Pediatric Respirology and Critical Care Medicine

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 4  |  Issue : 2  |  Page : 28--32

Comparative analysis of computed tomography scan and flexible bronchoscopy in the evaluation of suspected foreign body aspiration in children and the role of later in its removal


Javeed Iqbal Bhat1, Naseer Ahmad Choh1, Shihab Zahoor2, Bashir Ahmad Charoo1, Zubair Mushtaq Tramboo1,  
1 Department of Pediatrics, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
2 Department of Radio Diagnosis, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India

Correspondence Address:
Javeed Iqbal Bhat
Department of Pediatrics, Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar - 190 011, Jammu and Kashmir
India

Abstract

Background: Foreign body aspiration (FBA) in children is considered one of the most important diagnostic and therapeutic challenges for physicians. Often there is no history of aspiration of foreign body in this population and these children present with a wide range of nonspecific signs and symptoms. The objective of the study was to study the diagnostic utility of chest computed tomography (CT) scan in children with suspected FBA in comparison to flexible bronchoscopy (FB) and the role of later as a therapeutic tool in the removal of airway foreign bodies. Methods: This was a prospective observational study conducted from January 2015 to August 2019. Children admitted for persistent respiratory symptoms underwent CT chest and FB for confirmation of the diagnosis and retrieval of the foreign body if present. Results: A total of 101 patients of both genders were enrolled in the study. Fifty-three participants were boys and 48 were girls. FBA was diagnosed in 53 patients on chest CT. On FB, FBA was confirmed in 55 patients. The sensitivity and specificity of chest CT in our study were 85% and 87% respectively. In 25 of these patients, removal was successfully done by the FB. Conclusion: We conclude that a Chest CT scan is inferior to FB in the diagnosis of suspected trachea-bronchial foreign bodies in children. FB as a therapeutic tool has an excellent safety record in the retrieval of airway foreign bodies in this population.



How to cite this article:
Bhat JI, Choh NA, Zahoor S, Charoo BA, Tramboo ZM. Comparative analysis of computed tomography scan and flexible bronchoscopy in the evaluation of suspected foreign body aspiration in children and the role of later in its removal.Pediatr Respirol Crit Care Med 2020;4:28-32


How to cite this URL:
Bhat JI, Choh NA, Zahoor S, Charoo BA, Tramboo ZM. Comparative analysis of computed tomography scan and flexible bronchoscopy in the evaluation of suspected foreign body aspiration in children and the role of later in its removal. Pediatr Respirol Crit Care Med [serial online] 2020 [cited 2021 Apr 16 ];4:28-32
Available from: https://www.prccm.org/text.asp?2020/4/2/28/311044


Full Text



 Introduction



Foreign body aspiration (FBA) into the tracheobronchial tree is an important cause of childhood mortality especially in young children between six months to 3 years of age.[1] According to the National Safety Council of USA, the rate of fatal choking in American children <5 years of age is 0.43/100,000 of the general population.[2] The majority of times there is no history of FBA especially in toddlers, these patients usually present with nonspecific symptoms of persistent cough, hemoptysis, collapse, asymmetrical air entry, and nonresolving pneumonia.[3] Delayed diagnosis is associated with increased complication rate,[4],[5] hence early diagnosis is essential to reduce complication rate and overall mortality in these patients.

Chest X-ray is the initial investigation in children evaluated for persistent respiratory symptoms; however, X-ray findings especially in the case of radiolucent FBA are usually nonspecific, which may include unilateral hyperlucency, persistent collapse, mediastinal shift, etc. In about 30% of patients, there may be no abnormality on chest X-ray.[6] Computed tomography (CT) scan chest with or without virtual bronchoscopy is being increasingly used as a diagnostic tool in suspected FBA in children. It has excellent sensitivity in picking up radio-opaque foreign bodies; however, sensitivity is variable in the case of radiolucent foreign bodies, which is the commonest one in children.[7] In contemporary Pulmonology, flexible bronchoscopy (FB) has found an important place in the initial evaluation of children with suspected FBA. It is a very safe procedure in expert hands with nearly 100% sensitivity and specificity in diagnosing FBA.[8],[9],[10] Besides diagnosis, it is now increasingly used for the removal of foreign bodies from the trachea-bronchial tree with an established safety profile.[11] FB is especially useful in removing foreign bodies at difficult locations like upper lobe bronchus, deep lower lobe bronchus. The present study was conducted to study the diagnostic utility of chest CT scan in children with suspected FBA in comparison to FB and the role of the later as a therapeutic tool in the removal of airway foreign bodies.

