1329 Unique Presentation and Complications in a Patient with Congenital Central Hypoventilation Syndrome (CCHS)

Abstract Introduction Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation and autonomic dysregulation. This case highlights the importance of obtaining a detailed family history and ensuring adherence to ventilatory support for accurate diagnosis and effective management. Report of case(s) A 13-month-old female with no known medical history was transferred from an outside hospital for management of acute hypoxemic respiratory failure secondary to RSV. At time of transfer, she was treated with 2.5 LPM of supplemental oxygen. Upon admission, she developed progressive hypoxemia, bradypnea and lethargy. Despite escalating supplemental oxygen, hypoxemia worsened, necessitating a code response. Venous blood gas showed pH 7.11, pCO₂ > 95 mmHg. She was intubated and transferred to the PICU. She was extubated to BLPAP on hospital day two but continued to demonstrate hypercapnia when attempts were made to wean support. Her father was at bedside but was frequently difficult to arouse, prompting initial concern for drug abuse. However, further family history revealed her father had been diagnosed with CCHS at 16 months and required a tracheostomy until 15 years of age. He was currently prescribed BLPAP but had poor compliance. With increased concern for CCHS, baseline polysomnogram was obtained and demonstrated persistent hypercapnia with minimal heart-rate variability. Genetic testing revealed PHOX2B 20/25 PARM expansion, confirming the diagnosis of CCHS. The patient was treated with BLPAP to be used during sleep. She was discharged to live with mom and maternal grandmother after they received extensive training. Six months later, the patient was readmitted due to respiratory distress and altered mental status, found to be in acute on chronic hypercapnic respiratory failure in the setting of rhinovirus and poor BLPAP adherence. Hospital course was complicated by ARDS and ventilator-associated pneumonia. A tracheostomy was placed to facilitate increased ventilatory support and concerns regarding her medical care at home. She was ultimately discharged to a long-term care facility with subspecialty follow-up. Conclusion Unexplained hypercapnia in children during sleep warrants evaluation with detailed family history, polysomnography, and genetic testing. CCHS, though rare, can lead to life-threatening respiratory failure without adequate ventilatory support, requiring consistent caregiver attention and involvement. Support (if any)