Fig. 36.1
Peanut identified in the left mainstem bronchus
Inorganic
Inorganic material can further be divided into metallic and plastic materials. Metallic foreign bodies that are often implicated include different types of pins and coins. Other aspirated metallic foreign bodies include nails (Fig. 36.2), jewelry, metallic crowns, coins, and even wiring from undergarments (Fig. 36.3). In regard to plastic foreign bodies, other objects that are responsible included medical-related devices such as broken endotracheal and tracheostomy tubes, nasopharyngeal airways, intubating introducers, and drug delivery devices such as inhalers and inhaler caps. Thumbtacks (Fig. 36.4), plastic toys, and pen caps are also commonly implicated [23, 24].
Fig. 36.2
Metal nail aspirated into the distal trachea. White arrow points to the nail in each radiologic study. (a) Posterior-anterior chest plain film. (b) Lateral chest plain film. (c) Coronal CT chest
Fig. 36.3
Wire from women’s bra aspirated into the trachea and right mainstem bronchus. (a) Posterior-anterior chest plain film. (b) Bra wiring seen in right mainstem bronchus and bronchus intermedius. (c) Bra wiring visualized after bronchoscopic removal
Fig. 36.4
A thumbtack aspirated by a patient. (a) Axial CT scan with white arrow pointing to thumbtack in the right lower lobe bronchus. (b) Thumbtack after bronchoscopic retrieval
Dental-related appliances usually account for the most frequently aspirated objects after organic matter. Examples of dental-related appliances include bridges, porcelain or metal crowns (Fig. 36.5), mouth guards, dentures, and fillings. There have even been reports of aspiration of dentistry tools during procedures [25].
Fig. 36.5
Types of dental appliances aspirated into the airway. (a) Dental bridge. (b) Gold dental crown
Mineral
Aspiration of teeth compromises the majority of cases under mineral-related foreign bodies (Fig. 36.6). This can occur in relation to trauma, impaired airway reflexes (i.e., neurological disease), and during impaired states of consciousness (i.e., sleep, alcohol/drug intoxication, anesthesia, etc.). Bones from meats and fish are also not uncommonly aspirated. Another mineral is glass, which can be from broken glass pipe fragments (used for inhalation of illicit drugs) and from motor vehicle accidents with shattered glass. It is important to understand that even endogenous substances can act as foreign bodies when they produce airflow obstruction with or without gas exchange abnormalities. As an example, broncholiths that have eroded into the intraluminal can act as foreign bodies (Fig. 36.7).
Fig. 36.6
Tooth that was aspirated and bronchoscopically retrieved
Fig. 36.7
Multiple broncholiths retrieved from a single patient
Miscellaneous
Pills and Capsules: There are various factors that promote the aspiration of pills and capsules including (but not limited to) the motion of placing them into the oral cavity, the state of airway reflexes in the subject (i.e. neurological disease, age, etc.), as well as the quantity and frequency of medication regiments which tend to be more prevalent in the elderly population. When evaluating pill aspiration, it is important to evaluate the obstructive properties of the implicated pill(s), as well as the early and late inflammatory potential of the pill(s). Technically any pill has the potential to be aspirated; however, there are well-known sequelae related to specific medications such as iron supplementation, potassium preparations, and activated charcoal.
Iron pill aspiration is a well-recognized problem. Any medication containing ferrous sulfate (FeSO4), when aspirated, has a caustic effect on the bronchial mucosa secondary to its acidic pH (usually <3), which leads to a local inflammatory cascade of effects including acute mucosal damage and, eventually, airway stenosis [26–28]. This can lead to the formation of granulomas and fibrosis. Further specifics of iron pill aspiration will be discussed in depth later in this chapter.
Potassium preparations are also very well associated with local inflammatory effects when aspirated. Of the potassium-based formulations, potassium chloride (KCL) is the most commonly aspirated preparation. Due to the hyperosmolar properties of KCL, it leads to mucosal irritation with additional erosive properties to the airway [29]. Similar to ferrous sulfate, late effects can result in airway stenosis. Enteric-coated KCL preparations take time to dissolve and may initially present with airway obstruction.
