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Biomedical subjects

M Hack

Publications and source records attributed to M Hack.

At least 55 records · Page 3Linked to original sources

Very-low-birth-weight outcomes of the National Institute of Child Health and Human Development Neonatal Network, November 1989 to October 1990.

OBJECTIVE: Our purpose was to describe the neonatal outcomes of 1804 very-low-birth-weight (< or = 1500 gm) infants delivered between November 1989 and October 1990 in the participating centers of the National Institute of Child Health and Human Development Neonatal Research Network. STUDY DESIGN: In an observational study sociodemographic, pregnancy, and delivery data were collected soon after birth, and neonatal and outcome data at discharge, at 120 days, or at death. RESULTS: Maternal and birth weight characteristics included 64% black, 29% white; 71% single mothers; 18% no prenatal care; 17% antenatal steroids; and 12% multiple gestations. Birth weight distributions included 18% weighing 501 to 750 gm, 23% 751 to 1000 gm, 28% 1001 to 1250 gm, and 31% 1251 to 1500 gm. Survival was 39% at < 751 gm birth weight, 77% at 751 to 1000 gm, 90% at 1001 to 1250 gm, and 93% at 1251 to 1500 gm. Survival was 15% to 18% at < or = 23 weeks' gestation, 54% at 24 weeks, 59% at 25 weeks, and 71% at 26 weeks. Surfactant was administered to 45% of the 56% of infants with respiratory distress syndrome. Morbidity, including intraventricular hemorrhage (40%), septicemia (24%), symptomatic patent ductus arteriosus (22%), and necrotizing entercolitis (8%), increased with decreasing birth weight. Oxygen was administered for > or = 28 days to 82% of < 751 gm infants, 49% of 751 to 1000 gm infants, and 10% of > 1001 gm infants. Steroids were administered to 28% of infants who required oxygen for > or = 28 days. Mean hospital stay was 62 days for survivors and 18 days for infants who died. There were large intercenter variations in mortality and morbidity. CONCLUSION: Mortality and morbidity in very-low-birth-weight infants improved in 1989 to 1990 without an increase in morbidity or length of hospital stay. The threshold of the improved survival was > or = 24 weeks and 601 to 700 gm. Although such data are reassuring, the rate of major morbidity in < 1001 gm birth weight infants continues to be high.

Birth Weight↗

Twenty-month outcome in ventilator-dependent, very low birth weight infants born during the early years of dexamethasone therapy.

We sought to examine the effect of the introduction of dexamethasone therapy on health, growth, and neurodevelopmental outcome in very low birth weight (VLBW) infants at 20 months of age. We compared outcomes in all 86 VLBW infants (mean birth weight 871 gm, mean gestational age 26.4 weeks) who were ventilator dependent on day 21 of life during the 2 years preceding October 1988 (period 1), when dexamethasone therapy became accepted clinical practice in our unit, with outcomes in all 124 infants (mean birth weight 891 gm, mean gestational age 26.9 weeks) with similar ventilator status during the subsequent 2 years (period 2). In addition, we compared outcomes in infants who received dexamethasone during period 2 with those in a concurrent cohort of less ill infants who were not given dexamethasone. There were no significant differences between periods 1 and 2 in mortality rates after 21 days (17% vs 21%), need for home oxygen (23% vs 25%), oxygen dependence at 20 months of corrected age (11% vs 10%), rate of neurosensory impairment (24% vs 25%), and mean Bayley Mental scores (81.5 vs 77.2) or Psychomotor Development Index (81.6 vs 71.1). Infants who received dexamethasone during period 2 had significantly more severe lung disease and poorer respiratory, growth, and developmental outcomes. We conclude that VLBW infants with ventilator-dependent chronic lung disease have very poor outcomes, even when treated with dexamethasone. More information is needed from prospective, randomized trials before dexamethasone can be accepted as routine therapy for chronic lung disease.

Child Development↗

Achievement in children with birth weights less than 750 grams with normal cognitive abilities: evidence for specific learning disabilities.

Examined achievement, behavior, and neuropsychological outcomes at early school age in a regional population of children < 750-g birth weight who were neurologically intact and who scored in the broad average range on a test of cognitive ability. Comparison groups included children of birth weight 750-1,499 g and children born at full-term. The children < 750 g performed more poorly than the higher birth weight groups on tests of math, even after adjusting for group differences in cognitive ability. Corresponding group differences were found in language, perceptual motor, and attentional skills, but not in behavior outcomes. Findings document specific weaknesses in achievement and neuropsychological skills in children < 750 g birth weight and support the need for early identification and special education interventions.

Achievement↗

Long-term developmental outcomes of low birth weight infants.

