FOREIGN BODIES

Reported by Leigh Cadavos

3BSRT-2B

FOREIGN BODIES

These are materials, microorganisms or tiny objects that enters within our body but not part of the system . this can be subjected to inflammation that may lead to infection.

MOST COMMON FOREIGN BODIES

seeds nuts bone fragments nails small toys coins pins medical instrument fragments dental appliances

METHODS OF ENTERING OUR BODY

• Inhaled• Ingest• Surgical procedures

COMMON SITES OF FOREIGN BODIES

Respiratory tractEsophagusGastrointestinal

AGE GROUP

Children, especially those aged 1-3 years, are at risk for foreign body.

Adults who (1) undergo oropharyngeal procedures, (2) have various oral appliances, (3) become intoxicated,

FOREIGN BODY ASPIRATION 

Background Anatomy

The human body has numerous defense mechanisms to keep the airway free and clear of extraneous matter. These include:

the physical actions of the epiglottis in blocking the airway,

the intense spasm of the true and false vocal cords any time objects come near the vocal cords,

highly sensitive cough reflex with afferent impulses generated throughout the larynx, trachea, and all branch points in the proximal tracheobronchial tree.

AIRWAY FOREIGN BODIES CAN BECOME LODGED IN THE LARYNX, TRACHEA, AND BRONCHUS.

PATHOPHYSIOLOGY

Near-total obstruction of the larynx or trachea can cause immediate death.

Once aspirated, objects migrate distally, particularly after unsuccessful attempts to remove the object or if the object fragments

The airway becomes more likely to bleed with manipulation; the object is more likely to be obscured and becomes more difficult to dislodge

Local inflammation, edema, cellular infiltration, while making bronchoscopic identification and removal of the object more difficult.

air trapping may occur, leading to local emphysema, hypoxic vasoconstriction

Patients with bronchial foreign bodies may have normal findings on CXRs; however, the affected lung may show hyperaeration (obstructive emphysema) and shifting of the mediastinum away from the affected lung on expiratory CXRs because of the ball-valve effect of the tracheal foreign .

the patients can inspire air past the foreign body but have difficulty exhaling.

Expiratory chest radiograph in a 12-month-old boy with a 2-month history of wheezing demonstrates continued hyperlucency and hyperexpansion of the right hemithorax. A greater mediastinal shift is noted toward the left lung field. A corn kernel was removed from the patient's right mainstem bronchus during bronchoscopy.

Left lateral decubitus chest radiograph demonstrates failure of collapse in an 11-month-old girl with a 2-week history of persistent coughing. A corn kernel was found in the patient's left mainstem bronchus during bronchoscopy.

Images in patients with chronic bronchial foreign bodies may show atelectasis, with a mediastinal shift toward the foreign body and/or recurrent pneumonias in the affected lung segment

Chest radiograph in a 6-year-old boy who complained of chest pain and dysphagia. Complete atelectasis of the left lung is noted, with a mediastinal shift towards the left lung.,

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Chest radiograph obtained 2 days after a piece of popcorn was removed from the patient's left mainstem bronchus. Resolution of the atelectasis is complete, and the mediastinum is in its normal position.

Aspirated foreign body (backing to an earring) lodged in the right main stem bronchus.

ASPIRATION OF FOREIGN BODIES PRODUCES THE FOLLOWING 3 PHASES: Initial phase –

Choking and gasping, coughing, or airway obstruction at the time of aspiration

Asymptomatic phase – Subsequent lodging of the object with relaxation of reflexes that often results in a reduction or cessation of symptoms, lasting hours to weeks

Complications phase – Foreign body producing erosion or obstruction leading to pneumonia, atelectasis, or abscess

Foreign body aspiration can mimic other respiratory problems, such as asthma. Foreign body aspiration differs in the presence of unilateral wheezing and decreased breath sounds.

PREFERRED EXAMINATION

anteroposterior (AP)

lateral imaging of the soft tissues of the neck,

inspiratory and expiratory posteroanterior (PA) chest

Radiopaque foreign bodies are easy to diagnose by using radiographs. With radiolucent foreign bodies, secondary radiographic signs, such as obstructive emphysema, atelectasis, pneumonia, and a mediastinal shift, help in diagnosing foreign body aspiration

ESOPHAGEAL FOREIGN BODY IMAGING 

The most common site of foreign body lodgment is the upper esophagus at the level of the thoracic inlet.

The second most common site for esophageal foreign body retention is the level of the carina and aortic arch because of normal physiologic narrowing in the mid esophagus at this level.

The third location is the distal esophagus slightly above the gastroesophageal junction.

PATHOPHYSIOLOGY

Anteroposterior chest radiograph depicts a penny at the thoracic inlet of a 13-month old infant .

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Lateral chest radiograph (obtained in the same patient as in the previous image) depicts soft-tissue thickening at the tracheoesophageal interface. A penny was removed at esophagoscopy.

Tracheal displacement or compression suggests mediastinal inflammation and airway compromise.

Anteroposterior radiograph of the neck (obtained in the same patient as in the previous image) demonstrates tracheal deviation to the right

If the presence of a nonradiopaque foreign body is suspected, contrast-enhanced esophagography is indicated. Positive findings on the esophagram include:

irregularity of the contrast medium column or esophageal mucosa

deviation in the expected course of the esophagus.

Anteroposterior esophagram (obtained in the same patient as in the previous images) demonstrates irregularity of the contrast material column along the right lateral aspect of the esophagus. These findings suggest the presence of a nonradiopaque foreign body, and the patient was referred for further evaluation with CT.

Contrast-enhanced computed tomography (CT) scanning is indicated for the assessment of a suspected esophageal foreign body when the plain radiographic findings are negative.

Nonenhanced axial CT scan demonstrates a retained esophageal foreign body. Its attenuation is similar to that of adjacent bone. Note the adjacent soft-tissue swelling and tracheal narrowing. At esophagoscopy, a metal-coated plastic disk was retrieved.

GASTROINTESTINAL FOREIGN BODIES

Foreign bodies in the upper GI tract are usually swallowed, purposefully or accidentally. The presentation is usually straightforward but may be extremely subtle.

A screw in the stomach; peristaltic action will carry the screw through the GI tract with the blunt end (head) leading and the sharp end trailing.

RELATED ANATOMY

The esophagus is a tubular structure approximately 20-25 cm in length.

Patients can usually localize foreign bodies in the upper esophagus but localize them poorly in the lower two thirds of the structure.

The esophagus has 3 areas of narrowing where foreign bodies are most likely to become entrapped:

the upper esophageal sphincter (UES), which consists of the cricopharyngeus muscle;

the crossover of the aorta;

and the lower esophageal sphincter (LES).

PATHOPHYSIOLOGY

Foreign bodies may involve the entire upper GI tract. The oropharynx is well innervated, and patients can typically localize oropharyngeal foreign bodies. Scratches or abrasions to the mucosal surface of the oropharynx can create a foreign body sensation. Chronic foreign bodies or perforations can cause infections in surrounding soft tissues of the throat and neck.

Reference:

www.emedicine.medscape.com