Airway Foreign Bodies: Diagnosis and Treatment

The classic location for airway foreign bodies is in the right main stem bronchus because the takeoff to the right lung is more in line, and aspirated objects take the most direct path into that right main stem.

Airway foreign bodies most commonly occur in children younger than 4 years, with peak incidence between 1 to 2 years, because these children are most likely to put things into their mouth while exploring their environment.

In children under 1 year, airway foreign bodies may not be immediately suspected, but if they have siblings and the history fits, a foreign body should be considered because it is not uncommon for an older sibling to share something that the baby then aspirates.

Aspirated food items tend to be things that are not easy to chew, including nuts, popcorn or popcorn kernels, seeds, and edamame, which despite being considered healthy are shaped like nuts and hard to chew.

The most common presenting symptoms of airway foreign body are cough following a choking event, wheezing, or noisy breathing, usually after a choking event or having something in their mouth.

Patients with foreign bodies higher up in the airway may present with stridor or actual impaired difficulty breathing, and in some cases may be cyanotic or apneic because the foreign body is causing obstruction.

Initial assessment of a patient with suspected airway foreign body includes evaluating respiratory status upon entering the room: whether they are working hard to breathe, have retractions, are tachypneic, or are sitting very still and focused on breathing, which can indicate severe airway compromise.

Physical exam findings in airway foreign body include subtle signs of impaired respiratory status such as tachypnea, nasal flaring, and retractions (subcostal or suprasternal), especially in infants and toddlers who breathe with their whole body when working hard.

Auscultation may reveal unequal breath sounds or very focal wheezing, which is a telltale sign of airway foreign body; lungs may be completely clear except for one specific lobe, making it less likely to be a viral process or reactive airway disease.

The first imaging study for suspected airway foreign body is a chest X-ray, though many aspirated objects are radiolucent and will not be visible on X-ray.

Lateral decubitus X-rays can detect air trapping on the affected side; when the affected side is positioned down, the lung volume should normally decrease, but with an airway foreign body creating a ball valve effect, the down lung will stay inflated, which is considered pathognomonic for airway foreign body.

Many bronchoscopies for suspected airway foreign body are negative, resulting in airway instrumentation in patients with reactive airway disease, and recent studies suggest using CT scan to help diagnose these patients.

A retrospective study from Akron Children's Hospital found that low-dose CT scan of the chest had a specificity of 98% and a sensitivity of 100% for diagnosing foreign body aspiration in children, while being much less invasive than traditional rigid bronchoscopy.

A child in acute distress with significant respiratory compromise from suspected airway foreign body requires emergent management and should be moved to the trauma bay for immediate direct laryngoscopy, not waiting for anesthesia clearance to go to the operating room.

Direct laryngoscopy in emergency airway foreign body cases checks for obstruction in the supraglottis or at the level of the glottis, and McGill forceps, which are readily available with standard intubating equipment or crash cart, can be used to remove accessible foreign bodies.

If a foreign body causing severe obstruction cannot be grasped or removed, the next step is a surgical airway: cricothyrotomy in children older than 8 years, or needle cricothyrotomy or emergency tracheotomy in children under 8 years, because performing a cricothyrotomy in a small child is technically incredibly challenging due to the smaller relative size.

The vast majority of airway foreign bodies fall into a gray area where there is high suspicion but no emergency requiring immediate cricothyrotomy, and these cases should be taken to the operating suite for rigid bronchoscopy under general anesthesia.

Airway foreign body cases can be rushed emergent cases, and staff at night may not be comfortable with bronchoscope setup, so clinicians should ensure they know exactly how to set up their own bronchoscope.

Instruction pictures on the bronchoscopy cart showing step-by-step setup can help ensure proper equipment preparation.

A variety of endoscopic graspers should be available for rigid bronchoscopy, with different forms designed for different objects such as special coin graspers and peanut graspers, where the shape of the instrument matches the anticipated foreign body.

The bronchoscope grasper is sometimes difficult to use in small patients because it doesn't have enough room for the jaws to open wide enough to grab the foreign body and it obstructs the view.

A wire urology endoscopic grasper can be put down the aspiration side channel of the bronchoscope as an alternative technique in small patients.

Acute airway foreign bodies that are removed without complications do not require follow-up; patients should be instructed to call or see their pediatrician if cough persists or fever develops.

Chronic foreign bodies require follow-up because granulation tissue or inflammation at the removal site can lead to subsequent stenosis of the bronchus, and proactive management can prevent development of bad stenosis.

Removing large or sharp foreign bodies can create injuries at the level of the glottis because the bronchoscope and foreign body must pass between the vocal cords, which are vulnerable to injury at this narrow point.

Removing sharp objects like pins or needles from the airway can create a rent in the airway, and these patients should be watched postoperatively to ensure this complication has not occurred.