Empirical estimation of the normative blood pressure in infants <28 weeks gestation using a massive data approach

Abstract

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.

Blood Pressure Profiles in Infants With Hypoxic Ischemic Encephalopathy (HIE), Response to Dopamine, and Association With Brain Injury

“…More likely is that MABP is a crude measure of perfusion; MABP is captured via pressure catheter at the level of a large vessel and may not reflect the complex of factors which govern perfusion in more distal vessels. Indeed, the entire concept of normal or adequate blood pressure threshold in neonates remains in question ( 25 ). Of note, the mean MABP measurements of the dopamine-exposed infants in this study was still above the widely accepted threshold of MABP > gestational age in weeks ( 37 ).…”

“…The files were then converted to a MATLAB (The Math Works, Natick, MA) matrix for analysis. As blood pressure is known to increase in a linear fashion following birth ( 25 , 26 ), comparison of average MABP at equivalent time points in the case and control groups was essential. For infants in the case group, T 0 was defined at the time of dopamine initiation.…”

Gestational age-dependent relationship between cerebral oxygen extraction and blood pressure

“…The median FTOE was compared between three blood pressure states: low, medium and high. Normative data suggests most preterm infants have a MABP between 30 and 40 mmHg during the first 72 hours of life ( 23 , 24 ). Additionally, a number of studies support 30 mmHg as the lower limit of autoregulatory control ( 8 , 25 – 27 ), and 40–45 mmHg as the upper limit ( 28 , 29 ).…”

Turkish Neonatal Society guideline on the neonatal hemodynamics and management of hypotension in newborns

“…It is higher in female babies compared with male babies, and in babies born by cesarean section compared with those born by vaginal delivery; it is lower in asphyctic babies (9, 11). In the literature, there are various tables and graphs showing normal BP values in the neonatal period (9, 19-21). Table 1 and 2 show normal BP values as specified by Zubrow et al (19).…”