Occult foreign body airway in children – Case series with review of literature

Case 1

A 7-year-old girl was referred from North Karnataka with a chronic cough in the past 3 months. The child presented with low-grade fever and chronic cough. Although there was no contact with any tuberculosis patient, the child was on anti-tubercular therapy from the referral hospital without any improvement for 2 months. The child was clinically stable with weight more than the 25^th centile. The Bacillus Calmette-Guerin scar was evident. The trachea was central, but air entry was decreased on the left side. Repeat laboratory evaluation for tuberculosis (erythrocyte sedimentation rate [ESR] and Mantoux) was not contributory. Chest X-ray [Figure 1] showed complete opacification on the left side without any shift of the mediastinum. As the child was not malnourished and did not show any improvement to Anti-Tubercular Therapy (ATT) (in spite of good compliance), suspicion towards malformation of lungs, such as cystic adenomatoid malformation and forgotten FB was suspected. The child was subjected to further radiological evaluation by computed tomography (CT) chest [Figure 1] which showed complete consolidation of the left lung due to obstruction of the left bronchus. After discussion with radiologists, it was decided to consider occult FB and subject the child to rigid bronchoscopy. The child underwent rigid bronchoscopy for FB removal.

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Figure 1:

(a) CT chest and chest X-ray of Case 1. CT* The chest shows obstruction of the left main bronchus due to foreign body (pointed by arrow) and collapse consolidation of the left lung as depicted in the arrow. (b) Chest X-ray of the child shows complete opacity of the left lung. *CT: Computed tomography.

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The FB could not be removed completely due to exuberant granulation tissue obstructing the bronchus. The FB got dislodged during removal and obstructed the right bronchus, when already the left bronchus was compromised due to an impacted FB. The procedure was abandoned as the child suffered cardiac arrest due to hypoxic-ischaemic injury during this procedure. Unfortunately, the child expired in 48 h due to complications (hypoxic-ischaemic injury). The child did not have any comorbidities before the procedure. It was an areca nut obstructing the bronchus in this case. When the history was revisited, it was noted that the grandparents had the habit of chewing areca nut (a common practice in north Karnataka), and the child used to play with them at home.

Case 2

A 2-year-old boy was referred from North Karnataka with a chronic cough in the past 2 months. The child used to have low-grade fever on and off, as noted by the parents. Over the past 2 months, the child used to get an intractable cough with noisy breathing and distress which used to get relieved by nebulisations at the local clinic. The child was never hospitalised for these complaints. In view of the persistence of cough and wheeze, the child was referred to our hospital. The child was on metered dose inhaler therapy with salbutamol and budesonide for hyperreactive airway disease without any complete relief at presentation. The child was clinically well nourished and active without any respiratory distress. As they were referred from a distant place with chronic symptoms, the child was admitted for evaluation. During hospital stay, it was noted that the child used to get distressed suddenly and develop an intractable cough. Although the vitals used to be stable, the child remained distressed despite the use of bronchodilators. Although bilateral air entry was equal, the child used to have significant polyphonic rhonchi heard bilaterally, with occasional whooping type of cough. The child did not respond to oral macrolides for over 1 week. In view of a persistent cough without complete relief to bronchodilators or antibiotics, a suspicion of hidden FB was considered in this child. Laboratory tests such as complete blood count (CBC), C-reactive protein (CRP) and ESR were within normal limits. Chest X-ray showed bilateral infiltrates with hyperinflation of the left lung [Figure 2]. This led to the suspicion of hidden FB, which was confirmed in the CT [Figure 2].

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Figure 2:

(a) HRCT image and chest X-ray of Case 2. HRCT* image shows foreign body (pointed by arrow) at the level of the carina. (b) Chest X-ray shows infiltrates in bilateral lungs. *HRCT: High-resolution computed tomography.

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Rigid bronchoscopy was done which showed an areca nut as the obstructing FB. It was noted that the FB was engulfed with mucus and was adherent to the carina with a pedicle of granulation tissue, which was intermittently obstructing the left and right bronchus as visualised during bronchoscopy [Figure 3]. The post-procedure course of the child was uneventful, and the child continued to do well on follow-up.

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Figure 3:

Foreign body (areca nut) engulfed in mucus and exudates stuck with a pedicle over the carina in Case 2. Note: The foreign body was noted to intermittently block the right and left bronchus during the procedure. This could be the reason for the paroxysmal nature of cough as noted in the history of the patient.

