Reproducibility between preschool and school-age Social Responsiveness Scale forms in the Environmental influences on Child Health Outcomes program

Evidence suggests core autism trait consistency in older children, but development of these traits is variable in early childhood. The Social Responsiveness Scale (SRS) measures autism-related traits and broader autism phenotype, with two age-dependent forms in childhood (preschool, 2.5-4.5 years; school age, 4-18 years). Score consistency has been observed within forms, though reliability across forms has not been evaluated. Using data from the Environmental Influences on Child Health Outcomes (ECHO) program (n = 853), preschool, and school-age SRS scores were collected via maternal report when children were an average of 3.0 and 5.8 years, respectively. We compared reproducibility of SRS total scores (T-scores) and agreement above a clinically meaningful cutoff (T-scores ≥ 60) and examined predictors of discordance in cutoff scores across forms. Participant scores across forms were similar (mean difference: 3.3 points; standard deviation: 7), though preschool scores were on average lower than school-age scores. Most children (88%) were classified below the cutoff on both forms, and overall concordance was high (92%). However, discordance was higher in cohorts following younger siblings of autistic children (16%). Proportions of children with an autism diagnoses were also higher among those with discordant scores (27%) than among those with concordant scores (4%). Our findings indicate SRS scores are broadly reproducible across preschool and school-age forms, particularly for capturing broader, nonclinical traits, but also suggest that greater variability of autism-related traits in preschool-age children may reduce reliability with later school-age scores for those in the clinical range.

Presurgical Pulmonary Function Tests in the First Few Days of Life in Neonates with Congenital Heart Disease, A Pilot Study

Objective

To compare early pulmonary function tests (PFTs) in neonates with critical congenital heart disease (CHD) compared to a historical reference group.

Design

Infants > 37 weeks gestation with critical CHD were studied within the first few days of life and prior to cardiac surgery and compared to data from a published reference group. Passive respiratory resistance (Rrs) and compliance (Crs) were measured with the single breath occlusion technique following specific acceptance criteria. The study was powered for a 30% difference in Rrs.

Results

PFTs in 24 infants with CHD were compared to 31 historical reference infants. There was no difference in the Rrs between the groups. The infants with CHD had a significantly decreased Crs (1.02 ± 0.26 mL/cmH2O/kg versus 1.32 ± 0.36; (p < 0.05; mean ± SD)).

Conclusions

Further prospective studies are required to quantify early PFTs in infants with CHD of different phenotypes.

Late Preterm Antenatal Steroid Use and Infant Outcomes in a Single Center

Objective

To characterize late preterm antenatal steroids (AS) use and associated neonatal outcomes in a single academic center.

Study Design

Retrospective study of 503 singleton, mother-infant dyads delivered between 34 0/7 to 36 6/7 weeks gestation between January 1, 2016 to December 31, 2020.

Results

43% did not receive AS (No AS) prior to delivery. Among AS treated, 50% were sub-optimal dosing. No AS had higher preterm premature rupture of membranes and maternal diabetes. AS group had lower mean gestational age and birthweight and longer time from admission to delivery and longer NICU study. There was no difference in neonatal hypoglycemia.

Conclusions

Sub-optimal AS dosing in late preterms remains high in our center. AS did not improve neonatal outcomes. Studies are needed to evaluate the impact of AS in diabetics delivering late preterm, to optimize the timing of AS dosing, and evaluate the longer term impact on late preterm infants.

Caregiver Perceived Stress and Child Sleep Health: An Item-Level Individual Participant Data Meta-Analysis

Up to 50% of children and adolescents in the United States (U.S.) experience sleep problems. While existing research suggests that perceived stress in caregivers is associated with poorer sleep outcomes in children, research on this relationship is often limited to infant and early childhood populations; therefore, we investigated this association in school-age children and adolescents. We used cross-sectional caregiver-reported surveys and applied item response theory (IRT) followed by meta-analysis to assess the relationship between caregiver perceived stress and child sleep disturbance, and moderation of this relationship by child age and the presence of a child mental or physical health condition. We analyzed data from the National Institutes of Health (NIH) Environmental influences on Child Health Outcomes (ECHO) Program, a collaboration of existing pediatric longitudinal cohort studies that collectively contribute a diverse and large sample size ideal for addressing questions related to children's health and consolidating results across population studies. Participants included caregivers of children ages 8 to 16 years from four ECHO cohorts. Caregiver perceived stress was measured using the Perceived Stress Scale (PSS), and child sleep disturbance was assessed using five sleep-related items from the School-Age version of the Child Behavior Checklist (CBCL). Increases in caregiver perceived stress and child mental or physical health condition were independently associated with greater sleep disturbance among children. The findings reinforce the importance of accounting for, and potentially intervening on, the broader family context and children's mental and physical health in the interest of improving sleep health.

Incidence rates of childhood asthma with recurrent exacerbations in the US Environmental influences on Child Health Outcomes (ECHO) program

BACKGROUND

Descriptive epidemiological data on incidence rates (IRs) of asthma with recurrent exacerbations (ARE) are sparse.

OBJECTIVES

This study hypothesized that IRs for ARE would vary by time, geography, age, and race and ethnicity, irrespective of parental asthma history.

METHODS

The investigators leveraged data from 17,246 children born after 1990 enrolled in 59 US with 1 Puerto Rican cohort in the Environmental Influences on Child Health Outcomes (ECHO) consortium to estimate IRs for ARE.

RESULTS

The overall crude IR for ARE was 6.07 per 1000 person-years (95% CI: 5.63-6.51) and was highest for children aged 2-4 years, for Hispanic Black and non-Hispanic Black children, and for those with a parental history of asthma. ARE IRs were higher for 2- to 4-year-olds in each race and ethnicity category and for both sexes. Multivariable analysis confirmed higher adjusted ARE IRs (aIRRs) for children born 2000-2009 compared with those born 1990-1999 and 2010-2017, 2-4 versus 10-19 years old (aIRR = 15.36; 95% CI: 12.09-19.52), and for males versus females (aIRR = 1.34; 95% CI 1.16-1.55). Black children (non-Hispanic and Hispanic) had higher rates than non-Hispanic White children (aIRR = 2.51; 95% CI 2.10-2.99; and aIRR = 2.04; 95% CI: 1.22-3.39, respectively). Children born in the Midwest, Northeast and South had higher rates than those born in the West (P < .01 for each comparison). Children with a parental history of asthma had rates nearly 3 times higher than those without such history (aIRR = 2.90; 95% CI: 2.43-3.46).

CONCLUSIONS

Factors associated with time, geography, age, race and ethnicity, sex, and parental history appear to influence the inception of ARE among children and adolescents.

Assessment of Psychosocial and Neonatal Risk Factors for Trajectories of Behavioral Dysregulation Among Young Children From 18 to 72 Months of Age

Importance

Emotional and behavioral dysregulation during early childhood are associated with severe psychiatric, behavioral, and cognitive disorders through adulthood. Identifying the earliest antecedents of persisting emotional and behavioral dysregulation can inform risk detection practices and targeted interventions to promote adaptive developmental trajectories among at-risk children.

Objective

To characterize children's emotional and behavioral regulation trajectories and examine risk factors associated with persisting dysregulation across early childhood.

