Pulse oximetry MCQs – Anesthesia

By: Prof. Dr. Fazal Rehman Shamil | Last updated: September 13, 2024

Pulse Oximetry MCQs – Anesthesia

1. What does a pulse oximeter primarily measure?
   a) Blood pressure
   b) Oxygen saturation
   c) Heart rate
   d) Carbon dioxide levelsAnswer: b) Oxygen saturation
2. Which wavelength of light is used to measure oxygen saturation in pulse oximetry?
   a) Infrared and ultraviolet
   b) Red and infrared
   c) Blue and green
   d) Red and blueAnswer: b) Red and infrared
3. What is the typical range of normal oxygen saturation values as measured by a pulse oximeter?
   a) 80-85%
   b) 85-90%
   c) 90-100%
   d) 70-90%Answer: c) 90-100%
4. Which factor can affect the accuracy of pulse oximetry readings?
   a) Ambient temperature
   b) Nail polish
   c) Patient’s weight
   d) Patient’s ageAnswer: b) Nail polish
5. What does a pulse oximeter detect to calculate oxygen saturation?
   a) Pulse pressure
   b) Blood volume
   c) Oxygenated and deoxygenated hemoglobin
   d) Carbon dioxide levelsAnswer: c) Oxygenated and deoxygenated hemoglobin
6. Which condition is most likely to cause a false high reading on a pulse oximeter?
   a) Hypothermia
   b) Low perfusion
   c) Carbon monoxide poisoning
   d) HyperventilationAnswer: c) Carbon monoxide poisoning
7. In which situation is a pulse oximeter least reliable?
   a) High blood pressure
   b) Severe hypovolemia
   c) Normal temperature
   d) Regular breathing rateAnswer: b) Severe hypovolemia
8. What does a low pulse oximetry reading typically indicate?
   a) Hyperoxia
   b) Hypoxia
   c) Hypercapnia
   d) Normal oxygenationAnswer: b) Hypoxia
9. Which of the following could lead to a false low reading on a pulse oximeter?
   a) Bright lighting
   b) Patient movement
   c) Good perfusion
   d) Accurate calibrationAnswer: b) Patient movement
10. How does a pulse oximeter estimate oxygen saturation levels?
    a) By measuring the partial pressure of oxygen
    b) By calculating the absorption of light at two different wavelengths
    c) By analyzing the carbon dioxide concentration in the blood
    d) By detecting heart rate variabilityAnswer: b) By calculating the absorption of light at two different wavelengths
