Identifying Obstructive from Central Apnoeas in Infancy using Pulse Transit Time

J.Y.A. Foo, S.J. Wilson, G.R. Williams, M.-A. Harris, and D.M. Cooper (Australia)


Noninvasive measurement, pulse transit time, obstructive sleep apnea, and sleep disordered breathing


The prevalence of obstructive sleep apnea syndrome (OSAS) can be common for infants. Current gold standard for its diagnosis is nocturnal polysomnography (PSG) but this procedure can be complex to perform. Pulse transit time (PTT) shows potential to indicate abrupt blood pressure (BP) changes during upper airway obstruction. Objective of this study was to assess the capability of PTT to differentiate central from obstructive sleeping respiratory events. This study involved 4 infants with mean age of 7.8 1.9months. 58 valid respiratory events free from motion artefacts were pre-scored by 2 blinded observers. PTT results were then evaluated against the corresponding PSG scorings. Tidal breathing varied with standard deviation (SD) of 5.13ms and maximal decrease of 3.57% from baseline. Obstructive events showed a mean change of 4.95% (p<0.05), with SD of 13.10ms and maximal decrease of 14.92% (p<0.05) from tidal breathing. Central events showed a mean 1.72% (p>0.05) change, with SD of 2.47ms and maximal decrease of 2.90% (p>0.05). PTT is able to categorise central and obstructive respiratory events accordingly. Furthermore, PTT has showed its sensitivity to monitor marginal BP fluctuations during tidal breathing. Hence, preliminary results suggest that PTT can be a valuable OSAS screening tool for infants.

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