741 - Characteristics of Intraventricular Hemorrhage Timing, Progression and Clinical Correlations in Neonates 22 0/7 week to 24 6/7 weeks gestation.

Publication Number: 2723.741

Madison Pelton, University of Washington School of Medicine, Seattle, WA, United States; Claire B. Vietri, Seattle Children's, Seattle, WA, United States; Amisha Tarkunde, OHSU/University of Washington School of Medicine, Portland, OR, United States; Rishabh Jain, University of Washington, Seattle, WA, United States; Robert Schmicker, University of Washington, Seattle, WA, United States; Kendell German, University of Washington School of Medicine, Seattle, WA, United States; Ulrike Mietzsch, University of Washington School of Medicine/ Seattle Children's Hospital, Seattle, WA, United States; Sarah Kolnik, University of Washington - Seattle Children's Hospital, Seattle, WA, United States

Background: Very extreme preterm (VEP) neonates born between 22 0/7 weeks to 24 6/7 weeks gestation are at high risk of intraventricular hemorrhage (IVH) due to fragility of the germinal matrix compounded by impaired autoregulation of cerebral perfusion. The first 72 hours after birth has been shown in older gestational age infants as the time when IVH occurs; however, whether this timing is consistent in VEP infants is unknown.

Objective: Describe the timing, evolution, and factors associated with changes in cerebral blood flow and IVH in VEP infants.

Design/Methods: A retrospective observational study of VEP neonates born at a Level IV NICU over a 2 year period with continuous rScO2 monitoring and cranial ultrasound within the first 72 hours after birth. Fisher's exact and Kruskal-Wallis rank sum tests were used to evaluate the correlation between perinatal demographics, clinical variables, and presence and grade of IVH. A correlation matrix was used to assess factors associated with IVH in the first 72 hours after birth. LOESS regression adjusted for gestational age, CRIB-II score, and head circumference was used to generate rScO2 reference curves stratified by presence, grade, and timing of IVH. A tracking graph was used to demonstrate progression of IVH.

Results: Of the 33 VEP infants who met inclusion criteria, 51% (n=17) had any IVH and 21% (n=7) had grade 3-4 IVH. There was a difference (p < 0.05) between infants with no IVH, Grade I-2 IVH, and Grade 3-4 IVH in CRIB-II scores, RBC transfusion, meningitis treatment and hospital mortality (Table1). A correlation (p < 0.05) was identified between IVH and base deficit (r = 0.3) in the first 72 after birth (Fig 1a). Infants with Grade 3-4 IVH compared to infants with no IVH or Grade 1-2 IVH had lower rScO2 values in the first 48 hours which then reversed to higher rScO2 trajectories (Fig 1b), which may reflect the negative correlation between IVH and rScO2 (-0.14) was not significant (Fig 1a). Of the 17 infants with IVH, 41% (n=7) had IVH first detected after 72 hours and 35% (n=6) had progression of their bleed after 72 hours (Fig 2a). Furthermore, infants with Grade 3-4 IVH identified within the first 72 hours had lower rScO2 compared to other groups, including Grade 3-4 IVH that developed after 72 hours (Fig 2b).

Conclusion(s): Although IVH occurs most frequently in the first 72 hours after birth in VEP infants, 70% of infants had bleeds that occurred and/or progressed after 72 hours. Early detection with monitoring of base deficit and rScO2 may help decipher those at risk of developing or progressing to more severe bleed aiding in preventative strategies.

Table 1
Table 1. IVH (Intraventricular Hemorrhage); CRIB - II (Clinical Risk Index for Babies); PDA (Patent Ductus Arteriosus); pRBC (Packed Red Blood Cell), PVL (Periventricular Leukomalacia).

Figure 1: Metrics associated with changes in cerebral blood flow in first 72 hours after birth in EP infants (n=33)
1a: Correlation matrix plot illustrates the relationship between hourly hemodynamic metrics and grade of IVH (Intraventricular Hemorrhage) (0-4) in the first 72 hours after birth. IVH (Intraventricular Hemorrhage); MAP, mean arterial pressure; SpO2, peripheral oxygenation; rScO2, regional cerebral oxygen saturation as measured by near-infrared spectroscopy; BD, base deficit; Lowest CO2 within first 72 hours, Highest CO2 within first 72 hours. *denotes significance p <0.05 , R values denoted positive or negative correlation 1b. rScO2 trends in all infants from 6-72 hours after birth stratified by presence and grade of IVH.

Figure 2. rScO2 trajectories and progression of bleed in patients with IVH (n=17)
2a. rScO2 trajectories from 6-72 hours after birth in patients with IVH stratified by if the IVH occurred before or after 72 hours. 2b Tracking graph of evolution of IVH over time, legend indicating bleed before or after 72 hours of life. Hourly tracking for each patient included in the study that developed IVH during hospitalization. Each patient is represented by a horizontal row indicating the hours after birth when the cranial US was obtained. Each circular marker indicates when the cranial ultrasound was performed and the grade of IVH. Note, for patients 3, 12, 13, 15, and 17 there was no new or progressed bleed after 72 hours so the color indicating when the bleed occurred does not change. These points are included in the graph to indicate that further ultrasounds were obtained and showed the same grade of IVH that was detected < 72 hours after birth. Hourly data was winsorized to the 88th percentile to account for outliers.