 Methods



This was a 56-month prospective observational study from January 2015 to August 2019 conducted in the department of pediatrics of a tertiary care hospital of northern India. The study material consisted of Children admitted or referred to or hospital as suspected FBA. Suspected FBA was defined by “a child with persistent respiratory symptoms like chronic cough and/or indirect radiological evidence of trachea-bronchial foreign body like unilateral hyperinflation, persistent collapse, non-resolving pneumonia or soft tissue shadow in the trachea-bronchial tree with no definite history of FBA/chocking.” Patients, with X-ray chest and/or CT chest documented radio-opaque foreign bodies were excluded from the study, and these patients were directly subjected to the rigid bronchoscopy for its removal. A standardized data extraction form was used to obtain the demographic and clinical data including age, sex, weight, and the duration of the symptoms. Chest CT scan findings were documented in all the enrolled patients. FB (Olympus video bronchoscope) was done in all the enrolled patients. The authors used a BF-XP160F™ scope with channel size 1.2 mm in children <4 years of age and BF-MP-160F™ scope with a channel diameter of 2 mm in children above 4 years of age. Written informed consent was taken from all the patients before undertaking the procedure. All procedures were performed in a bronchoscopy suite which is close to the pediatric intensive care unit. Bronchoscopy team comprised of two bronchoscopists, one pediatric resident, one bronchoscopy technologist, and one nurse. During the procedure blood pressure, ECG, and oxygen saturation were continuously monitored using multi-channel Nelcor™ Monitor. All patients received supplemental oxygen via nasal cannula during the procedure. Nasal mucosa was anesthetized by using lidocaine gel locally. 2% lidocaine in 1 mL aliquots in 1:1 dilution with normal saline was instilled in the tracheobronchial tree by the “spray-as-you-go” technique. Supplemental local anesthesia was given as per requirement. All patients received midazolam bolus at the dose of 0.1 mg/kg over 1 min. In addition to midazolam bolus, the majority of our patients received intravenous (IV) ketamine bolus at the dose of 1 mg/kg over 2 min diluted in normal saline. Signs of pain or discomfort, agitation, persistent cough, and inadequate motor or verbal response to manipulation were considered indicators for insufficient sedation, leading to the administration of additional doses of IV ketamine bolus at 1 mg/kg/dose. Patients, who received ketamine, were also given IV glycopyrrolate 5 μg/kg to reduce ketamine-induced increased respiratory secretions. Bronchoscopy findings were recorded in a standard format, which included all anatomic and functional details, presence of foreign body if any and its location, type of foreign body, any granulation tissue, purulent secretions, and bleeding tissue surrounding the foreign body. Complications if any during or postprocedure were recorded in a standard format.

Statistical analysis was performed using SPSS 20, IBM; Armonk, United states. The normality of the data was checked by using the Shapiro–Wilk test. Parametric data are expressed as mean ± standard deviation and nonparametric tests as median (interquartile range). Categorical variables are presented as percentages. The study was cleared by the ethical committee.

 Results



During the 56 months of the study period, 143 patients were fulfilling the inclusion criteria. In 20 patients, CT chest could not be done; these were excluded from the study. Twenty-two patients couldn't be enrolled due to the refusal of consent for a bronchoscopy. So a total of 101 patients were enrolled in the study. Fifty-three participants were boys and 48 were girls. The baseline characteristics of the study population are shown in [Table 1]. On CT chest FBA was diagnosed in 53 patients. It was seen in a right bronchus in 38 patients and left bronchus in 15 patients. Among 53 patients with CT diagnosis of FBA, a second differential diagnosis of thick mucus plug was given in 23 patients [Figure 1].{Figure 1}{Table 1}

FB was done in all 101 patients. FBA was confirmed in 55 patients with 41 foreign bodies visualized in right bronchus and 14 in the left bronchus. In 25 patients, removal was successfully done with the help of the flexible scope. Removal was done by Dormia basket, loop, or forceps [Figure 2]. Success in foreign body retrieval was inversely related to the duration of symptoms. [Table 2] shows the characteristics of the two groups. The most frequently aspirated foreign body was nut and kernel (52.7%) followed by bean (30.9%). Plastic foreign bodies were seen in 7 (12.7%) patients and two patients had aspirated chewing gum. There was no statistically significant difference between the type of foreign body and the success of removal with the flexible scope. Among 53 patients with CT diagnosis of FBA, six patients had no foreign body visualized in the tracheobronchial tree on FB (thick mucus plug in four patients, granulation tissue in two patients). Similarly, in eight patients CT chest was reported as normal, however, FBA was detected on FB. The sensitivity and specificity of chest CT scan in our study were 85% and 87% respectively. No major adverse event was noticed during the procedure. Minor adverse events like transient desaturation were seen in five patients (11%), apnea in two patients (4.7%), and post bronchoscopy wheeze in one patient (2.5%) requiring salbutamol nebulization.{Figure 2}{Table 2}

 Discussion



In this 56-months prospective study, we found that the CT scan is 85% sensitive and 87% specific in diagnosing suspected airway foreign bodies. FB not only helped us in confirming the presence of a foreign body but also enabled us to identify its position and attempt its removal in the case of a small and recently aspirated foreign body. We encountered a very few minor procedural side effects during the removal.