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Case 3

A 9-year-old girl from a nearby town in Mangalore was seen in the paediatric outpatient department with cough and occasional chest pain for 2 months. The cough was dry without any disturbance in sleep or any post-tussive vomiting. The child was treated by paediatricians from nearby clinics with oral antibiotics for the past three weeks, with a suspicion of recurrent lower respiratory tract infection. However, upon review, we noted that all laboratory reports (CBC, CRP, ESR, Mantoux, and chest X-ray) from the referral clinics were within normal limits. In view of chest pain, the child was evaluated for any cardiac disease and musculoskeletal pain in our centre. The child did not have any local tenderness of the costochondral joints. As the child was clinically stable with normal vitals without any cardiac murmur or any other symptoms related to cardiac illness, a detailed evaluation with chest X-ray and echocardiogram was done to rule out any mitral valve prolapse. A repeat chest X-ray [Figure 4], which was done in our institution, revealed subtle hyperinflation on the left side. After discussion with radiologists, a suspicion of FB airway was considered in this child. As the child was an adolescent, the child psychologist’s help was sought to counsel the child and revisit the history which clarified the doubts. The child agreed to have a habit of chewing on a pen cap which accidently was aspirated 2 months ago. With the fear of parental punishment, the child had concealed this history in the initial evaluation. With this history, an HRCT chest was done which confirmed the obstruction of the left bronchus as depicted in Figure 4.

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Figure 4:

(a) CT chest and chest X-ray of the Case 3 CT* image depicts the foreign body (pointed by arrow) obstructing the left main bronchus. (b) Chest X-ray shows hyperinflation of the left lung due to ball valve mechanism due to partial obstruction of the left main bronchus on expiratory film. *CT: Computed tomography.

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The child underwent rigid bronchoscopy, and a green plastic pen cap [Figure 5] was noted to be the obstructing object which was difficult to remove in one sitting. Cryotherapy was used during rigid bronchoscopy in this case to clear the necrotic tissue surrounding the FB. The FB was completely removed in the second sitting. This child continued to be under close follow-up for a persistent cough which was evaluated by follow-up flexible bronchoscopy. There were no residual FB particles noted on follow-up flexible bronchoscopy in this case and the child showed gradual improvement to supportive treatment with bronchodilators.

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Figure 5:

Foreign body (part of pen cap) noted in Case 3. Note: The foreign body pen cap was removed by rigid bronchoscopy in two sittings in this case.

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Age and gender distribution

In a systematic review by Lorenzoni et al., it was noted that out of 294 cases of FBA, almost half of the cases were reported from Asian countries (43%) amongst which 52 cases were reported from India.^[17] Boys were more commonly involved in these injuries. Published literature from all over the world proves that FB airway is most common in children <3-year age group. Higher incidence in this age group is due to the oral exploratory behaviour in toddlers; improper chewing habits due to incomplete development of the molars and children of this age often engage in playing, jumping and crying during feeding.^[14] Some studies have noted a second age group, usually 8–14 years which is common for FBA due to inorganic items like metallic objects such as coins and plastic caps.^[13,17,23] Like our case, Hilliard et al. in their case series noted a plastic pen cap as the FB retrieved from airway during rigid bronchoscopy in a 10-year-old boy.^[24]

Clinical presentation of long-standing FB airway

FBA can initially present with sudden symptoms such as choking, cough and life-threatening asphyxiation.^[6] The classic triad of cough, wheezing and diminished breath sounds is observed in less than 50% of paediatric cases.^[15] However, in approximately 15% of cases, the choking episode may go unnoticed which can result in the FB going undetected and diagnosed late.^[3] Initial symptoms largely depend on the anatomical location, type of FB and the child’s age. FBs are most often found in the right lung (59%), particularly in the principal bronchus, followed by the left lung (23%) and the trachea (13%).^[7] Symptoms may get masked when the FB slips into the bronchus.^[3] A long-standing retained bronchial FB may cause the production of arachidonic acid, which results in an abnormal mucus secretion and exudates that clog up the lungs.^[15] These occult FBs can cause chronic symptoms like persistent cough, which may be misdiagnosed as other respiratory illnesses, such as asthma, bronchiolitis, bronchitis or pneumonia.^{[14,16,18,25]} Moreover, delay in diagnosis can lead to complications such as recurrent pulmonary infections, atelectasis, bronchiectasis and lung abscess.^[19] Cases may be mistakenly treated for tuberculosis, bronchial asthma or hyperreactive airways, as seen in the cases presented in this case series. Penugonda et al., in their retrospective study of 296 cases, noted that 32% (87/269) of cases who were initially treated as respiratory tract infections were later diagnosed as airway FB.^[14] They further went on to formulate a Weighted Risk Score to improve the diagnostic accuracy of FB detection by clinical (choking with cough – 3 points and unilateral decreased breath sounds – 1 point) and radiological parameters (abnormal chest radiograph – 1 point and mediastinal shift – 3 points). Any score >5 was 100% sensitive and specific to having an FB airway and in all the cases with a score >5, FB was isolated in rigid bronchoscopy in their study.

