RESUMEN
OBJECTIVE: Ballard scores are commonly used to estimate gestational age (GA). The purpose of this study was to determine the accuracy of the New Ballard Score (NBS) for infants <28 weeks GA by accurate menstrual history and to evaluate NBS as an outcome predictor. METHODS: Infants weighing 401 to 1500 g in 12 National Institute of Child Health and Human Development Neonatal Research Network centers had NBS performed before age 48 hours. Accuracy of NBS estimates of GA was assessed for infants with GA determined by accurate menstrual history. In a larger cohort of infants, NBS was included in regression models of the association of NBS and death, poor outcome, and duration of hospital stay. RESULTS: At each week from 22 to 28 weeks GA by accurate menstrual history, NBS estimates exceeded GA by dates by 1.3 to 3.3 weeks, and estimates varied widely (range of widths of 95% CIs for the observations, 6.8 to 11.9 weeks). NBS did not contribute significantly to regression models of death, poor outcome, or duration of hospital stay. CONCLUSIONS: Inaccuracies in GA determined by the NBS should be considered when treating extremely premature infants, particularly in decisions to forego or administer intensive care. Refinement of GA scoring systems is needed to optimize clinical benefit.
Asunto(s)
Edad Gestacional , Recien Nacido Prematuro/crecimiento & desarrollo , Recién Nacido de muy Bajo Peso/crecimiento & desarrollo , Examen Neurológico/métodos , Examen Físico/métodos , Femenino , Humanos , Recién Nacido , Cuidado Intensivo Neonatal , Modelos Lineales , Modelos Logísticos , Menstruación , Oportunidad Relativa , Embarazo , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: The objective of this study was to assess a modified consent procedure allowed under federal regulations and developed for studies, particularly clinical trials, that are judged by the Institutional Review Board to reduce or have no effect on patient risk. STUDY DESIGN: This was a randomized trial of a conventional consent procedure that required parental signature to give consent (opting in) after a comprehensive disclosure of the rights of participants in research versus a modified consent procedure that required parental signature to refuse consent (opting out) after specific disclosures appropriate when risk is not increased. Consent was sought for a trial of primary follow-up care for disadvantaged infants at high risk, a trial judged by our Institutional Review Board to increase access to care for both groups. A blinded assessor interviewed mothers within 24 hours of the consent decision. RESULTS: Among the 44 mothers interviewed, the modified consent group scored higher than the conventional consent group in recall and understanding of study purpose and methods (47% vs 30%; p < 0.02). Other comparisons provided no evidence that the modified consent procedure was less desirable. Virtually all mothers reported satisfaction. CONCLUSIONS: The modified approach may improve communication and facilitate studies judged by the Institutional Review Board to be risk-neutral or risk-reducing. Further evaluation of a modified consent procedure for such studies is warranted.
Asunto(s)
Comprensión , Cuidado del Lactante , Consentimiento Informado , Consentimiento Paterno , Adulto , Formularios de Consentimiento , Revelación , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Consentimiento Informado/legislación & jurisprudencia , Madres , Participación del Paciente , Medición de Riesgo , Factores de Riesgo , Poblaciones VulnerablesRESUMEN
OBJECTIVE: Late-onset sepsis (occurring after 3 days of age) is an important problem in very low birth weight (VLBW) infants. To determine the current incidence of late-onset sepsis, risk factors for disease, and the impact of late-onset sepsis on subsequent hospital course, we evaluated a cohort of 7861 VLBW (401 to 1500 gm) neonates admitted to the 12 National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centers during a 32-month period (1991 to 1993). METHODS: The NICHD Neonatal Research Network maintains a prospectively collected registry of all VLBW neonates cared for at participating centers. Data from this registry were analyzed retrospectively. RESULTS: Of 6911 infants who survived beyond 3 days, 1696 (25%) had one or more episodes of blood culture-proven sepsis. The vast majority of infection (73%) were caused by gram-positive organisms, with coagulase-negative staphylococci accounting for 55% of all infections. Rate of infection was inversely related to birth weight and gestational age. Complications of prematurity associated with an increased rate of infection included intubation, respiratory distress syndrome, prolonged ventilation, bronchopulmonary dysplasia, patent ductus arteriosus, severe intraventricular hemorrhage, and necrotizing enterocolitis. Among infants with bronchopulmonary dysplasia, those with late-onset sepsis had a significantly longer duration of mechanical ventilation (45 vs 33 days; p <0.01). Late-onset sepsis prolonged hospital stay: the mean number of days in the hospital for VLBW neonates with and without late-onset sepsis was 86 and 61 days, respectively (p <0.001). Even after adjustment for other complications of prematurity, including intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia, infants with late-onset sepsis had a significantly longer hospitalization (p <0.001). Moreover, neonates in whom late-onset sepsis developed were significantly more likely to die than those who were uninfected (17% vs 7%; p <0.000 1), especially if they were infected with gram-negative organisms (40%) or fungi (28%). Deaths attributed to infection increased with increasing chronologic age. Whereas only 4% of deaths in the first 3 days of life were attributed to infection, 45% of deaths after 2 weeks were related to infection. CONCLUSIONS: Late-onset sepsis is a frequent and important problem among VLBW preterm infants. Successful strategies to decrease late-onset sepsis should decrease VLBW mortality rates, shorten hospital stay, and reduce costs.
