Objective To determine the expected systolic, mean and diastolic blood pressures at birth and respective rates of change during the first 72 hours of life in infants born <28 weeks EGA with a favorable short-term outcome, defined as survival to 14 days with grade II or less IVH. Study Design Systolic, mean and diastolic blood pressures were continuously sampled at 0.5 Hz via umbilical artery catheter from birth through 72 hours. The raw data were aligned by postnatal hour and underwent error correction. For each infant, the mean values of systolic, mean and diastolic blood pressure were calculated for each postnatal hour. The slope and intercept of best-fit line for each of the three blood pressure parameters was then calculated. Infants that received inotropic medications, died in the first 14 days of life, or had IVH grade III or IV were excluded. Result Using 11.9 million valid data points from 35 infants (mean EGA = 25.7±1.5 weeks, mean birth weight = 865 ± 201 grams), we found independent associations of African-American race (p<0.01) and a complete course of antenatal steroids (p<0.01) with higher blood pressures at birth and a slower rate of increase. Acute chorioamnionitis was independently associated (p=0.02) with lower blood pressures at birth and a faster rate of increase. EGA and birth weight were not independently predictive of blood pressure parameters. Conclusion We found that (i) the estimated mean blood pressure at birth is approximately 33 mmHg in a cohort of very preterm infants (ii) blood pressure gradually increases with postnatal age (iii) systolic blood pressure increases at a faster rate than diastolic blood pressure, (iv) race, antenatal steroid exposure, and chorioamnionitis are independent modulators of blood pressure while EGA and birth weight are not.

aEEG may be used at TEA as a new tool for risk stratification of infants at higher risk of poor neurodevelopmental outcomes. Therefore, a larger study is needed to validate these results in premature infants at low and high risk of brain injury.

Hydrogel electrodes are a reasonable alternative for use in long-term EEG studies in preterm neonates.

Background: Limited-channel EEG research in neonates is hindered by lack of open, accessible analytic tools. To overcome this limitation, we have created the Washington University-Neonatal EEG Analysis Toolbox (WU-NEAT), containing two of the most commonly used tools, provided in an open-source, clinically-validated package running within MATLAB. Methods:The first algorithm is the amplitude-integrated EEG (aEEG), which is generated by filtering, rectifying and time-compressing the original EEG recording, with subsequent semilogarithmic display. The second algorithm is the spectral edge frequency (SEF), calculated as the critical frequency below which a user-defined proportion of the EEG spectral power is located. The aEEG algorithm was validated by three experienced reviewers. Reviewers evaluated aEEG recordings of fourteen preterm/term infants, displayed twice in random order, once using a reference algorithm and again using the WU-NEAT aEEG algorithm. Using standard methodology, reviewers assigned a background pattern classification. Inter/intra-rater reliability was assessed. For the SEF, calculations were made using the same fourteen recordings, first with the reference and then with the WU-NEAT algorithm. Results were compared using Pearson's correlation coefficient.Results: For the aEEG algorithm, intra-and inter-rater reliability was 100% and 98%, respectively. For the SEF, the mean±SD Pearson correlation coefficient between algorithms was 0.96±0.04. Conclusion:We have demonstrated a clinically-validated toolbox for generating the aEEG as well as calculating the SEF from EEG data. Open-source access will enable widespread use of