74 Chapter 4 For the primary analysis, recording periods where no supplemental oxygen was administered were removed. Infants receiving less than 72 h of supplemental oxygen were excluded from the primary analysis. We then calculated the proportion of time within SpO2 target range (SpO2 91%-95%), proportions of time in various degrees of hypoxia (SpO2 <80%, SpO2 80%-84%, SpO2 85-90%, SpO2 ≤90%) or hyperoxia (SpO2 >95%, SpO2 96%-98%, and SpO2 >98, and average FiO2. These outcomes were calculated overall and per day. Finally, we calculated the proportion of time within target range per week of postmenstrual age. For the secondary analysis we calculated the overall outcomes using all periods of respiratory support (i.e. also room air) from infants receiving at least 72 hours of respiratory support. Continuous data is represented as median (IQR) or mean ±SD as appropriate, with standard tests for normality. Differences in time in target range and other outcomes were assessed with the Kruskal-Wallis test. Statistical analyses were performed using MATLAB (Matlab R2020b; The MathWorks Inc., Natick, Massachusetts, USA). Results Patient characteristics In the study period 449 preterm infants born at 24-29 weeks of gestation were admitted to the LUMC NICU within 24 hours after birth, 154 in the OxyGenie epoch and 295 in the CLiO2 epoch. Of these, 146 infants remained in the OxyGenie epoch and 269 infants in the CLiO2 epoch after exclusion of infants receiving less than 72 hours of respiratory support. The primary analysis, including only infants receiving at least 72 h supplemental oxygen, involved 75 infants in the OxyGenie epoch and 111 infants in the CLiO2 epoch. There were no significant differences in any of the baseline characteristics for the primary outcome population (Table 1). The median recording length of vital parameters was 336 hours [IQR 186 – 598] in the OxyGenie epoch and 398 [IQR 165 – 693] in the CLiO2 epoch (p = not significant (ns)).
RkJQdWJsaXNoZXIy MTk4NDMw