A nasopharyngeal airway (NPA), often called a nasal trumpet, is a soft, hollow tube used as a basic airway adjunct. This device is inserted through a nostril and advanced into the posterior pharynx, the area behind the nasal cavity and mouth. The primary function of an NPA is to bypass upper airway obstruction, particularly when the tongue or soft tissues relax and block airflow, which is common in patients with an altered mental status. It maintains a clear channel for air to move into the lungs, often acting as a temporary measure until the patient’s breathing improves or a more definitive airway can be secured.
Assessing Patient Tolerance
The NPA is frequently used in patients who are not fully conscious but still retain some responsiveness. This gives the NPA a distinct advantage over the oropharyngeal airway (OPA), which is inserted through the mouth. The soft palate and pharynx are much less sensitive to stimulation than the back of the throat, meaning the NPA is less likely to trigger the patient’s gag reflex.
The presence of an intact gag reflex in a patient with a decreased level of consciousness is the defining factor for choosing an NPA over an OPA. Placing an OPA in a semi-conscious patient with a gag reflex can provoke vomiting, creating a serious risk of aspiration, where stomach contents enter the lungs. The NPA is generally well-tolerated, allowing for airway maintenance without stimulating this protective reflex.
Patients with an altered mental status, such as those who are semiconscious or responsive only to painful stimuli, are the ideal candidates for NPA placement. A truly conscious person would likely find the device too uncomfortable and resist insertion, but a patient with sufficiently depressed consciousness benefits without gagging. This makes the nasal trumpet a versatile tool for managing a partially obstructed airway, especially when the patient’s mouth is inaccessible due to trauma or trismus (jaw clenching).
Absolute Safety Warnings and Contraindications
Despite the utility of the NPA, there are conditions that forbid its use due to a serious risk. The most serious contraindication is the presence or suspicion of a basilar skull fracture (BSF), which is a break in the bones forming the base of the skull. This type of fracture can create an open pathway between the nasal cavity and the cranial vault.
Inserting the NPA in a patient with a BSF risks inadvertently tracking the tube through the fracture and into the brain, known as intracranial misplacement. Even with correct technique, the device could follow the path created by the fracture and cause severe injury to brain structures. Severe mid-face trauma, such as extensive facial fractures, is also a contraindication because the damage may be associated with a BSF or disrupt the normal nasal anatomy.
Healthcare providers look for specific clinical signs that may indicate a basilar skull fracture. These signs include “raccoon eyes” (bruising around both eyes) or Battle’s sign (bruising behind the ear over the mastoid process). Leakage of cerebrospinal fluid (CSF) from the nose or ears, sometimes appearing as a clear or pink-tinged fluid, is another concerning sign. When any of these indicators are present, the risk of intracranial placement outweighs any benefit of using the device.
Proper Insertion Technique
The safe and effective placement of an NPA relies on correct sizing and a precise insertion method. Before insertion, the correct length is estimated by measuring the distance from the tip of the patient’s nose to the earlobe or the angle of the jaw. Selecting a device that is too long can stimulate the gag reflex or enter the esophagus, potentially leading to gastric inflation during ventilation.
Lubrication of the entire tube with a water-soluble gel is mandatory to minimize friction and prevent trauma to the delicate nasal lining, which can cause significant nosebleeds (epistaxis). The device is then gently inserted into the nostril that appears larger or less obstructed, following the natural curvature of the nasal passage. The bevel, or angled opening of the tube, should be directed toward the nasal septum.
The NPA must be advanced along the floor of the nasal cavity, parallel to the roof of the mouth, not tilted upwards toward the eye. This posterior trajectory is important to avoid the thinner bone structure at the base of the skull. If resistance is met during insertion, the tube should never be forced; instead, it should be withdrawn, and insertion should be attempted into the other nostril. Proper placement is confirmed when the flared end of the device rests flush against the patient’s nostril and airflow improves.