Preoxygenation & Apneic Oxygenation

Why this matters

An old habit was to pull off the non-rebreather and take a look. The sat starts falling the moment breathing stops. Patients who are obese, pregnant, very young, septic, or already hypoxic desaturate in seconds. If you give oxygen well first, you have time to be careful. If you do not, you create the emergency airway you then have to manage. You do this on a stairwell, a bathroom floor, or a moving stretcher. You do not have an operating room.

Clinical sequence

1. Position first. Line the ear up with the sternal notch. Build a ramp if you need one.
2. Get a real seal. If they need breaths, use a two-person bag. A two-handed jaw-thrust seal beats a one-handed E-C clamp. If they are still breathing, use a tight non-rebreather at a high flow and leave them on it before the first look. Your protocol sets how long. If they are already not breathing, you are behind. Start with the two-person bag.
3. Put a nasal cannula under the mask only if you are authorized. Apneic oxygenation can lengthen the time you can look before the sat falls. It does not replace the bag if the patient is deteriorating.
4. Stage the waveform so the first breath after the tube is confirmed, not guessed. End-tidal carbon dioxide is that waveform on the monitor.
5. If the sat falls during the look, stop. Bag again with two people. Change one thing. Do not take the same look again.

Fill the Lungs Before the Look

• Suction and a backup airway are part of the setup, not something you hunt for after the sat falls.
• This lesson does not teach rapid sequence intubation drug doses. Drugs without oxygen first are how patients arrest when you induce them.

While You Are Looking

• Limit the look. If the sat is falling, come out and bag. Then change the plan. See the difficult-airway lesson and DOPE-S. That check is displacement, obstruction, pneumothorax, equipment, and seal.
• A clear plan beats a second identical look. Change the blade, the position, or move to a supraglottic airway before you look again.

Common errors

• Taking the first look with no suction, no backup device, and the head flat.
• Taking several attempts without giving oxygen between them.
• Calling preoxygenation done because a non-rebreather was near the face with a large leak.

Practice

Related: Difficult airway, Effective BVM.

Sources & Further Study

Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.

• NASEMSO National Model EMS Clinical Guidelines (2022) — U.S. EMS model language; follow your protocol
• Difficult Airway Society guidelines
• ASA 2022 Practice Guidelines for Management of the Difficult Airway
• Give oxygen first, line the ear up with the sternal notch or build a ramp, and give oxygen again between attempts. Apneic oxygenation is an add-on. It is not a substitute for the bag or for a failed-airway plan.