Advances in neonatal medicine have resulted in the increased survival of infants at lower and lower birth weight. While these medical success stories highlight the power of medical technology to save many of the tiniest infants at birth, serious questions remain about how these infants will develop and whether they will have normal, productive lives. Low birth weight children can be born at term or before term and have varying degrees of social and medical risk. Because low birth weight children are not a homogeneous group, they have a broad spectrum of growth, health, and developmental outcomes. While the vast majority of low birth weight children have normal outcomes, as a group they generally have higher rates of subnormal growth, illnesses, and neurodevelopmental problems. These problems increase as the child's birth weight decreases. With the exception of a small minority of low birth weight children with mental retardation and/or cerebral palsy, the developmental sequelae for most low birth weight infants include mild problems in cognition, attention, and neuromotor functioning. Long-term follow-up studies conducted on children born in the 1960s indicated that the adverse consequences of being born low birth weight were still apparent in adolescence. Adverse sociodemographic factors negatively affect developmental outcomes across the continuum of low birth weight and appear to have far greater effects on long-term cognitive outcomes than most of the biological risk factors. In addition, the cognitive defects associated with social or environmental risks become more pronounced as the child ages. Enrichment programs for low birth weight children seem to be most effective for the moderately low birth weight child who comes from a lower socioeconomic group. Continued research and attempts to decrease the rate of low birth weight and associated perinatal medical sequelae are of primary importance. Ongoing documentation of the long-term outcome of low birth weight children needs to be mandated, as does the implementation of environmental enrichment programs to help ameliorate the long-term consequences for infants who are born low birth weight.

Adolescent↗

School-age outcomes in children with birth weights under 750 g.

BACKGROUND: Since the mid-1980s, increasing numbers of children with birth weights under 750 g have survived to school age. METHODS: We matched a regional cohort of 68 surviving children born from 1982 through 1986 with birth weights under 750 g (mean, 670 g; gestational age, 25.7 weeks) with 65 children weighting 750 to 1499 g at birth and 61 children born at term. Growth, neurosensory status, and functioning at school age in the three groups were compared. Associations of biologic and social risk factors with major developmental outcomes were examined by means of logistic-regression analyses. RESULTS: Children with birth weights under 750 g were inferior to both comparison groups in cognitive ability, psychomotor skills, and academic achievement. They had poorer social skills and adaptive behavior and more behavioral and attention problems. The mean (+/- SD) Mental Processing Composite score for the cohort was 87 +/- 15, as compared with 93 +/- 14 for children with birth weights of 750 to 1499 g and 100 +/- 13 for children born at term (P < 0.001). The rates of mental retardation (IQ < 70) in the three groups were 21, 8, and 2 percent, respectively; the rates of cerebral palsy were 9, 6, and 0 percent; and the rates of severe visual disability were 25, 5, and 2 percent. Major cerebral ultrasonographic abnormalities were associated with mental retardation (odds ratio, 5.4; 95 percent confidence interval, 1.8 to 15.8) and cerebral palsy (odds ratio, 15.2; 95 percent confidence interval, 3.0 to 77.4). Oxygen dependence at 36 weeks was associated with mental retardation (odds ratio, 4.5; 95 percent confidence interval, 1.2 to 10.7) and severe visual disability (odds ratio, 4.3; 95 percent confidence interval, 1.3 to 14.2). Social disadvantage, though associated with several neuropsychological outcomes, was not associated with major developmental impairment. CONCLUSIONS: Children with birth weights under 750 g who survive represent a subgroup of very-low-birth-weight children who are at high risk for neurobehavioral dysfunction and poor school performance.

Adaptation, Physiological↗

Extensive intraalveolar pulmonary hemorrhage in infants dying after surfactant therapy.

To assess the possible relationship between exogenous surfactant therapy and pulmonary hemorrhage in premature infants, we compared autopsy findings in 15 infants treated with exogenous surfactant and in 29 who died before the introduction of surfactant therapy. Infants who met the following criteria were included: birth weight 501 to 1500 gm, survival 4 hours to 7 days, and no congenital anomalies. Average birth weight, gestational age, and age at death were equivalent for the two groups. High rates of pulmonary hemorrhage were present in both groups (treated 80% vs untreated 83%). The untreated group had higher incidences of interstitial hemorrhage and lung hematomas and significantly more large interstitial hemorrhages: 31% untreated versus 0% treated (p < 0.05). The overall rate of intraalveolar hemorrhage was similar in the two groups, but surfactant-treated infants were more likely to have extensive intraalveolar hemorrhage: 53% versus 14% (p < 0.05). Most surfactant-treated infants who survived more than 24 hours had extensive intraalveolar hemorrhage (8/9). Patients who had extensive intraalveolar hemorrhage, with or without prior surfactant therapy, frequently had clinically significant pulmonary hemorrhage (7/12). These findings indicate that infants who die after surfactant therapy have higher rates of a specific type of pulmonary hemorrhage--extensive intraalveolar hemorrhage.

