Recorded Flexible Nasolaryngoscopy for Neonatal Vocal Cord Assessment in a Prospective Cohort

Abstract

Objective: Assessing vocal cord mobility by flexible nasolaryngoscopy (FNL) can be difficult in neonates. To date, prospective studies evaluating the incidence and diagnostic accuracy of vocal cord paralysis (VCP) after surgical patent ductus arteriosus (PDA) ligation are limited. It is unknown whether video FNL improves diagnosis in this population. This study compared video recordings with bedside evaluation for diagnosis of VCP and determined inter-rater reliability of the diagnosis of VCP in preterm infants after PDA ligation. Methods: Prospective cohort of preterm neonates undergoing bedside FNL within two weeks of extubation following PDA ligation. In a subset, FNL was recorded. Two pediatric otolaryngologists, blinded to the initial diagnosis, reviewed the FNL video recordings. Results: Eighty infants were enrolled and 37 with a recorded FNL were included in the cohort. Average gestational age at birth was 25.2 weeks (SD: 1.2) and postmenstrual age at FNL was 37.0 weeks (SD: 4.5), which was 9.5 days (SD: 14.7) after extubation following PDA repair. There were 6 diagnosed with left VCP (16.2%; 95% CI: 4.3-28.1%) at bedside, and 9 diagnosed by video review (24.3%; 95% CI: 10.5-38.1%) ( P = .56). Videos confirmed all 6 VCP diagnosed initially, but also identified 3 additional cases. Though imperfect, reviewing FNL by video showed substantial reliability (kappa = .75), with 91.9% agreement. Conclusion: Video recorded FNL most often confirms a bedside diagnosis of VCP, but may also identify discrepancies. Physicians should consider the limitations of diagnosis especially when infants persist with symptoms such as weak voice or signs of postoperative aspiration. Level of Evidence 2b