C. It stops the patient's heart D. It causes immediate dehydration

Answer: A. It may allow carbon dioxide rebreathing
A simple mask requires an adequate oxygen flow to flush exhaled carbon dioxide from the mask and maintain the intended oxygen delivery.

Q10. Which device is most commonly used for controlled oxygen delivery at specific FiO₂ settings?

A. Venturi mask B. Nasal cannula C. Non-rebreather without oxygen D. Face tent only

Answer: A. Venturi mask
Venturi masks are designed to deliver a selected oxygen concentration with relatively consistent FiO₂.

Q11. A patient with SpO₂ of 84% is restless and dyspneic. What should the nurse do first?

A. Assess airway and breathing and initiate appropriate oxygen support according to protocol B. Give oral fluids immediately C. Ask the patient to walk D. Ignore the reading

Answer: A. Assess airway and breathing and initiate appropriate oxygen support according to protocol
SpO₂ of 84% with respiratory distress indicates significant hypoxemia. Immediate assessment of airway, breathing and circulation with appropriate oxygen support is a priority.

Q12. Which position often helps improve ventilation in a conscious dyspneic patient?

A. High Fowler's position B. Flat supine position in every case C. Prone with no assessment D. Trendelenburg routinely

Answer: A. High Fowler's position
An upright position can improve chest expansion and reduce the work of breathing in many patients with dyspnea.

Q13. Which factor can make pulse oximetry readings unreliable?

A. Poor peripheral perfusion B. Normal circulation C. Stable patient condition D. Correct sensor placement

Answer: A. Poor peripheral perfusion
Low perfusion, motion, nail products, sensor problems and other factors can affect pulse oximeter accuracy.

Q14. A patient's fingers are cold and the pulse oximeter reads 82%, but the patient appears comfortable. What should the nurse do?

A. Assess the patient and verify the reading using appropriate measures B. Immediately assume respiratory failure C. Ignore the reading completely D. Remove all oxygen permanently

Answer: A. Assess the patient and verify the reading using appropriate measures
Cold extremities and poor perfusion can produce unreliable pulse oximetry readings. Always correlate the number with clinical assessment and verify questionable readings.

Q15. Which clinical finding is consistent with hypoxemia?

A. Restlessness and confusion B. Improved alertness only C. Normal oxygenation by definition D. Increased appetite only

Answer: A. Restlessness and confusion
Neurological manifestations such as restlessness, anxiety, confusion and altered level of consciousness may occur with significant hypoxemia.

Q16. A patient on oxygen therapy complains of nasal dryness and irritation. What intervention may help?

A. Appropriate humidification when indicated and prescribed B. Apply petroleum-based product inside the nostrils C. Stop all oxygen regardless of clinical need D. Increase oxygen flow without an order

Answer: A. Appropriate humidification when indicated and prescribed
Humidification may reduce mucosal dryness when clinically indicated. Petroleum-based products should be avoided around oxygen equipment because of fire risk.

Q17. Which substance should be avoided around oxygen equipment because of fire risk?

A. Petroleum-based products B. Water-based products when appropriate C. Sterile water in a humidifier D. Normal saline in an approved clinical system

Answer: A. Petroleum-based products
Oxygen supports combustion. Petroleum-based products should not be used near oxygen equipment because they can increase fire risk.

Q18. Which statement about oxygen safety is correct?

A. Oxygen supports combustion and should be kept away from flames and ignition sources B. Smoking is safe if oxygen flow is low C. Oxygen extinguishes fires D. Candles are safe around oxygen

Answer: A. Oxygen supports combustion and should be kept away from flames and ignition sources
Oxygen itself is not flammable, but it greatly supports combustion. Strict no-smoking and ignition-source precautions are essential.

Q19. A patient using home oxygen asks whether smoking near the oxygen cylinder is safe. What is the best response?

A. Smoking is unsafe and must be avoided around oxygen B. Smoking is safe if a window is open C. Smoking is safe if oxygen is below 2 L/min D. Only cigarettes are unsafe; candles are safe

Answer: A. Smoking is unsafe and must be avoided around oxygen
Smoking, flames and other ignition sources can cause severe fire and burn injuries in oxygen-enriched environments.

Q20. Which assessment is most important before and during oxygen therapy?

A. Respiratory status and oxygenation B. Hair texture C. Nail length D. Appetite alone

Answer: A. Respiratory status and oxygenation
Respiratory rate, work of breathing, breath sounds, mental status, SpO₂ and other relevant findings help determine response to oxygen therapy.

