Bronchoscopy findings in recurrent croup: A systematic review and meta-analysis.

Importance: The etiology of recurrent croup is often anatomic. Currently there is no set criteria for determining who should undergo diagnostic bronchoscopy and which patients are at most risk for having a clinically significant finding. Few studies have addressed these questions.

Objective: To identify risk factors for clinically significant findings on bronchoscopy in children with recurrent croup and the frequency of bronchoscopy findings in general.

Data Sources: PUBMED, Ovid MEDLINE, EMBASE.

Study Selection: Articles addressing bronchoscopy in children with recurrent croup, up to July 2016, were reviewed. Related keywords and medical subject headings were used during the search. The abstracts were reviewed to determine suitability for inclusion based on a set of criteria. Manual crosscheck of references was performed.

Data Extraction: We analyzed the bronchoscopy findings of individual patients in each study and their associated risk factors when available.

Results: We reviewed 11 articles, published between 1992 and 2016, including 885 patients (654 males, 237 females). Only 5 studies, including 455 patients, had sufficient data for meta-analysis. Our study revealed that the three most common bronchoscopy findings were subglottic stenosis, reflux changes, and broncho/tracheomalacia. Only 8.7% of patients were noted to have clinically significant findings on bronchoscopy. Meta analysis showed an association between significant bronchoscopy findings and History of Intubation [OR = 5.17, 95% CI 2.65-10.09], Inpatient Consultation [OR = 4.01, 95% CI 1.44-11.20], Age < 3 [OR = 3.22, 95% 1.66-6.27], Age < 1 [OR = 2.86, 95% CI 1.28-6.40], and Prematurity [OR = 2.90, 95% CI 1.39-6.06]. Our study found a high incidence of a History of GERD (20%) and Asthma/Allergies (35%) among patients with recurrent croup, but these variables did not reach statistical significance in patients with significant bronchoscopy findings ([OR = 1.62, 95% CI 0.79-3.30], [OR = 0.57, 95% CI 0.30-1.08] respectively).

Conclusion: The risk factors most associated with clinically significant bronchoscopy findings in recurrent croup are Intubation, Inpatient Consultation, Age < 3, Age <1, and Prematurity. A History of GERD and Asthma/Allergy, though highly prevalent in recurrent croup patients, were not statistically associated with significant bronchoscopy findings.

Relevance: The results should guide physicians in selecting which recurrent croup patients are most at risk for significant findings and thus may warrant bronchoscopy.