Stridor in asphyxiated neonates undergoing therapeutic hypothermia

Neonatal Vocal Fold Paralysis

Vocal fold paralysis (VFP) is an important cause of respiratory and feeding compromise in infants. The causes of neonatal VFP are varied and include central nervous system disorders, birth-related trauma, mediastinal masses, iatrogenic injuries, and idiopathic cases. Bilateral VFP often presents with stridor or respiratory distress and can require rapid intervention to stabilize an adequate airway. Unilateral VFP presents more subtly with a weak cry, swallowing dysfunction, and less frequently respiratory distress. The etiology and type of VFP is important for management. Evaluation involves direct visualization of the vocal folds, with additional imaging and testing in select cases. Swallowing dysfunction, also known as dysphagia, is very common in infants with VFP. A clinical assessment of swallowing function is necessary in all cases of VFP, with some patients also requiring an instrumental swallow assessment. Modification of feeding techniques and enteral access for feedings may be necessary. Airway management can vary from close monitoring to noninvasive ventilation, tracheostomy, and laryngeal surgery. Long-term follow-up with otolaryngology and speech-language pathology service is necessary for all children with VFP to ensure adequate breathing, swallowing, and phonation. The short- and long-term health and quality-of-life consequences of VFP can be substantial, especially if not managed early.

Stridor in infants with hypoxic-ischemic encephalopathy and whole body hypothermia: A case series

BACKGROUND

Stridor is one of the rare side effects of neonatal hypothermia treatment for hypoxic-ischemic encephalopathy. We aimed to describe the clinical characteristics of the infants who underwent whole-body hypothermia and developed stridor.

METHODS

We reviewed the medical records of 171 infants with moderate or severe hypoxic-ischemic encephalopathy who underwent hypothermia therapy. Demographics, as well as clinical characteristics, were documented.

RESULTS

A total of 18 infants developed transient stridor out of 171 infants who underwent whole-body hypothermia (10.5%). The stridor was transient and resolved in all infants. All infants with stridor received treatment with one or more of the following: racemic epinephrine, dexamethasone, positive pressure ventilation and/or heliox. Two infants required otorhinolaryngologist (ENT) evaluation due to persistent and severe symptoms, of whom one was found to have left vocal cord paresis that improved with time.

CONCLUSION

Stridor is a transient complication associated with hypoxic-ischemic encephalopathy and whole-body hypothermia in neonates. The exact mechanism is unclear and most likely multifactorial. ENT evaluation is recommended in the presence of prolonged symptoms or significant respiratory distress.

[Stridor in neonates with hypoxic-ischaemic encephalopathy subject to selective cerebral or whole body hypothermia]

INTRODUCTION

Hypothermia treatment has improved the prognosis of asphyxiated neonates. Widely used, it has demonstrated to be safe without severe side effects. The aim of this article is to review the incidence of stridor amongst asphyxiated newborns treated with hypothermia in our unit.

METHODS

Retrospective chart review of our patients.

RESULTS

Stridor was presented in 7/75 (9.3%) of patients during hypothermia. Three received whole body hypothermia, 3 selective cerebral, and in one case both techniques were used. All cases required increased respiratory support.

CONCLUSIONS

Different mechanisms may be responsible for the appearance of stridor in patients with hypoxic-ischaemic encephalopathy (HIE). In our series the incidence of stridor was similar for the two hypothermia devices. To better understand these possible side effects of hypothermia, further prospective studies (which should include laryngoscopy) are needed.