Publications

Introduction and Aims:
Respiratory rate is an important parameter in the assessment of children with acute illness, but can be time-consuming and difficult to measure. Applying engineering techniques to allow automated measurement of respiratory rate in primary care using a pulse oximeter could simplify the monitoring of this vital sign.
Method:
We monitored 44 children aged 1month-11years attending an out-of-hours GP centre in Oxford. Respiratory rate was measured manually while pulse oximetry signals were recorded. The pulse oximeter waveform was analysed to estimate signal quality and respiratory rate.
Results:
Many records showed periods of poor signal quality. Automated signal quality analysis rejected 8 complete records (18%), and removed poor-quality sections of data from further analysis. Calculated respiratory rates differed from the manual rates by less than 5 breaths/minute in 24 of the remaining 36 records (66%). Given that many of the manual respiratory rates were measured over 15 or 30 seconds, an accuracy of 5 breaths/minute is likely to be similar to that obtained manually.
Conclusion:
Pulse oximetry can be used to measure respiratory rate in children. Given that routine measurement of paediatric respiratory rates is uncommon in primary care, and that manual measurement can be both difficult and time-consuming, this method would allow a simple finger clip sensor to provide automated measures of three vital signs (heart rate, respiratory rate, and oxygen saturation). More research is needed to improve the accuracy and robustness of this method, and to validate its accuracy in a variety of clinical situations.