Design, Setting, and Participants

This cohort study examined data from 20 United States cohorts participating in Environmental influences on Child Health Outcomes, which included 3934 mother-child pairs (singleton births) from 1990 to 2019. Statistical analysis was performed from January to August 2022.

Exposures

Standardized self-reports and medical data ascertained maternal, child, and environmental characteristics, including prenatal substance exposures, preterm birth, and multiple psychosocial adversities.

Main Outcomes and Measures

Child Behavior Checklist caregiver reports at 18 to 72 months of age, with Dysregulation Profile (CBCL-DP = sum of anxiety/depression, attention, and aggression).

Results

The sample included 3934 mother-child pairs studied at 18 to 72 months. Among the mothers, 718 (18.7%) were Hispanic, 275 (7.2%) were non-Hispanic Asian, 1220 (31.8%) were non-Hispanic Black, 1412 (36.9%) were non-Hispanic White; 3501 (89.7%) were at least 21 years of age at delivery. Among the children, 2093 (53.2%) were male, 1178 of 2143 with Psychosocial Adversity Index [PAI] data (55.0%) experienced multiple psychosocial adversities, 1148 (29.2%) were exposed prenatally to at least 1 psychoactive substance, and 3066 (80.2%) were term-born (≥37 weeks' gestation). Growth mixture modeling characterized a 3-class CBCL-DP trajectory model: high and increasing (2.3% [n = 89]), borderline and stable (12.3% [n = 479]), and low and decreasing (85.6% [n = 3366]). Children in high and borderline dysregulation trajectories had more prevalent maternal psychological challenges (29.4%-50.0%). Multinomial logistic regression analyses indicated that children born preterm were more likely to be in the high dysregulation trajectory (adjusted odds ratio [aOR], 2.76; 95% CI, 2.08-3.65; P < .001) or borderline dysregulation trajectory (aOR, 1.36; 95% CI, 1.06-1.76; P = .02) vs low dysregulation trajectory. High vs low dysregulation trajectories were less prevalent for girls compared with boys (aOR, 0.60; 95% CI, 0.36-1.01; P = .05) and children with lower PAI (aOR, 1.94; 95% CI, 1.51-2.49; P < .001). Combined increases in PAI and prenatal substance exposures were associated with increased odds of high vs borderline dysregulation (aOR, 1.28; 95% CI, 1.08-1.53; P = .006) and decreased odds of low vs high dysregulation (aOR, 0.77; 95% CI, 0.64-0.92; P = .005).

Conclusions and Relevance

In this cohort study of behavioral dysregulation trajectories, associations were found with early risk factors. These findings may inform screening and diagnostic practices for addressing observed precursors of persisting dysregulation as they emerge among at-risk children.

211 ASSOCIATION OF PLASMA ANTIOXIDANTS AND COGNITIVE OUTCOMES IN NORTHERN IRISH MEN FROM PROSPECTIVE EPIDEMIOLOGICAL STUDY OF MYOCARDIAL INFARCTION (PRIME) STUDY

Background

Oxidative stress and chronic inflammation have been demonstrated to contribute to cognitive decline in older age and the development of neurodegenerative disorders. Antioxidants have been revealed to help mitigate the effects of the damage caused by oxidative stress and inflammation, but their relationship with cognitive decline is not yet fully understood. The aim of this study was to investigate the association between various plasma antioxidant levels and cognitive status in participants from the Prospective Epidemiological Study of Myocardial Infarction (PRIME) study.

Methods

10,600 men were recruited to the PRIME study between 1991-1993 and have been followed up across eleven time points. Baseline health and lifestyle characteristics were assessed, and plasma antioxidants were obtained and quantified. Baseline cognitive status was screened in 2000 using Mini-Mental State Examination (MMSE). Follow up assessment of cognitive status was performed in 2015 with MMSE and Addenbrooke’s Cognitive Examination-Revised (ACE-R) examinations.

Results

2,009 men underwent cognitive assessment in 2000 and 873 men in 2015. At both 2000 and 2015 with the use of the MMSE and ACE-R examinations to assess cognitive status, serum concentration of all the antioxidants except for gamma-tocopherol and lycopene were higher in the men with better cognitive performance at a significant level of p&lt;0.05. Better cognitive performance was associated with more time spent in education and higher level of education achieved at a statistically significant level (p&lt;0.01). Furthermore, those with cognitive impairment were more likely to be older. After adjustments for lifestyle variables with a linear regression model, the only significant variable associated with cognition was time spent in education (B = 0.521, p= 0.02).

Conclusion

The findings suggest that the concentration of plasma antioxidants is associated with cognitive status. Smoking and education, as well as other lifestyle factors were, demonstrated to have an impact on cognitive status.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

"All these people saved her life, but she needs me too": Understanding and responding to parental mental health in the NICU

OBJECTIVE

To explore the mental health needs of parents of infants in a neonatal intensive care unit (NICU), as well as barriers and solutions to meeting these needs.

DESIGN

Qualitative interviews conducted with parents and staff (n = 15) from a level IV NICU in the Northwestern United States. Thematic analysis completed using an inductive approach, at a semantic level.

RESULTS

(1) Information and mental health needs change over time, (2) Staff-parent relationships buffer trauma and distress, (3) Lack of continuity of care impacts response to mental health concerns, (4) NICU has a critical role in addressing parental mental health.

CONCLUSION

Mental health support should be embedded and tailored to the NICU trajectory, with special attention to the discharge transition, parents living in rural areas, and non-English-speaking parents. Research should address structural factors that may impact mental health such as integration of wholistic services, language barriers, and staff capacity.

Effects of repeat prenatal corticosteroids given to women at risk of preterm birth: An individual participant data meta-analysis

BACKGROUND

Infants born preterm compared with infants born at term are at an increased risk of dying and of serious morbidities in early life, and those who survive have higher rates of neurological impairments. It remains unclear whether exposure to repeat courses of prenatal corticosteroids can reduce these risks. This individual participant data (IPD) meta-analysis (MA) assessed whether repeat prenatal corticosteroid treatment given to women at ongoing risk of preterm birth in order to benefit their infants is modified by participant or treatment factors.