Asunto(s)
Recién Nacido de muy Bajo Peso , Sepsis/epidemiología , Edad de Inicio , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Infecciones Bacterianas/mortalidad , Candidiasis/epidemiología , Candidiasis/microbiología , Candidiasis/mortalidad , Causas de Muerte , Estudios de Cohortes , Femenino , Humanos , Incidencia , Recién Nacido , Tiempo de Internación , Masculino , Análisis Multivariante , Estudios Prospectivos , Sistema de Registros , Factores de Riesgo , Sepsis/microbiología , Sepsis/mortalidadRESUMEN
OBJECTIVE: Early-onset sepsis (occurring within 72 hours of birth) is included in the differential diagnosis of most very low birth weight (VLBW) neonates. To determine the current incidence of early-onset sepsis, risk factors for disease, and the impact of early-onset sepsis on subsequent hospital course, we studied a cohort of 7861 VLBW neonates (401 to 1500 gm) admitted to the 12 National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centers during a 32-month period (1991-1993). METHODS: The NICHD Neonatal Research Network maintains a prospectively collected registry on all VLBW neonates born or cared for at participating centers. Data from this registry were analyzed retrospectively. RESULTS: Blood culture-proven early-onset sepsis was uncommon, occurring in only 1.9% of VLBW neonates. Group B streptococcus was the most frequent pathogen associated with early-onset sepsis (31%), followed by Escherichia coli (16%) and Haemophilus influenzae (12%). Decreasing gestational age was associated with increased rates of infection. Antibiotic therapy for suspected sepsis is frequently initiated at birth in VLBW neonates. Almost half of the infants in this cohort were considered to have clinical sepsis and continued to receive antibiotics for 5 or more days, despite a negative blood culture result in 98% of cases. These findings underscore the difficulty of ruling out sepsis in the symptomatic immature neonate and the special concern for culture-negative clinical sepsis in the face of maternal antibiotic use. Neonates with early-onset sepsis were significantly more likely to have subsequent comorbidities, including severe intraventricular hemorrhage, patent ductus arteriosus, and prolonged assisted ventilation. Although 26% of VLBW neonates with early-onset sepsis died, only 4% of the 950 deaths that occurred in the first 72 hours of life were attributed to infection. For those infants discharged alive, early-onset sepsis was associated with a significantly prolonged hospital stay (86 vs 69 days; p <0.02). CONCLUSIONS: Early-onset sepsis remains an important but uncommon problem among VLBW preterm infants. Improved diagnostic strategies are needed to enable the clinician to distinguish between the infected and the uninfected VLBW neonate with symptoms and to target continued antibiotic therapy to those who are truly infected.