Types of FB

According to the Surveillance SYstem on Suffocation injuries due to Foreign bodies in children in Europe (SUSY SAFE) (largest international registers that collect cases of FB accidents in children aged 0–14 years from EU countries and some non-EU countries), food-related FBs were the most common cause of FBA in children, accounting for up to 26% of injuries, with chicken and fish bones (32%), peanuts (22%) and seeds (16%) being the most frequently reported items.^[26] Few studies from India have reported organic FBs like peanuts in >80% of the reported cases. In the same study, inorganic FBs, such as plastic beads, pen caps and metal objects, were also noted in relatively older children.^[14,25] Button batteries, which can cause severe complications, were isolated in a significant number of cases by Lorenzoni et al. in their study.^[17] As we could isolate areca nuts in two cases in our case series, we would like to highlight that certain cultural habits (areca nut and betel leaf chewing habits) can influence the types of airway FBs in specific regions like North Karnataka. This information can be used to educate the people of this region.

Radiological evaluation

Chest X-ray is commonly done in suspected FBA, but its diagnostic accuracy varies in different studies (sensitivity 61–88% and specificity 30–97%).^{[15,18,19,24,25]} While X-rays can confirm the diagnosis, they may not detect radiolucent airway FBs. Inspiratory and expiratory films in a cooperative child can aid diagnosis by showing hyperinflation due to air trapping. However, CT scans have higher sensitivity (99%) and specificity (92%) for detecting FBA, though they are less preferred due to significant radiation exposure.^[20,21] Flexible bronchoscopy is often the diagnostic method of choice in tertiary care settings. This is less invasive, less traumatic, and can be done under local anaesthesia, with the advantage of reaching the more distal airways with a lower risk of complications.^[22]

Treatment and outcome

Rigid bronchoscopy is the gold standard in the treatment of suspected or confirmed FBA in children.^[3,5,15,22] It provides optimal airway control with good visualisation and manipulation of the object with different forceps and rapid management of complications like mucosal haemorrhage during FB removal, further facilitating the usage of cryotherapy for clearing granulation tissue in long-standing FBs. Reported complications may vary from 1% to 9% in different studies.^[12,17] Complications include hypoxemia, lacerations, bleeding, pneumothorax and rarely cardiac arrest.^[27] Delay in the diagnosis of airway FB increases the risk of severe complications during bronchoscopy. Flexible bronchoscopy, being less invasive, has emerged as a game-changer in airway FB removal, allowing specialists to pioneer cutting-edge techniques (using biopsy forceps, snares and baskets) that have significantly improved patient outcomes in recent times.^[25] The only disadvantage is limited instrumentation, suctioning, lack of airway control and ventilatory capability, with the danger of dislodging the FB, further compromising the airway. In complex cases, surgical intervention may be required, and a multidisciplinary approach ensures better outcomes, as demonstrated by Lorenzoni et al. in their systematic review.^[17]

In a scenario of complete obstruction of the trachea and consequent asphyxia during an attempt to remove the FB, the rescue technique involves pushing the object into the bronchus and ventilating the other lung. In the event of complications such as rupture of the trachea during extraction of the FB, it is imperative that the endotracheal tube be placed distal to the disruption to avoid the risk of rapid pneumothorax and death. In older children, double-lumen intubation is preferred to protect both lungs from bleeding distal to the injury. In these situations, early diagnosis and surgical repair are critical to preserve lung function.^[12] In the event of complications, a multidisciplinary approach (paediatric surgeon, cardiothoracic surgeon, expert anaesthetist, Extracorporeal Membrane Oxygenation (ECMO) expert and paediatric intensivist) is the best practice for a favourable outcome. FB that cannot be removed by bronchoscopy needs other procedures such as tracheostomy or open thoracotomy or bronchotomy or lung resection.^[27] Thoracotomy has been reported to be necessary in less than 1% to 2.5% of cases.^[25]

Prevention

Preventive measures in children recommended by the American Academy of Pediatrics in 2012 and collaborations with the US Food and Drug Administration and Consumer Product Safety Commission have significantly reduced the incidence of FBA to <0.43/100000 population, as noted in 2016 in a report by the National Safety Council.^[28] Surveillance systems like maintaining a surveillance register by SUSY SAFE in the European Union, have also reduced the incidence of FBA in this region.^[26] The public needs regular awareness campaigns and regulations on food items and toys to effectively reduce such fatal choking episodes in any country.^[9] Education of parents and caregivers about hazardous food items that can get choked and age-appropriate toys prove helpful. Furthermore, training of school teachers on the first aid measures in choking episodes by healthcare providers on a regular basis is the need of the hour.^[29] However, such measures are still underdeveloped in India, where implementing these regulations could significantly reduce FBA-related injuries.

Lessons learnt

• Any child can present with FBA, unlike the previous belief that it occurs only in toddlers.

• An occult FB airway should be suspected in all children with chronic respiratory symptoms

• Bronchoscopy is the gold standard in the diagnosis and treatment of FBAs.