METHODS AND FINDINGS

Trials were eligible for inclusion if they randomised women considered at risk of preterm birth who had already received an initial, single course of prenatal corticosteroid seven or more days previously and in which corticosteroids were compared with either placebo or no placebo. The primary outcomes for the infants were serious outcome, use of respiratory support, and birth weight z-scores; for the children, they were death or any neurosensory disability; and for the women, maternal sepsis. Studies were identified using the Cochrane Pregnancy and Childbirth search strategy. Date of last search was 20 January 2015. IPD were sought from investigators with eligible trials. Risk of bias was assessed using criteria from the Cochrane Collaboration. IPD were analysed using a one-stage approach. Eleven trials, conducted between 2002 and 2010, were identified as eligible, with five trials being from the United States, two from Canada, and one each from Australia and New Zealand, Finland, India, and the United Kingdom. All 11 trials were included, with 4,857 women and 5,915 infants contributing data. The mean gestational age at trial entry for the trials was between 27.4 weeks and 30.2 weeks. There was no significant difference in the proportion of infants with a serious outcome (relative risk [RR] 0.92, 95% confidence interval [CI] 0.82 to 1.04, 5,893 infants, 11 trials, p = 0.33 for heterogeneity). There was a reduction in the use of respiratory support in infants exposed to repeat prenatal corticosteroids compared with infants not exposed (RR 0.91, 95% CI 0.85 to 0.97, 5,791 infants, 10 trials, p = 0.64 for heterogeneity). The number needed to treat (NNT) to benefit was 21 (95% CI 14 to 41) women/fetus to prevent one infant from needing respiratory support. Birth weight z-scores were lower in the repeat corticosteroid group (mean difference -0.12, 95%CI -0.18 to -0.06, 5,902 infants, 11 trials, p = 0.80 for heterogeneity). No statistically significant differences were seen for any of the primary outcomes for the child (death or any neurosensory disability) or for the woman (maternal sepsis). The treatment effect varied little by reason the woman was considered to be at risk of preterm birth, the number of fetuses in utero, the gestational age when first trial treatment course was given, or the time prior to birth that the last dose was given. Infants exposed to between 2-5 courses of repeat corticosteroids showed a reduction in both serious outcome and the use of respiratory support compared with infants exposed to only a single repeat course. However, increasing numbers of repeat courses of corticosteroids were associated with larger reductions in birth z-scores for weight, length, and head circumference. Not all trials could provide data for all of the prespecified subgroups, so this limited the power to detect differences because event rates are low for some important maternal, infant, and childhood outcomes.

CONCLUSIONS

In this study, we found that repeat prenatal corticosteroids given to women at ongoing risk of preterm birth after an initial course reduced the likelihood of their infant needing respiratory support after birth and led to neonatal benefits. Body size measures at birth were lower in infants exposed to repeat prenatal corticosteroids. Our findings suggest that to provide clinical benefit with the least effect on growth, the number of repeat treatment courses should be limited to a maximum of three and the total dose to between 24 mg and 48 mg.

Smoking cessation in pregnancy: a continuing challenge in the United States

Despite significant population level declines, smoking during pregnancy remains a major public health issue in the United States (US). Approximately 360,000-500,000 smoke-exposed infants are born yearly, and prenatal smoking remains a leading modifiable cause of poor birth outcomes (e.g. birth < 37 gestational weeks, low birth weight, perinatal mortality). Women who smoke during pregnancy are more likely to be younger and from disadvantaged socioeconomic and racial and ethnic groups, with some US geographic regions reporting increased prenatal smoking rates since 2000. Such disparities in maternal prenatal smoking suggests some pregnant women face unique barriers to cessation. This paper reviews the current state and future direction of smoking cessation in pregnancy in the US. We briefly discuss the etiology of smoking addiction among women, the pathophysiology and effects of tobacco smoke exposure on pregnant women and their offspring, and the emerging issue of electronic nicotine delivery systems. Current population-based and individual smoking cessation interventions are reviewed in the context of pregnancy and barriers to cessation among US women. Finally, we consider interventions that are on the horizon and areas in need of further investigation.

Long-term Sequelae of Pediatric Neurocritical Care: The Parent Perspective

Critical neurologic disease and injury affect thousands of children annually with survivors suffering high rates of chronic morbidities related directly to the illness and to critical care hospitalization. Postintensive care syndrome (PICS) in patients and families encompasses a variety of morbidities including physical, cognitive, emotional, and psychological impairments following critical care. We conducted a focus group study with parents of children surviving pediatric neurocritical care (PNCC) for traumatic brain injury, stroke, meningitis, or encephalitis to determine outcomes important to patients and families, identify barriers to care, and identify potential interventions to improve outcomes. Sixteen parents participated in four groups across Oregon. Three global themes were identified: (1) PNCC is an intense emotional experience for the whole family; (2) PNCC survivorship is a chronic illness; and (3) PNCC has a significant psychological and social impact. Survivors and their families suffer physical, emotional, psychological, cognitive, and social impairments for many years after discharge. Parents in this study highlighted the emotional and psychological distress in survivors and families after PNCC, in contrast to most PNCC research focusing on physical outcomes. Several barriers to care were identified with potential implications on survivor outcomes, including limited pediatric resources in rural settings, perceived lack of awareness of PICS among medical providers, and the substantial financial burden on families. Parents desire improved education surrounding PICS morbidities for families and medical providers, improved communication with primary care providers after discharge, access to educational materials for patients and families, direction to mental health providers, and family support groups to assist them in dealing with morbidities and accessing appropriate resources. Clinicians and researchers should consider the parent perspectives reported here when caring for and evaluating outcomes for children requiring PNCC.

Pulmonary function and outcomes in infants randomized to a rescue course of antenatal steroids

BACKGROUND/OBJECTIVE

Our objective was to obtain follow-up pulmonary function testing and assessment of clinical respiratory outcomes, at 1-2 years, in preterm infants whose mothers were randomized to a single rescue course of antenatal steroids (AS) versus placebo.

METHODS

Follow-up of a randomized, double-blinded trial. In the original trial pregnant women ≥14 days after initial course of AS were randomized to rescue AS or placebo. Pulmonary function testing and a standardized respiratory questionnaire were obtained at 1-2 years of corrected age. Respiratory compliance (Crs) was measured with the single-breath occlusion and functional residual capacity (FRC) with the nitrogen washout method. Analysis was by intention-to-treat.

RESULTS

A total of 96 (87%) of available survivors were administered a respiratory questionnaire. Seventy-seven percent of available patients had pulmonary function testing performed. There was no significant difference between groups in incidence of wheezing, asthma, respiratory syncytial virus infection, respiratory readmissions, use of bronchodilators or other medications, or in measurements of pulmonary function. There was also no significant difference in corrected age at study, race, gender, or length at the time of pulmonary function testing. Infants in the rescue group had a comparable mean FRC (249.4 mL vs 246.2 mL; adjusted 95%CI for difference -15.45, 38.20; P = 0.37) versus placebo. There were no differences in tidal volume or Crs.

CONCLUSION

A rescue course of AS significantly increases Crs within 72 h of age and decreases oxygen need in newborn infants, without an adverse impact on pulmonary function or clinical respiratory outcomes at 1-2 years of age [NCT00669383].

Beyond the uterine environment: a nonhuman primate model to investigate maternal-fetal and neonatal outcomes following chronic intrauterine infection

BackgroundIntrauterine infection is a significant cause of early preterm birth. We have developed a fetal-neonatal model in the rhesus macaque to determine the impact of chronic intrauterine infection with Ureaplasma parvum on early neonatal reflexes and brain development.MethodsTime-mated, pregnant rhesus macaques were randomized to be inoculated with U. parvum (serovar 1; 10⁵c.f.u.) or control media at ~120 days' gestational age (dGA). Neonates were delivered by elective hysterotomy at 135-147 dGA (term=167d), stabilized, and cared for in our nonhuman primate neonatal intensive care unit. Neonatal reflex behaviors were assessed from birth, and fetal and postnatal brain magnetic resonance imaging (MRI) was performed.ResultsA total of 13 preterm and 5 term macaque infants were included in the study. Ten preterm infants survived to 6 months of age. U. parvum-infected preterm neonates required more intensive respiratory support than did control infants. MRI studies suggested a potential perturbation of brain growth and white matter maturation with exposure to intra-amniotic infection.ConclusionWe have demonstrated the feasibility of longitudinal fetal-neonatal studies in the preterm rhesus macaque after chronic intrauterine infection. Future studies will examine long-term neurobehavioral outcomes, cognitive development, neuropathology, and in vivo brain imaging to determine the safety of antenatal antibiotic treatment for intrauterine infection.

