From: Guidelines for diagnosis and management of congenital central hypoventilation syndrome
Issue | Current Guidelines (2020) | ATS Statement (2010) |
---|---|---|
Phenotype | Disease may have varying respiratory impact, with predominance of other system dysfunction | Hypoventilation with other autonomic disturbance |
Cardiac issues | All CCHS at risk for sinus arrest | Longer PARMs at risk for sinus arrest |
Targets for ventilatory support | pCO2 35–45 mmHg SpO2 ≥ 95% | Reasonably: Et CO2 30–50 mmHg Ideally: PCO2 35–40 mmHg SpO2 ≥ 95% |
Ventilation support | Use of new modalities, such as volume guaranteed to allow varying needs to be met with less swings in CO2 | Largely non-varying tracheostomy / mask ventilation |
Tracheostomy ventilation | The commonest method of ventilation support in the first years of life | Recommended in the first years of life |
Airway assessment procedure | Simple fibre-optic tracheoscopy preferred | Bronchoscopy |
Indications for Airway assessment procedure | -If new symptoms -After changing tube size or type -Before decannulation -Every 3–6 months in children in the first 2 years after tracheostomy | Every 12–24 months |
Ventilatory Device | -Home ventilators while on tracheostomy and mask ventilation: -Home ventilators or bi-level devices with all safety requirements while on mask ventilation | -Home ventilators while on tracheostomy ventilation -Bi-level devices on timed mode while on mask |
Ventilation mode | -Recommended: Pressure-control ventilation (e.g. pressure control on the ventilators, or timed mode on the bi-level devices) -To be avoided: Pressure support mode with no ability to set back-up rate and minimum inspiratory time on spontaneous breaths, and CPAP mode. | -Recommended: Pressure control or pressure plateau mode via tracheostomy -Bi-level positive airway pressure ventilation by mask or nasal prongs: timed mode |
Non-invasive ventilation (mask ventilation) | -May be considered in infants and young children with close monitoring -The first option for older children and adults presenting with late-onset CCHS | -Not considered as an optimal mode of ventilation in infants and children -Not considered until 6–8 yo at the earliest in stable patients on sleep time ventilation only |
Prevention of mid-face hypoplasia (related to mask ventilation) | -Use of total face masks -Alternating masks of different shapes | Extreme caution recommended while used in young children |
Mask models available | Total face mask used to reduce pressure on facial structure or to prevent oral air leaks | Full face mask discouraged because of discomfort and aspiration risks. |
Age at transition from trach to mask ventilation | Can be initiated at varying ages during childhood | After 6 to 8 yo |
Procedure for transition from trach to mask ventilation or phrenic nerve pacemaker | -Tracheal fiberscope -Downsize the tracheostomy cannula -Sleep study while on mask ventilation or pacing with capped tracheostomy | / |
Is PHOX2B the sole CCHS gene? | -A few other genes, responsible for autosomal recessive hypoventilation, like MYO1H and LBX1, were identified in consanguineous families negative for PHOX2B mutations. -CCHS is a genetically heterogeneous trait | Besides CCHS associated PHOX2B mutations, only patients carrying coincidental mutations in genes already involved in other neurocristopathies and/or in the development of Neural Crest derived cell lines were reported |
Novel kind of CCHS associated PHOX2B anomalies | Interstitial deletions of the PHOX2B found in association with atypical CCHS presentations, neonatal respiratory distress, Hirschsprung disease, BRUE, etc | Unknown at that time |
Mutation penetrance and expressivity | For most PARMs and NPARMs, a wide variability in intra-familial mutation penetrance & expressivity is emerging. | Reduced penetrance only reported for a few NPARMs and the shortest PARMs |
Genotype – phenotype correlation | Differences for NPARM have been recognized both within and between missense, nonsense, and frameshift mutations | NPARM mutations did have roughly the same effect without distinguishing among them |