11. What is the role of a pulse oximeter in anesthesia?
    a) To monitor blood glucose levels
    b) To assess oxygenation and detect hypoxia
    c) To measure blood pressure
    d) To evaluate cardiac outputAnswer: b) To assess oxygenation and detect hypoxia
12. What is the most common site for applying a pulse oximeter probe?
    a) Forehead
    b) Ear lobe
    c) Finger
    d) ToeAnswer: c) Finger
13. Which physiological condition could lead to a false high reading of oxygen saturation on a pulse oximeter?
    a) Anemia
    b) Hypercapnia
    c) Carbon monoxide exposure
    d) HypothermiaAnswer: c) Carbon monoxide exposure
14. What does a rapid decrease in pulse oximeter readings indicate during anesthesia?
    a) Improved oxygenation
    b) Hypoxemia or impaired ventilation
    c) Hyperoxia
    d) Normal blood gas levelsAnswer: b) Hypoxemia or impaired ventilation
15. Which type of light is absorbed more by oxygenated hemoglobin?
    a) Red light
    b) Infrared light
    c) Blue light
    d) Green lightAnswer: b) Infrared light
16. Which of the following factors can affect pulse oximeter accuracy?
    a) Skin pigmentation
    b) Age of the patient
    c) Body temperature
    d) Type of anesthesiaAnswer: a) Skin pigmentation
17. What can cause a pulse oximeter to give inaccurate readings in a patient with low blood flow?
    a) High blood pressure
    b) Poor perfusion
    c) High oxygen levels
    d) Normal heart rateAnswer: b) Poor perfusion
18. What is the primary use of a pulse oximeter in postoperative care?
    a) To assess pain levels
    b) To monitor oxygen saturation levels
    c) To measure wound healing
    d) To evaluate fluid balanceAnswer: b) To monitor oxygen saturation levels
19. Which substance can interfere with pulse oximeter readings by mimicking oxygen saturation?
    a) Methanol
    b) Carbon monoxide
    c) Alcohol
    d) AspirinAnswer: b) Carbon monoxide
20. What should be done if a pulse oximeter reading is consistently low?
    a) Recalibrate the device
    b) Change the probe location
    c) Increase ambient lighting
    d) Use a different brand of pulse oximeterAnswer: b) Change the probe location
21. Which parameter is NOT directly measured by a pulse oximeter?
    a) Oxygen saturation
    b) Heart rate
    c) Carbon dioxide levels
    d) Pulse rateAnswer: c) Carbon dioxide levels
22. What could cause a false reading of 100% oxygen saturation in a patient with severe hypovolemia?
    a) High perfusion
    b) Good cardiac output
    c) Low perfusion and signal interference
    d) Proper probe placementAnswer: c) Low perfusion and signal interference
23. Which device is used alongside pulse oximetry to monitor patients’ respiratory status?
    a) Blood pressure monitor
    b) Capnometer
    c) Thermometer
    d) GlucometerAnswer: b) Capnometer
24. Which setting is recommended to improve pulse oximeter accuracy in a patient with poor peripheral perfusion?
    a) Apply the probe to a central location
    b) Increase room temperature
    c) Use a larger probe
    d) Decrease oxygen flow rateAnswer: a) Apply the probe to a central location
25. How does a pulse oximeter calculate the SpO2 level?
    a) By comparing light absorption before and after passing through the tissue
    b) By measuring the partial pressure of oxygen in the blood
    c) By analyzing the patient’s respiratory rate
    d) By detecting changes in heart rhythmAnswer: a) By comparing light absorption before and after passing through the tissue
