The Role of Lung Function Testing in Newborn Infants With Congenital Thoracic Arterial Anomalies

Abstract

Introduction: Congenital thoracic arterial anomalies (CTAAs), such as complete or incomplete vascular rings, pulmonary artery sling, and innominate artery compression syndrome, may cause severe tracheomalacia and upper airway obstruction. An obstructive ventilatory pattern at lung function testing (LFT) has been suggested in the presence of CTAA. The severity of obstruction may be evaluated by LFT. Little is known about the use of LFT in newborn infants with CTAA. The aim of our study is to evaluate the role of LFT in CTAA diagnosis.Methods: This is a retrospective study, conducted between February 2016 and July 2020. All CTAA cases for whom LFT was performed preoperatively were considered for inclusion. Tidal volume (Vt), respiratory rate, and the ratio of time to reach the peak tidal expiratory flow over total expiratory time (tPTEF/tE) were assessed and compared to existing normative data. Demographics and CTAA characteristics were also collected.Results: Thirty cases were included. All infants with CTAA showed a significantly reduced Vt and tPTEF/tE, compared to existing normative data suggesting an obstructive pattern.No significant differences were found for LFT between cases with a tracheal obstruction <50% compared to those with tracheal obstruction ≥50%, or between cases with and without symptoms. Sixteen infants (53.3%) had respiratory symptoms related to CTAA. Of these, only two cases had also dysphagia.Conclusion: LFT values were significantly reduced in cases with CTAA before surgery. LFT represents a potential feasible and non-invasive useful tool to guide diagnosis in the suspect of CTAA.

Changes in Breathing Patterns after Surgery in Severe Laryngomalacia

“…In particular the results showed a significant improvement ( p < 0.001) after surgery in tidal volume and the mean expiratory/mean inspiratory flow ratio (index of the patency of the upper airways). Supra-glottoplasty, as already described in other studies, is a safe and efficient procedure to treat severe laryngomalacia during infancy [ 25 , 26 , 30 , 31 , 35 ]. This procedure is an effective technique which results in a significant improvement in breathing patterns.…”

“…Starting from our experience of feasibility of using LFT in children and infants with suspected congenital thoracic arterial anomalies (CTAAs) [ 26 ], the aim of this work was to highlight the reliability of these respiratory tests in a series of diagnostic procedures, in the evaluation of the therapeutic results after supra-glottoplasty, and in the follow-up and future monitoring of respiratory patterns.…”

Vocal Cord Paralysis and Feeding Difficulties as Early Diagnostic Clues of Congenital Myasthenic Syndrome with Neonatal Onset: A Case Report and Review of Literature

“…Lung function was assessed using analysis of the tidal-volume and flow-volume loop using an ultrasonic flowmeter (ndd Medical Technologies, Zurich, Switzerland) connected to an Exhalyzer D (Eco Medics, Dürnten, Switzerland). Neonatal lung function tests (LFTs) were performed in a neutral supine position during normal sleep, without any sedation, recording at minimum 10 consecutive breaths of each patient while also measuring the following parameters: tidal volume (Vt, mL/kg), respiratory rate (RR), and the ratio of time to reach peak tidal expiratory flow over total expiratory time (tPTEF/tE), as previously described [ 6 ].…”