The Oropharyngeal Airway (OPA), also known as an oral or Guedel airway, is a rigid, J-shaped plastic device designed to maintain an open upper airway in a patient with an impaired level of consciousness. Its primary function is to physically prevent the tongue from relaxing and falling backward to obstruct the pharynx. This commonly occurs when muscle tone is lost in an unresponsive individual. The device fits over the tongue to hold soft tissues away from the posterior pharyngeal wall, creating a clear passage for air.
Indications and Contraindications for Use
The decision to insert an OPA depends entirely on the patient’s neurological status and protective reflexes. The device is indicated only for patients who are unresponsive and are at risk for airway obstruction due to tongue relaxation. These situations often arise during cardiac arrest, post-seizure recovery, or deep sedation when the jaw and tongue muscles lose their tone. Using an OPA can improve the effectiveness of bag-valve-mask (BVM) ventilation by ensuring a patent pathway for airflow into the lungs.
The most significant contraindication for OPA placement is the presence of an intact gag reflex. Inserting the device into a conscious or semi-conscious patient will stimulate this reflex, potentially leading to vomiting. Vomiting creates a dangerous risk of aspiration, where stomach contents are inhaled into the lungs. Therefore, if a patient shows any signs of protective reflexes, such as coughing or actively resisting the device, an OPA must not be used. In cases where an OPA is not suitable, a Nasopharyngeal Airway (NPA) may be considered, as it is better tolerated in semi-conscious individuals.
Proper Sizing and Selection
Selecting the correct size of the OPA is necessary for effective airway management, as an incorrectly sized device can worsen the obstruction. An OPA that is too short may fail to hold the tongue away from the pharynx, or it could push the tongue backward, further blocking the airway. Conversely, a device that is too long can extend past the epiglottis, potentially causing trauma or pressing the epiglottis down over the laryngeal opening, which also creates an obstruction.
The most common method for determining the appropriate size involves using external anatomical landmarks. Place the flange, the flat end of the OPA, at the corner of the patient’s mouth. The curved tip of the OPA should then extend to the angle of the mandible (the corner of the lower jaw) or alternatively, to the earlobe. The chosen size should always be clinically verified after insertion to ensure adequate ventilation is achieved.
Step-by-Step Insertion Procedure
Before attempting insertion, the patient should be positioned supine, lying on their back. Initial airway maneuvers should be performed. If no cervical spine injury is suspected, a head-tilt/chin-lift maneuver can be used to align the airway axes, or a jaw-thrust can be performed if trauma is a concern. The mouth must first be cleared of any foreign material, secretions, or vomit, typically using a rigid suction catheter to prevent aspiration during the procedure.
180-Degree Rotation Technique (Adults)
Once the mouth is clear, the most commonly taught method for adult patients is the 180-degree rotation technique. The OPA is initially inserted upside down, meaning the curved, concave tip is facing toward the roof of the mouth or the hard palate. This inverted orientation is used to slide the device along the natural curve of the mouth without pushing the tongue back into the throat, which would create a complete obstruction. The device is advanced until the tip reaches the junction between the hard and soft palate at the back of the throat.
At this point, the OPA is gently rotated 180 degrees, causing the tip to sweep over the tongue. The rotation guides the OPA into its final resting position, with the concave side now facing the tongue and the tip pointing down toward the pharynx. The insertion is complete when the flat flange of the device rests securely against the patient’s lips or teeth. Care must be taken to ensure the lips are not pinched between the flange and the teeth, which can cause soft tissue injury.
Tongue Depressor Technique (Pediatrics)
For children and infants, the standard 180-degree rotation is generally avoided to prevent trauma to the more delicate oral tissues. Instead, an alternative technique involves using a tongue depressor. The tongue depressor is used to gently press the tongue downward and forward, creating a clear space. The OPA is then inserted “right-side up,” with the curve already pointing toward the tongue, and advanced directly into its final position over the depressor.
The final placement should result in the flange being flush with the mouth opening, and the curved body should be holding the tongue away from the posterior pharyngeal wall. If any resistance is met during insertion, the OPA should never be forced. The operator should stop, remove the device, and attempt to reposition or resize it. Proper technique minimizes the risk of pushing the tongue further down or causing damage to the soft palate.
Post-Insertion Assessment and Monitoring
Immediately following OPA insertion, the effectiveness of the procedure must be confirmed by assessing the patient’s ventilation. The operator should look for symmetrical chest rise and fall, listen for clear breath sounds, and note any improvement in oxygen saturation levels. If ventilation remains ineffective, the OPA might be incorrectly sized or positioned, requiring immediate removal and reinsertion after re-measuring the patient.
If the OPA is correctly placed but the patient begins to gag or cough, this is a clear sign that the device has stimulated the gag reflex, and it must be removed immediately. A change in the patient’s level of consciousness can trigger this reflex. The OPA is considered a temporary airway adjunct and requires continuous monitoring because if the patient wakes up enough to regain their protective reflexes, the device is no longer tolerated and becomes a hazard.
The OPA must be secured to prevent accidental dislodgement. If the OPA is used to facilitate bag-valve-mask ventilation, it must remain in place until a more definitive method, such as endotracheal intubation, can be established. The flange of the OPA acts as a bite block, which prevents a patient from biting down on an already-placed endotracheal tube.