26. Which patient condition may cause unreliable pulse oximetry readings due to impaired perfusion?
    a) Hyperthermia
    b) Hypothermia
    c) Normal hydration status
    d) Normal cardiac outputAnswer: b) Hypothermia
27. Which of the following is a common artifact affecting pulse oximeter readings?
    a) Patient movement
    b) Stable heart rate
    c) Normal oxygen levels
    d) Proper probe fitAnswer: a) Patient movement
28. What can cause a pulse oximeter to falsely read low oxygen saturation in a patient with adequate oxygenation?
    a) Bright external light
    b) Proper probe placement
    c) Accurate calibration
    d) Good perfusionAnswer: a) Bright external light
29. Which measurement is NOT provided by a pulse oximeter?
    a) Oxygen saturation percentage
    b) Heart rate
    c) Blood glucose level
    d) Pulse rateAnswer: c) Blood glucose level
30. What is the primary advantage of using pulse oximetry over other oxygen monitoring methods?
    a) Invasiveness
    b) Accuracy in measuring CO2 levels
    c) Non-invasiveness and ease of use
    d) Complexity of setupAnswer: c) Non-invasiveness and ease of use
31. Which of the following may lead to inaccurate pulse oximeter readings in a patient with dark skin pigmentation?
    a) Standard calibration
    b) Use of appropriate wavelengths
    c) Light absorption differences
    d) Proper probe placementAnswer: c) Light absorption differences
32. What can cause a pulse oximeter to display an erroneous reading of 100% saturation in a patient with hypoxia?
    a) High ambient light interference
    b) Correct probe placement
    c) Accurate calibration
    d) Stable patient conditionAnswer: a) High ambient light interference
33. Which factor could cause a pulse oximeter to give a falsely high reading in a patient with anemia?
    a) Proper calibration
    b) Adequate perfusion
    c) Oxygen saturation near normal
    d) Low hemoglobin levelsAnswer: d) Low hemoglobin levels
34. How often should pulse oximeters be calibrated?
    a) Monthly
    b) Annually
    c) When malfunctioning
    d) Only during initial setupAnswer: c) When malfunctioning
35. What is the primary purpose of using a pulse oximeter during sedation procedures?
    a) To assess sedation depth
    b) To monitor oxygen saturation and detect hypoxemia
    c) To measure blood pressure
    d) To record patient movementAnswer: b) To monitor oxygen saturation and detect hypoxemia
36. Which of the following conditions could lead to a falsely normal oxygen saturation reading on a pulse oximeter?
    a) Severe hypoxia
    b) Hyperoxia
    c) Carbon monoxide poisoning
    d) Normal perfusionAnswer: c) Carbon monoxide poisoning
37. What is the primary reason for the pulse oximeter probe to be placed on a finger or toe?
    a) To enhance light absorption
    b) To minimize interference from ambient light
    c) To maximize blood flow detection
    d) To reduce artifact from movementAnswer: c) To maximize blood flow detection
38. Which of the following is NOT a common feature of modern pulse oximeters?
    a) Adjustable alarm settings
    b) Ability to measure CO2 levels
    c) Display of heart rate
    d) Integration with electronic health recordsAnswer: b) Ability to measure CO2 levels
39. What should be done if a pulse oximeter reading is inconsistent with the patient’s clinical condition?
    a) Ignore the reading
    b) Recheck probe placement and calibration
    c) Change the probe type
    d) Adjust the oxygen flow rateAnswer: b) Recheck probe placement and calibration
40. Which patient characteristic is least likely to affect pulse oximeter accuracy?
    a) Skin color
    b) Heart rate
    c) Body temperature
    d) Respiratory rateAnswer: d) Respiratory rate
41. What is the main limitation of pulse oximetry in detecting certain respiratory conditions?
    a) Inability to measure carbon dioxide levels
    b) Limited accuracy in detecting hypoxemia
    c) Requirement for frequent calibration
    d) Inability to assess heart rateAnswer: a) Inability to measure carbon dioxide levels
42. Which condition is most likely to cause a pulse oximeter to read falsely high oxygen saturation?
    a) Cyanosis
    b) Anemia
    c) Carbon monoxide poisoning
    d) HyperventilationAnswer: c) Carbon monoxide poisoning
43. What is the best practice for ensuring accurate pulse oximeter readings?
    a) Regularly changing the probe location
    b) Ensuring proper calibration and probe placement
    c) Increasing ambient light
    d) Using high-intensity light sourcesAnswer: b) Ensuring proper calibration and probe placement
44. Which of the following can cause a pulse oximeter to display unreliable readings during surgical procedures?
    a) Low blood flow
    b) Stable blood pressure
    c) High oxygen levels
    d) Proper probe attachmentAnswer: a) Low blood flow
45. What is the role of a pulse oximeter in preoperative assessment?
    a) To evaluate lung function
    b) To measure oxygen saturation levels
    c) To assess cardiovascular health
    d) To determine anesthesia depthAnswer: b) To measure oxygen saturation levels
46. Which of the following is a common reason for a pulse oximeter to give a false reading of 100% saturation in a patient with poor perfusion?