Q21. A patient receiving oxygen suddenly becomes increasingly drowsy and develops shallow breathing. What should the nurse do?

A. Immediately reassess airway, breathing and oxygenation and seek urgent clinical assistance B. Leave the patient to sleep C. Reduce observation D. Give oral food

Answer: A. Immediately reassess airway, breathing and oxygenation and seek urgent clinical assistance
New deterioration in consciousness and breathing may indicate worsening respiratory failure or another serious problem and requires immediate assessment.

Q22. Which device is generally used for high-flow nasal oxygen with heated humidification?

A. High-flow nasal cannula B. Simple face mask C. Standard nasal cannula at 1 L/min D. Partial face shield

Answer: A. High-flow nasal cannula
HFNC can deliver heated and humidified oxygen at high flow rates, with adjustable FiO₂, while providing respiratory support to spontaneously breathing patients.

Q23. One important benefit of high-flow nasal cannula therapy is:

A. Delivery of heated, humidified high-flow gas with controlled FiO₂ B. Complete replacement of mechanical ventilation in every patient C. No need for patient monitoring D. Guaranteed 100% oxygen saturation

Answer: A. Delivery of heated, humidified high-flow gas with controlled FiO₂
HFNC provides high flows of heated and humidified gas and can deliver a controlled oxygen concentration while improving patient comfort and respiratory support.

Q24. A patient with severe hypoxemia remains distressed despite conventional oxygen therapy. What is the appropriate nursing response?

A. Reassess the patient and escalate respiratory support according to clinical protocol B. Continue the same therapy indefinitely without reassessment C. Turn off oxygen D. Encourage vigorous exercise

Answer: A. Reassess the patient and escalate respiratory support according to clinical protocol
Persistent hypoxemia or respiratory distress requires reassessment and timely escalation, which may include advanced oxygen support or ventilatory assistance.

Q25. Which oxygen device generally requires the patient to be able to breathe spontaneously?

A. Non-rebreather mask B. Mechanical ventilator C. Bag-valve-mask operated by a trained rescuer D. Endotracheal tube connected to ventilator

Answer: A. Non-rebreather mask
A non-rebreather mask is intended for spontaneously breathing patients. Patients unable to maintain adequate ventilation may require assisted or mechanical ventilation.

Q26. Which finding suggests that oxygen therapy is effective?

A. Improved oxygen saturation and reduced respiratory distress B. Increasing cyanosis C. Increasing confusion D. Increasing work of breathing

Answer: A. Improved oxygen saturation and reduced respiratory distress
An improvement in oxygenation and clinical respiratory status indicates a positive response, although the underlying cause must also be addressed.

Q27. Which sign may indicate severe hypoxemia?

A. Cyanosis B. Warm dry skin only C. Increased appetite D. Normal mental status in every case

Answer: A. Cyanosis
Cyanosis can occur with significant hypoxemia, although its absence does not rule out hypoxemia. Pulse oximetry and clinical assessment are important.

Q28. A nurse notices that a patient's oxygen tubing is disconnected. The patient's SpO₂ is falling. What should the nurse do first?

A. Reconnect or restore the oxygen supply and immediately reassess the patient B. Wait 30 minutes C. Remove the pulse oximeter D. Document without intervention

Answer: A. Reconnect or restore the oxygen supply and immediately reassess the patient
A disconnected oxygen system can rapidly reduce oxygen delivery. Restore the prescribed oxygen source and reassess respiratory status and SpO₂.

Q29. Which nursing action helps prevent pressure injury from an oxygen mask or tubing?

A. Inspect the skin regularly and adjust/protect pressure areas appropriately B. Tighten the mask as much as possible C. Never inspect the ears D. Keep wet tubing against the skin

Answer: A. Inspect the skin regularly and adjust/protect pressure areas appropriately
Oxygen devices can cause pressure-related skin injury, especially around the ears, nose and face. Regular inspection and appropriate device positioning are important.

Q30. Which nursing diagnosis may be appropriate for a patient with inadequate oxygenation and respiratory distress?

A. Impaired Gas Exchange B. Risk for Constipation only C. Disturbed Body Image only D. Readiness for Enhanced Nutrition only

Answer: A. Impaired Gas Exchange
Impaired Gas Exchange may be appropriate when there is an alteration in oxygenation and/or carbon dioxide elimination across the alveolar-capillary membrane.