Respiratory function in healthy late preterm infants delivered at 33-36 weeks of gestation

OBJECTIVE

To compare pulmonary function testing including respiratory compliance (Crs) and time to peak tidal expiratory flow to expiratory time (TPTEF:TE) at term corrected age in healthy infants born at 33-36 weeks of gestation versus healthy infants delivered at term.

STUDY DESIGN

We performed a prospective cohort study of late preterm infants born at 33-36 weeks without clinical respiratory disease (<12 hours of >0.21 fraction of inspired oxygen) and studied at term corrected age. The comparison group was term infants matched for race and sex to the preterm infants and studied within 72 hours of delivery. Crs was measured with the single breath occlusion technique. A minimum of 50 flow-volume loops were collected to estimate TPTEF:TE.

RESULTS

Late preterm infants (n = 31; mean gestational age 34.1 weeks, birth weight 2150 g) and 31 term infants were studied at term corrected age. The late preterm infants had decreased Crs (1.14 vs 1.32 mL/cm H(2)O/kg; P < .02) and decreased TPTEF:TE (0.308 vs 0.423; P < .01) when compared with the term infants. Late preterm infants also had an increased respiratory resistance (0.064 vs 0.043 cm H(2)O/mL/s; P < .01).

CONCLUSIONS

Healthy late preterm infants (33-36 weeks of gestation) studied at term corrected age have altered pulmonary function when compared with healthy term infants.

Fetal pulmonary arterial vascular impedance reflects changes in fetal oxygenation at near-term gestation in a nonhuman primate model

OBJECTIVE

We tested the hypothesis that fetal pulmonary arterial circulation reacts to changes in fetal oxygenation status at near-term gestation.

STUDY DESIGN

A total of 20 rhesus macaques underwent fetal Doppler ultrasonography at near-term gestation. Right pulmonary artery (RPA), umbilical artery (UA), ductus arteriosus (DA), and ductus venosus (DV) blood velocity waveforms were obtained, and pulsatility index (PI) values were calculated. Fetal right and left ventricular cardiac outputs were determined. Ultrasonographic data were collected during 3 maternal oxygenation states: room air (baseline), hyperoxemia, and hypoxemia.

RESULTS

Fetal RPA PI values increased (P < .05) during maternal hypoxemia and decreased (P < .05) during maternal hyperoxemia, compared with baseline. Maternal hyperoxemia increased (P < .05) DA PI values from baseline. Fetal cardiac outputs, UA, and DV PI values were not affected.

CONCLUSIONS

Our results demonstrate that at near-term gestation, fetal pulmonary arterial circulation is a dynamic vascular bed that reflects acute and short-term changes in fetal oxygenation.

Healthy Moms, a randomized trial to promote and evaluate weight maintenance among obese pregnant women: study design and rationale

BACKGROUND

Obesity and excessive weight gain during pregnancy are associated with adverse pregnancy outcomes. Observational studies suggest that minimal or no gestational weight gain (GWG) may minimize the risk of adverse pregnancy outcomes for obese women.

OBJECTIVE

This report describes the design of Healthy Moms, a randomized trial testing a weekly, group-based, weight management intervention designed to help limit GWG to 3% of weight (measured at the time of randomization) among obese pregnant women (BMI≥30 kg/m(2)). Participants are randomized at 10-20 weeks gestation to either the intervention or a single dietary advice control condition.

PRIMARY OUTCOMES

The study is powered for the primary outcome of total GWG, yielding a target sample size of 160 women. Additional secondary outcomes include weight change between randomization and one-year postpartum and proportion of infants with birth weight>90th percentile for gestational age. Statistical analyses will be based on intention-to-treat.

METHODS

Following randomization, all participants receive a 45-minute dietary consultation. They are encouraged to follow the Dietary Approaches to Stop Hypertension diet without sodium restriction. Intervention group participants receive an individualized calorie intake goal, a second individual counseling session and attend weekly group meetings until they give birth. Research staff assesses all participants at 34-weeks gestation and at 2-weeks and one-year postpartum with their infants.

SUMMARY

The Healthy Moms study is testing weight management techniques that have been used with non-pregnant adults. We aim to help obese women limit GWG to improve their long-term health and the health of their offspring.

Repeat prenatal corticosteroid prior to preterm birth: a systematic review and individual participant data meta-analysis for the PRECISE study group (prenatal repeat corticosteroid international IPD study group: assessing the effects using the best level of evidence) - study protocol

BACKGROUND

The aim of this individual participant data (IPD) meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol.

METHODS/DESIGN

The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE) Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants are eligible for the PRECISE IPD meta-analysis. The primary study outcomes for the infants will be serious neonatal outcome (defined by the PRECISE International IPD Study Group as one of death (foetal, neonatal or infant); severe respiratory disease; severe intraventricular haemorrhage (grade 3 and 4); chronic lung disease; necrotising enterocolitis; serious retinopathy of prematurity; and cystic periventricular leukomalacia); use of respiratory support (defined as mechanical ventilation or continuous positive airways pressure or other respiratory support); and birth weight (Z-scores). For the children, the primary study outcomes will be death or any neurological disability (however defined by trialists at childhood follow up and may include developmental delay or intellectual impairment (developmental quotient or intelligence quotient more than one standard deviation below the mean), cerebral palsy (abnormality of tone with motor dysfunction), blindness (for example, corrected visual acuity worse than 6/60 in the better eye) or deafness (for example, hearing loss requiring amplification or worse)). For the women, the primary outcome will be maternal sepsis (defined as chorioamnionitis; pyrexia after trial entry requiring the use of antibiotics; puerperal sepsis; intrapartum fever requiring the use of antibiotics; or postnatal pyrexia).

DISCUSSION

Data analyses are expected to commence in 2011 with results publicly available in 2012.

Estimates and relationships between aboveground and belowground resource exchange surface areas in a Sitka spruce managed forest

Our knowledge of the nature of belowground competition for moisture and nutrients is limited. In this study, we used an earth impedance method to determine the root absorbing area of Sitka spruce (Picea sitchensis (Bong.) Carr.) trees, making measurements in stands of differing density (2-, 4- and 6-m inter-tree spacing). We compared absorbing root area index (RAI(absorbing); based on the impedance measure) with fine root area index (RAI(fine); based on estimates of total surface area of fine roots) and related these results to investment in conductive roots. Root absorbing area was a near-linear function of tree stem diameter at 1.3 m height. At the stand level, RAI(absorbing), which is analogous to and scaled with transpiring leaf area index (maximum stomatal pore area per unit ground area; LAI(transpiring)), increased proportionally with basal area across the three stands. In contrast, RAI(fine) was inversely propotional to basal area. The ratio of RAI(absorbing) to LAI(transpiring) ranged from 7.7 to 17.1, giving an estimate of the relative aboveground versus belowground resource exchange areas. RAI(absorbing) provides a way of characterizing ecosystem functioning as a physiologically meaningful index of belowground absorbing area.

