Airway Management and Oxygen Therapy Flashcards

What is the most common cause of airway obstruction in a sedated dental patient?

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.

Which oxygen delivery device can provide the highest inspired oxygen concentration (up to 90–100%)?

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.

The head-tilt chin-lift maneuver opens the airway primarily by:

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.

At what SpO2 level should supplemental oxygen intervention typically be initiated during dental sedation?

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.

Which airway adjunct is contraindicated in a conscious or semiconscious patient who retains a gag reflex?

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.

What is the primary purpose of preoxygenating a patient before initiating sedation?

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.

A nasal cannula at 4–6 L/min delivers an approximate FiO2 of:

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%.