Defining Body Mass Index Using Weight and Length for Gestational Age in the Growth Assessment of Preterm Infants at Birth

OBJECTIVE

 The objectives of this study were to describe (1) body mass indexes (BMIs) using weight and length for gestational age (GA) classifications, and (2) the additional information BMI, as a measure of body proportionality, provides for preterm infant growth assessment and care plans at birth.

STUDY DESIGN

 Birth weight, length, and BMI of 188,646 preterm infants (24-36 weeks gestation) admitted to U.S. neonatal intensive care units (Pediatrix Clinical Data Warehouse, 2013-2018) were classified (Olsen curves) as small, appropriate, or large for GA (SGA < 10th, AGA 10-90th, LGA > 90th percentile for GA, respectively). The distribution for the 27 weight-length-BMI combinations was described.

RESULTS

 At birth, most infants were appropriate for weight (80.0%), length (82.2%), head circumference (82.9%), and BMI (79.9%) for GA. Birth weight for GA identified approximately 20% of infants as SGA or LGA. Infants born SGA (or LGA) for both weight and length ("proportionate" in size) were usually appropriate for BMI (59.0% and 75.6%). BMI distinguished disproportionate weight for length in infants with SGA or LGA weight at birth (58.3%, 49.9%). BMI also identified 11.4% of AGA weight infants as small or large for BMI ("disproportionate" in size) at birth; only using weight for GA missed these underweight/overweight for length infants.

CONCLUSION

 The unique, additional information provided by birth BMI further informs individualized preterm infant growth assessment by providing an assessment of an infant's body proportionality (weight relative to its length) in addition to the routine assessment of weight, length, and head circumference for GA and may better inform care plans and impact outcomes.

KEY POINTS

· Most preterm infants were born AGA for all growth measures.. · AGA weight infants may be under- or overweight for length.. · BMI distinguished body disproportionality in SGA/LGA infants.. · Recommend BMI assessed along with weight, length and head.. · Further research on BMI in preterm infants is needed..

Trends in Neonatal Extracorporeal Membrane Oxygenation During a Venovenous Cannula Shortage

OBJECTIVES

To report temporal trends in venovenous extracorporeal membrane oxygenation (ECMO) use for neonatal respiratory failure in U.S. centers before and after functional venovenous cannula shortage due to withdrawal of one dual lumen venovenous cannula from the market in 2018.

DESIGN

Retrospective cohort study.

SETTING

ECMO registry of the Extracorporeal Life Support Organization.

PATIENTS

Infants who received neonatal (cannulated prior to 29 d of age) respiratory ECMO at a U.S. center and had a record available in the ECMO registry from January 1, 2010 to July 20, 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was receipt of venovenous ECMO (vs venoarterial or other), and secondary outcomes were survival to hospital discharge and adverse neurologic outcomes. Using an interrupted time series design, we fit multivariable mixed effects logistic regression models with receipt of venovenous ECMO as the dependent variable, treatment year modeled as a piecewise linear variable using three linear splines (pre shortage: 2010-2014, 2014-2018; shortage: 2018-2021), and adjusted for center clustering and multiple covariates. We evaluated trends in venovenous ECMO use by primary diagnosis including congenital diaphragmatic hernia, meconium aspiration, pulmonary hypertension, and other. Annual neonatal venovenous ECMO rates decreased after 2018: from 2010 to 2014, adjusted odds ratio (aOR) for yearly trend 0.98 (95% CI 0.92-1.04), from 2014 to 2018, aOR for yearly trend 0.90 (95% CI 0.80-1.01), and after 2018, aOR for yearly trend 0.46 (95% CI 0.37-0.57). We identified decreased venovenous ECMO use after 2018 in all diagnoses evaluated, and we failed to identify differences in temporal trends between diagnoses. Survival and adverse neurologic outcomes were unchanged across the study periods.

CONCLUSIONS

Venovenous ECMO for neonatal respiratory failure in U.S. centers decreased after 2018 even after accounting for temporal trends, coincident with withdrawal of one of two venovenous cannulas from the market.

Antibiotic use and outcomes among children hospitalized with suspected pneumonia

BACKGROUND

Although viral etiologies predominate, antibiotics are frequently prescribed for community-acquired pneumonia (CAP).

OBJECTIVE

We evaluated the association between antibiotic use and outcomes among children hospitalized with suspected CAP.

DESIGNS, SETTINGS AND PARTICIPANTS

We performed a secondary analysis of a prospective cohort of children hospitalized with suspected CAP.

INTERVENTION

The exposure was the receipt of antibiotics in the emergency department (ED).

MAIN OUTCOME AND MEASURES

Clinical outcomes included length of stay (LOS), care escalation, postdischarge treatment failure, 30-day ED revisit, and quality-of-life (QoL) measures from a follow-up survey 7-15 days post discharge. To minimize confounding by indication (e.g., radiographic CAP), we performed inverse probability treatment weighting with propensity analyses.

