oa A New Clinical Algorithm and Scoring System for Management of Suspected Foreign Body Aspiration in Children

Background

Foreign Body Aspiration (FBA) is a serious common problem in children, which needs prompt diagnosis and management; delays can result in devastating consequences. Physicians often struggle with the all too important, yet elusive, decision of “To bronch, or not to bronch” patients who present with a suspected FBA. In most cases, the history is often vague, with only subtle, if any, physical and chest radiograph abnormalities. With this study, we aim to use our local experience in Qatar to retrospectively analyze broncho-scopically proven cases of FBA in an attempt to determine the key statistically significant clinical predictors of foreign body aspiration in children.

Objective

To develop a clinical algorithm with a scoring system for aiding physicians to accurately predict patients with FBA, needing bronchoscopy, based on the patient's historical, physical and radiological findings at presentation.

Methods

This is a retrospective observational study, including all patients, aged 0 to 14 years, who were admitted to the pediatric department of Hamad medical corporation, Qatar between January 2001 to January 2011 with a diagnosis of suspected FBA. All patients underwent bronchoscopy, either flexible or rigid or both. Detailed data regarding the history, presenting clinical signs and symptoms, physician documented physical exam assessment as well as radiological findings were collected and analyzed. The bronchoscopy records were reviewed for bronchoscopy details like type (Flexible vs rigid), size and instrumentation used, outcomes including presence, type and location of foreign body (FB) and pre and post procedure complications. The focus of the data analysis was to determine the predictive accuracy of the various variables in diagnosing FBA. For this, the sensitivity, specificity, positive and negative predictive values of these parameters were calculated, using bronchoscopy diagnosis of FBA as the point of reference. Univariate and multivariate logistic regression methods were used to determine their statistical predictive value.

Results

Based on the inclusion criteria, a total of 300 children were included in this study. Male, female ratio of 1.2:1. The mean age was 2.1 ± 1.7 years. 46.3% of the patients were Qatari nationals. These 300 patients, cumulatively underwent a total of 410 bronchoscopies, which included both flexible and rigid bronchoscopies (88 patients underwent 2 bronchoscopies, 17 had 3, 4 patients had 4 and one patient underwent 5 bronchoscopies). A FB was found in the airway of 91 of these 300 children (30.3%). In all of these cases, the FB was successfully removed, in 67 cases (∼75%) with a rigid bronchoscopy and in 23 patients (∼25%), using a flexible bronchoscopy. 1 patient required a thoracotomy. Post bronchoscopy complications were reported in only 2.6% cases, with no procedure related mortalities. The most common site of FB lodging was the right main stem bronchus (47.3%), followed by left main stem bronchus, bilateral main bronchi, carina and trachea. The rest were recovered from segmental smaller airways. Organic FB accounted for 62.6% of the FB removed, with peanuts being the most common type. A complete list of the clinical signs and symptoms based on parent's history, physical exam findings and radiological findings in both groups of children i.e. those with a recovery of FB during bronchoscopy (FBA positive) and those without a FBA (FBA negative), can be viewed in Table 1. Using multivariable logistic regression analysis controlling for all other potential predictors, we found that the risk factors with the strongest association with FBA are witnessed choking crisis (adjusted OR 2.1, 95% CI 1.03–4.3.8; P = 0.041), noisy breathing/stridor/dysphonia (adjusted OR =  2.7, 95% CI 1.22–6.17; P = 0.015), new onset, recurrent or persistent wheeze (adjusted OR 4.6, 95% CI 1.77–11.76; P = 0.002) and unilateral reduced air entry (adjusted OR 2.9, 95% CI 1.53–5.52; P = 0.001). No significant interactions were found between the various otherhistorical signs and symptoms, radiological and physical examination findings. Figure 1 shows the cumulative proportion of children with proven FBA according to the above 4 risk factors. Only 8% of the children without any of these risk factors had a proven FBA, the likelihood increased significantly with an increasing number of risk factors. When all 4 risk factors were present, the likelihood of FBA was a 100%. 242 of these 300 patients were also analyzed and grouped based on whether they had normal or abnormal physical or radiological findings on presentation. (The remainder of the patients did not have a documented exam or a chest radiograph on record review). The results were as follows: in children with both abnormal physical and radiological findings, 47.2% had a proven FBA. If only one was abnormal (i.e. either physical exam or chest x-ray), the likelihood of FBAreduced to 32–33.3%. In children who presented with a completely normal physical exam and chest radiograph, only 7.4% had a FB removed by bronchoscopy (Fig. 2). Based on the above results, we designed a clinical algorithm, with a scoring system (Fig. 3), to aid in determining those children who require bronchoscopy to rule out FBA, and those who can be discharged on close follow up, without any intervention.

Conclusion

Accurately diagnosing FBA in children who need quick intervention will always be challenging. A high index of suspicion is required, along with a comprehensive historical account, detailed physical exam and a chest radiograph. The ultimate decision for bronchoscopy is based on the physician's clinical judgment as there is no 100% diagnostic predictor of FBA, perhaps with the exception of a radio-opaque foreign body. Our proposed clinical algorithm hopes to empower physicians dealing with such cases to accurately predict patients with a high likelihood of FBA and initiate prompt management, as well as avoid unnecessary intervention in those who have a very low probability of FBA.