PT  - JOURNAL ARTICLE
AU  - Sonia Khirani
AU  - Jade Pautrat
AU  - Michèle Boulé
AU  - Nicole Beydon
AU  - Brigitte Fauroux
TI  - Carbon dioxide monitoring during polygraphy in children with sleep-disordered breathing: Is it necessary?
DP  - 2013 Sep 01
TA  - European Respiratory Journal
PG  - P4667
VI  - 42
IP  - Suppl 57
4099  - http://erj.ersjournals.com/content/42/Suppl_57/P4667.short
4100  - http://erj.ersjournals.com/content/42/Suppl_57/P4667.full
SO  - Eur Respir J2013 Sep 01; 42
AB  - IntroductionMost adult sleep laboratories do not measure carbon dioxide (CO2) routinely during polygraphy (PG). In children, CO2 measurements are “recommended” but few studies have analyzed systematic CO2 monitoring during PG.ObjectivesThe aim of the study was to assess the prevalence and predictors of nocturnal hypercapnia in children with sleep-disordered breathing (SDB).MethodsSystematic transcutaneous CO2 (PtcCO2) monitoring was performed during overnight PG. Three definitions of nocturnal hypercapnia were used: a maximal PtcCO2>50 mmHg, percentage of sleep time with PtcCO2>50 mmHg >2%, and a PtcCO2>10 mmHg above waking baseline level. PtcCO2 indices were correlated to the apnoea-hypopnoea index (AHI) and oxygenation indices (desaturation index, minimal SpO2 and percentage of time with SpO2<90%).Results221 PGs from patients with suspicion of obstructive sleep apnoea (72%), neuromuscular (21%) and lung diseases (7%) were analyzed. The percentage of hypercapnic patients ranged between 20 and 60%, and was not different between groups whatever the definition of hypercapnia. Significant but weak correlations were observed between hypercapnia according to the 3 definitions and the AHI (r=0.137, p=0.047 for maximal PtcCO2) and oxygenation indices. The Receiver operating characteristic curves showed a poor sensitivity and specificity of the AHI and SpO2 to predict nocturnal hypercapnia.ConclusionThis study shows that 20 to 60% of children undergoing an overnight PG for SDB have nocturnal hypercapnia which is poorly correlated to the AHI and oxygenation indices. A systematic nocturnal CO2 recording is useful in all children presenting with SDB, whatever the underlying disease.