DAANCE Airway Management and Oxygen Therapy 1 — Questions and Answers
Question 1: What is the most common cause of airway obstruction in a sedated dental patient?
- Laryngospasm
- Tongue falling back against the posterior pharynx (Correct answer)
- Foreign body aspiration
- Bronchospasm
Correct answer: Tongue falling back against the posterior pharynx
Sedation-induced muscle relaxation causes the tongue to fall posteriorly and obstruct the pharynx, making it the most common cause of airway obstruction.
Question 2: Which oxygen delivery device can provide the highest inspired oxygen concentration (up to 90–100%)?
- Nasal cannula
- Simple face mask
- Non-rebreather mask (Correct answer)
- Venturi mask
Correct answer: Non-rebreather mask
A non-rebreather mask with a reservoir bag and one-way valves delivers 90–100% O2 at flow rates of 10–15 L/min by preventing exhaled air from mixing with the oxygen supply.
Question 3: The head-tilt chin-lift maneuver opens the airway primarily by:
- Flexing the neck to reduce airway resistance
- Extending the neck and displacing the tongue anteriorly (Correct answer)
- Rotating the head to drain secretions
- Compressing the hyoid bone upward
Correct answer: Extending the neck and displacing the tongue anteriorly
Tilting the head back and lifting the chin extends the cervical spine and moves the tongue forward, relieving posterior pharyngeal obstruction.
Question 4: At what SpO2 level should supplemental oxygen intervention typically be initiated during dental sedation?
- Below 99%
- Below 95% (Correct answer)
- Below 88%
- Below 80%
Correct answer: Below 95%
An SpO2 below 95% falls outside the normal range and signals the need for supplemental oxygen to prevent progression to clinically significant hypoxia.
Question 5: Which airway adjunct is contraindicated in a conscious or semiconscious patient who retains a gag reflex?
- Nasopharyngeal airway (NPA)
- Oropharyngeal airway (OPA) (Correct answer)
- Nasal cannula
- Non-rebreather mask
Correct answer: Oropharyngeal airway (OPA)
An OPA placed over the tongue in a patient with an intact gag reflex stimulates gagging and vomiting, creating an aspiration risk.
Question 6: What is the primary purpose of preoxygenating a patient before initiating sedation?
- To lower the patient's heart rate before drug administration
- To create an oxygen reserve that extends safe apnea time (Correct answer)
- To verify that the nasal cannula is functioning
- To reduce the required sedation drug dose
Correct answer: To create an oxygen reserve that extends safe apnea time
Breathing 100% oxygen replaces nitrogen in the functional residual capacity with oxygen, creating a reserve that delays desaturation if the patient becomes apneic.
Question 7: A nasal cannula at 4–6 L/min delivers an approximate FiO2 of:
- 21–24%
- 28–36%
- 36–44% (Correct answer)
- 60–80%
Correct answer: 36–44%
Each liter per minute of flow via nasal cannula adds approximately 4% FiO2 above room air (21%), so 4–6 L/min delivers roughly 36–44%.
DAANCE Airway Management and Oxygen Therapy 1
What is the most common cause of airway obstruction in a sedated dental patient?