Interobserver Agreement When Diagnosing Hypoventilation in Children With Neuromuscular Disorders

Abstract

Neuromuscular disorders can lead to nocturnal hypoventilation. Accurate diagnosis of hypoventilation is imperative to guide treatment decisions. This study determined interobserver agreement for a number of definitions of nocturnal hypoventilation in children and adolescents with neuromuscular disorders. Overall mean interobserver agreement was 89% (range 66–100%); however, reliability of agreement was moderate at best (Fleiss κ = 0.574, p < 0.001). When hypoventilation was present, the objective definition used most frequently was an average increase in partial pressure of carbon dioxide (pCO2) ≥ 3 mm Hg from NREM to REM. The appearance of the transcutaneous CO2 (TCO2) trend graph and an increase in pCO2 ≥ 10 mm Hg from awake to asleep were most often associated with a false positive diagnosis. The variation and at best moderate agreement between pediatric sleep physicians observed in this study when diagnosing hypoventilation in children with neuromuscular disorders may be partially explained by the existence of multiple definitions and failure to remove artifact and “drift” from the TCO2 data.

Keywords

• hypoventilation
• hypercapnia
• neuromuscular disorder
• polysomnography
• interobserver agreement