How to Insert an Oropharyngeal Airway: Sizing, Insertion Technique, and Checks

An oropharyngeal airway (OPA) fails for one of three reasons: the wrong size, the wrong head position, or the wrong path around the tongue. In practice the third cause is the most common, and it is the easiest to fix. An adult OPA inserted with its curve the wrong way round sweeps the tongue back into the pharynx and can turn a partly obstructed airway into a completely blocked one. Measure the device against the jaw, extend the head unless the cervical spine says otherwise, and let the tip travel over the tongue rather than under it. Done that way, the airway seats in seconds and holds a clear channel between the teeth and the posterior pharyngeal wall.

Everything below is the detail behind that summary: how to confirm the patient has no gag reflex, which size to pick, why the rotational technique suits adults, when a tongue blade is safer, and what to do when the first attempt does not move air.

Confirm the patient has no gag reflex first

An OPA is a bite block and a breathing channel, nothing more. It holds the tongue away from the posterior pharyngeal wall in an unconscious patient and gives you a route for suction. It does not seal the trachea, does not protect against aspiration, and does not ventilate anyone on its own.

Check these points before you touch the mouth:

• No response to a loud verbal command or a painful stimulus.
• No gag when a suction catheter or tongue depressor reaches the back of the mouth.
• No cough or swallow on stimulation.
• No dentures, loose teeth, blood clots, or food sitting in the oral cavity.

If the patient gags, stop. Forcing an OPA past an intact gag reflex causes retching, vomiting, aspiration, and occasionally laryngospasm. A patient who gags usually needs a nasal airway or a supraglottic device, not a larger oral one.

The oral route is also a poor choice in trismus, severe maxillofacial or mandibular trauma, recent oral surgery, and caustic ingestion. Those are not limitations of the device; they are limitations of the doorway.

Measure from the mouth corner to the jaw angle

Size the airway on the patient, not on the packet. Place the flange at the corner of the mouth and lay the body of the device along the jaw line. The tip should reach the angle of the mandible, roughly below and slightly behind the earlobe. In adults that single measurement is more reliable than estimating from weight or height.

Both directions of error cause trouble:

• Too short: the tip stops mid-tongue, pushes the tongue backwards, and can make the obstruction worse.
• Too long: the tip presses on the epiglottis or the arytenoid region, which may obstruct the laryngeal inlet and provoke gagging or coughing as the patient lightens.

The flange is your cross-check. A correctly seated OPA rests against the lips and incisors rather than floating in front of them.

Position the head before you open the mouth

Work from the head of the bed rather than from the side, so the flange ends up sitting where you can see it. Suction blood, vomit, or secretions first; an OPA will not correct a blocked lumen, and pushing debris downwards only creates a bigger problem. Bring the head into a sniffing position, with slight flexion of the lower neck and extension at the upper neck, so the external ear canal is roughly level with the sternal notch.

If you suspect a cervical spine injury, keep manual in-line stabilisation and use a jaw thrust to pull the tongue forward instead of tilting the head. Where a supraglottic device or a tracheal tube may follow, pre-oxygenate with a bag-valve-mask before inserting the OPA. A patient who arrives with saturations in the low eighties needs oxygen, not a plastic tube.

Two insertion techniques that reliably work

Rotational technique: the adult default

1. Hold the OPA upside down, so the curve points towards the hard palate and the flange sits at your fingers.
2. Open the mouth with your thumb and index finger, using a crossed-finger or scissor grip.
3. Slide the tip along the hard palate until it passes the soft palate, usually three to four centimetres short of its final position.
4. Rotate the device 180 degrees as you keep advancing, so the curve ends up following the posterior pharyngeal wall.
5. Advance until the flange rests against the incisors or lips.

Rotating too early is the classic error. If the tip is still on the hard palate when you twist, the edge scrapes the mucosa and the airway comes back bloodstained. If that happens, withdraw, suction, improve the head position, and start again.

