Variability of RRate: breathing and quality data

Background: Respiratory rate is difficult to measure, especially in neonates who have an irregular breathing pattern. The World Health Organisation recommends a one minute count, but there is limited data to support this length of observation. We sought to evaluate agreement between the respiratory rate (RR) derived from capnography in neonates, over 15 seconds, 30 seconds, 120 seconds and 300 seconds, against the recommended 60 seconds rate.

Methods: Neonates at two hospitals in Nairobi were recruited and had capnograph waveforms recorded using the Masimo Rad 97. A single high quality 5 minute epoch was randomly chosen from each subject. For each selected epoch, the mean RR was calculated using a breath-detection algorithm applied to the waveform. The RR in the first 60 seconds was compared to the mean RR measured over the first 15 seconds, 30 seconds, 120 seconds, full 300 seconds, and last 60 seconds. We calculated bias and limits of agreement for each comparison and used Bland-Al...