The Oropharyngeal Airway (OPA) is a curved plastic device designed to maintain a clear passage for air through the mouth and into the throat. This medical adjunct functions by holding the tongue away from the posterior pharyngeal wall, which often obstructs the airway in an unconscious individual. Its use is limited to specific emergency situations where manual methods fail to keep the airway open, and the procedure requires professional training to be performed safely.
Indications for Airway Intervention
The OPA is considered when basic positioning techniques, such as the head-tilt/chin-lift or jaw thrust maneuvers, fail to achieve or sustain a clear airway. Mechanical assistance becomes necessary when the patient’s level of consciousness is so depressed that the muscle tone supporting the tongue is lost.
The device is indicated for unresponsive patients requiring ventilation assistance, such as during cardiopulmonary resuscitation (CPR) or assisted breathing with a bag-valve-mask device. Crucially, the infant must be deeply unconscious and lack a protective gag reflex before the OPA is introduced. Inserting the device bypasses the obstruction caused by the tongue, creating a stable channel for airflow.
Distinct Anatomical Features of the Infant Airway
The anatomy of an infant’s airway differs significantly from an adult’s, necessitating a modified approach for OPA insertion. Infants have a proportionally larger tongue relative to their small oral cavity, making them highly susceptible to airway obstruction when muscle tone relaxes.
The larynx is positioned higher and more anteriorly in an infant’s neck, sitting at the level of the third or fourth cervical vertebra compared to the adult’s lower position. This higher placement, along with a floppy, U-shaped epiglottis, makes the airway more prone to injury and obstruction if instruments are not inserted with precision. Furthermore, the infant’s relatively large occiput, or back of the head, naturally causes the neck to flex when lying flat, which can further collapse the upper airway structures.
Sizing and Safe Insertion Technique
Correct sizing of the OPA is essential for safe and effective use, as an improperly sized device can worsen the obstruction. To select the appropriate size, a clinician measures the OPA externally, from the corner of the infant’s mouth to the angle of the jaw or the earlobe. The flange of the device should rest against the lips, and the tip should sit at the angle of the mandible when fully inserted.
The technique for insertion in an infant differs significantly from the adult method to avoid trauma and prevent reflex airway closure. The rotation technique, often used in adults (inserting the OPA upside down and rotating 180 degrees), is avoided in infants and young children. The preferred method involves using a tongue depressor to gently push the tongue down and forward.
With the tongue secured, the OPA is inserted directly into the mouth with the curve facing downward, following the natural curvature of the tongue. This direct approach minimizes the risk of pushing the large tongue backward, which would worsen the obstruction, or causing soft tissue damage. After placement, constant monitoring is necessary to ensure the device remains in the correct position and the airway remains clear.
Critical Contraindications and Associated Risks
The primary contraindication for OPA placement in an infant is the presence of an intact gag reflex, even if the patient exhibits an altered level of consciousness. Inserting the device when the gag reflex is active can induce vomiting, putting the infant at high risk for pulmonary aspiration (inhaling stomach contents into the lungs). Aspiration can lead to severe lung injury.
The OPA should also not be used if there is evidence of significant oral trauma or a known foreign body obstruction that has not been successfully cleared. Improper sizing or forceful insertion carries the risk of damaging the soft tissues of the mouth and pharynx. If the OPA is too large, its tip can press on structures near the voice box, potentially causing laryngospasm—a reflex closure of the vocal cords that results in complete airway obstruction.