Autopsy↗

Severe respiratory failure in neonates: mortality and morbidity rates and neurodevelopmental outcomes.

OBJECTIVE: To compare the survival, neurodevelopmental, and health outcomes of children with severe respiratory illness treated with and without extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective collection of clinical and demographic data of all neonates reaching illness severity criteria, with follow-up at 8 and 20 months of age. Patients were assigned to treatment by the attending physician. PATIENTS: Consecutive sample of 74 neonates during a 24-month period with an alveolar-to-arterial gradient exceeding 620 for 8 or more hours. RESULTS: Eighteen (69%) of 26 neonates treated with conventional therapy survived to 20 months, in comparison with 43 (90%) of 48 neonates treated with ECMO. The conventionally treated group had significantly more chronic lung disease, longer duration of oxygen therapy, more chronic reactive airway disease, and more rehospitalizations than those treated with ECMO. Hospital charges were similar in the two groups. Macrocephaly was noted in 24% of those treated with ECMO and in none of the conventional group. Of those completing evaluation, 4 (24%) of 17 conventionally treated survivors and 20 (26%) of 38 ECMO-treated survivors had neurodevelopmental impairment. CONCLUSION: Survivors of severe neonatal respiratory illness have significant pulmonary and neurodevelopmental impairment, regardless of the treatment used. Neonates treated with ECMO had neurodevelopmental outcomes similar to those of patients treated conventionally, but better pulmonary outcomes.

Chronic Disease↗

Health of very low birth weight children during their first eight years.

To determine the impact of very low birth weight (VLBW) on medical outcomes during childhood, we compared the health of 249 VLBW children born from 1977 through 1979 with that of 363 normal birth weight (NBW) control children at 8 years of age. Measures included the rates of specific illnesses, surgical procedures and accidents, growth, and other physical findings. The number of medical conditions and surgical procedures was significantly greater in the VLBW children than in the NBW control children. Eighteen percent of VLBW versus 5% of NBW children had had respiratory conditions (p < 0.001), mainly before 3 years of age. Surgical procedures were more common both before and after 3 years of age, but accidents occurred with similar frequency. The VLBW children had significantly lower weight, height, and head circumference and more minor physical stigmata. Thus medical illness, surgical interventions, and poor growth attainment are part of the ongoing morbidity of VLBW children during childhood.

Accidents↗

Early ABRs in infants undergoing assisted ventilation.

ABR was performed on 42 preterm infants undergoing assisted ventilation with conventional or high-frequency oscillatory ventilation (HFOV). ABRs from these very young neonates were evaluated to further detail the emerging response and to determine if type of ventilation or other perinatal factors had effects on the ABR. While responses were present down to 26 weeks gestational age, the only factors which appeared related to absent ABRs were birthweight and gestational age.

Auditory Cortex↗

Inguinal hernias in very low birth weight infants: incidence and timing of repair.

Although the increased occurrence of inguinal hernias (IH) in premature children is well known, its incidence in the very low birth weight (VLBW, < 1,500 g) subpopulation has not been previously established. Additionally, because of associated problems, these children present the surgeon with a dilemma in regards to the most appropriate time for repair. We sought to determine the incidence of IH, rate of incarceration, perioperative problems, and to possibly define the ideal time for correction. Between 1977 and 1987, 1,933 children under 1,500 g birth weight were admitted to our neonatal intensive care unit. Of these, 1,391 lived for at least 28 days and were followed until 20 months corrected age. IH was diagnosed in 222 of 1,391 (16%) of those who survived 28 days or more. IH occurred in 174 of 670 (26%) of the boys and 48 of 721 (7%) of the girls. The incidence by side was right 19.8%, left 14.9%, bilateral 61.7%, and was unclear 3.6%. Of the 222 infants with IH, 192 were operated at our institution at a mean postnatal age of 28 weeks (range, 5 to 110 weeks). Of these, 35 were operated prior to neonatal discharge. One or more incarcerations occurred in 35 VLBW operated at this hospital. In only one infant, an emergency operation was needed because of irreducibility. There was no operative mortality and minimal morbidity. Five recurrences occurred during the 20 months' follow-up. This series establishes the incidence of IH in VLBW (during the first 20 months). The wide range in age at operation suggests that no single criterion can be established for ideal timing of repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergencies↗

Neonatal auditory brainstem response failure of very low birth weight infants: 8-year outcome.

Fifty-six very low birth weight infants (less than 1.5 kg) were followed until 8 y of age to see if predischarge auditory brainstem response (ABR) results were predictive of neurobehavioral development. The results suggest that early ABR may predict subsequent performance on measures of intelligence quotient, language, and reading. Unilateral ABR abnormalities did not appear predictive, but bilateral abnormalities did. Analysis of a variety of neonatal risk factors in conjunction with early ABR and hearing loss with respect to educational outcome was also undertaken.

