Extra Topic 5.7 -- Foreign Body Aspiration Flashcards
A 2-year-old boy presents to the emergency room with difficulty breathing and wheezing. His parents report that he began to have trouble breathing an hour ago, shortly after an afternoon snack. They further report that the child has been afebrile, without any signs of recent illness.
What do you think is causing his acute respiratory distress?
While this could simply be an asthmatic attack, the occurrence of the child’s respiratory distress shortly after a snack would be consistent with other potential etiologies such as foreign body aspiration and food allergy-induced anaphylaxis.
In an attempt to diagnose the cause of his respiratory distress, I would perform a careful history to identify any known food allergies or previous diagnosis of asthma; similar episodes of respiratory distress; the type of food ingested during the afternoon snack (peanuts, jellybeans, popcorn and hotdogs are the foods most commonly associated with foreign body aspiration); and the occurrence of coughing or choking during food ingestion (suggestive of foreign body aspiration).
Moreover, assuming the child were stable, I would observe his response to a bronchodilator, recognizing that a lack of response is more consistent with foreign body aspiration;
examine him for additional signs of anaphylaxis, such as pulmonary edema, hypotension, urticaria, and pruritus;
examine him for other signs of foreign body aspiration such as stridor, hoarseness, aphonia, retractions, and use of accessory muscles of respiration; and
consider a chest radiograph to help identify the presence and location of a foreign body.
Although most foreign bodies are radiolucent, inspiration/expiration chest x-rays may indirectly identify the location of an aspirated object by demonstrating hyperinflation (air trapping in the affected lung), atelectasis, and/or mediastinal shifting toward the unaffected side.
The mother tells you that her son’s snack consisted of applesauce and unroasted peanuts.
Since the child is stable, would you order a chest x-ray to potentially identify an aspirated foreign body?
While a chest x-ray may prove helpful in identifying the presence and location of a foreign body, I would not delay bronchoscopy in this case where the child may have aspirated an unroasted peanut.
Peanut aspiration is not only associated with the absorption of water and increasing friability over time, but unroasted peanuts may lead to a peanut oil-induced chemical irritation of the airway with subsequent atelectasis and complete airway obstruction.
However, if the patient were stable and, if I were not concerned about an aspirated object becoming friable, swelling with water, or causing chemical irritation of the airway, I would consider pre-bronchoscopy radiographic examination.
What are the radiographic findings associated with foreign body aspiration?
Most aspirated material is radiolucent and not easily visualized by standard x-ray.
However, radiographic examination may provide indirect evidence of the presence and location of an aspirated foreign body.
For instance, radiographic findings associated with bronchial obstruction may include hyperinflation, air trapping, and atelectasis of the affected lung (distal to the foreign body).
In the case of significant atelectasis or hyperinflation, a chest x-ray may show mediastinal shift.
Assuming this patient’s respiratory distress is secondary to foreign body aspiration,
how would you induce him?
In preparing for induction, I would administer metoclopramide to facilitate stomach emptying in this patient with a history of recent food ingestion.
I would also consider giving glycopyrrolate to reduce airway secretions and attenuate the reflex bradycardia often associated with airway instrumentation and bronchoscopy.
Next, I would apply the appropriate monitors and ensure the presence of emergency airway equipment, the ENT surgeon, and a rigid bronchoscope.
Given the potential for distal migration of the foreign body with assisted ventilation, I would perform an inhalational induction using oxygen and Sevoflurane and attempt to maintain spontaneous ventilation; recognizing that this method of induction places him at increased risk for aspiration of gastric contents.
After ensuring an adequate depth of anesthesia to prevent coughing, laryngospasm, or bronchospasm, I would obtain intravenous access, allow the ENT surgeon to perform direct laryngoscopy, spray the vocal cords with lidocaine (to reduce the risk of laryngospasm during endoscopy), and insert the rigid bronchoscope.
Once the bronchoscope was in place, I would connect the anesthesia circuit to the bronchoscope to allow for ventilation during foreign body removal.
Shouldn’t you perform a rapid sequence induction, since this patient had a snack just a couple of hours ago?
Despite the risk of aspiration, I would NOT perform a rapid sequence induction in this situation, recognizing that positive-pressure ventilation may place the patient at risk for:
- distal migration of the foreign body, making extraction more difficult; and
- hyperinflation and/or pneumothorax, if the foreign body is producing a ball-valve effect.
Rather, I would perform an inhalational induction with the goal of maintaining spontaneous respirations.
However, I do recognize that there is no evidence that outcomes for this procedure are altered by the chosen method of ventilatory management during induction (i.e. spontaneous vs. controlled ventilation), and would consider altering or modifying my strategy depending on the circumstances (e.g. patient is vomiting preoperatively, further increasing the risk of aspiration).
During attempted removal, the foreign body becomes lodged at the carina causing complete airway obstruction. What would you do?
I would immediately inform the surgeon that ventilation has become impossible and ask him to either quickly remove the foreign body or attempt to push it distally into one of the main bronchi so that one-lung ventilation was possible.
If these interventions were unsuccessful, I would attempt to improve ventilation by moving the patient into the lateral or prone position, or by advancing an ETT beyond the obstruction.
If these interventions were also unsuccessful and life-threatening hypoxia was imminent, I would consider placing the patient on cardiopulmonary bypass until the obstruction could be cleared.
What are the complications that may occur with foreign body aspiration?
Complications arising from foreign body aspiration depend on – the location and type of foreign body aspirated (organic vs. non-organic, sharp vs. dull), and the duration of time the foreign body remained in the airways.
Nuts and certain vegetable materials are highly irritating to the bronchial tree and produce a chemical pneumonitis.
If the foreign body is successfully removed within 24 hours of the incident, the complication rate is very low.
However, the longer the foreign body remains in the airways, the more likely complications such as – bronchial stenosis, bronchiectasis, pneumonia, lung abscess, tissue erosion/perforation, and pneumomediastinum or pneumothorax will occur.