Activated charcoal is reported to be aspirated in approximately 2.3% of all patients receiving it for gastric emptying indications [30]. Although charcoal is biologically inert and nonabsorbable, it is immunogenic, which can cause a local inflammatory response within the airways. Bronchospasm, airway obstruction (due to inflammatory response), pneumonitis, and acute respiratory distress syndrome (ARDS) have all been reported with charcoal aspiration [29].
Other medications that are associated with similar inflammatory response include nortriptyline, metformin, pomegranate supplements, barium sulfate, and alendronate. While technically not a medication (but are administered similar to oral medications), endoscopic capsules (pill camera) used in diagnostic gastrointestinal evaluation have also been aspirated into the airway [31]. As endoscopic capsules are inorganic, they do not dissolve and act more as obstructive foreign bodies (Fig. 36.8). While extremely rare, aspiration occurs more commonly in elderly patients, whom may or may not have a history of swallowing dysfunction.
Fig. 36.8
An aspirated endoscopic capsule (pill camera). White arrows are pointing toward the capsule in the radiologic studies. (a) Posterior-anterior chest plain film. (b) Lateral chest plain film. (c) Bronchoscopic image of capsule in the right mainstem bronchus. (d) Endoscopic capsule after retrieval
Stents: While airway stents are used in the treatment of airway obstruction, it is well known among bronchoscopists that stents have the ability to migrate. Airway stent migration rates have been reported between 4.6 and 17% [32, 33]. Migration of airway stents can occur due to inappropriate choice of stent in relation to airway size but can also be a result of successful treatment of the underlying etiology for stent requirement. For example, stents are deployed for the management of malignant central airway obstruction, and after successful treatment of tumor, there may be shrinkage or resolution of the initial malignant obstruction. The response to therapy may lead to stent migration because of the lack of airway support on the outer surface of the stent. Additionally, stents used for benign disease in conditions such as tracheal and bronchial stenosis, similar response to therapy, and/or excessive coughing may lead to inadvertent stent migration. Airway stents are also known to promote bronchial secretions with the risk of developing airway obstruction due to tenacious secretions. While secretions are not foreign bodies, airway stents obstructed with mucus present in a similar manner.
Esophageal stents have also been implicated in FB airway obstruction. Although, esophageal stent migrations are associated with distal esophageal/gastric migrations [34], there have been reports of acute airway obstruction from proximal migration of esophageal stents with occlusion of the glottis [35]. There have also been case reports of esophageal stents migrating through the posterior membrane of the trachea leading to severe acute airway obstruction and asphyxiation [36].
Photodynamic Therapy (PDT): PDT is a photoablative therapy used as an adjunct treatment of central airway malignant disease not amenable to further standard treatment options. Routine practice is to perform a follow-up bronchoscopy 48–72 h post-procedure to clear necrotic debris induced by the therapy. In some instances, this debris can slough off and can obstruct the central airways. There have been reports of acute airway obstruction in the immediate hours after completion of PDT [37]. Similar to other incidences, tumor slough is typically not thought of as a true FB, yet its clinical presentation mirrors that of other foreign bodies.
Other Miscellaneous Foreign Bodies: Other rare causes of FB aspiration include erosion of grafted rib material during tracheoplasty, endobronchial suture material from bronchial stumps status post lobectomy/pneumonectomy, and migrated gauze packing from nasal and oropharyngeal indications.
Clinical Presentation
Patients that aspirate an airway FB can have a wide array of presentations, ranging from asymptomatic to immediate death. Patients present with one of two conditions: acute or retained FB. Acute FBs represent those cases associated with minimal airway inflammation and are relatively early in the sequence of events, either immediately after the aspiration event or within hours/days. Retained FBs are those cases where the FB has initiated a significant airway inflammatory cascade with subsequent complications such as severe mucosal inflammation, granulation tissue, stenosis, or post-obstructive pneumonia (Fig. 36.9). Patients with such cases tend to have presented in a relatively delayed manner (i.e., weeks, months, or years later) or aspirated a FB known to be associated with mucosal inflammatory effects. While children commonly present in the acute time period, adults more commonly seek medical attention in a delayed manner [38].