Age Factors↗

The high-risk infant environment. Part 2. The role of caregiving and the social environment.

Neonatal intensive care units are essential for the successful care of very immature and sick infants. The technology of NICUs has contributed significantly to the reduction of neonatal mortality and improvement of neonatal outcome. While the outcome for high-risk neonates has vastly improved over the past three decades, a number of infants sustain injuries and complications that result in long-term disabilities. It is now clear that some of the long-term problems of high-risk infants are a result of the environment and care practices and are not attributable to the original disease or condition that necessitated intensive care. There is accumulating evidence that environmental factors and care practices can interact with disease processes in ways that can increase morbidity, and possibly mortality. In addition to developmental and behavioral problems, there is growing evidence of effects on visual function and perhaps other sensory systems. Many of the environmental and care factors may cause delay in recovery and increase NICU time or unnecessary discomfort, yet not produce long-term disabilities or problems, as currently assessed. Many of the potential behavioral and developmental problems, as well as many of the potential problems with visual, auditory, and other modes of sensory discrimination, are not included in the usual follow-up assessments. The absence of data or the limitations of existing studies are not a cause for comfort or the assumption that the environment and care practices are safe or not harmful.(ABSTRACT TRUNCATED AT 250 WORDS)

Environment↗

The effect of very low birth weight and social risk on neurocognitive abilities at school age.

We tested the hypothesis that very low birth weight (VLBW < 1.5 kg) children would have significantly poorer neurocognitive abilities at school age than would normal birth weight full-term age mates, that differences would persist after control for neurologic impairment and social risk, and that VLBW would interact with social risk. Two hundred forty-nine VLBW children and a randomly selected sample of 363 normal birth weight age mates born 1977 through 1979 were tested at 8 years. A neurologic examination and tests of intelligence, language, speech, reading, mathematics, spelling, visual and fine motor abilities, and behavior were performed. Twenty-four (10%) VLBW had a major neurologic abnormality compared with none of the controls. VLBW had significantly poorer scores on all tests, with the exception of speech and the total behavior score. These differences persisted among VLBW children without major neurologic abnormality, with the exception of social competence, reading, and spelling. Even normal IQ, neurologically normal VLBW had significantly poorer scores than did controls in expressive language, memory, visuomotor, and fine motor function, and measures of hyperactivity. When social risk was controlled in multiple regression analyses, VLBW still had an adverse effect on all outcome measures with the exception of speech. Social risk was, however, the major determinant of outcome. We found an interaction between VLBW and social risk only in verbal IQ and in the opposite direction than hypothesized.

Brain Damage, Chronic↗

Effect of very low birth weight and subnormal head size on cognitive abilities at school age.

BACKGROUND: We tested the hypothesis that very-low-birth-weight (less than 1.5 kg) infants with perinatal growth failure whose head size is not normal by eight months of age (corrected for prematurity) have significantly poorer growth and neurocognitive abilities at school age than very-low-birth-weight children with a normal head size at eight months. We also hypothesized that these differences would persist even after control for major neurologic impairment and perinatal and sociodemographic risk factors. METHODS: We have followed a cohort of very-low-birth-weight children since their birth during the period 1977 to 1979. At eight to nine years of age 249 children were evaluated with a neurologic examination and tests of intelligence; receptive and expressive language skills; speech, reading, mathematics, and spelling aptitude; visual and fine motor abilities; and behavior. Ages were corrected for premature birth. RESULTS: Among these 249 very-low-birth-weight children, head size was subnormal (less than the mean -2 SD for age) at birth in 30 (12 percent), at term in 57 (23 percent), and at eight months in 33 (13 percent). As compared with the 216 children with normal head sizes, the 33 children with subnormal head sizes at the age of eight months had significantly lower mean birth weights (1.1 vs. 1.2 kg) and higher neonatal risk scores (71 vs. 53) and at the age of eight years had a higher incidence of neurologic impairment (21 percent vs. 8 percent) and lower IQ scores (mean verbal, 84 vs. 98). Even among the children without neurologic abnormalities, a subnormal head size at eight months of age was predictive of poorer verbal and performance IQ scores at eight years of age; lower scores for receptive language, speech, reading, mathematics, and spelling; and a higher incidence of hyperactivity. In multiple regression analyses to control for socioeconomic and neonatal risk factors, intrauterine growth failure, birth weight, and neurologic impairment, a subnormal head size at eight months of age had an independently adverse effect on IQ and on scores for receptive language, speech, reading, and spelling. CONCLUSIONS: In very-low-birth-weight infants, perinatal growth failure, as evidenced by a subnormal head circumference at eight months of age, is associated with poor cognitive function, academic achievement, and behavior at eight years of age.

Cephalometry↗