Changes in oximeter averaging times have been noted to affect alarm settings. Automated algorithms (A-FiO2) assess FiO2 faster than oximeter averaging, potentially impacting their effectiveness.
In a single NICU routinely using 15 fabian-PRICO A-FiO2 systems, neonates were randomly exposed to SpO2 averaging time settings switched every 12 h among short (2–4 s), medium (10 s), and long (16 s) oximeter averaging times for the entire duration of their A-FiO2 exposure. Primary endpoints were the percent time in the set SpO2 target range (dependent on PMA), SpO2 < 80%, and SpO2 > 98%, excluding FiO2 = 0.21.
Ten VLBW neonates were enrolled over 11 months. At entry, they were 17 days old (IQR: 14–19), with an adjusted gestational age of 29 weeks (IQR: 27–30). The study included data from 272 days of A-FiO2 control (34% short, 32% medium, and 34% long). Respiratory support was predominantly non-invasive (53% NCPAP, 40% HFNC, and 6% NIPPV). The aggregate SpO2 exposure levels were 67% (IQR: 55–82) in the target range, 5.4% (IQR: 2.0–10) with SpO2 < 80%, and 1.2% (IQR: 0.4–3.1) with SpO2 > 98%. There were no differences in the target range time between the SpO2 averaging time settings. There were differences at the SpO2 extremes (
This A-FiO2 algorithm is effective regardless of the SpO2 averaging time setting. There is an advantage to the longer settings, which suggest an interaction with the controller.