Abstract
It has previously been shown that respiratory data can be derived from pulse oximetry plethysmogram (pleth) recordings in newborn term babies and older infants (Wertheim D. et al., Arch Dis Child Fetal Neonatal Ed., 2009; 94: F310-3, Wertheim D. et al., Acta Paedtr., 2014). The aim of this study was to examine if respiratory rate can be derived from pleth traces in preterm infants. Recordings of oximetry pleth, SpO2, thoracic and abdominal respiratory inductance plethysmography (RIP) bands from 6 infants were recorded for about five minutes using a SOMNOscreen system (S-Med Ltd., Birmingham, UK). The median (range) gestation at birth was 32 (28 to 35) and the post-conceptional median (range) age at the time of recording of the babies was 33 (32 to 36) weeks. The pleth data were low pass filtered (LPF) in order to derive respiratory data using software that we developed using MATLAB (The MathWorks, Inc., USA). Further software was developed in order to display the LPF pleth data together with the RIP traces. Visual assessment of the recordings showed good agreement between the LPF pleth and RIP band data in traces with little or no artefact; periods with low amplitude 'raw' pleth traces were excluded. Respiratory rate calculated from the LPF pleth data (median 56, range 45 to 65 breaths / minute) was compared with that computed from the RIP bands (median 58, range 46 to 70 breaths/ minute); the median difference (LPF pleth – RIP band) was -3 and the maximum absolute difference was 6 breaths / minute. Thus the results of this study suggest that respiratory rate can be derived from good quality pleth recordings in preterm infants.
- © 2014 ERS