Detection of Vocal Fold Motion Impairment on Noninvasive Positive Pressure

Vocal fold motion impairment (VFMI) is a known sequela of airway, esophageal, and great vessel surgery, due to direct damage of the recurrent laryngeal nerve(s). VFMI can be diagnosed with the gold standard approach, direct visualization using fiberoptic nasolaryngoscopy (FNL).

Paralysis of the vocal folds leads to glottic incompetence, which can cause dysphonia, feeding and swallowing difficulties, risk of aspiration, and airway compromise. Taken together, these symptoms can then lead to poor weight gain, chronic aspiration, need for hospitalization, recurrent pneumonias, and needs for alternative routes of nutrition.

The presence of VFMI after cardiovascular surgeries occurs anywhere from 8.8% to 58.7%, depending on the procedure performed and institution. Nerve injury may recover spontaneously, however the extent and timing are variable.

Although FNL has been historically thought to be a safe procedure, recent literature and case reports have noted that FNL is potentially noxious to the pediatric patient. This noxious stimuli can lead to tachycardia, tachypnea, oxygen desaturation, epistaxis, vasovagal events, laryngospasm, and aspiration events. In pediatric patients who have undergone cardiovascular surgery, the noxious stimuli from FNL can be potentially life-threatening. Specifically for those with single ventricle physiology and pulmonary hypertension, the noxious FNL can lead to a rapid increase in pulmonary vascular resistance, which can cause the pulmonary arterial pressure to exceed that of the systemic vascular pressure. This could then lead to an acute decrease in the right ventricular ejection fraction, right heart failure, and even sudden death.

Recently, laryngeal ultrasound (LUS) has been proposed as a safer, non-invasive modality to help screen patients who are at risk of VFMI. It has high sensitivity and specificity for VFMI and is simple to before by radiology technicians or bedside providers in the pediatric intensive care unit with POCUS.

This study aims to answer the question: Can POCUS be used to reliably detect VFMI while pediatric patients on supported with NIV PPV? We predict that LUS will have high sensitivity and specificity to detect VFMI, despite the addition of NIV PPV.

Inclusion criteria

• Age 0 to 18 years
• Scheduled to receive a fiberoptic nasolaryngoscopy with the otolaryngology team to assess for vocal fold motion impairment
• Status post great vessel, esophageal, or tracheal surgery that could disrupt the recurrent laryngeal nerve

Exclusion criteria

• Tracheostomy in place
• Age >18 years
• History of vocal cord paralysis/paresis
• Patients who cannot have their neck placed in a neutral or slightly extended position due to injury or ligament laxity