Fig. 36.9
Aspiration of vegetative matter leading to a retained foreign body presentation. White arrows are indicating air space consolidation in the right middle lobe. (a) Posterior-anterior chest plain film. (b) Axial CT chest. (c) Bronchoscopy demonstrating right middle lobe bronchus occluded by a calcified lesion and granulation tissue. Endobronchial biopsy of this lesion revealed retained vegetative debris with surrounding mild inflammation
Acute FB
Most patients in this population will seek and require medical attention in the immediate post-aspiration time period, often with a relatively inert FB. Patients will usually know exactly when the aspiration event occurred and what type of FB was aspirated. When the patient is unable provide history, witnesses may provide information regarding the event. Depending on the type of FB, the size, the location of FB impaction, and the time taken to reach medical services, presentation can range from coughing to acute asphyxiation and death. Acute asphyxiation, also known as café coronary, is more commonly found in children compared to adults. Usually in these cases, the laryngotracheal region is obstructed by a relatively large FB. While choking is the most frequent complaint on presentation, it is more common with children as opposed to adults [39].
As in most of the practice of medicine, history is our most important tool. Correctly identifying the risk factors, potential etiologies, and comorbidities will allow the interventional pulmonologist to plan their intervention carefully and completely to ensure that the best management plan is chosen for each patient. Physical examination findings will vary depending on the location of FB impaction. However, keep in mind, the initial symptoms are heavily reliant upon one’s airway reflexes, and patients with blunted reflexes, from any cause, may not demonstrate these symptoms and/or findings.
When the laryngotracheal region is involved, choking, stridor, wheezing, dyspnea, and hoarseness of voice are commonly observed. Generally, inspiratory stridor occurs with obstruction of the larynx, while expiratory stridor occurs when the tracheobronchial tree is involved. As would be expected with an upper airway obstruction, cyanosis and/or cardiopulmonary decompensation can occur with prolonged hypoxia. Approximately one-third of patients with acute asphyxiation will have FB impaction at the level of the supraglottic region [40]. This said, the oral cavity must undergo a thorough evaluation in any presentation of aspiration to ensure that the FB or any remnants of it are not left behind.
With primary bronchial involvement, there is usually an initial choking event that is followed by dyspnea, wheezing, and usually coughing. Although less commonly, hemoptysis can also be a presenting symptom. More serious findings such as severe hypoxia can occur with complete mainstem bronchial obstruction. With more distal airway involvement, patients will usually have an initial choking event that is followed by a relatively symptom-free period. For such patients, the choking event may or not be followed by respiratory symptoms such as coughing, shortness of breath, or hemoptysis.
Retained FB
A retained FB presentation is more common in the adult population. Seeking medical attention not uncommonly can be delayed by weeks or even months and, in some cases, years later. The hallmark in this population usually encompasses patients seeking medical attention for persistent respiratory symptoms due to the complications which develop because of retained foreign bodies such as chronic cough, recurrent pulmonary infections, shortness of breath, fever of unknown origin, and hemoptysis. The most common presenting symptom is chronic cough. A subset of patients may have a FB discovered as a consequence of clinical evaluation for suspected lung cancer because of concerning findings during a diagnostic work-up (i.e., radiologic findings, advanced age, constitutional symptoms, etc.).
History is paramount to the successful management of any medical condition. As patients presenting with the symptoms of prolonged aspiration of a FB is not common in most practices, having a high index of suspicion is key to rapid diagnosis. The literature suggests that most adults with aspirations are unable to recall a choking episode in their history [21, 38]. This may be due to the size difference of foreign bodies in comparison to the adult airway, neurologic disease prevalence in this population, influence of medications and drugs, as well as adults in iatrogenic circumstances such as intensive care and anesthesia related. To complicate obtaining a thorough history further, it is well known that even when patients have a transient choking event that this is not uncommonly followed by a relatively asymptomatic period due to the distal migration of the FB. In addition to many adults’ aversion to seeing a physician, this may lead many patients to delay seeking treatment until respiratory symptoms recur or become significantly bothersome.
