Transcutaneous carbon dioxide monitoring and capnography during pediatric polysomnography.

INTRODUCTION: Transcutaneous monitoring and capnography are 2 surrogate methods of measuring arterial carbon dioxide levels employed by pediatric sleep laboratories. Both techniques are noninvasive, validated, and quantitative indirect predictors of arterial carbon dioxide level, and both have been widely adopted for use during pediatric and adult polysomnography (PSG). We hypothesized that there would be close agreement between the two techniques when compared in a pediatric population. METHODS: Children referred for diagnostic polysomnography to the Pediatric Sleep Laboratory at the Alberta Children's Hospital from June 2000 to October 2003 were included. All subjects underwent an overnight computerized PSG as per American Thoracic Society standards, including both transcutaneous and end-tidal monitoring. A registered PSG technician manually scored studies and eliminated all CO2 data that was not interpretable. Total "uninterpretable data" time was calculated for both channels. Statistical analysis of the level of agreement between transcutaneous and end-tidal signals was performed using a Bland-Altman analysis. RESULTS: The PSG studies of 609 children (363 males), mean age 7.9 +/- 4.6 years (range 0.1-18.4), were reviewed. On average, interpretable data was available for 61.8% +/- 35.1% and 71.5% +/- 25.2 % of total recording time from the end-tidal and transcutaneous channels respectively. The maximum and mean CO2 measurements obtained by both devices showed close agreement with a mean difference of 0.1 +/- 5.4 mm Hg and 0.6 +/- 3.9 mm Hg respectively. CONCLUSION: Transcutaneous and end-tidal carbon dioxide monitoring during polysomnography are well tolerated and provide interpretable and comparable results in the majority of children.

Compliance rates in children using noninvasive continuous positive airway pressure.

STUDY OBJECTIVES: For a subpopulation of children with obstructive sleep apnea, the mainstay of treatment is nasal continuous positive airway pressure (nCPAP). Accurate measures of "time in use" have not been used to assess compliance with nCPAP in large numbers of children. Data from a comprehensive nCPAP program are used to describe nCPAP use among children aged 6 months to 18 years and provide time-in-use compliance rates. DESIGN: Retrospective cohort study SETTING: University Pediatric Teaching Hospital INTERVENTIONS: Initiation of nCPAP treatment MEASUREMENTS AND RESULTS: Seventy-nine children were identified as requiring treatment with nCPAP, with 65 (82%) successfully established on nCPAP during the 46-month study period. Objective compliance data were available on 50 children: 66% were boys, 78% had a complicating medical disorder, the mean age was 10 +/- 5.1 years, and the median apnea-hypopnea index was 11.3 (interquartile range, 5.4-25.9). Follow-up ranged from 8 to 979 days. Forty-eight percent of children used nCPAP immediately. Seventy-six percent of children used nCPAP for at least half the days, with use defined as 1 or more hours of recording during a 24-hour period. Mean daily use was 4.7 hours (interquartile range, 1.4-7.0), and mean daily use on days nCPAP was used was 6.3 hours (interquartile range, 3.3-8.5) CONCLUSIONS: With patience, a behavioral modification approach, and parental commitment, children will be accepting of nCPAP and reasonably compliant with treatment.

Comparison of home oximetry monitoring with laboratory polysomnography in children.

STUDY OBJECTIVES: To measure the accuracy and reliability of a portable home oximetry monitor with an automated analysis for the diagnosis of obstructive sleep apnea (OSA) in children. DESIGN: Prospective cohort study. SETTING: Alberta Lung Association Sleep Center, Alberta Children's Hospital Sleep Clinic. STUDY SUBJECTS: Consecutive, otherwise healthy children, aged 4 to 18 years, presenting to the Pediatric Sleep Service at the Alberta Children's Hospital for assessment of possible OSA. INTERVENTIONS: All subjects underwent 2 nights of monitoring in the home with an oximetry-based portable monitor with an automatic internal scoring algorithm. A third night of monitoring was done simultaneously with computerized laboratory polysomnography according to American Thoracic Society guidelines. MEASUREMENTS AND RESULTS: Both test-retest reliability of the portable monitor-based desaturation index (DI) between 2 nights at home and between laboratory and home were high using the Bland and Altman analysis (mean agreement, 0.32 and 0.64; limits of agreement, - 8.00 to 8.64 and - 0.75 to 6.50, respectively). The polysomnographic apnea-hypopnea index (AHI) agreed poorly with the portable monitor DI (mean difference, 1.27; limits of agreement, - 12.02 to 15.02). The sensitivity and specificity of the monitor for the identification of moderate sleep apnea (polysomnography AHI > 5/h) were 67% and 60%, respectively. CONCLUSION: Portable monitoring based only on oximetry alone is not adequate for the identification of OSA in otherwise healthy children.