A plethysmography investigation comparing respiration rate before onset and after the end of central sleep apnoea episodes

Abstract

The study explored possible changes in respiration rate immediately before onset and after end of central sleep apnoea (CSA) episodes using respiratory inductive plethysmography (RIP). RIP signals were recorded simultaneously from the chest and abdomen of 31 paediatric patients (mean age 7.12 years, standard deviation 4.40 years, 20 females, 11 males) attending a children’s hospital for overnight sleep disorder monitoring. The patients were also monitored for electrocardiogram, electroencephalogram, electrooculogram, electromyograph, CO2, body position, SpO2 and if they tolerated, their respiratory airflow using a thermistor (placed under the nose) and nasal prongs (placed in the nostrils). An experienced clinical physiologist scored the recorded data by indicating the time point of each respiratory pause, its duration and type (i.e., apnoea or hypopnoea; central or obstructive). The RIP signals from the chest and abdomen were summed and converted to a respiration rate signal by determining the time points they crossed the time axis. Events were scored using standard paediatric sleep and breathing scoring rules. Statistical analysis indicated significant differences between the skewness and kurtosis of respiratory rate values immediately before the onset and after the end of CSA episodes, however the mean respiration rate did not change significantly. This indicates possible changes in the pattern of respiration rate immediately after the end of CSA episodes. It may be possible to use these results to predict the onset of a CSA episode, however, to confirm the finding a larger study will be needed.