Radiologic Findings
While the sensitivity of plain films for visualizing radiopaque foreign bodies is notoriously low and is approximately 4–21% in the pediatric and adult populations [41–46], it is reasonable to start with plain films of the neck and chest because of the its availability, ease of use, and cost. Associated radiographic changes for foreign bodies do tend to improve the sensitivity for plain films to above 70–85% [3, 22, 38, 47]. These include air trapping, atelectasis, volume loss with mediastinal shift, and air space opacities. In evaluating plain films, it is important to evaluate two different aspects: visualization of FB and radiographic changes related to foreign body presence/impaction. Patients with retained FBs may have additional findings such as persistent/recurrent air space disease, presence of a mass, and/or a pleural effusion. Visualization of foreign bodies is inherently dependent upon size and material. Most foreign bodies tend to be organic material which tends to be radiolucent, while inorganic metallic materials are radiopaque. Once again, it is important to emphasize that one must have high index of suspicion in evaluation of this population and to understand how FB size and properties may have effects on plain film appearance. Interestingly, normal chest films may be noted in approximately 9–37% of adults and children [38, 39, 44, 48]. If foreign body aspiration is of high concern and a normal plain film is encountered, computed tomography (CT) imaging should be obtained.
CT imaging of the chest and neck is considered to be the most sensitive method for imaging in suspected airway FB aspiration. CT imaging has many advantages over plain films such as the superior ability to define location, spatial relationship to important anatomic structures (i.e., vascular structures), and better definition of associated FB effects. Depending on the size of the FB, CT imaging also has the ability to identify radiolucent materials. Thin-slice CT imaging may be preferred for identification of smaller foreign bodies and debris. The detection for airway foreign bodies is much greater with CT imaging than plain films, and CT imaging has been reported to have a sensitivity of 100% in this regard [47–49]. Additionally, in situations like these, CT imaging has the benefit of providing useful information that can assist bronchoscopists in their therapeutic approach to FB retrieval. It is important to note that false positives can occur with CT imaging due to mucus impaction.
Bronchoscopy
Regardless of symptoms and radiology findings, bronchoscopy remains the gold standard for diagnosing FB aspiration. The decision to start with flexible versus rigid bronchoscopy will be discussed under the “Airway Management” section of this chapter. When performing flexible bronchoscopy, it is of the utmost priority to perform a detailed airway exam of not only the central and segmental airways but to also thoroughly assess the nasopharynx, oropharynx, and glottal structures. In examining the segmental airways, not only do the bronchopulmonary segments need to be evaluated, but complete examination of the most distal visible subsegments needs to be performed to ensure that there is no distal impaction or residual debris. This is particularly important in the evaluation of smaller foreign bodies such as nuts, seeds, and pills. Flexible bronchoscopy has the benefit of not only acting as a diagnostic tool but can also be used for therapeutic FB retrieval with various instruments that can be inserted through the working channel of the bronchoscope. Additionally, flexible bronchoscopy can also be used for procedure planning in preparation for rigid bronchoscopy.
Airway Management
Rigid vs. Flexible Bronchoscopy
Traditionally, the gold standard method for FB retrieval has been rigid bronchoscopy. This said, the decision to use rigid or flexible bronchoscopy depends significantly on institutional practices, stability of the patient, equipment availability, and operator experience. The success rates for rigid bronchoscopy in the retrieval of foreign bodies are reported between 95 and 100% [21, 22, 39], compared to flexible bronchoscopy which has reported rates of success between 61 and 90% [21, 38, 39]. In our practice, we avoid viewing rigid and flexible bronchoscopy as mutually exclusive techniques but more as valuable complimentary tools. Each patient is unique and their clinical presentation should guide the selection of the best method for FB retrieval. Patient safety should always outweigh the bronchoscopist’s personal preference and equipment availability. If rigid bronchoscopy is required for safe retrieval of a FB, then arrangements should be made for this to occur, including the transfer of a patient to a specialized center.
