Ellen de Kort

131 Blood pressure after propofol in neonates 8 baseline hypotension and no sepsis/NEC); group 2, patients with baseline hypotension; and group 3, patients with a high risk of hemodynamic failure because of sepsis or NEC as indication for intubation. To elucidate the influence of cumulative propofol doses on blood pressure, we also performed a secondary analysis into the maximum decrease in MBP after different cumulative propofol doses. Statistical analysis Data analysis was performed using SPSS (IBM SPSS Statistics for Windows, version 22.0. Armonk, NY, USA) and Stata (Stata, version 15, StataCorp LLC, TX, USA). Baseline characteristics were described by numbers and percentages for qualitative variables and median and interquartile range (IQR) for quantitative variables. Comparison between groups was performed with the Mann-Whitney U test for continuous variables and the Fisher’s exact test for categorical variables. Development of MBP over time-epochs was expressed as absolute change compared to baseline. Comparison of MBP development between groups was determined using a linear mixed model analysis to take into account the dependency of observations within patients. The linear mixed models included time (added to themodel as a categoricalvariable represented bydummyvariables), dose group and the interaction between time and dose group. Besides a crude analysis, also analyses adjusted for volume resuscitation and the administration of additional doses of propofol were performed. This was done by adding volume resuscitation and the administration of additional doses of propofol to the linear mixed models as time-dependent covariates. In addition, a linear mixed model analysis was performed with the cumulative dose of propofol as independent variable and the repeatedly measured MBP values as outcome. RESULTS Study population Of the 91 patients in the NEOPROP-2 study, 79 patients received a starting dose of either 1.0, 1.5 or 2.0 mg/kg of propofol and were included in this analysis. Median gestational age was 27.71 weeks (IQR 25.86-30.71), median birth weight was 1,065 grams (IQR 860- 1,560) and the median postnatal age at intubation was 33.53 hours (IQR 8.37-279.53). Fifty-two patients (66%) were boys and 18 patients (23%) had a birth weight below the 10 th percentile. Thirty patients (38%) received a propofol starting dose of 1.0mg/kg, 23 patients (29%) received a propofol starting dose of 1.5 mg/kg and 26 patients (33%) received a propofol starting dose of 2.0 mg/kg. Patient characteristics, sedative effect of propofol and need for extra propofol doses in these three dosing groups are presented in detail in the initial publication. 14 A summary of these findings relevant to the purpose of this analysis is presented in Table 1.