What are the primary treatment recommendations for a patient with congenital hypoventilation syndrome (CHS)?

Primary Treatment for Congenital Central Hypoventilation Syndrome

Patients with congenital central hypoventilation syndrome require lifelong mechanical ventilatory support, with positive pressure ventilation via tracheostomy recommended as the optimal initial approach in infants and young children to ensure optimal neurocognitive outcomes. 1, 2

Critical Foundation: Why Mechanical Ventilation is Non-Negotiable

• Ventilator weaning is not a realistic goal and should never be attempted in CCHS—patients cannot be "trained" to breathe adequately, as the innate mechanisms of respiratory drive are absent or severely attenuated. 1, 2

• Oxygen supplementation alone is inadequate and dangerous—while it improves cyanosis and PaO₂, hypoventilation persists and pulmonary hypertension inevitably develops. 1, 2, 3

• Pharmacologic respiratory stimulants are ineffective in this population. 2

Age-Specific Ventilation Strategy

Infants and Young Children (Birth to 6-8 Years)

Positive pressure ventilation via tracheostomy is the recommended modality for the first several years of life to ensure optimal oxygenation, ventilation, and neurocognitive development from the earliest days. 1, 2

• Tracheostomy should typically be performed before 1 month of age once PHOX2B genetic testing confirms the diagnosis. 1

• The tracheostomy tube should be sized smaller than the airway caliber to reduce tracheomalacia risk, allow for speaking valve use (Passy-Muir valve), and provide a safety margin if occlusion occurs. 1

• Pressure control or pressure plateau mode is preferred over volume mode to compensate for air leaks around the tracheostomy. 1

• A backup ventilator must be kept in the home to prevent emergency admissions during equipment failure. 1

Older Children (≥6-8 Years) and Stable Patients

Noninvasive ventilation is not a consideration until 6 to 8 years of age at the earliest, and only in stable patients requiring ventilatory support exclusively during sleep. 1, 2

• Bilevel positive airway pressure (BiPAP) via nasal mask or nasal prongs can be used after this age in appropriate candidates. 1

• Full face masks are discouraged due to patient discomfort and aspiration concerns. 1

Alternative Ventilation Modalities

The American Thoracic Society recognizes four primary modalities for chronic ventilatory support: 1, 2

1. Portable positive pressure ventilator via tracheostomy (most common method)
2. Bilevel positive airway pressure via nasal mask or prongs
3. Diaphragm pacing (offers maximal mobility for full-time ventilatory patients and may permit tracheostomy decannulation in sleep-only support patients) 1, 4
4. Negative pressure ventilators (chest shell, wrap, or portable tank)

Important caveat: Negative pressure ventilation is contraindicated in patients with tracheomalacia, as it worsens tracheal collapse by increasing transmural pressure gradients. 5

Mandatory Monitoring Requirements

Continuous Monitoring During All Sleep

• Pulse oximetry and end-tidal CO₂ (PETCO₂) monitoring are mandatory during all sleep periods and recommended for hourly/periodic checks during wakefulness. 1, 2

• Target parameters: SpO₂ ≥95% and PETCO₂ 30-50 mm Hg (ideally 35-40 mm Hg). 1, 2

• Alarm settings: SpO₂ ≤85% and PETCO₂ ≥55 mm Hg (set differently than target levels to reduce nuisance alarms while allowing adequate response time). 1, 2

Why Standard Monitors Fail

Apnea/bradycardia transthoracic impedance monitors have no role in CCHS care—they cannot detect hypoventilation, tracheal obstruction, or the characteristic abrupt sinus pauses that may spontaneously terminate before detection. 1, 2

Critical Safety Measures

Continuous Supervision

• Patients require continuous observation by a registered nurse trained in ventilator management, as they may suffer complete respiratory arrest or severe hypoventilation at sleep onset. 1

• Children with CCHS lack typical respiratory distress signs (retractions, increased work of breathing, dyspnea sensation) despite severe hypoxemia and hypercarbia. 1, 2, 3

Medications and Activities to Avoid

• Avoid all sedative medications and CNS depressants, as they worsen hypoventilation. 1, 2

• Correct metabolic imbalances (especially chronic metabolic alkalosis), as they further inhibit central respiratory drive. 1

• Swimming should ideally be prohibited; if permitted, careful supervision is mandatory regardless of tracheostomy presence. 1

• Underwater swimming contests are absolutely prohibited—patients will not perceive asphyxia and will swim longer than unaffected children, dramatically increasing drowning risk. 1

Emergency Preparedness

• Power generators are mandatory for home use in case of outages or natural disasters. 1, 2

• Families must be placed on emergency lists for local power companies and fire departments. 1, 2

• A spare tracheostomy tube must be carried with an Ambu bag for any travel outside the home. 1

Comprehensive Assessment and Follow-Up

Annual Physiologic Testing

• Biannual (initially) then annual in-hospital comprehensive physiologic testing is required, including awake and asleep assessments, exogenous and endogenous gas challenges, and autonomic testing. 1, 2

• Bronchoscopy by an experienced pediatric otolaryngologist every 12-24 months allows early diagnosis of granulomas or airway abnormalities. 1

Genotype-Specific Surveillance

The American Thoracic Society provides specific testing recommendations based on PHOX2B genotype, including assessment for Hirschsprung disease, annual neurocognitive assessment, 72-hour Holter recording, echocardiogram, and tumor surveillance for certain mutations. 1

Ventilator Settings Philosophy

Ventilators should be adjusted to completely meet ventilatory demands, with settings specific to varying activity levels, leaving the child's energy available for academic and physical activities rather than attempting to "wean" or "train" breathing. 1, 2