Q31. A patient with COPD has a prescribed target oxygen saturation range. Why should the nurse avoid unnecessarily giving excessive oxygen?

A. Oxygen should be titrated to the prescribed target because excessive oxygen may worsen hypercapnia in some susceptible patients B. Oxygen is always harmful in COPD C. COPD patients never need oxygen D. Oxygen causes immediate infection

Answer: A. Oxygen should be titrated to the prescribed target because excessive oxygen may worsen hypercapnia in some susceptible patients
Some patients with COPD are vulnerable to oxygen-induced hypercapnia. Oxygen should be prescribed and titrated to the appropriate target rather than withheld when clinically needed.

Q32. A patient with COPD has SpO₂ 88% and a prescribed target range of 88–92%. What is the best nursing action?

A. Maintain/titrate oxygen according to the prescribed target and monitor the patient B. Automatically increase oxygen to maximum flow C. Stop oxygen because the value is below 95% D. Ignore the prescription

Answer: A. Maintain/titrate oxygen according to the prescribed target and monitor the patient
When a target range is prescribed, oxygen should be titrated to that range while monitoring respiratory status and clinical response.

Q33. Oxygen toxicity is most strongly associated with:

A. Prolonged exposure to high concentrations of oxygen B. A few minutes of room air C. Normal breathing D. Drinking water

Answer: A. Prolonged exposure to high concentrations of oxygen
High inspired oxygen concentrations for prolonged periods can cause oxygen toxicity, particularly affecting pulmonary tissue.

Q34. Which symptom may be associated with pulmonary oxygen toxicity?

A. Substernal discomfort and cough B. Improved lung function C. Increased appetite only D. Better sleep only

Answer: A. Substernal discomfort and cough
Pulmonary oxygen toxicity can cause respiratory symptoms including cough, chest discomfort and worsening pulmonary function after significant exposure.

Q35. Which device can deliver oxygen concentration up to approximately 100% under ideal conditions?

A. Non-rebreather mask with adequate flow and proper fit B. Nasal cannula at 1 L/min C. Simple mask at 2 L/min D. Room air

Answer: A. Non-rebreather mask with adequate flow and proper fit
A properly functioning non-rebreather mask can deliver a very high inspired oxygen concentration, although the actual FiO₂ depends on fit, flow and patient ventilation.

Q36. Which oxygen delivery device is most suitable when a patient cannot maintain adequate spontaneous ventilation?

A. Mechanical ventilation or assisted ventilation as clinically indicated B. Nasal cannula only C. Simple mask only D. Venturi mask only

Answer: A. Mechanical ventilation or assisted ventilation as clinically indicated
Oxygen alone does not correct inadequate ventilation. Patients unable to maintain adequate ventilation may require bag-mask ventilation, non-invasive ventilation or invasive mechanical ventilation depending on the situation.

Q37. A patient with acute respiratory distress is receiving oxygen, but the SpO₂ continues to fall. What should the nurse prioritize?

A. Immediate reassessment and escalation of respiratory support B. Waiting for the next routine observation C. Removing oxygen D. Encouraging the patient to sleep

Answer: A. Immediate reassessment and escalation of respiratory support
Worsening hypoxemia despite oxygen therapy may indicate severe respiratory compromise. Prompt reassessment and escalation are required.

Q38. Which assessment helps determine the effectiveness of oxygen therapy beyond SpO₂ alone?

A. Work of breathing and mental status B. Hair growth C. Appetite alone D. Nail polish color only

Answer: A. Work of breathing and mental status
Clinical response includes respiratory effort, respiratory rate, breath sounds, mental status, skin color and overall patient condition in addition to oxygen saturation.

Q39. A patient wearing a nasal cannula develops redness behind the ears. What is the best nursing intervention?

A. Inspect the area, relieve pressure and use appropriate protective measures B. Tighten the tubing further C. Ignore the redness D. Apply petroleum jelly

Answer: A. Inspect the area, relieve pressure and use appropriate protective measures
Oxygen tubing can cause pressure injury behind the ears. Regular skin assessment and pressure-relieving measures are important.

Q40. Which finding requires immediate attention in a patient receiving oxygen therapy?

A. Increasing respiratory distress with falling SpO₂ B. Comfortable breathing with stable saturation C. Mild nasal dryness D. Properly positioned tubing

Answer: A. Increasing respiratory distress with falling SpO₂
Worsening respiratory distress and falling oxygen saturation indicate possible deterioration and require immediate assessment and intervention.

Q41. Which statement about oxygen administration is correct?

