Improving detection of obstructive sleep apnoea by overnight oximetry in children using pulse rate parameters.
OBJECTIVE
Overnight oximetry is a simple tool for investigation of obstructive sleep apnoea (OSA) in children, but only severe cases will be detected, and children with obstructive events resulting in arousal, but not desaturation, will have a normal (inconclusive) result. We hypothesised that pulse rate rises using pulse rate indices per hour (PRI) and pulse rate standard deviation (PR-SD) automatically calculated from commercially available software would improve oximetry as a diagnostic tool.


METHODS
Children having home overnight oximetry for suspected OSA were identified over 12 months, and those with a normal result who went on to have polysomnography (PSG) were included. Oximetry, including PR-SD and PRI (rises of 8, 10 and 15 beats/min per hour), was analyzed using commercially available software. PR parameters were compared between those with OSA (obstructive apnoea-hypopnoea index (OAHI) >1 event/h) and those without OSA.


RESULTS
One hundred sixteen children had normal oximetry, of whom 93 (median age 4.5 years; 55 % M) had PSG. Fifty-seven of 93 (61 %) children had OSA (median OAHI 4.5 events/h, range 1.1-24). PR-SD was not different between the OSA and non-OSA groups (p = 0.87). PRI tended to be higher in those with OSA, but there was considerable overlap between the groups: PRI-8 (mean ± SD 58.5 ± 29.0/h in OSA group vs 48.6 ± 20.2/h in non-OSA group, p = 0.07), PRI-10 (45.1 ± 25.0 vs 36.2 ± 16.7, p = 0.06) and PRI-15 (24.4 ± 14.5 vs 18.9 ± 9.0, p = 0.04). A PRI-15 threshold of >35/h had specificity of 97 % for OSA.


CONCLUSIONS
The PRI-15 shows promise as an indicator of OSA in children with normal oximetry.
Paediatric Respiratory Unit, Serdang Hospital, Selangor Darul Ehsan, Malaysia.
Dg Zuraini
DZ
Sahadan
Melbourne Children's Sleep Centre, Monash Children's Hospital, Monash Health, Melbourne, Victoria, Australia.|The Ritchie Centre, MIMR-PHI Institute of Medical Research and Department of Paediatrics, Monash University, Melbourne, Victoria, 3168, Australia.
Margot J
MJ
Davey
The Ritchie Centre, MIMR-PHI Institute of Medical Research and Department of Paediatrics, Monash University, Melbourne, Victoria, 3168, Australia.
Rosemary S C
RS
Horne
Melbourne Children's Sleep Centre, Monash Children's Hospital, Monash Health, Melbourne, Victoria, Australia. gillian.nixon@monashhealth.org.|The Ritchie Centre, MIMR-PHI Institute of Medical Research and Department of Paediatrics, Monash University, Melbourne, Victoria, 3168, Australia. gillian.nixon@monashhealth.org.
Gillian M
GM
Nixon
D000293:Adolescent; D000553:Ambulatory Care; D002648:Child; D002675:Child, Preschool; D005260:Female; D006339:Heart Rate; D006801:Humans; D007223:Infant; D008297:Male; D010092:Oximetry / Q000379:methods*; D017286:Polysomnography / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*; D012984:Software; D014739:Victoria
Child; Obstructive sleep apnoea; Oximetry; Pulse rate