Predicting Infection in Very Preterm Infants: A Study Protocol

Prenatal and Postnatal Disparities in Very-Preterm Infants in a Study of Infections between 2018-2023 in Southeastern US

BACKGROUND

The birthrate of Black preterm (BPT) infants is 65% higher than White preterm (WPT) infants with a BPT mortality that is 2.3 times higher. The incidence of culture-positive late-onset sepsis is as high as 41% in very-preterm infants. The main purpose of this study was to examine thermal gradients and the heart rate in relation to the onset of infection. This report presents disparities in very-preterm infection incidence, bacteria, and mortality data amongst BPT and WPT infants.

METHODS

367 preterms born at <32 weeks gestational age (GA) between 2019-2023 in five neonatal intensive care units (NICUs) were enrolled to study the onset of infections and dispositions; REDCap data were analyzed for descriptive statistics.

RESULTS

The 362 infants for analyses included 227 BPTs (63.7%) and 107 WPTs (29.6%), with 28 infants of other races/ethnicities (Hispanic, Asian, and other), 50.6% female, mean GA of 27.66 weeks, and 985.24 g birthweight. BPT infants averaged 968.56 g at birth (SD 257.50), and 27.68 (SD 2.07) weeks GA, compared to WPT infants with a mean birthweight of 1006.25 g (SD 257.77, p = 0.2313) and 27.67 (SD 2.00, p = 0.982) weeks GA. Of the 426 episodes of suspected infections evaluated across all the enrolled infants, the incidence of early-onset sepsis (EOS) was 1.9%, with BPT infants having 2.50 times higher odds of EOS than WPT infants (p = 0.4130, OR (odds ratio) = 2.50, p_or = 0.408). The overall incidence of late-onset sepsis (LOS) was 10.8%, with LOS in 11.9% of BPT infants versus 9.3% (p = 0.489, OR = 1.21, p_or = 0.637) of WPT infants. BPT infants made up 69.2% of the 39 infants with Gram-positive infections vs. 25.6% for WPT infants; 16 infants had Gram-negative culture-positive infections, with 81.2% being BPT infants versus 18.8% being WPT infants. Of the 27 urinary tract infections, 78% were in BPTs. The necrotizing enterocolitis incidence was 6.9%; the incidence in BPT infants was 7.5% vs. 6.5% in WPT infants. The overall mortality was 8.3%, with BPTs at 8.4% vs. WPT infants at 9.3%, (p = 0.6715).

CONCLUSIONS

BPTs had a higher rate of positive cultures, double the Gram-negative infections, a much higher rate of urinary tract infections, and a higher rate of mortality than their WPT counterparts. This study emphasizes the higher risk of morbidity and mortality for BPTs.

Neonatal Autonomic Regulation as a Predictor of Autism Spectrum Disorder in Very Preterm Infants

Infants born preterm are at a significantly higher likelihood of having autism spectrum disorder (ASD). Preterm birth and ASD are both associated with neurological differences, notably autonomic nervous system (ANS) dysfunction, pointing to preterm ANS dysfunction as a potential pathway to ASD, particularly in VPT infants. In this study, a subset of very preterm (VPT) infants enrolled in a large, multisite clinical trial were enrolled in this study at birth (N=20). Continuous measures of minute-by-minute thermal gradients, defined by the difference between central and peripheral temperatures, and hour-by-hour abnormal heart rate characteristics (HRCs) were collected from birth-28 days (>40,000 samples/infant). Following NICU discharge, standardized measures of cognition, language, and motor skills were collected at adjusted ages 6, 9, and 12 months. At 12 months, assessments of social communication and early ASD symptoms were administered. Results suggest significant ASD concerns for half of the sample by 12 months of age. Neonatal abnormal HRCs were strongly associated with 12-month ASD symptoms (r=0.81, p<.01), as was birth gestational age (GA), birth weight (BW), and abnormal negative thermal gradients. ANS measures collected in the first month of neonatal life, more than a year prior to the ASD evaluation, were surprisingly strong predictors of ASD. This study highlights complementary ANS measures that describe how ANS dysfunction, likely resulting from an imbalance between the parasympathetic and sympathetic systems, may impact very early regulatory processes for neonates who later develop ASD. This finding offers a promising avenue for researching ANS-related etiological mechanisms and biomarkers of ASD.