Aspiration of foreign body in the tracheobronchial tree is a common and life-threatening situation in children. Up to 50% of patients especially toddlers have no history of aspiration. These patients present with non-specific respiratory symptoms in the form of cough, wheeze, recurrent/non-resolving pneumonia, persistent collapse, and decreased air entry.[3],[12] The complication rate is highest in this subgroup of patients. Chest X-ray is the first investigation for the evaluation of persistent respiratory symptoms in children; however, its role in the evaluation of FBA is controversial. In a study by Mallick[6] chest X-ray was normal in 32.2% of patients. CT scan chest with or without virtual bronchoscopy has gained importance in the evaluation of suspected FBA in children because of its ease of availability and non-invasive nature of the investigation. CT scan chest may reveal the impacted foreign body directly as a hyperdensity in the lumen of the airway or from ancillary findings like lobar/unilateral emphysema, atelectasis, consolidation, and bronchiectasis.[13] Three-dimensional CT has excellent sensitivity in detecting radio-opaque foreign bodies, however, in the case of radiolucent foreign body, sensitivity is variable. We found an overall sensitivity of 85% in our study cohort. In a study by Applegate et al.[7] on a cadaveric model using a spiral CT scan, they reported a combined sensitivity and specificity of 83% and 89% respectively in the detection of aspiration of LEGO foreign bodies. However, sensitivity was only 34% in the case of peanut aspiration. As the majority of FBA in children are due to organic foreign bodies, the chance of false-negative rate is high, making this investigation less useful in the investigation of radiolucent FBA in children. CT scan also exposes a child to a high radiation dose. The radiation dose from a typical chest CT scan in a child is about 250–300 times higher than a chest X-ray.[14] Mathews et al.[15] in their study on a large cohort of patients found an increase in cancer incidence by 24%, and the risk was greater for persons exposed at a younger age.

FB is increasingly being used for the evaluation of persistent/recurrent respiratory symptoms in children. This procedure helps us to obtain the detailed anatomic and functional information of the tracheobronchial tree. In the case of FBA, it can provide us information about the foreign body's nature, its orientation, and associated changes in the airway mucosa as well as attempts its extraction in the same setting.[16] FB has proven an excellent and safe tool for the removal of foreign bodies from the tracheobronchial tree in children. In our study, about 50% of foreign bodies were successfully removed with a flexible scope. Swanson et al.[17] published 8 years of experience of foreign body retrieval through FB. In their series, all airway foreign bodies were successfully removed with a fiberoptic bronchoscope. Tang et al.[18] in their study successfully removed airway foreign bodies by FB in 91.3% of the patients without any major complications. The reason for the less retrieval rate in our series was because our study was done in patients with no clear cut history of FBA. All patients in our study had non-specific chest problems like persistent lobar/segmental collapse, non-resolving consolidation, unilateral emphysema, with a mean duration of the symptoms of 17.35 ± 7.3 days. The vegetative foreign body swells and gets stuck-up with time, making its retrieval difficult with the flexible scope, this might be the reason for less extraction rate in our patients.

FB in children is a very safe procedure.[9],[19] The authors also did not find any major complications during the procedure. Minor adverse events like transient desaturation were seen in five patients (11%), apnea in two patients (4.7%), and post bronchoscopy wheeze in one patient (2.5%) requiring salbutamol nebulization making this procedure very safe.

The limitation of our study is that it is an observational study; a well-controlled RCT comparing FB with rigid bronchoscopy would be more accurate and will be helpful in further assessing the clinical utility of the FB in suspected FBA.

 Conclusion



We conclude that a Chest CT scan is inferior to FB in the diagnosis of suspected FBA in children. FB is a good therapeutic tool for retrieval of airway foreign bodies. Besides, it is a safe procedure with minimum complication rate and can be done as a daycare procedure under conscious sedation.

Acknowledgments

Mr. Ghulam Qadir Bhat Senior bronchoscopy technologist, Resident staff SKIMS Srinagar.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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