Overnight polysomnography versus respiratory polygraphy in the diagnosis of pediatric obstructive sleep apnea.
BACKGROUND
Substantial discrepancies exist in the type of sleep studies performed to diagnose pediatric obstructive sleep apnea (OSA) in different countries. Respiratory polygraphic (RP) recordings are primarily performed in sleep laboratories in Europe, whereas polysomnography (PSG) constitutes the majority in the US and Australia. Home RP show consistent apnea-hypopnea index (AHI) underscoring, primarily because the total recording time is used as the denominator when calculating the AHI compared to total sleep time (TST). However, laboratory-based RP are less likely affected, since the presence of sleep technicians and video monitoring may enable more accurate TST estimates. We therefore examined differences in AHI in PSG and in-lab RP, and whether RP-based AHI may impact clinical decision making.


METHODS
Of all the children assessed for possible OSA who underwent PSG evaluation, 100 were identified and divided into 4 groups: (A) those with AHI < 1/h TST (n = 20), (B) 1 ≤ AHI < 5/h TST (n = 40), (C) 5 ≤ AHI < 10/h TST (n = 20), and (D) AHI ≥ 10/h TST (n = 20). Electroencephalography, electrooculography, and electromyography channels were deleted from the original unscored recordings to transform them into RP, and then rescored in random sequence. AHI-RP were compared to AHI-PSG, and therapeutic decisions based on AHI-RP and AHI-PSG were formulated and analyzed using clinical details derived from the patient's clinic letter.


RESULTS
Bland Altman analysis showed that in lab RP underestimated the AHI despite more accurate estimates of TST. This underestimation was due to missed hypopneas causing arousals without desaturation. Basing the therapeutic management decision on RP instead of PSG results changed the clinical management in 23% of all patients. The clinical management for patients in groups A and D was unaffected. However, 27.5% of patients in group B would have been given no treatment, as they would be diagnosed as having no OSA (AHI < 1/h TST) when they should have received a trial of anti-inflammatory therapy or been referred for ear, nose, and throat (ENT) review. Sixty percent of patients in group C would have received either a trial of medical treatment to treat mild OSA or no treatment, instead of referral to ENT services or commencement of continuous positive airway pressure.


CONCLUSIONS
Apnea-hypopnea index (AHI) is underestimated in respiratory polygraphy (RP), and the disparity in AHI-RP and AHI-polysomnography can significantly affect clinical management decisions, particularly in children with mild and moderate obstructive sleep apnea (1 < AHI < 10/h total sleep time).
Section of Pediatric Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL ; Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK.
Hui-Leng
HL
Tan
Section of Pediatric Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
David
D
Gozal
Section of Pediatric Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
Helena Molero
HM
Ramirez
Section of Pediatric Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
Hari P R
HP
Bandla
Section of Pediatric Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
Leila
L
Kheirandish-Gozal
D000293:Adolescent; D001143:Arousal; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D008297:Male; D010372:Pediatrics; D017286:Polysomnography / Q000379:methods*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology
Pediatric obstructive sleep apnea; polysomnography; respiratory polygraphy