Ariel A. Salas

Prospective Analysis of Pulmonary Hypertension in Extremely Low Birth Weight Infants

OBJECTIVES: Pulmonary hypertension is associated with bronchopulmonary dysplasia in extremely low birth weight (ELBW) infants and contributes to morbidity and mortality. The objective was to determine the prevalence of pulmonary hypertension among ELBW infants by screening echocardiography and evaluate subsequent outcomes. METHODS: All ELBW infants admitted to a regional perinatal center were evaluated for pulmonary hypertension with echocardiography at 4 weeks of age and subsequently if clinical signs suggestive of right-sided heart failure or severe lung disease were evident. Management was at discretion of the clinician, and infants were evaluated until discharge from the hospital or pre-discharge death occurred. RESULTS: One hundred forty-five ELBW infants (birth weight: 755 ± 144 g; median gestational age: 26 weeks [interquartile range: 24–27]) were screened from December 2008 to February 2011. Overall, 26 (17.9%) were diagnosed with pulmonary hypertension at any time during hospitalization (birth weight: 665 ± 140 g; median gestational age: 26 weeks [interquartile range: 24–27]): 9 (6.2%) by initial screening (early pulmonary hypertension) and 17 (11.7%) who were identified later (late pulmonary hypertension). Infants with pulmonary hypertension were more likely to receive oxygen treatment on day 28 compared with those without pulmonary hypertension (96% vs 75%, P < .05). Of the 26 infants, 3 died (all in the late group because of cor pulmonale) before being discharged from the hospital. CONCLUSIONS: Pulmonary hypertension is relatively common, affecting at least 1 in 6 ELBW infants, and persists to discharge in most survivors. Routine screening of ELBW infants with echocardiography at 4 weeks of age identifies only one-third of the infants diagnosed with pulmonary hypertension. Further research is required to determine optimal detection and intervention strategies.

Significant weight loss in breastfed term infants readmitted for hyperbilirubinemia.

BackgroundWeight loss of greater than 7% from birth weight indicates possible feeding problems. Inadequate oral intake causes weight loss and increases the bilirubin enterohepatic circulation. The objective of this study was to describe the association between total serum bilirubin (TSB) levels and weight loss in healthy term infants readmitted for hyperbilirubinemia after birth hospitalization.MethodsWe reviewed medical records of breastfed term infants who received phototherapy according to TSB levels readmitted to Caja Petrolera de Salud Clinic in La Paz, Bolivia during January 2005 through October 2008.ResultsSeventy-nine infants were studied (64.6% were males). The hyperbilirubinemia readmission rate was 5% among breastfed infants. Term infants were readmitted at a median age of 4 days. Mean TSB level was 18.6 ± 3 mg/dL. Thirty (38%) had significant weight loss. A weak correlation between TSB levels and percent of weight loss was identified (r = 0.20; p < 0.05). The frequency of severe hyperbilirubinemia (> 20 mg/dL) was notably higher among infants with significant weight loss (46.7% vs. 18.4%; p < 0.05). The risk of having severe hyperbilirubinemia was approximately 4 times greater for infants with significant weight loss (OR: 3.9; 95% CI: 1.4-10.8; p < 0.05).ConclusionsSignificant weight loss could be a useful parameter to identify breastfed term infants at risk of severe hyperbilirubinemia either during birth hospitalization or outpatient follow-up visits in settings where routine pre-discharge TSB levels have not been implemented yet.

Plastic Bags for Prevention of Hypothermia in Preterm and Low Birth Weight Infants

BACKGROUND AND OBJECTIVES: Hypothermia contributes to neonatal mortality and morbidity, especially in preterm and low birth weight infants in developing countries. Plastic bags covering the trunk and extremities of very low birth weight infants reduces hypothermia. This technique has not been studied in larger infants or in many resource-limited settings. The objective was to determine if placing preterm and low birth weight infants inside a plastic bag at birth maintains normothermia. METHODS: Infants at 26 to 36 weeks’ gestational age and/or with a birth weight of 1000 to 2500 g born at the University Teaching Hospital in Lusaka, Zambia, were randomized by using a 1:1 allocation and parallel design to standard thermoregulation (blanket or radiant warmer) care or to standard thermoregulation care plus placement inside a plastic bag at birth. The primary outcome measure was axillary temperature in the World Health Organization–defined normal range (36.5–37.5°C) at 1 hour after birth. RESULTS: A total of 104 infants were randomized. At 1 hour after birth, infants randomized to plastic bag (n = 49) were more likely to have a temperature in the normal range as compared with infants in the standard thermoregulation care group (n = 55; 59.2% vs 32.7%; relative risk 1.81; 95% confidence interval 1.16–2.81; P = .007). The temperature at 1 hour after birth in the infants randomized to plastic bag was 36.5 ± 0.5°C compared with 36.1 ± 0.6°C in standard care infants (P < .001). Hyperthermia (>38.0°C) did not occur in any infant. CONCLUSIONS: Placement of preterm/low birth weight infants inside a plastic bag at birth compared with standard thermoregulation care reduced hypothermia without resulting in hyperthermia, and is a low-cost, low-technology tool for resource-limited settings.