Respiratory compliance in preterm infants after a single rescue course of antenatal steroids: a randomized controlled trial

OBJECTIVE

To compare respiratory compliance and functional residual capacity in infants randomized to a rescue course of antenatal steroids vs placebo.

STUDY DESIGN

Randomized, double-blinded trial. Pregnant women > or =14 days after initial antenatal steroids were randomized to rescue antenatal steroids or placebo. The primary outcomes were measurements of respiratory compliance and functional residual capacity. This study is registered with clinicaltrials.gov (NCT00669383).

RESULTS

Forty-four mothers (56 infants) received rescue antenatal steroids and 41 mothers (57 infants) received placebo. There was no significant difference in birthweight, or head circumference. Infants in the rescue group had an increased respiratory compliance (1.21 vs 1.01 mL/cm H(2)O/kg; adjusted 95% confidence interval, 0.01-0.49; P = .0433) compared with placebo. 13% in the rescue vs 29% in the placebo group required > or =30% oxygen (P < .05). Patients delivered at < or =34 weeks had greater pulmonary benefits.

CONCLUSION

Infants randomized to rescue antenatal steroids have a significantly increased respiratory compliance compared with placebo.

Decreased respiratory compliance in infants less than or equal to 32 weeks' gestation, delivered more than 7 days after antenatal steroid therapy

OBJECTIVES

Our objective was to compare the pulmonary function (respiratory compliance) of infants who were < or = 32 weeks' gestation and delivered > 7 days after a single course of antenatal steroids versus infants who were delivered 1 to 7 days after a single course of antenatal steroids.

METHODS

A prospective cohort study of respiratory system compliance was conducted of infants < or = 32 weeks' gestation within 72 hours of life and before surfactant therapy if needed. The study (remote) group was composed of infants who were treated with antenatal steroids > 7 days before delivery and the comparison group (ideal group) of matched infants who were treated with antenatal steroids 1 to 7 days before delivery. Respiratory system compliance was measured with the single-breath occlusion technique.

RESULTS

Twenty-eight remotely treated infants and 28 ideally treated infants were studied. The remote group had a significantly lower respiratory system compliance per kilogram and total respiratory system compliance when compared with the ideal antenatal steroids group. Within the remote group, infants who received antenatal steroids 8 to 14 days (n = 10) before delivery had a significantly higher respiratory system compliance and a trend to less surfactant need (10% vs 33%) as compared with infants who received antenatal steroids > 14 days (n = 18) before delivery.

CONCLUSIONS

Infants who were < or = 32 weeks' gestation and remotely treated with antenatal steroids (average 21 days) had a significantly lower respiratory compliance compared with matched infants who were ideally treated with antenatal steroids. We speculate that the lower respiratory system compliance may reflect the dissipation of beneficial effects of antenatal steroids on pulmonary function when delivery occurs > 7 days after therapy and particularly when therapy is > 14 days before delivery.

Acute effects of vecuronium on pulmonary function and hypoxemic episodes in preterm infants

BACKGROUND

Varying effects of pancuronium on neonatal pulmonary mechanics have been documented, including a decrease in pulmonary compliance or no significant change in compliance; but measurements of respiratory mechanics or quantification of episodes of hypoxemia in preterm newborns receiving vecuronium (Norcuron, Bedford Labs, Bedford, OH, USA) have not been reported. The objective of the present study was to quantify the short-term effects of vecuronium on pulmonary mechanics and episodes of hypoxemia in preterm infants receiving mechanical ventilation.

METHODS

A total of 15 preterm infants (birthweight 610-1560 g, gestational age 25-32 weeks, postnatal age 0.2-22 days) was studied. The initial dose of vecuronium used for the study was 0.2 mg/kg i.v. Measurements of respiratory mechanics were obtained 1 h prior to and 1 h after the initial dose of vecuronium at comparable ventilator settings and fractional inspired oxygen concentration (FiO(2)). Dynamic respiratory compliance and respiratory resistance were calculated by two-factor least mean square analysis. Pulse oximeter oxygen saturation (SpO(2)) was measured during both 1 h intervals with the Nellcor N-200 oximeter, a computer, and a software program for quantification of episodes of hypoxemia. Heart rate and blood pressure were also monitored.

RESULTS

There were no significant differences in tidal volume, respiratory compliance, or respiratory resistance when comparing measurements obtained before and after vecuronium administration. However, fewer episodes of hypoxemia (SpO(2) < 85%, P = 0.025; and SpO(2) < 80%, P = 0.04) were observed during muscle relaxation. No significant changes in heart rate or blood pressure were noted.

CONCLUSIONS

The preliminary data indicate: (i) a single dose of vecuronium does not significantly change respiratory compliance or respiratory resistance in preterm infants and (ii) during muscle relaxation fewer episodes of desaturation (hypoxemia) are observed.

Extracorporeal membrane oxygenation in infants with meconium aspiration syndrome: a decade of experience with venovenous ECMO

BACKGROUND

Despite the emergence of new therapies for respiratory failure of the newborn with meconium aspiration syndrome (MAS), extracorporeal membrane oxygenation (ECMO) has a significant role as a rescue modality in these infants. Our objective was to compare the use of venovenous (VV) vs venoarterial (VA) ECMO in newborns with MAS who need ECMO and to ascertain the impact of new therapies in these infants during the last decade. We also evaluated how disease severity or time of ECMO initiation affected mortality and morbidity.

METHODS

A report of 12 years experience (1990-2002) of a single center, comparing VV and VA ECMO, is given. Venovenous ECMO was the preferred rescue modality for respiratory failure unresponsive to maximal medical therapy. Venoarterial ECMO was used only when the placement of a VV ECMO 14-F catheter was not possible; 128 patients met ECMO criteria, 114 were treated with VV ECMO, and 12 with VA ECMO. Two patients were converted from VV to VA ECMO.

RESULTS

Venovenous and VA ECMO patients had comparable birth weight (mean +/- SEM, 3.48 +/- 0.05 vs 3.35 +/- 0.15 kg) and gestational age (40.3 +/- 0.1 vs 40.7 +/- 0.3 weeks). Before ECMO, there was no difference between VV and VA ECMO patients in oxygenation index (60 +/- 3 vs 63 +/- 8), mean airway pressure (19.5 +/- 0.4 vs 20.8 +/- 1.5 cm H2O), alveolar-arterial O2 gradient (630 +/- 2 vs 632 +/- 4 torr), ECMO cannulation age (median [25th-75th percentiles], 23 [14-47] vs 26 [14-123] hours), or in the % of patients who needed vasopressors/inotropes (98% vs 100%). From November 1994, inhaled nitric oxide (NO) was available. Before VV ECMO, 67% of the patients received NO, 24% received surfactant, and 48% were treated with high-frequency ventilation (HFV). There was no significant difference between VV and VA ECMO patients in survival rate (94% vs 92%), ECMO duration (88 [64-116] vs 94 [55-130] hours), time of extubation (9 [7-11] vs 14 [9-15] days), age at discharge (23 [18-30] vs 27 [15-41] days), or incidence of short-term intracranial complications (5.3% vs 16.7%). For the total cohort of 126 infants, indices of disease severity (oxygenation index, alveolar-arterial O 2 gradient, mean airway pressure) did not correlate with outcome measures. Delay in ECMO initiation (> 96 hours) was associated with prolonged mechanical ventilation and hospitalization (P < .01). New therapies (NO, HFV, surfactant) in the second part of the decade were associated with a longer ECMO duration (98 [80-131] vs 87 [60-116] hours; P < .05), no delay in ECMO initiation time (23 [10-40] vs 24 [14-52] hours), and no significant change in survival (97% vs 92.5%). No patient was treated with VA ECMO after 1994.

