TcCO changes correlate with partial obstruction in children suspected of sleep disordered breathing.

INTRODUCTION

Pediatric sleep disordered breathing (SDB) is characterized by long periods of partial upper airway obstruction (UAO) with low apnea-hypopnea indices (AHI). By measuring snoring and stertor, Sonomat studies allow quantification of these periods of partial UAO.

AIM

To determine whether transcutaneous CO (TcCO ) levels correlate with increasing levels of partial UAO and to examine patterns of ΔTcCo in the transitions from (a) wakefulness to sleep and (b) non-rapid eye movement (NREM) to rapid eye movement (REM) sleep.

METHODS

This was a retrospective review of sleep studies in seven asymptomatic controls aged 7 to 12 years and 62 symptomatic children with suspected SDB and no comorbidities, aged 2 to 13 years. Both groups underwent overnight polysomnography, including continuous TcCO , at one of two pediatric hospitals in Sydney. Changes in carbon dioxide levels between wake to NREM (sleep onset) and NREM to REM sleep were evaluated using an all-night TcCO trace time-linked to a hypnogram. Paired Sonomat recordings were used to quantify periods of UAO in the symptomatic group.

RESULTS

The ΔTcCO at sleep onset was greater in SDB children than controls and ΔTcCO with sleep onset correlated with the duration of partial obstruction (r = .60; P < .0001). Children with an increase in TcCO from NREM to REM had a higher number of snoring and stertor events compared to those in whom TcCO decreased from NREM to REM (91 vs 30 events/h; P = < .0001).

CONCLUSIONS

In children without comorbidities, the measurement of TcCO during sleep correlates with indicators of partial obstruction.