Airway foreign bodies
Introduction:
Foreign bodies involving airways still remains a diagnostic challenge. It is also difficult to manage these patients. Foreign bodies inside airway should always be considered as a surgical emergency. Sudden onset of respiratory symptoms must alert the clinician to the possibility of airway foreign body.
Clinical presentation:
Airway foreign bodies are common seen in children in the age group of 1 - 3. It is commonly seen in children of this age group because of immature dentition and poorly co-ordinated swallowing mechanism. More over children of this age group tend to be more likely to be active while eating, and hence are prone to aspiration.
Characteristic features include:
1. Choking / gagging episode as described by mother / caregiver
2. Followed by coughing spells
3. Wheezing
4. Diminished breath sounds
When the foreign body moves distally in the airway, symptoms may become less apparent or may even subside. Sometimes x-ray chest could also be deceptively normal. A high index of suspicion is a must to diagnose this condition. Children with doubtful history / symptoms should undergo diagnostic bronchoscopy.
Types of foreign bodies commonly aspirated:
Peanuts, seeds, and beans are the most commonly aspirated foreign bodies. Peanuts and other organic objects may cause severe tissue reaction leading to the formation of granulation tissue. The shape and consistency of the aspirated item can also affect the clinical picture. Narrow and oval objects can change position in the airway and lead to intermittent complete airway obstruction. Grains, beans and other vegetable matter may absorb water and may expand causing rapid clinical deterioration.
Chest radiographs:
Plain radiograph chest plays an important role in the diagnosis of airway foreign bodies. Majority of the foreign bodies are radiolucent, hence indirect changes should be looked for. The cross sectional area of the airway increases during inspiration, air can pass beyond the foreign body. During expiration, the cross sectional area decreases and the air becomes trapped. Expiratory films can reveal hyperinflation of ipsilateral lung.
Atelectasis can be seen when the aspirated object completely obstructs the distal airway. This is commonly seen in delayed presentation.
Caution: * Radiographs should not be used to rule out the presence of an airway foreign body. In fact more than 50% of patients with airway foreign bodies show a negative chest radiograph.*
Diagnostic bronchoscopy should be performed if any of the following is positive (history, physical examination, chest radiograph) is considered positive.
Endoscopic removal:
Removal of airway foreign body needs lot of skill to prevent further trauma to the respiratory epithelium. The skill of the anesthetist is also vital. It is better to keep the patient breathing spontaneously because this avoids significant amounts of positive pressure ventilation which could cause distal migration of the foreign body. The patient should be sprayed with 2% xylocaine topically to the glottis, trachea and carina.
Post op care:
Chest physiotherapy can be useful in the immediate post operative period.
Complications of Bronchoscopy:
1. Post op stridor
2. Bronchospasm
3. Hypoxia
4. Transient arrhythmias
5. Bradycardia