CONCLUSIONS

Venovenous ECMO is as reliable as VA ECMO in newborns with MAS in severe respiratory failure who need ECMO. Delay in ECMO initiation may result in prolonged mechanical ventilation and increased length of hospital stay. The emergence of new conventional therapies (NO, HFV, surfactant) and particularly increased experience enable sole use of VV ECMO with no significant change in survival in infants with MAS.

Randomized, double-blinded trial of low-dose dexamethasone: II. Functional residual capacity and pulmonary outcome in very low birth weight infants at risk for bronchopulmonary dysplasia

We previously reported on a 7-day course of dexamethasone starting at 0.5 mg/kg/day in intubated very low birth weight (VLBW) infants, 7-14 days of age, with increased dynamic pulmonary compliance and decreased bronchopulmonary dysplasia (BPD). The effect of low-dose dexamethasone on functional residual capacity (FRC) in VLBW infants is unknown. The objective of this study was to compare the effect of two regimens of moderately early dexamethasone on FRC and passive respiratory compliance (Crs) in VLBW infants at risk for BPD. Sixty-two intubated VLBW infants were randomized (double-blinded) at 7-21 days of age; 29 patients (mean birth weight, 839 g) received "high" dose dexamethasone (0.5 mg/kg/day for 3 days, 0.25 mg/kg/day for 3 days, and 0.1 mg/kg/day on day 7, total dose of 2.35 mg/kg), and 33 infants (mean birth weight, 830 g) received "low-dose" dexamethasone (0.2 mg/kg/day for 3 days and 0.1 mg/kg/day for 4 days, total dose of 1 mg/kg). FRC and Crs were measured with the nitrogen washout technique and single breath occlusion technique, before and on days 2, 5, and 7 of therapy. Clinical outcome and early neurodevelopmental follow-up were evaluated. FRC significantly increased in the high-dose (19.3 ml/kg at baseline to 34 ml/kg on day 7; P < 0.001) and low-dose (18.1 ml/kg at baseline to 30.3 ml/kg on day 7; P < 0.001) dexamethasone groups when compared to baseline. There was a significant increase in Crs and a decrease in FiO2 within each group. The improvements in FRC and Crs were comparable between groups, and specific compliances (Crs/FRC) were not different. There were no significant differences in other clinical outcome parameters, including BPD and neurodevelopmental outcome. In conclusion, there are significant increases in FRC during a 7-day course of moderately early dexamethasone in VLBW infants. The lower total dose (1 mg/kg) appears as effective as the higher total dose of dexamethasone (2.35 mg/kg) in increasing FRC. Comparable significant increases in Crs were observed in both groups of infants. Additional long-term follow-up is underway.

The effect of a single remote course versus weekly courses of antenatal corticosteroids on functional residual capacity in preterm infants: a randomized trial

OBJECTIVE

There are no randomized data on the effect of repeat courses of corticosteroids during pregnancy on newborn pulmonary function. Our objective was to compare the effect of a single remote course of antenatal steroids (AS) with weekly courses of AS on functional residual capacity (FRC) and respiratory compliance in preterm infants.

STUDY DESIGN/METHODS

Pregnant women 25 to 33 weeks' gestation, who remained undelivered 1 week after their first course of antenatal corticosteroids (two 12-mg doses of betamethasone) were randomized to weekly courses of corticosteroids versus weekly placebo until delivery or 34 weeks' gestation. FRC was measured with the nitrogen washout technique and respiratory compliance with the single breath occlusion technique within 48 hours of life.

RESULTS

Thirty-seven infants (mean gestational age at delivery approximately 32.5 weeks) were studied. Maternal and infant demographics were similar. There was no significant difference in FRC (28.5 vs 27.5 mL/kg) or respiratory compliance between the infants who received a single remote course of antenatal corticosteroids and those who received weekly courses of corticosteroids until delivery. There was no significant difference in admission head circumference or birth weights between the groups.

CONCLUSIONS

Our results demonstrate that weekly repetitive courses of AS do not significantly increase FRC or respiratory compliance in preterm infants when compared with a single remote course of steroids given at a mean gestational age of 29 weeks.

A randomized trial of moderately early low-dose dexamethasone therapy in very low birth weight infants: dynamic pulmonary mechanics, oxygenation, and ventilation

OBJECTIVE

Dexamethasone is used in very low birth weight (VLBW) ventilator-dependent infants to prevent or decrease the severity of chronic lung disease. We reported a significant increase in respiratory compliance during a 7-day weaning course of moderately early dexamethasone therapy (0.5 mg/kg/d) in VLBW infants, along with a shorter duration of mechanical ventilation and O2 supplementation. Although 0.5 mg/kg/d has been the most commonly used dose in preterm infants, the use of a lower dose of dexamethasone may reduce potential adverse effects of steroid therapy. Quantification of dynamic pulmonary mechanics in VLBW infants who receive low-dose dexamethasone has not been reported. The objective of this study was to compare the effect of 2 dose regimens of dexamethasone on dynamic pulmonary mechanics, mean airway pressure (MAP), and fractional inspired oxygen concentration (Fio2) in intubated VLBW infants who were at risk for chronic lung disease.

METHODS

We studied 47 VLBW (birth weight: 550-1290 g; gestational age: 24-30 weeks) ventilator-dependent infants at 7 to 14 days of age. Twenty-three infants were randomized to receive dexamethasone at 0.5 mg/kg/d intravenously for 3 days (high dose), 0.25 mg/kg/d for 3 days, and 0.1 mg/kg/d during the 7th day; 24 infants received low-dose dexamethasone as 0.2 mg/kg/d for 3 days and 0.1 mg/kg/d for 4 days. Respiratory compliance (Crs) and resistance were measured before and on days 2, 5, and 7 of dexamethasone therapy. We recorded airway pressure, flow, and tidal volume, and mechanical breaths were analyzed.

RESULTS

Crs significantly increased during dexamethasone therapy in both groups of infants when compared with baseline (74% increase in the high-dose group and 66% increase in the low-dose group). Dexamethasone increased tidal volume and significantly reduced Fio2 and MAP in both groups of infants. A transient increase in blood pressure was noted in both groups.

CONCLUSIONS

Our findings indicate that 1) comparable significant increases in Crs are present in the low-dose dexamethasone as well as the high-dose dexamethasone groups on days 2, 5, and 7 of steroid therapy; and 2) MAP and Fio2 are significantly decreased during dexamethasone therapy in both groups of infants. We conclude that low-dose and high-dose dexamethasone, as used in this study, have comparable beneficial effects on dynamic pulmonary mechanics and subsequently on oxygen requirement and applied ventilatory support in VLBW infants.

Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants

Studies in preterm animal models have shown that antenatal corticosteroids enhance lung maturation by improving a variety of physiologic variables, including lung volumes. Changes in lung volume of preterm infants treated with a full course of antenatal steroids have not been investigated. We hypothesized that a full course of antenatal steroids would significantly increase functional residual capacity (FRC) in treated vs. untreated preterm infants. The objective of our study was to compare FRC and respiratory mechanics in steroid treated vs. untreated preterm infants. FRC and passive respiratory mechanics were prospectively studied within 36 hr of life in 20 infants (25-34 weeks of gestation) who had received a full course of antenatal steroids and in 20 matched untreated preterm infants. FRC was measured with the nitrogen washout method, and respiratory mechanics with the single-breath occlusion technique. Preterm infants who received steroids (n = 20; mean birth weight = 1,230 g; gestational age = 28.8 weeks) had a significantly higher FRC (29.5 vs. 19.3 mL/kg; P < 0.001) than untreated infants (n = 20; birth weight = 1,202 g; gestational age = 28.5 weeks). Passive respiratory system compliance was also increased in treated vs. untreated infants (P < 0.05). In conclusion, FRC and passive respiratory system compliance were significantly improved in preterm infants (25-34 weeks gestation) treated with a full course of antenatal steroids, compared to matched untreated infants. Although this study was not randomized, it confirms that antenatal steroids have important effects on pulmonary function that may contribute to a decreased risk of respiratory distress syndrome in treated preterm infants.

Timing of antenatal corticosteroids and neonatal pulmonary mechanics

OBJECTIVE

We sought to compare lung mechanics in infants treated with multiple courses of antenatal corticosteroids with those in matched control infants delivered >7 days from dosing and those of matched untreated infants.

STUDY DESIGN

Eighteen infants who received multiple courses of corticosteroids and were delivered within 7 days of dosing were matched with 18 infants who received 1 course of corticosteroids >7 days before delivery (remote) and 18 untreated infants. Respiratory compliance and functional residual capacity were measured within 36 hours. Differences were compared by analysis of variance.

RESULTS

Infant demographics were similar. Respiratory compliance was higher in the multiple-course group than in the remote or untreated group (P <.02). Functional residual capacity was higher in the multiple-course group than in the untreated group (P <.05) but similar to that found in the remote group.

CONCLUSION

Babies delivered after multiple courses of corticosteroids and within 7 days of dosing demonstrated improved respiratory compliance compared with untreated and remotely treated infants. This suggests that the enzyme system responsible for surfactant production can be repetitively induced despite prior treatment with corticosteroids. The increased functional residual capacity in remotely treated infants may reflect a maturation of lung architecture independent of surfactant production.

(+) 3,4-methylenedioxymethamphetamine ('ecstasy') transiently increases striatal 5-HT1B binding sites without altering 5-HT1B mRNA in rat brain

(+) 3,4-Methylenedioxymethamphetamine (MDMA) is a psychedelic drug of abuse that causes selective degeneration of serotonergic fibers of dorsal raphe neurons that project throughout the forebrain. Previous studies using pharmacological and behavioral approaches suggested that MDMA treatment leads to desensitization of 5-HT1B receptors. We proposed to test whether this occurs by downregulation of 5-HT1B messenger RNA in dorsal raphe, striatum or CA1 hippocampal neurons and/or 5-HT1B binding site density in hippocampus and basal ganglia. In Experiment I, rats were treated with MDMA using several dosing protocols (2.5 or 10 mg kg-1 day-1 s.c. given a single time or twice daily for 4 days). The animals were killed 24 h after the last dose. [3H]-citalopram binding to serotonin transporters in hippocampus was reduced in the high dose protocol, indicating degeneration of forebrain serotonergic fibers. Despite the extensive reduction in serotonergic content, 5-HT1B mRNA did not change from control levels in any region when measured by in situ hybridization. [125I]-Iodocyanopindolol binding to 5-HT1B sites in hippocampus was also not changed. In Experiment II, high dose MDMA had no effect on 5-HT1B mRNA in any brain region either 1 or 14 days after treatment. However, [125I]-iodocyanopindolol binding more than doubled in striatum 1 day after MDMA treatment but returned to control levels by 14 days. This may have been a transient compensation to early neuronal damage caused by MDMA exposure. These results suggest that previously described changes in 5-HT1B function following MDMA treatment involve only posttranscriptional changes in receptor regulation and do not alter 5-HT1B mRNA levels.

Prone positioning decreases episodes of hypoxemia in extremely low birth weight infants (1000 grams or less) with chronic lung disease

Extremely low birth weight infants with chronic lung disease (CLD) have frequent episodes of desaturation (hypoxemia). We quantified oxygenation and episodes of hypoxemia in 55 infants (birth weight < or = 1000 gm) with CLD in the supine versus prone position, for 1-hour time intervals. Oxygen saturation was measured with the Nellcor N-200 pulse oximeter and a computer program. Prone positioning increased oxygen saturation from 92.0% to 94.1% (p < 0.001) and significantly decreased episodes of hypoxemia to oxygen saturation levels of less than 90%, 85%, and 80% (p < 0.001). Our findings support prone positioning for the extremely low birth weight infant with CLD in an intensive care setting.

Pulse oximetry in newborn infants with birth weights of 620 to 4285 grams receiving dopamine and dobutamine

The reliability of pulse oximetry in neonates receiving inotropic drugs because of hypotension and microcirculatory perfusion failure has not been well documented. Signal loss of the pulse oximeter in adult patients receiving dopamine infusions has been reported. To evaluate the relationship between pulse oximeter oxygen saturation (SaO2) and co-oximeter directly measured oxygen saturation, we studied 30 infants in the first 4 days of life (birth weight 620 to 4285 gm, gestational age 26 to 43 weeks) receiving dopamine (30 patients) and dobutamine (10 infants). Infants had normal blood pressures at the time of the study. To minimize motion artifact a Nellcor N-200 (Nellcor Incorporated, Hayward, Calif.) oximeter with electrocardiographic synchronization was used. We compared pulse oximeter values with simultaneous arterial samples analyzed for oxygen saturation with an IL 282 co-oximeter (Instrumentation Laboratory, Inc., Lexington, Mass.). The values were corrected for spuriously elevated carboxyhemoglobin levels and fetal hemoglobin level was quantitatively measured. The partial pressure of oxygen at 90% hemoglobin saturation for each patient was calculated. The dosage of dopamine ranged from 4 to 28 micrograms/kg per minute and the dosage of dobutamine varied from 4 to 24 micrograms/kg per minute. Over a wide range of values for mean blood pressure (23 to 66 mm Hg), partial pressure of oxygen at 90% hemoglobin saturation (43.1 to 70.2 mm Hg), and oxygen saturation (SaO2 80% to 100%), linear regression analysis revealed a close correlation between pulse oximeter SaO2 and co-oximeter SaO2 values (r = 0.83, standard error of the estimate 2.2%, p < 0.0001). Our findings indicate that pulse oximetry can be used reliably for continuous oxygen monitoring in normotensive neonates with an SaO2 of 80% to 100% who are receiving dopamine and dobutamine.

Neonatal pulmonary mechanics and oxygenation after prophylactic amnioinfusion in labor: a randomized clinical trial

OBJECTIVE

Amnioinfusion has been reported to improve the perinatal outcome of pregnancies complicated by decreased amniotic fluid volume, but detailed information on its possible adverse effects on neonatal pulmonary mechanics and oxygenation is not available.