Histological Characteristics of the Fetal Inflammatory Response Associated with Neurodevelopmental Impairment and Death in Extremely Preterm Infants

OBJECTIVE To test the hypothesis that increasing severity of the fetal inflammatory response (FIR) would have a dose-dependent relationship with severe neurodevelopmental impairment or death in extremely preterm infants. STUDY DESIGN We report 347 infants of 23-28 weeks gestational age admitted to a tertiary neonatal intensive care unit between 2006 and 2008. The primary outcome was death or neurodevelopmental impairment at the 18- to 22-month follow-up. Exposure status was defined by increasing stage of funisitis (stage 1, phlebitis; stage 2, arteritis with or without phlebitis; stage 3, subacute necrotizing funisitis) and severity of chorionic plate vasculitis (inflammation with or without thrombosis). RESULTS A FIR was detected in 110 placentas (32%). The rate of severe neurodevelopmental impairment/death was higher in infants with subacute necrotizing funisitis compared with infants without placental/umbilical cord inflammation (60% vs 35%; P < .05). Among infants with stage 1 or 2 funisitis, the presence of any chorionic vasculitis was associated with a higher rate of severe neurodevelopmental impairment/death (47% vs 23%; P < .05). After adjustment for confounding factors, only subacute necrotizing funisitis (risk ratio, 1.87; 95% CI, 1.04-3.35; P = .04) and chorionic plate vasculitis with thrombosis (risk ratio, 2.21; 95% CI, 1.10-4.46; P = .03) were associated with severe neurodevelopmental impairment/death. CONCLUSION Severe FIR, characterized by subacute necrotizing funisitis and severe chorionic plate vasculitis with thrombosis, is associated with severe neurodevelopmental impairment/death in preterm infants.

Exchange transfusion in infants with extreme hyperbilirubinemia: an experience from a developing country

Objective: To determine the clinical and epidemiological features of infants with extreme hyperbilirubinemia who require exchange transfusion (ET).

Acute cerebellar ataxia in childhood: initial approach in the emergency department

Acute childhood ataxia is a relatively common presenting complaint in paediatric emergency settings. Because life-threatening causes of pure ataxia are rare in children, an approach in a stepwise fashion is recommended. Acute cerebellar ataxia is the most common cause of childhood ataxia, accounting for about 30–50% of all cases. Varicella is the most commonly associated virus. Post-varicella acute cerebellar ataxia (PVACA) is the most common neurological complication of varicella, occurring about once in 4000 varicella cases among children younger than 15 years of age, even in the postvaccine era. We describe an unimmunised child with PVACA to remind emergency physicians about its autoimmune pathogenesis. We also briefly discuss current controversies about the diagnostic approach and management.

Pulse oximetry values in healthy term newborns at high altitude

Abstract Background: Normal reference values for pulse oximetry saturation (POS) have been established for healthy term newborns at sea level; however, normal values for POS have not been clearly defined for infants born at high altitudes. Objective: To determine reference values of POS during the 1st day of life in a sample of healthy term newborns born at >3500 m above sea level. Design/methods: A prospective cohort study in healthy term infants with a normal cardiopulmonary examination and an Apgar score of ≥8 was conducted in a community hospital in La Paz, Bolivia during August and September 2006. POS on the right hand, heart rate and respiratory rate were measured at 1, 12 and 24 hours after birth. Exclusion criteria were congenital malformations and having received supplemental oxygen during the 1st day of life. Results: 122 mothers and their infants were included. Mean (SD) birthweight was 3195 (416) g and 74.6% were born by vaginal delivery. Mean (SD) SpO2 at 1 hour in 84 infants was 88.7% (4.6) and this did not differ significantly during the 1st day of life [87.2% (3.9) at 12 hours (n=89), 88.2% (3.9) at 24 hours (n=93)]. There were no significant differences in SpO2 values at 1 hour between infants born by vaginal or caesarean delivery [88.6% (4.6) vs 88.9% (5.0), respectively; p=0.89]. Heart rate at the 1st hour ranged from 107 to 160 beats/min. Mean (SD) respiratory rate at the 1st hour was 52 (8) respirations/min. Conclusions: In healthy newborn infants born at >3500 m above sea level, the mean SpO2 values are in the high 80s, and these values persist during the 1st 24 hours of life. If these figures are confirmed by other large studies at similar altitude, they should be used as reference values in the medical care of neonates born at a similarly high altitude.