Asunto(s)
Recién Nacido de muy Bajo Peso , Sepsis/epidemiología , Edad de Inicio , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Infecciones Bacterianas/mortalidad , Estudios de Cohortes , Femenino , Humanos , Incidencia , Recién Nacido , Masculino , Factores de Riesgo , Sepsis/microbiología , Sepsis/mortalidadRESUMEN
Because formula-fed preterm infants may be at risk of omega 3 essential fatty acid deficiency, we tested experimental formulas supplemented with soy oil to provide alpha-linolenic acid or marine oil to provide preformed omega 3 long-chain polyunsaturated fatty acids at a level comparable to that of human milk. This report addresses the effect of feeding formula supplemented with soy oil or with soy and marine oils on growth, clinical tolerance, coagulation test results, changes in erythrocyte membrane fluidity, and plasma concentrations of vitamins A and E in very low birth weight infants from 30 to 57 weeks of postconceptional age. "Healthy" preterm infants were maternally selected to receive human milk or selected at random to receive commercial ready-to-feed liquid formula, which provided limited omega 3 fatty acid, or experimental formulas supplemented with soy oil or soy and marine oils. Results of this study indicate that formula enriched with soy oil or soy and marine oils containing preformed omega 3 long-chain polyunsaturated fatty acids does not induce abnormalities in growth, clotting function, erythrocyte membrane fluidity, or vitamin A or E levels in healthy very low birth weight preterm infants. Additional studies to evaluate safety in a representative preterm population are required.
Asunto(s)
Aceites de Pescado/administración & dosificación , Alimentos Fortificados , Alimentos Infantiles , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido de Bajo Peso/fisiología , Aceite de Soja/administración & dosificación , Análisis de Varianza , Femenino , Crecimiento , Humanos , Recién Nacido , Recien Nacido Prematuro/fisiología , Masculino , Ácido alfa-Linolénico/administración & dosificaciónRESUMEN
To obtain growth data on a large sample of low birth weight preterm infants, we monitored 608 infants longitudinally in an eight-site collaborative program. Ninety-nine infants weighed less than or equal to 1250 gm at birth, 289 between 1250 and 2000 gm, and 220 infants between 2000 and 2500 gm. Thirty-four percent were white, 52% black, and 14% Hispanic. Weight, height, and head circumference were measured at birth and at 40 weeks and 4, 8, and 12 months of gestation-corrected age on at least 553 infants each time. Descriptive statistics for all growth variables and a body mass index (kilograms per square meter), plotted by sex and birth weight group, demonstrated growth patterns lower than published standards for term infants of the same age and sex. These patterns of growth differed by birth weight group. No catch-up growth was noted by the 12-month examination (gestation-corrected age) for any birth weight group. We conclude that low birth weight preterm infants have different patterns of growth than term infants during the first year of life, even with plotting corrected for gestational age.
Asunto(s)
Recién Nacido de Bajo Peso/crecimiento & desarrollo , Recien Nacido Prematuro/crecimiento & desarrollo , Peso al Nacer , Índice de Masa Corporal , Estudios de Cohortes , Femenino , Cabeza/anatomía & histología , Humanos , Recién Nacido , Estudios Longitudinales , Masculino , Estudios Multicéntricos como Asunto , Estándares de Referencia , Estados UnidosRESUMEN
This study describes an attempt to define intrauterine growth retardation low birth weight preterm infants by comparing reference standards for intrauterine growth in weight, length, and head circumference on their variability across ethnic groups and cities, and on their specificity in independently classifying infants as short, thin, or having small heads. The sample consisted of 985 inborn preterm low birth weight infants enrolled at eight participating sites in a randomized clinical trial using uniform sampling criteria. When gestational age was used as the reference standard, striking differences were found by ethnicity and site in the prevalence of low weight infants at birth. These differences, as well as the potentially false overlap of classification, were attenuated when the use of gestational age as a reference standard was used only for birth length, while length itself was used (as an alternative to gestational age) as the reference standard for birth weight, and weight was used as the reference standard for head circumference. These results raise questions about the use of gestational age as the primary or only reference standard in assessing weight and head circumference at bith.
Asunto(s)
Retardo del Crecimiento Fetal/diagnóstico , Recién Nacido de Bajo Peso , Recien Nacido Prematuro , Diagnóstico Prenatal , Negro o Afroamericano , Peso al Nacer , Cefalometría , Femenino , Edad Gestacional , Humanos , Recién Nacido , Embarazo , Estándares de Referencia , Población BlancaRESUMEN
The relative validities of three clinical assessment methods for estimating gestational age in newborn low birth weight infants were evaluated with reference to estimates based on the date of the mother's last menstrual period. For 1246 infants in eight diverse institutions, estimates based on physical criteria correlated more strongly with dates estimates, yielded estimates more similar on average to dates estimates, and yielded higher proportions of correct classifications of prematurity and small for gestational age than did estimates based on neurologic criteria or neurologic and physical criteria combined. These results support the use of physical criteria rather than neurologic or combined criteria for the clinical assessment of gestational age in low birth weight infants. In a subsample of 511 black and white infants, there were no ethnic differences in mean error of estimate for any of the three methods.