RESULTS

Among 523 children, 66% were <5 years, 88% were febrile, 55% had radiographic CAP, and 55% received ED antibiotics. The median LOS was 41 h (IQR: 25, 54). After propensity analyses, there were no differences in LOS, escalated care, treatment failure, or revisits between children who received antibiotics and those who did not. Seventy-one percent of patients completed follow-up surveys after discharge. Among 16% of patients with fevers after discharge, the median fever duration was 2 days, and those who received antibiotics had a 37% decrease in the mean number of days with fever (95% confidence interval: 20% and 51%). We found no statistical differences in other QoL measures.

Feeding Practice and Delivery Mode Are Determinants of Vitamin K in the Infant Gut: An Exploratory Analysis

Background

Infants have low stores of vitamin K at birth. Dietary intake of phylloquinone (PK) differs dramatically by infant feeding practice, but the contribution of microbially produced vitamin K (menaquinones) to infant vitamin K status is not well understood.

Objectives

The objective of this study was to investigate determinants of infant fecal vitamin K profiles in mother-infant dyads at 6 wk postpartum.

Methods

Fecal and breast milk samples were collected from a subsample of breastfeeding (n = 23) or formula-feeding (n = 23) mother and infant dyads, delivered vaginally (n = 26) or by cesarean section (CS) (n = 20) in the Synergistic Theory and Research on Nutrition and Growth (STRONG) Kids 2 cohort. Vitamin K concentrations in breast milk and feces were analyzed by LC/MS and/or HPLC. Fecal bacterial metagenomes were analyzed to derive taxonomy and vitamin K biosynthetic genes. Multivariate linear modeling was used to assess effects of delivery and feeding modes on infant fecal vitamin K.

Results

Breast milk contained 1.3 ± 0.2 ng/mL PK, and formula was reported to contain 52 ng/mL PK. Fecal PK was 38-times higher (P < 0.001) in formula-fed than breastfed infants. Infant fecal menaquinones (MKn) MK6, MK7, MK12, and MK13 were higher (P < 0.001) in formula-fed than breastfed infants, whereas MK8 predominated in breastfed and was 5-times higher than formula-fed infants. Total MKn were greater (P < 0.001) in vaginally delivered than CS infants. Relative abundances of 33 bacterial species were affected by feeding mode, 2 by delivery mode, and 4 by both (P < 0.05). Bacterial gene content of 5/12 vitamin K biosynthetic genes were greater (P < 0.05) in breastfed compared with formula-fed infants, and 1 differed by delivery mode.

Conclusions

Feeding practice and delivery mode influence bacterial vitamin K production in the infant gut. High concentrations of unmetabolized PK in feces of formula-fed infants suggests formula PK content exceeds the absorptive capacity of the infant gut.

Transcriptional profiling of lung macrophages identifies a predictive signature for inflammatory lung disease in preterm infants

Lung macrophages mature after birth, placing newborn infants, particularly those born preterm, within a unique window of susceptibility to disease. We hypothesized that in preterm infants, lung macrophage immaturity contributes to the development of bronchopulmonary dysplasia (BPD), the most common serious complication of prematurity. By measuring changes in lung macrophage gene expression in preterm patients at risk of BPD, we show here that patients eventually developing BPD had higher inflammatory mediator expression even on the first day of life. Surprisingly, the ex vivo response to LPS was similar across all samples. Our analysis did however uncover macrophage signature genes whose expression increased in the first week of life specifically in patients resilient to disease. We propose that these changes describe the dynamics of human lung macrophage differentiation. Our study therefore provides new mechanistic insight into both neonatal lung disease and human developmental immunology.

Patterns of Electrolyte Testing at Children's Hospitals for Common Inpatient Diagnoses

BACKGROUND

Overuse of laboratory testing contributes substantially to health care waste, downstream resource use, and patient harm. Understanding patterns of variation in hospital-level testing across common inpatient diagnoses could identify outliers and inform waste-reduction efforts.

METHODS

We conducted a multicenter retrospective cohort study of pediatric inpatients at 41 children's hospitals using administrative data from 2010 to 2016. Initial electrolyte testing was defined as testing occurring within the first 2 days of an encounter, and repeat testing was defined as subsequent testing within an encounter in which initial testing occurred. To examine if testing rates correlated across diagnoses at the hospital level, we compared risk-adjusted rates for gastroenteritis with a weighted average of risk-adjusted rates in other diagnosis cohorts. For each diagnosis, linear regression was performed to compare initial and subsequent testing.

RESULTS

In 497 719 patient encounters, wide variation was observed across hospitals in adjusted, initial, and repeat testing rates. Hospital-specific rates of testing in gastroenteritis were moderately to strongly correlated with the weighted average of testing in other conditions (initial: r = 0.63; repeat r = 0.83). Within diagnoses, higher hospital-level initial testing rates were associated with significantly increased rates of subsequent testing for all diagnoses except gastroenteritis.

CONCLUSIONS

Among children's hospitals, rates of initial and repeat electrolyte testing vary widely across 8 common inpatient diagnoses. For most diagnoses, hospital-level rates of initial testing were associated with rates of subsequent testing. Consistent rates of testing across multiple diagnoses suggest that hospital-level factors, such as institutional culture, may influence decisions for electrolyte testing.