A. Oxygen is a medication and should be administered according to prescription/protocol B. Oxygen can always be given at any flow rate C. Oxygen requires no monitoring D. Oxygen has no adverse effects

Answer: A. Oxygen is a medication and should be administered according to prescription/protocol
Oxygen should be treated as a medication: correct device, flow/FiO₂, indication, monitoring and documentation are important.

Q42. Which equipment is necessary to deliver oxygen from a wall outlet to a patient?

A. Appropriate flowmeter and oxygen delivery device B. Thermometer only C. Stethoscope only D. Blood pressure cuff only

Answer: A. Appropriate flowmeter and oxygen delivery device
The oxygen source is connected through an appropriate flow-control system to the selected delivery interface.

Q43. A patient on oxygen therapy becomes anxious and repeatedly removes the mask. What should the nurse do first?

A. Assess the reason, respiratory status and oxygenation B. Restrain the patient immediately without assessment C. Turn off oxygen D. Leave the patient alone

Answer: A. Assess the reason, respiratory status and oxygenation
Anxiety may be caused by hypoxemia, respiratory distress, discomfort or fear. Assess the patient first and address the underlying cause.

Q44. Which finding suggests improvement in a patient receiving oxygen for acute hypoxemia?

A. SpO₂ improves and respiratory rate/work of breathing decreases B. Increasing cyanosis C. Increasing confusion D. Increasing respiratory effort

Answer: A. SpO₂ improves and respiratory rate/work of breathing decreases
Improved oxygen saturation together with reduced respiratory distress indicates a favorable clinical response.

Q45. A patient is prescribed oxygen through a Venturi mask. The nurse should primarily ensure that:

A. The correct Venturi adapter and prescribed flow are used B. The entrainment ports are blocked C. The mask is removed during breathing D. Any flow rate can be used

Answer: A. The correct Venturi adapter and prescribed flow are used
Venturi masks depend on the correct adapter and flow setting to deliver the intended oxygen concentration.

Q46. Which patient is most likely to require urgent oxygen therapy?

A. A patient with acute respiratory distress and severe hypoxemia B. A patient with normal oxygenation and no respiratory symptoms C. A patient asking for oxygen for comfort without clinical indication D. A patient with normal SpO₂ and normal breathing in every situation

Answer: A. A patient with acute respiratory distress and severe hypoxemia
Acute hypoxemia and respiratory distress are clear clinical indications for prompt oxygenation support and urgent evaluation.

Q47. A patient on a non-rebreather mask has a reservoir bag that completely collapses during inspiration. What should the nurse do?

A. Check and increase the oxygen flow as appropriate and assess the system and patient B. Ignore it C. Remove the reservoir bag D. Turn off oxygen

Answer: A. Check and increase the oxygen flow as appropriate and assess the system and patient
A collapsing reservoir bag suggests inadequate flow or another equipment problem. The oxygen source, tubing and patient should be assessed immediately.

Q48. Which instruction is appropriate for a patient receiving oxygen at home?

A. Keep oxygen away from flames, smoking and ignition sources B. Store oxygen beside an open flame C. Smoke only when oxygen is running at a low rate D. Use petroleum products freely near the equipment

Answer: A. Keep oxygen away from flames, smoking and ignition sources
Fire safety is a critical component of home oxygen education. Smoking and open flames must be strictly avoided around oxygen.

Q49. A patient with acute hypoxemia is receiving oxygen. Which outcome should the nurse prioritize?

A. Adequate oxygenation with reduced respiratory distress B. Maximum possible FiO₂ regardless of need C. Complete elimination of all respiratory symptoms immediately D. Oxygen saturation of 100% in every patient

Answer: A. Adequate oxygenation with reduced respiratory distress
The goal is adequate oxygenation appropriate to the patient's clinical condition and prescribed target—not automatically achieving 100% saturation.

Q50. Which principle best summarizes safe oxygen therapy?

A. Use the appropriate device and prescribed oxygen concentration, monitor the patient, and maintain oxygen safety B. Give the highest possible oxygen concentration to every patient C. Oxygen does not require monitoring D. Fire precautions are unnecessary in hospitals

Answer: A. Use the appropriate device and prescribed oxygen concentration, monitor the patient, and maintain oxygen safety
Safe oxygen therapy requires correct device selection, appropriate flow/FiO₂, ongoing clinical monitoring, skin care and strict fire-safety precautions.

NORCET Exams Preparation Series - Day 2 ( Oxygen Therapy )