    a) High ambient temperature
    b) Normal oxygen delivery
    c) Poor signal quality and artifact
    d) Correct probe fitAnswer: c) Poor signal quality and artifact
47. What should be done if a pulse oximeter consistently shows a low reading despite appropriate patient conditions?
    a) Increase oxygen flow
    b) Adjust the probe position and check calibration
    c) Replace the oxygen mask
    d) Decrease the ventilation rateAnswer: b) Adjust the probe position and check calibration
48. Which parameter does a pulse oximeter NOT directly measure?
    a) Oxygen saturation
    b) Heart rate
    c) Blood glucose level
    d) Pulse rateAnswer: c) Blood glucose level
49. What does a rapid change in pulse oximeter readings often indicate?
    a) Improvement in oxygenation
    b) Change in patient’s respiratory or cardiovascular status
    c) Stable patient condition
    d) Proper oxygenationAnswer: b) Change in patient’s respiratory or cardiovascular status
50. Which method can enhance the reliability of pulse oximetry in patients with high levels of movement or tremors?
    a) Using a smaller probe
    b) Securing the probe with adhesive
    c) Increasing ambient lighting
    d) Regularly changing probe locationsAnswer: b) Securing the probe with adhesive

Topic-wise Anesthesia MCQs

1. Anesthesiology MCQs
2. Anesthesia Basics:
   • Levels of sedation and anesthesia MCQs
   • Stages of anesthesia MCQs
3. Anesthesia Agents MCQs:
   • Inhaled anesthetics MCQs
   • Intravenous anesthetics MCQs
   • Neuromuscular blocking agents MCQs
   • Local anesthetics MCQs
4. Airway Management:
   • Endotracheal intubation MCQs – Anesthesia
   • Supraglottic airway devices MCQs – Anesthesia
   • Video laryngoscopy MCQs – Anesthesia
   • Difficult airway management MCQs – Anesthesia
5. Anesthesia Monitoring MCQs – Anesthesia:
   • Hemodynamic monitoring MCQs – Anesthesia
   • Pulse oximetry MCQs – Anesthesia
   • Capnography MCQs – Anesthesia
   • Temperature monitoring MCQs – Anesthesia
6. Regional Anesthesia MCQs :
   • Epidural anesthesia MCQs
   • Spinal anesthesia MCQs
   • Peripheral nerve blocks MCQs
7. Patient Assessment and Optimization:
   • Pre-operative assessment MCQs – Anesthesia
   • Patient history and physical examination MCQs – Anesthesia
   • Risk assessment and optimization MCQs – Anesthesia
8. Anesthesia Delivery Systems MCQs:
   • Inhalation anesthesia machines MCQs – Anesthesia
   • Intravenous anesthesia techniques MCQs – Anesthesia
9. Pediatric Anesthesia MCQs :
   • Considerations for anesthesia in pediatric patients MCQs – Anesthesia
   • Pediatric airway management MCQs – Anesthesia
   • Pediatric drug dosages MCQs – Anesthesia
10. Obstetric Anesthesia MCQs – Anesthesia:
    • Anesthesia for labor and delivery MCQs
    • Epidural analgesia in obstetrics MCQs – Anesthesia
    • Anesthetic considerations for cesarean section
11. Anesthesia Complications and Emergencies MCQs:
    • Malignant hyperthermia MCQs – Anesthesia
    • Anaphylaxis MCQs – Anesthesia
    • Cardiac arrest during anesthesia MCQs – Anesthesia
12. Post-Anesthesia Care MCQs:
    • Recovery room management MCQs – Anesthesia
    • Pain management strategies MCQs – Anesthesia
    • Post-operative complications related to anesthesia MCQs
13. Geriatric Anesthesia:
    • Considerations for anesthesia in elderly patients MCQs – Anesthesia
    • Geriatric pharmacology MCQs – Anesthesia
    • Management of common comorbidities MCQs – Anesthesia
14. Ethics and Professionalism in Anesthesia MCQs:
    • Informed consent MCQs – Anesthesia
    • Patient autonomy MCQs – Anesthesia
    • Professional conduct and communication MCQs – Anesthesia
15. Simulation and Skills Training MCQs :
    • Hands-on training in airway management and procedures MCQs – Anesthesia
    • Simulation exercises for crisis management MCQs – Anesthesia