Nasal mask average volume-assured pressure support in an infant with congenital central hypoventilation syndrome

Abstract

Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation and autonomic dysregulation secondary to mutations of the PHOX 2B genes. Treatment consists of assisted ventilation using positive pressure ventilators via tracheostomy, bi-level positive airway pressure (BPAP), negative pressure ventilators, or diaphragm pacing. Previous case reports have highlighted early use of nasal non-invasive BPAP use in infants with CCHS. We present a case of a 10-month-old infant who was successfully managed on a new feature of non-invasive ventilation called average volume assured pressure support (AVAPS) without the need for tracheostomy. The AVAPS feature enables the machine to automatically adjust the inspiratory pressures to deliver a constant targeted tidal volume. This feature enabled a better control of ventilation as indicated by a more stable transcutaneous carbon dioxide profile compared to conventional nasal non-invasive BPAP, making non-invasive ventilation a more accessible method of managing sleep hypoventilation in CCHS.

Keywords: Average volume‐assured pressure support; congenital central hypoventilation syndrome; infant; transcutaneous carbon dioxide.

Figure 1

Transcutaneous carbon dioxide (TcCO₂) on conventional bi‐level positive airway pressure (BPAP) and average volume assured pressure support (AVAPS). (A) TcCO₂ trace on polysomnography using conventional nasal BPAP. Note the highly regular slow oscillation of TcCO₂ of 10 mmHg varying between 35 and 45 mmHg. While the mechanism of this periodicity is uncertain, it may reflect slow oscillations in breathing control induced by the BPAP settings or by slower changes in acid‐base levels revealed in the absence of usual chemoreceptor control. (B) TcCO₂ trace on polysomnography. Arrow indicates change from conventional nasal BPAP to nasal BPAP with AVAPS feature. Note the more consistent control of TcCO₂.