Case Comparison of Preterm Infant Stability During Packed Red Blood Cell Transfusions

BACKGROUND

Very preterm infants (less than 32 weeks gestational age) experience acute morbidity during their stay in a neonatal intensive care unit. Because of their prematurity and frequent laboratory testing, they experience anemia, requiring correction with packed red blood cell (PRBC) transfusion(s). PRBC transfusions have been linked to neonatal morbidity, such as necrotizing enterocolitis, but never signs and symptoms of physiological stability.

OBJECTIVE

The secondary data analysis aimed to examine very preterm infants' physiological stability before, during, and after PRBC transfusions.

METHODS

A within-case, mixed-methods design was used in a secondary data analysis for 16 transfusion cases from 13 very preterm infants.

RESULTS

The findings showed very preterm infants with physiological variables falling within defined limits based on gestational age during the transfusion. Two contrasting case exemplars will be presented.

DISCUSSION

PRBC transfusions are necessary and prevent morbidity in very preterm infants. Observing instability during transfusions and prospectively studying hypothermia, cardiac instability, and thermal gradients is essential to design interventions to decrease morbidity associated with PRBC transfusions.

Vital signs as physiomarkers of neonatal sepsis

Neonatal sepsis accounts for significant morbidity and mortality, particularly among premature infants in the Neonatal Intensive Care Unit. Abnormal vital sign patterns serve as physiomarkers of sepsis and provide early warning of illness before overt clinical decompensation. The systemic inflammatory response to pathogens signals the autonomic nervous system, leading to changes in temperature, respiratory rate, heart rate, and blood pressure. In infants with comorbidities of prematurity, vital sign abnormalities often occur in the absence of infection, which confounds sepsis diagnosis. This review will cover the mechanisms of vital sign changes in neonatal sepsis, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve, which is critical to the host response to infectious and inflammatory insults. We will also review the clinical implications of vital sign changes in neonatal sepsis, including their use in early warning scores and systems to direct clinicians to the bedside of infants with physiologic changes that might be due to sepsis. IMPACT: This manuscript summarizes and reviews the relevant literature on the physiological manifestations of neonatal sepsis and how we monitor and analyze these through vital signs and advanced analytics.

Conducting Neonatal Intensive Care Unit Research During a Pandemic: Challenges and Lessons Learned

BACKGROUND

The coronavirus pandemic disrupted normal clinical operations and research. Nurse scientists conducting research studies in the neonatal intensive care unit experienced significant challenges to continuing their research studies amid national lockdowns and hospital visitation restrictions.

OBJECTIVES

The purpose of this article is to describe the challenges encountered by nurse scientists conducting research studies in the neonatal intensive care unit during the pandemic, the creative solutions devised to overcome these barriers, and the lessons learned during this unprecedented time.

METHODS

Using our pandemic area studies as exemplars, we highlight the barriers encountered in continuing our research in the intense environment of the neonatal intensive care unit.

RESULTS

Visitor restrictions limited the presence of parents and researchers in the neonatal intensive care unit during the pandemic, causing disruptions to participant recruitment and data collection. Laboratory closures further limited research activities during the pandemic. Strategies to overcome these barriers include building formal collaborations among researchers and clinicians, creating the infrastructure to support virtual recruitment and electronic consent, and developing contingency plans for studies involving the analysis of biological samples.

DISCUSSION

The neonatal intensive care unit is a unique environment because of vulnerable patient population and need for researchers to interact with parents to recruit study participants. Implementing the strategies developed during the coronavirus pandemic may allow for the continuation of research activities during future public health crises.