STUDY DESIGN

We evaluated 42 infants with birth weights of 2600 to 4320 g and gestational ages of 36 to 44 weeks, who were born to mothers enrolled in a prospective, randomized trial of amnioinfusion for oligohydramnios in labor. Maternal entry criteria were gestational age 36 weeks or older, estimated fetal weight more than 2500 g, oligohydramnios defined as an amniotic fluid index of 5 cm or less, and a normal fetal heart rate pattern. Evaluation of pulmonary mechanics and oxygen saturation (SaO2) was done with the infants breathing room air between birth and day 3 of life. Transpulmonary pressure, flow, and tidal volume were recorded simultaneously, and pulmonary resistance and lung compliance were calculated. SaO2 was measured for 30 minutes with the Nellcor N-200 oximeter and IBM computer oximetry software.

RESULTS

Evaluation of the data revealed no significant difference between the two groups for tidal volume, lung compliance, pulmonary resistance, or work of breathing. There were no differences between the two groups in the number of desaturation episodes or in percent of desaturations to less than 90%, 85%, or 80% SaO2.

CONCLUSION

Prior studies have shown amnioinfusion to improve perinatal outcome. Our findings demonstrate that amnioinfusion for oligohydramnios in labor does not adversely affect neonatal pulmonary mechanics or oxygenation.

Effects of early dexamethasone therapy on pulmonary mechanics and chronic lung disease in very low birth weight infants: a randomized, controlled trial

OBJECTIVE

To determine the changes in pulmonary mechanics before and during early dexamethasone therapy, and to evaluate the effect of dexamethasone on the duration of mechanical ventilation in very low birth weight (VLBW) ventilator-dependent infants at risk for chronic lung disease (CLD).

METHODS

A prospective randomized trial was conducted. Forty-three patients (birth weight 600 to 1500 g, gestational age 24 to 32 weeks) who failed to be weaned from the respirator at 7 to 14 days of age were enrolled; 23 infants received a 7-day course of dexamethasone (0.5 mg/kg/day intravenously for 3 days, 0.25 mg/kg/day for 3 days, and 0.1 mg/kg/day for 1 day), and 20 patients were in the control group. At similar mean airway pressure (MAP) and fractional inspired oxygen concentration (FiO2), respiratory system mechanics were measured before and on days 2, 5, and 7 of the study. Airway pressure, flow and tidal volume (VT) were recorded and only mechanical breaths were analyzed. Respiratory compliance (Crs) and respiratory resistance (Rrs) were calculated by two factor least mean square analysis.

RESULTS

Eighty-three percent of infants in the dexamethasone group and 90% in the control group received surfactant in the first 24 hours of life. There was a significant increase in Crs and VT in the dexamethasone group as compared with the control group (P < .001). No major changes in Rrs were observed. Dexamethasone therapy significantly decreased FiO2 and MAP P < .001) and facilitated successful weaning from mechanical ventilation. In addition to a shorter duration of mechanical ventilation (P < .01), the occurrence of CLD (FiO2 > 0.21 at 36 weeks of corrected gestational age, chest radiograph changes) was significantly decreased in the dexamethasone group (P < .01). Except for a transient increase in blood pressure and serum glucose, there were no significant differences in infection rates, intraventricular hemorrhage, or retinopathy of prematurity. Thirteen patients in the control group received dexamethasone at a later age.

CONCLUSIONS

Our findings indicate that: 1) early dexamethasone therapy in VLBW infants markedly improves respiratory compliance and tidal volume, reduces FiO2 and MAP requirements, and facilitates extubation in these infants; 2) early dexamethasone therapy reduces the duration of mechanical ventilation and decreases CLD (at 28 days and 36 weeks) in a population of VLBW infants largely treated with surfactant.

Acute pancreatitis associated with acute hepatitis A in a young child

Acute hepatitis A infection is an unusual cause of pancreatitis in adults and has not been reported previously in young children. We describe a 4-year-old girl with acute pancreatitis associated with hepatitis A infection.

Episodes of spontaneous desaturations in infants with chronic lung disease at two different levels of oxygenation

The optimal range of pulse oximeter oxygen saturation (SaO2) for infants with chronic lung disease (CLD) has not been well established. We quantified episodes of spontaneous desaturation, at two different ranges of SaO2. For 1 hr each, we alternatively administered inspired O2 concentrations (FiO2) necessary to maintain an SaO2 of 94-96% or 87-91% to 21 patients (mean birth weight, 865 g; gestational age, 27.3 weeks; postnatal age 40.6 days) with CLD (defined by FiO2 > 0.21 at > or = 28 days and radiographic evidence). SaO2 was monitored with the Nellcor N-200 oximeter and analyzed by a computer program (SatMaster). The percentage of time the infants desaturated to levels of SaO2 < 85 and < 80% revealed significantly fewer spontaneous episodes during the hour of higher baseline SaO2 (P < 0.0002). Comparison of episodes of spontaneous desaturation to SaO2 < 80 and < 85%, lasting 0-15, 16-30, 31-45 sec also showed significant differences between the two levels of SaO2. We conclude that when infants with CLD are maintained at a higher SaO2 they probably experience fewer episodes of spontaneous desaturations, because of less alveolar hypoxia. We believe that attempts at weaning the FiO2 should be tempered with the need of maintaining an adequate SaO2. Therefore, prolonged monitoring of oxygenation in infants with CLD at different levels of SaO2 could be helpful during the weaning process.

Spontaneous desaturations in intubated very low birth weight infants with acute and chronic lung disease

Patients with chronic lung disease (CLD) have frequent episodes of spontaneous desaturations. Utilizing computerized pulse oximetry (CPO) we quantified the frequency and severity of spontaneous desaturations in very low birth weight (VLBW) infants with CLD. Thirty-four studies by CPO were performed in intubated infants for 4 hours; 17 patients (birth weight, 550-980 g; postnatal age 28-85 days) had CLD, and 17 (birth weight, 520-980 g; postnatal age, 1-7 days) had acute lung disease. Oxygen saturation (SaO2) was measured with the Nellcor N-200 oximeter, its serial output (updated once a second) captured by a computer. Pulse rate, pulse amplitude, and heart rate were also monitored continuously. We measured respiratory system mechanics in 23 patients. Tidal volume (VT), respiratory system compliance (Crs), and resistance (Rrs) were obtained by the PeDS system. Spontaneous desaturation to SaO2 less than 90% occurred for 4.5% of the time in acute patients vs. 27.1% of the time in chronic patients (P less than 0.0001); to SaO2 less than 85%, 0.7% vs. 7.6% of the time in acute vs. chronic patients (P less than 0.002); and to SaO2 less than 80%, 0.4% vs. 2.6% of the time in acute vs. CLD patients (P less than 0.05). Rrs was significantly higher in the ventilated patients with CLD (174 cmH2O/L/s) than in the ventilated patients with acute lung disease (94 cmH2O/L/s, P less than 0.0001). The mean Crs values of the two groups were comparable. Our preliminary data indicate that VLBW infants with CLD receiving assisted ventilation have a greater number of spontaneous desaturation episodes, as compared to patients with acute lung disease.