Randomised crossover trial comparing algorithms and averaging times for automatic oxygen control in preterm infants.

OBJECTIVE: Automatic control (SPOC) of the fraction of inspired oxygen (FiO(2)), based on continuous analysis of pulse oximeter saturation (SpO(2)), improves the proportion of time preterm infants spend within a specified SpO(2)-target range (Target%). We evaluated if a revised SPOC algorithm (SPOC(new), including an upper limit for FiO(2)) compared to both routine manual control (RMC) and the previously tested algorithm (SPOC(old,) unrestricted maximum FiO(2)) increases Target%, and evaluated the effect of the pulse oximeter's averaging time on controlling the SpO(2) signal during SPOC periods. DESIGN: Unblinded, randomised controlled crossover study comparing 2 SPOC algorithms and 2 SpO(2) averaging times in random order: 12 hours SPOC(new) and 12 hours SPOC(old) (averaging time 2 s or 8 s for 6 hours each) were compared with 6-hour RMC. A generated list of random numbers was used for allocation sequence. SETTING: University-affiliated tertiary neonatal intensive care unit, Germany PATIENTS: Twenty-four infants on non-invasive respiratory support with FiO(2) >0.21 were analysed (median gestational age at birth, birth weight and age at randomisation were 25.3 weeks, 585 g and 30 days). MAIN OUTCOME MEASURE: Target%. RESULTS: Mean (SD) [95% CI] Target% was 56% (9) [52, 59] for RMC versus 69% (9) [65, 72] for SPOC(old)_(2s), 70% (7) [67, 73] for SPOC(new)_(2s), 71% (8) [68, 74] for SPOC(old)_(8s) and 72% (8) [69, 75] for SPOC(new)_(8s). CONCLUSIONS: Irrespective of SpO(2)-averaging time, Target% was higher with both SPOC algorithms compared to RMC. Despite limiting the maximum FiO(2), SPOC(new) remained significantly better at maintaining SpO(2) within target range compared to RMC. TRIAL REGISTRATION: NCT03785899.