Diagnosis of Nocturnal Hypoventilation in Pediatric Neuromuscular Disorders: A Survey of Clinical Practice in Australia and New Zealand

Objectives: Nocturnal hypoventilation is a complication of neuromuscular disorders. There are various recommendations for measuring pCO₂ during polysomnography and numerous national and international definitions of hypoventilation that could contribute to significant variations in clinical practice. We therefore aimed to determine clinical practices implemented by Australasian pediatric sleep physicians.Methods: Pediatric sleep physicians completed an electronic survey for information regarding pCO₂ measurements and definitions of hypoventilation that are followed for children with neuromuscular disorders.Results: It was found that transcutaneous measurement of pCO₂ was performed in all centers, with 25% of the centers simultaneously performing capnography. Twelve definitions of hypoventilation were used, including published definitions from the American Academy of Sleep Medicine (AASM) manual and recommendations of the pediatric Australasian Sleep Association/Australasian Sleep Technologists Association. The most commonly used definition of hypoventilation (9/17, 53%) was the 2012 pediatric AASM definition (pCO₂ >50 mmHg for >25% of the total sleep time). There was a discrepancy between centers and individuals within the same center when defining hypoventilation. Answers stating the use of the Australasian definitions (rise in pCO₂ ≥10 mmHg from wake to sleep, average rise in pCO₂ ≥3 mmHg from non rapid eye movement to rapid eye movement sleep) were more frequent when asked specifically via a checkbox (yes/no) compared to free text.Conclusions: These results confirm the heterogeneity and lack of standardization of clinical practice within Australasia when measuring pCO₂ during polysomnography and defining hypoventilation. The Australasian definitions were not used as frequently as anticipated.