Pulmonary Function Tests in Infants with Airway Anomalies and Bronchoscopy Findings

A new study assessed the effectiveness of infant pulmonary function tests, specifically Tidal Breathing Flow Volume Loops (TBFVL), in diagnosing airway anomalies in children and compared these results with bronchoscopy findings.

This prospective cohort study enrolled children aged 0-2 years with airway anomalies in whom TBFVL and bronchoscopy were performed. The primary outcome measured was the graphic pattern of TBFVL in cases of laryngomalacia. Secondary outcomes included the types of TBFVL patterns observed in patients with various airway anomalies and control subjects.

Overall, 53 children were enrolled. Among the participants, 52.3% had laryngomalacia. The most common TBFVL pattern in laryngomalacia was Pattern 3 – characterized by inspiratory limb fluttering. Among the TBFVL parameters, the ratios of inspiratory time to expiratory time (Ti/Te) and tPTEF/tE were significantly higher in children with isolated laryngomalacia than in controls. On follow-up, Pattern 1 (normal) became the most common TBFVL pattern after six months.

Different types of airway anomalies may exhibit characteristic graphic patterns in TBFVL, and changes in these patterns can indicate improvement over time. Hence, TBFVL graphic patterns might help identify the site of airway obstruction. When available, TBFVL can be used as a screening tool for airway anomalies––potentially reducing the need for invasive bronchoscopy procedures. Based on the clinician's judgment, abnormal TBFVL patterns should be confirmed with bronchoscopy.

Source: Pathania A, Jat KR, Sankar J, Lodha R, Kabra SK. May 2024;61(5).