Asunto(s)
Edad Gestacional , Recién Nacido de Bajo Peso/fisiología , Análisis de Varianza , Población Negra , Estudios de Evaluación como Asunto , Femenino , Humanos , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Menstruación , Examen Neurológico/métodos , Examen Físico/métodos , Población BlancaRESUMEN
Banked human milk has been widely used, although its composition and nutritional adequacy for preterm infants are uncertain. We randomized 76 healthy infants of less than or equal to 1500 gm birth weight to ad lib feedings of frozen BHM or a protein-mineral-calorie-enriched formula (Similac Special Care) designed to sustain intrauterine accretion rates; BHM contained 2.2 gm fat/100 ml and 60 kcal/100 ml (gross energy). Infants fed BHM ingested more milk (197 vs 165 ml/kg/day) but less gross energy (118 vs 143 kcal/kg/day); grew less rapidly in weight (15 vs 30 gm/day), length (0.7 vs 1.1 cm/wk), and head circumference (0.8 vs 1.2 cm/wk); and were discharged at a lower weight (2200 vs 2348 gm) and older age (61 vs 47 day) than infants fed formula (P less than 0.02). At 37 weeks' postmenstrual age, infants fed BHM were less responsive to Brazelton inanimate stimuli (mean total score 5.0 vs 7.5; P less than 0.02). With few exceptions, blood amino acids, pH, and serum electrolyte values were similar in both groups. The different caloric intake of our feeding groups may explain only part of the large difference in growth rate. Donor milk should not be fed to preterm infants unless it has been analyzed and the feedings shown to provide a nutrient intake considered appropriate to the needs of these infants.
Asunto(s)
Crecimiento , Alimentos Infantiles , Recién Nacido de Bajo Peso , Leche Humana/metabolismo , Peso Corporal , Humanos , Alimentos Infantiles/análisis , Recién Nacido , Tiempo de Internación , Leche Humana/análisis , Necesidades Nutricionales , Distribución AleatoriaRESUMEN
Variables related to both the process and the outcome of neonatal intensive care were studied to compare care given during the day (0901-2100 hours) with that at night (2101-0900 hours). At night, intravenous infiltrations occurred more often, and the tidal volume of respirator-treated infants was verified less often. Blood pH values less than 7.20, excluding values within 12 hours of admission, were recorded more often and in more patients at night. During a 12-month period, there were significantly more deaths among infants less than 1,500 gm during the night than during the day. The deterioration of infants at night may result in part from current nursery staffing practices.
Asunto(s)
Ritmo Circadiano , Cuidados Críticos , Enfermedades del Recién Nacido/terapia , Peso al Nacer , Sangre , Humanos , Concentración de Iones de Hidrógeno , Mortalidad Infantil , Recién Nacido , Ontario , Calidad de la Atención de Salud , Respiración ArtificialRESUMEN
Since the effects of prostaglandin synthetase inhibitors on the developing human fetal pulmonary vasculature are unknown, we studied the lungs of two infants, one whose mother took salicylates and the other whose mother took indomethacin during pregnancy. Lungs were fixed by perfusion and fifth generation (resistance) vessels identified. The infant with chronic exposure to aspirin had premature constriction of the ductus arteriosus, tricuspid insufficiency, increased pulmonary arterial medial width/external diameter ratio due to increased smooth muscle, and a decreased number of pulmonary vessels/cm2 lung tissue. The infant with short-term exposure to indomethacin had hypoxemia, increased pulmonary arterial m/d ratio due to increased smooth muscle, and a normal number of pulmonary vessels/cm2 lung tissue. These abnormalities may be due to the effects of prostaglandin synthetase inhibitor drugs on the ductus arteriosus and/or the pulmonary vessels of the human fetus.