Prophylactic Indomethacin and Intestinal Perforation in Extremely Low Birth Weight Infants

OBJECTIVE: Prophylactic indomethacin reduces severe intraventricular hemorrhage but may increase spontaneous intestinal perforation (SIP) in extremely low birth weight (ELBW) infants. Early feedings improve nutritional outcomes but may increase the risk of SIP. Despite their benefits, use of these therapies varies largely by physician preferences in part because of the concern for SIP. METHODS: This was a cohort study of 15 751 ELBW infants in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network from 1999 to 2010 who survived beyond 12 hours after birth. The risk of SIP was compared between groups of infants with and without exposure to prophylactic indomethacin and early feeding in unadjusted analyses and in analyses adjusted for center and for risks of SIP. RESULTS: Among infants exposed to prophylactic indomethacin, the risk of SIP did not differ between the indomethacin/early-feeding group compared with the indomethacin/no-early-feeding group (adjusted relative risk [RR] 0.74, 95% confidence interval [CI] 0.49–1.11). The risk of SIP was lower in the indomethacin/early-feeding group compared with the no indomethacin/no-early-feeding group (adjusted RR 0.58, 95% CI 0.37–0.90, P = .0159). Among infants not exposed to indomethacin, early feeding was associated with a lower risk of SIP compared with the no early feeding group (adjusted RR 0.53, 95% CI 0.36–0.777, P = .0011). CONCLUSIONS: The combined or individual use of prophylactic indomethacin and early feeding was not associated with an increased risk of SIP in ELBW infants.

The Value of Paco2 in Relation to Outcome in Congenital Diaphragmatic Hernia

BACKGROUND Postnatal assessment of disease severity is critical for analysis of mortality rates and development of future interventions in congenital diaphragmatic hernia (CDH). OBJECTIVE The objective of this study was to stratify the risk of mortality based on arterial Paco 2. METHODS Retrospective analysis of infants (n = 133) with CDH admitted to a regional extracorporeal membrane oxygenation (ECMO) center in two different periods: period I (1987-1996; n = 46) and period II (2002-2010; n = 87). RESULTS The mortality rate (37%) was similar in both periods (p = 0.98). Paco 2 < 60 mm Hg in the first arterial blood gas (ABG) was an independent predictor of survival in both periods (p = 0.03). The predicted survival rate was 84% if initial Paco 2 was < 55 mm Hg. For infants with initial Paco 2 > 55 mm Hg treated with ECMO (n = 83), the predicted survival rate was 11% if the Paco 2 was > 88 mm Hg before the initiation of ECMO. CONCLUSION Paco 2, a surrogate of lung hypoplasia, may be useful for risk stratification in CDH. Paco 2 < 60 mm Hg in the first ABG may indicate milder pulmonary hypoplasia. A Paco 2 > 80 mm Hg in the first ABG and/or before ECMO may indicate severe pulmonary hypoplasia.

Gestational age and birthweight for risk assessment of neurodevelopmental impairment or death in extremely preterm infants

Background The risk of poor outcomes in preterm infants is primarily determined by birthweight (BW) and gestational age (GA). It is not known whether BW is a better outcome predictor than GA. Objective To test whether BW is better than GA (measured in days, rather than completed weeks) for prediction of neurodevelopmental impairment (NDI) and death. Design/methods Extremely preterm infants born at the National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centres between 1998 and 2009 were studied. For the unadjusted analysis, the associations of GA (in days based on best obstetrical estimate) and BW (in grams) with NDI or death were compared using area under the curve (AUC). Adjusted analyses were performed using birth year, sex, race, antenatal steroids, singleton birth, pre-eclampsia, Apgar score at 5 min and small for GA as covariates. Results 10 652 preterm infants (89%) had outcome data at 18–22 months’ corrected age. The mean BW was 678 g (SD: 155) and the mean GA was 173 days (SD: 10) or 245/7 weeks (SD: 13/7). The AUC for NDI or death was 80% with BW and 79% with GA (p=0.82). Unadjusted and adjusted analyses did not differ. NDI or death rates decreased with increasing GA through 26 weeks (estimated risk reduction with each additional day of gestation: 2.2%). Conclusion Both BW in grams and GA in days are good predictors of NDI and death in a preterm population selected on the basis of reliable GA. Trial registration number NCT00009633.