466 - Early-Onset Sepsis in Very Low Birth Weight Preterm Infants: Clinical Characteristics and Progression of Hemodynamic Aberrations

Publication Number: 2454.466

Yu-Tang Juan, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taoyuan, Taiwan (Republic of China); Kai-Hsiang Hsu, Chang Gung University and Chang Gung Memorial Hospital, Taoyuan, Taoyuan, Taiwan (Republic of China); Ming-Chou Chiang, Linkou Chang Gung Memorial Hospital, Gueishan District, Taoyuan, Taiwan (Republic of China); Reyin Lien, Chang Gung University, Gwei-Shan, Taoyuan, Taiwan (Republic of China)

Background: Early-Onset Sepsis (EOS) remains a major cause of mortality in very low birth weight (VLBW, < 1500 g) infants. In preterm infants, clinical presentations of septic shock are diverse and obscure, mainly due to uncertain timing of infection, maturational differences, and complex hemodynamic transition after birth. Data on the hemodynamic characteristics of EOS in this population remain limited and inconsistent.

Objective: To describe the clinical and cardio-respiratory characteristics in VLBW infants with EOS, so as to identify potential indicators of disease severity for suitable intervention.

Design/Methods: We retrospectively reviewed inborn VLBW infants admitted to a tertiary neonatal intensive care unit in Taiwan between January 2019 and December 2024. EOS was defined as a positive blood or cerebrospinal fluid culture within the first 72 hours of life, and non-survivors as death within 7 days. Demographics, maternal and perinatal characteristics were examined. Serial measurements of arterial blood pressure (BP), heart rate (HR) and oxygen index (OI) were collected during the first 72 hours. Blood pressure values were standardized as gestational age-adjusted z-scores, and within-patient standard deviation (SD) across 12-hour intervals were used to quantify hemodynamic instability. Other parameters were analyzed by statistical methods as appropriate.

Results: There were 1131 VLBW infants enrolled, among whom 15 (1.3%) episodes of EOS were detected. Median gestational age and birth weight were 26.0 (24.5-28.5) weeks, and 780 (698-1111) g, respectively. Seven infants (46.7%) with EOS died, all within the first three days of life. E. coli accounted for 60% of cases, of which 67% were ESBL-producing strains. During the first 12 hours, survivors and non-survivors showed similarly low variability of mean BP (median SD 0.37 vs. 0.48, p = 0.48). Group differences became significant during Hour 12-23, when variability of mean BP increased markedly in non-survivors (median SD 0.53 vs. 1.21, p < 0.01), resulting from greater fluctuation of diastolic BP. Variability in HR followed a similar trend (median coefficient of variation 4.53 vs. 10.77 during Hour 12-23, p = 0.02). Severe hypoxemic respiratory failure (OI > 25) was observed exclusively in the non-survivors, which started at Hour 24 of life and deteriorated afterwards.

Conclusion(s): Clinical presentations of septic shock in VLBW infants with EOS appear to follow a temporal pattern, heralded by diastolic dysfunction and severe hypoxemic respiratory failure emerging after 12 hours of life. Early and meticulous monitoring is the key to guide timely intervention.

Table 1. Demographic characteristics, maternal factors and clinical presentations of very low birth weight infants with early-onset sepsis.
Data are presented as median (interquartile range) or number (%).
Group comparisons were performed using the Mann-Whitney U test or Fisher's exact test, as appropriate.
PROM: preterm rupture of membrane; CRP: C-reactive protein; INR: International normalized ratio; aPTT: activated partial thromboplastin time.
An asterisk indicates statistical significance (p < 0.05).

Figure 1. Temporal trends of within-patient variability in blood pressure and heart rate among very low birth weight infants with early-onset sepsis.
Median within-patient standard deviations (SD) of (a) mean, (b) systolic, and (c) diastolic blood pressure (z-scores) and coefficient of variation (CV) of (d) heart rate are shown for survivors (S, black) and non-survivors (NS, gray) across sequential 12-hour intervals during the first 72 hours of life.
Asterisks indicate significant group differences by Mann-Whitney U test (* p < 0.05, ** p < 0.01).
Open symbols denote intervals with fewer than three patients per group (insufficient data for analysis).

Figure 2. Temporal trend of median oxygen index (OI) across time intervals among survivors and non-survivors.
Median oxygen index (OI) values are plotted for survivors (S, black) and non-survivors (NS, gray) across sequential 12-hour intervals during the first 72 hours of life.
Open symbols indicate intervals with fewer than three patients per group, representing insufficient data for analysis.