Averaging time, desaturation level, duration and extent.

Authors :: Vagedes J
Poets CF
Dietz K
Source :: Archives of disease in childhood. Fetal and neonatal edition [Arch Dis Child Fetal Neonatal Ed] 2013 May; Vol. 98 (3), pp. F265-6. Date of Electronic Publication: 2012 Sep 08.
Publication Year :: 2013
Abstract: Background: Pulse oximeter saturation values are usually obtained by averaging over preceding measurements. This study investigates the dynamics between the averaging time and desaturation level, duration and extent.<br />Methods and Results: Prospective observational study of 15 preterm infants. Oxygen saturation was recorded for 168 h using a pulse oximeter. The raw red-to-infrared data were reprocessed using seven different averaging times to determine the number of desaturations below four thresholds and for seven different minimal desaturation durations. The total number of desaturations <80% was 339 with an averaging time of 16 s and 1958 with an averaging time of 3 s (minimal event duration >0 s). There was a significantly lower pulse oximeter saturation nadir with the shorter averaging time, while the maximum duration was significantly longer when using a 16 s averaging time.<br />Conclusions: When using pulse oximeters, more attention should be given to averaging time and duration of desaturations.