Tongue-blade technique: safer in children and small mouths

Lift the tongue forward with a tongue depressor or the blade of a laryngoscope, then insert the OPA the right way up, following the natural curve of the palate. No rotation is needed, which is why this is the usual approach in infants and small children; a soft palate is easy to injure with a twisting movement. Whichever technique you choose, never force the device. Fixed resistance means the tip is against tissue, so withdraw a centimetre, oxygenate, and reassess before trying again.

Confirm placement before you tape it down

• Chest rise with each bag-mask breath, with no air leaking around the flange.
• Equal breath sounds on both sides of the chest.
• No gurgling over the epigastrium.
• A normal waveform on capnography, where available.
• Oxygen saturation holding or improving over the following minute.

If ventilation does not improve, resist the urge to reach for a bigger airway. Withdraw the OPA one or two centimetres and ventilate again; a device that is too long often obstructs precisely because its tip is pressing the epiglottis down. Then re-measure and re-insert, or change route entirely.

Once the airway is working, secure the flange with tape or a tie, note the size used, and record the time. A patient can bite down or roll and displace an unsecured OPA within minutes.

Mistakes that turn a five-second job into a difficult airway

1. Inserting an adult OPA the right way up, which drives the tongue backwards.
2. Rotating while the tip is still on the hard palate, causing bleeding and swelling.
3. Sizing down because the shorter device slides in more easily.
4. Inserting into a patient who still has a gag reflex.
5. Skipping suction, so secretions are pushed towards the larynx.
6. Leaving the OPA in place after the patient wakes and starts to gag.

Most of these are technique errors rather than equipment problems, and most become obvious within seconds of the first ventilation attempt.

When the oral route is the wrong route

The nasopharyngeal airway is the practical alternative when the mouth cannot be opened, when oral trauma or trismus blocks access, or when a patient tolerates a nasal device but gags on an oral one. It is passed along the floor of the nasal cavity, perpendicular to the face, with lubricant, and it should sit with its flange at the nostril. Avoid it if you suspect a basal skull fracture or a severe midface injury.

Having both routes on the trolley matters more than most checklists admit. A single-use nasopharyngeal airway designed for airway management work is a sensible item to stock alongside oral airways, so the decision stays clinical rather than logistical.

Single-Use Nasopharyngeal Airway for Upper Airway ManagementDisposable NPA for relieving upper airway obstruction and supporting ventilation in spontaneously breathing patients when an oral airway cannot be used.View Product →

If the patient needs a seal rather than a channel

An OPA keeps a passage open; it does not seal the larynx. If the patient needs positive-pressure ventilation, a higher inspired oxygen concentration, or a route that resists gastric insufflation, the next step is a supraglottic airway or a tracheal tube.

Sizing landmarks change completely at that point, because supraglottic devices are matched to body weight and cuff volume rather than the mouth-corner-to-jaw-angle distance, so review the sizing and insertion guidance for supraglottic airways before you open a new package.

A standard silicone laryngeal mask airway, for instance, depends on a soft cuff that conforms to the pharyngeal shape and holds a low-pressure seal, which is a different job from the rigid channel an OPA provides.

Standard Silicone Laryngeal Mask Airway for Anesthesia and ResuscitationMedical-grade silicone supraglottic airway for rapid temporary ventilation support during general anesthesia, emergency resuscitation, and intensive care, with size options.View Product →

Removal and documentation

Remove the OPA when the patient starts to gag, coughs purposefully, or follows commands. Suction before removal, because the tongue frequently falls back the moment the device comes out, especially in someone who is not fully awake. Reassess the airway immediately and keep suction and a bag-valve-mask within reach. Record the size used, the time of insertion and removal, and the reason the airway was needed. That short note is often the only evidence a colleague has when the patient reaches the emergency department or the intensive care unit.

Two habits separate a clean insertion from a difficult one. Measure every patient against their own jaw instead of guessing from the packaging, and keep the sizes you actually stock within arm's reach, so you are choosing between 80, 90, and 100 mm rather than whatever happens to be on top of the trolley. If you are equipping a department, an ambulance, or a training room and want to talk through which airway products belong on the shelf, contact our team and we will work through it with you.