Paeds SAQs · respiratory-sleep-and-airway
Central sleep apnoea and hypoventilation syndromes — formative SAQs
Two formative SAQs on central disorders of the control of breathing: a term neonate who breathes when awake but hypoventilates and desaturates in sleep with a normal heart and lungs, testing the recognition of congenital central hypoventilation syndrome, the ventilate-not-oxygenate principle and the PHOX2B confirmation; and a five-year-old with rapid-onset obesity then hypoventilation, testing the ROHHAD diagnosis, the search for a neural crest tumour and the multisystem surveillance.
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Target exams
SAQ 1 — The neonate who breathes awake but not asleep (10 marks, 15 minutes)
A term newborn boy is well and pink while awake and handling, but during sleep he becomes shallow-breathing, cyanosed and desaturates, with a rising carbon dioxide on blood gas. Echocardiography and chest imaging are normal and the lungs are clear. He repeatedly fails attempts to wean from respiratory support. There is a history of severe constipation since birth. [1]
a) What is the most likely diagnosis, and what single feature of the history and examination pattern points to a central disorder of the control of breathing rather than a cardiac or pulmonary cause? (3 marks) [1] [3]
b) What confirmatory investigation would you send, and what does it tell you about severity and associated risks? (3 marks) [1] [15]
c) Outline the immediate ventilatory principle that protects this baby and why supplemental oxygen alone is dangerous. (4 marks) [1]
SAQ 2 — Rapid weight gain then hypoventilation (10 marks, 15 minutes)
A previously well five-year-old girl has gained weight rapidly over four months. She now has disturbed thirst and sodium balance, and her parents report she is difficult to rouse in the mornings and has become cyanosed during sleep. A blood gas shows a raised carbon dioxide with a compensatory bicarbonate. A polysomnogram confirms sleep hypoventilation. [6]
a) What syndrome does this timeline suggest, and what does each part of its name represent? (3 marks) [6] [2]
b) What important associated condition must you actively exclude, and how would you investigate for it? (3 marks) [6] [7]
c) Outline your multisystem management and surveillance plan for this child. (4 marks) [7] [14]
References
- [1]Weese-Mayer DE; Berry-Kravis EM; Ceccherini I; et al An official ATS clinical policy statement: Congenital central hypoventilation syndrome: genetic basis, diagnosis, and management. Am J Respir Crit Care Med, 2010.PMID 20208042
- [2]Ceccherini I; Kurek KC; Weese-Mayer DE Developmental disorders affecting the respiratory system: CCHS and ROHHAD. Handb Clin Neurol, 2022.PMID 36031316
- [3]Kasi AS; Perez IA Congenital Central Hypoventilation Syndrome and Disorders of Control of Ventilation. Clin Chest Med, 2024.PMID 39069329
- [4]Fain ME; Westbrook AL; Kasi AS Congenital Central Hypoventilation Syndrome: Diagnosis and Long-Term Ventilatory Outcomes. Clin Med Insights Pediatr, 2023.PMID 37256017
- [5]Kasi AS; Li H; Harford KL; et al Congenital Central Hypoventilation Syndrome: Optimizing Care with a Multidisciplinary Approach. J Multidiscip Healthc, 2022.PMID 35360554
- [6]Harvengt J; Gernay C; Mastouri M; et al ROHHAD(NET) Syndrome: Systematic Review of the Clinical Timeline and Recommendations for Diagnosis and Prognosis. J Clin Endocrinol Metab, 2020.PMID 32407531
- [7]Marpuri I; Ra E; Naguib MN; et al Weight management in youth with rapid-onset obesity with hypothalamic dysregulation, hypoventilation, autonomic dysregulation, and neural crest tumor (ROHHAD-NET): literature search and case report. J Pediatr Endocrinol Metab, 2022.PMID 34954931
- [8]Tsolakis N; Sindelar R; Markström A; et al Applying diaphragm pacing in previously tracheostomised children with congenital central hypoventilation syndrome is a safe tool. Acta Paediatr, 2022.PMID 35266201
- [9]Dozor AJ; Vincent R Assessment of Phrenic Nerve Pacers in a Patient With Congenital Central Hypoventilation Syndrome. Pediatr Pulmonol, 2025.PMID 39688338
- [10]Berry RB; Ryals S; Wagner MH Use of Chest Wall EMG to Classify Hypopneas as Obstructive or Central. J Clin Sleep Med, 2018.PMID 29734977
- [11]Okai BK; Jaikumar V; Francois HB; et al Posterior fossa decompression in patients with Chiari malformation type 1: effect on sleep apnea and follow-up outcomes. Childs Nerv Syst, 2024.PMID 39365303
- [12]Marques KA; Bruschettini M; Roehr CC; et al Methylxanthine for the prevention and treatment of apnea in preterm infants. Cochrane Database Syst Rev, 2023.PMID 37905735
- [13]Basu SM; Chung FF; AbdelHakim SF; et al Anesthetic Considerations for Patients With Congenital Central Hypoventilation Syndrome: A Systematic Review of the Literature. Anesth Analg, 2017.PMID 27918326
- [14]Puri S; Yaddanapudi S; Menon P Peri-operative management of a child with ROHHAD-NET syndrome undergoing neural crest tumour excision. Anaesth Rep, 2022.PMID 35756834
- [15]Slattery SM; Wilkinson J; Mittal A; et al Computer-aided diagnostic screen for Congenital Central Hypoventilation Syndrome with facial phenotype. Pediatr Res, 2024.PMID 38238566