Flexible bronchoscopy has the benefit of being able to be performed with moderate sedation with the ability to remove FBs from distal airways. When using flexible bronchoscopy, a therapeutic bronchoscope with a working channel of 2.8–3.2 mm is recommended to allow passage of all available retrieval instruments. When performing flexible bronchoscopy, avoid the trans-nasal route as the nasal passage may be too narrow to allow passage of the retrieved FB. In patients with upper airway/tracheal FBs, stridor, or respiratory failure, rigid bronchoscopy is the preferred tool because of its capability to protect the airway and maintain oxygenation and ventilation. Rigid bronchoscopy also allows the use of various specialty instruments that are designed for FB retrieval; in addition, it is easily used in combination with a flexible bronchoscope. In children, rigid bronchoscopy is almost always recommended as airway size limits ventilation when a flexible bronchoscope is independently used.
Retrieval Procedure
As in any therapeutic procedure, preparation is of the utmost importance prior to onset of procedure. Always ensure that all potential equipment, personnel, and medications are available. Anticipation of complications is the best preventive strategy for such circumstances. When a central airway obstruction (i.e., trachea) is encountered, particularly in an unstable patient, consider distal advancement of the FB to allow for improved ventilation. Many FBs will have induced airway injury or stimulated certain inflammatory pathways. Blood, pus, and other secretions will often cover and/or surround the FB. Clear visualization of the FB is a priority and allows examination of various characteristics of the FB and the airways surrounding it, such as size, proximity to surrounding airways, and whether the FB is free-laying or adherent by granulation tissue and/or adhesions. Also, assess for the presence of surrounding inflammation, blood, and bleeding potential during FB manipulation. Topical epinephrine can be instilled in such circumstances to minimize bleeding.
Retained FBs have a higher potential for the development of associated granulation tissue and may require tissue resection in order to release the FB. Tissue debulking can be achieved mechanically or with ablative therapies (i.e., laser, argon plasma coagulation, cryotherapy, and electrocautery). Before using laser, argon plasma coagulation (APC) or electrocautery, one must consider if the involved FB has combustible properties and if the patient can tolerate an inspired fraction of oxygen less than 40%.
The choice of which instrument to use for retrieval will depend on whether retrieval is being achieved with rigid and/or flexible bronchoscopy, instrument availability, location of FB (i.e., central or distal), and FB qualities (i.e., hard, soft, smooth, rough, sharp, size, etc.). FB repositioning may introduce different options for retrieval and instrument selection, but this always increases the risk of the FB moving more distally and out of reach or further injury to the airway. Retrieval instruments and their respective advantages and disadvantages are discussed in the next section. After the FB has been secured with the selected instrument(s), care must be taken while pulling out to ensure that the path of least resistance is taken not only in the airways but also through a rigid scope or artificial airway. If the FB is too large for the rigid scope or artificial airway, the FB attached to the retrieval instrument and airway device (i.e., rigid scope or endotracheal tube) may need to be removed in an en bloc fashion. This also applies to cases where the FB was lost in the airway device. Occasionally, mucosal and vocal cord injury can occur during this process and bleeding may occur.
Once the FB is removed, distal airways must be assessed adequately to ensure there are not any additional foreign bodies or remnants that need removal. Also, assess the physical properties of the removed FB to identify if the FB was retrieved in a complete manner or if there is evidence of FB fracture suggesting the presence of retained pieces. In retained FB cases, there may be evidence of secretion retention and/or post-obstructive pneumonia, with expulsion of purulent secretions from the distal airways. Our practice is to perform airway washings, using 10 mL aliquots of normal saline instilled sequentially to remove small plugs which might have formed, assist with drainage of secretions, and ensure that no retained debris is left behind.
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