Are contrast swallows a relevant investigation for paediatric stridor?

The contrast swallow has traditionally been used in the investigation of paediatric stridor with the aim of identifying pathology such as vascular rings and confirming the presence of gastro-oesophageal reflux. Currently, a laryngotracheobronchoscopy (LTB) is the gold standard investigation for stridor and frequently, a child is commenced on antireflux medications based on clinical history. We seek to identify whether a contrast swallow has a valuable and cost effective role in the investigation of paediatric stridor. This was a retrospective audit study. All the children who underwent a contrast swallow as part of the investigation for stridor were identified from 2008 to 2011. All requests were made by clinicians from the ENT department at Birmingham Children's Hospital. All patient demographics and radiological reports were reviewed. The final patient list was cross referenced with theatre records to identify those that underwent a LTB The cost of the contrast swallow was identified by the contracting department at Birmingham Children's Hospital. A total of 117 contrast swallows were requested during the study period. The age range was 1 week to 50 months with an average patient age of 6 months. 45/117 (38 %) of contrast swallows identified pathology. 33/45 (73 %) demonstrated reflux. Only 12/117 (10 %) of all cases suggested pathology other than reflux. A total of 51 patients underwent LTB. 22/51 (43 %) had a subsequent contrast swallow. Since the average cost per contrast swallow in the outpatient setting was £ 77, and only 9 cases demonstrated significant unexpected pathology, 108 children had a contrast swallow that did not significantly alter the management of their stridor. 9 cases were identified in which the contrast study results altered the management of the child. An estimated £ 8,000 were spent on investigations that made no impact on the subsequent management of the child. Contrast swallows requested for the investigation of paediatric stridor identified 33 cases of gastro-oesophageal reflux and 12 cases of alternative pathology. Among those children with radiological evidence of reflux, 70 % (23/33) had already been commenced on antireflux medication based on their clinical symptoms. Only 8 % of findings from a contrast swallow investigation resulted in a change to the management of the stridulous child. The authors suggest that it is more cost effective to reserve requests for a contrast swallow until the diagnostic LTB is performed. This strategy will not only reduce exposure to ionising radiation in a significant number of children, but also identifies airway pathology more effectively and ensures that contrast swallows are used as an appropriate adjunctive diagnostic investigation.