Mean arterial blood pressure changes in premature infants and those at risk for intraventricular hemorrhage.

Bedside microcomputer-derived, minute-to-minute mean arterial pressure (MAP) values during the first 48 hours of life were studied in 100 preterm babies with birth weight less than or equal to 1500 gm. In those babies (n = 72) with no periventricular-intraventricular hemorrhage (PV-IVH) or with grade 1 PV-IVH, the MAP values increased during the study period, with minute-to-minute variation and interval undulation. The MAP values in those with birth weight greater than 1000 gm were higher than in those of lower birth weight. Infants in whom grades 2 to 4 PV-IVH developed (n = 28) had consistently lower MAP values during the study period. Minute-to-minute variability, expressed as the average of the coefficients of variation at 15-minute intervals, did not differ between birth weight groups, nor did they differ between the PV-IVH group and their matched control subjects. However, those with PV-IVH spent a greater percentage of time, with a coefficient of variation greater than or equal to 13% or less than 3%, than their matched control subjects spent (p less than 0.005). This study provides reference data for MAP changes in premature babies. The observed MAP changes in those with PV-IVH lend support to a significant role for MAP alterations in the pathogenesis of PV-IVH.

Frequent handling in the neonatal intensive care unit and intraventricular hemorrhage.

The association between periventricular-intraventricular hemorrhage (PV-IVH) and frequent handling resulting from various neonatal intensive care procedures and routine interventions was evaluated in a prospective clinical study. Inborn premature babies with birth weight less than or equal to 1500 gm (n = 156) who did not have PV-IVH or who had grade 1 PV-IVH at less than or equal to 1 hour were randomly assigned to the reduced manipulation protocol (n = 62) or to standard care (n = 94). A bedside microcomputer-based data acquisition system was used to monitor the duration of rest or the number of interventions per day. Infants assigned to receive reduced manipulation spent a significantly higher percentage of time each day at rest than did those who received standard manipulation (p less than 0.006). However, the incidence of grades 2 to 4 PV-IVH did not differ significantly (30% in the study vs 37% in the standard manipulation group). When we analyzed the effect of manipulation in relation to risk of PV-IVH, while taking into account other perinatal variables, standard manipulation was not associated with increased risk of grades 2 to 4 PV-IVH. However, low birth weight, maternal smoking, general anesthesia, early grade 1 PV-IVH, low hematocrit, lowest arterial oxygen pressure within the first 6 hours of life, and large base deficit at 6 hours of age all increased the relative risk of grades 2 to 4 PV-IVH.

Indomethacin reduces the risks of severe intraventricular hemorrhage.

A prospective, random selection, double-blind clinical trial was carried out to determine the efficacy of indomethacin in preventing periventricular-intraventricular hemorrhage (PV-IVH). Babies who were born in our institution, had birth weights less than or equal to 1500 gm, and had no PV-IVH or grade 1 PV-IVH were given either placebo (n = 70) or indomethacin (n = 71), 0.2 mg/kg intravenously at 6 hours of age and 0.1 mg/kg at 18 and 30 hours. Two major outcomes were determined: the development of grades 2 to 4 PV-IVH and the development of severe PV-IVH (i.e., hemorrhages with blood filling greater than 50% of the ventricles and in some cases with associated parenchymal echodensities). Grades 2 to 4 PV-IVH occurred in 16 (23%) of the indomethacin group and 27 (39%) of the placebo group (p less than 0.03). The incidence of severe PV-IVH was 3% in the indomethacin-treated babies and 14% in the control group (p less than 0.02). The influence of other perinatal factors on the incidence of grades 2 to 4 or severe PV-IVH was determined by stepwise logistic regression. Placebo use, early grade 1 PV-IVH, lower birth weight, and higher fraction of inspired oxygen at 6 hours of life were associated with higher estimated odds of the development of grades 2 to 4 PV-IVH. Placebo use, male gender, lower 5-minute Apgar score, and a large base deficit were predictive of severe PV-IVH. Estimated odds ratios of severe PV-IVH with placebo use and male gender were 11.25:1 and 9:1, respectively. Thus indomethacin prophylaxis reduced the relative risk of grades 2 to 4 PV-IVH and severe PV-IVH, but other perinatal variables contributed significantly to the overall risk of PV-IVH.