An OPA, or oropharyngeal airway, is a curved plastic device inserted into the mouth to keep a person’s airway open. It works by holding the tongue forward so it doesn’t fall back and block the throat, which is a common problem when someone is unconscious. OPAs are one of the most basic and widely used tools in emergency medicine, carried by paramedics, kept in emergency rooms, and stocked in first aid kits.
How an OPA Works
When a person loses consciousness, the muscles in their jaw relax. In a person lying on their back, this relaxation lets the tongue slide backward and cover the opening to the windpipe, blocking airflow. An OPA is a rigid, curved piece of plastic that slides into the mouth and sits along the roof of the mouth, physically holding the tongue away from the back of the throat. Air can then pass through and around the device with each breath.
Beyond tongue-related blockages, an OPA can also help bypass obstructions caused by other structures in the mouth, such as enlarged tonsils.
Two Main OPA Designs
The two most common styles are the Guedel airway and the Berman airway. Both are semicircular, hard plastic devices shaped to follow the curve of the roof of the mouth. The key difference is internal: a Guedel airway has a hollow central channel that air passes through, while a Berman airway uses open side channels instead. The Guedel design is more common and can double as a bite block to protect the tongue or any tubes already in the airway.
How It’s Sized
OPAs come in multiple sizes because using one that’s too large or too small can make things worse. The standard sizing method is straightforward: hold the device against the side of the face, measuring from the corner of the mouth to the tip of the earlobe. If the OPA matches that distance, it’s the right size. One that’s too short won’t reach past the tongue, and one that’s too long can push the tongue further back or irritate deeper structures in the throat.
Who It’s Used On
OPAs are used on unconscious patients who have no gag reflex. That last part is critical. If a person still has a gag reflex, inserting an OPA can trigger vomiting, which creates a serious risk of inhaling stomach contents into the lungs. In practice, the gag reflex acts as a built-in safety test: if the person gags or resists when the device is placed, they’re conscious enough that they don’t need one, and the device should be removed immediately.
Common scenarios include cardiac arrest, sedation during surgery, or any situation where someone is deeply unconscious and their breathing sounds obstructed or labored.
OPA vs. NPA
The other common airway device is the NPA, or nasopharyngeal airway, which goes through the nose instead of the mouth. Each has situations where it’s the better choice.
- Gag reflex present: If the patient still has a gag reflex, an NPA is preferred because it’s better tolerated.
- Oral trauma or facial fractures: When the mouth or jaw is injured, inserting an OPA could worsen the damage, making the NPA a safer option.
- Vomiting risk: NPAs reduce the chance of triggering vomiting compared to OPAs.
- Extended use: NPAs are generally more comfortable over longer periods without causing complications.
- Mouth blocked: If something is physically obstructing the oral route, the nasal route bypasses the problem entirely.
OPAs have the advantage of being quicker to place and more effective at keeping the tongue forward in deeply unconscious patients. They’re typically the first choice during CPR and cardiac arrest situations where the patient has no reflexes at all.
Risks of Incorrect Placement
An improperly placed OPA can cause more harm than good. If the device is the wrong size or inserted incorrectly, it can push the tongue further back into the throat, worsening the very blockage it’s meant to prevent. Forceful insertion risks injuring the teeth, gums, or soft tissues of the mouth. And placing one in a patient who still has protective reflexes can trigger gagging, vomiting, or a spasm of the vocal cords that clamps the airway shut.
For these reasons, an OPA is considered a temporary measure. It keeps the airway open while responders assess the situation and decide whether a more secure airway device is needed. It does not protect against inhaling fluids or replace more advanced airway management in critical situations.