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Biomedical subjects

M Hack

Publications and source records attributed to M Hack.

At least 37 records · Page 2Linked to original sources
PubMed1999

Outcomes of children of extremely low birthweight and gestational age in the 1990's.

Advances in perinatal care have improved the chances for survival of extremely low birthweight (< 800 g) and gestational age (< 26 weeks) infants. A review of the world literature and our own experience reveals that at 23 weeks gestation survival ranges from 2% to 35%. At 24 weeks gestation the range is 17% to 58%, and at 25 weeks gestation 35% to 85%. Differences in population descriptors, in the initiation and withdrawal of treatment and the duration of survival considered may account for the wide variations in the reported ranges of survival. Major neonatal morbidity increases with decreasing gestational age and birthweight. The rates of severe cerebral ultrasound abnormality range at 23 weeks gestation from 10% to 83%, at 24 weeks from 17% to 64% and at 25 weeks gestation from 10% to 22%. At 23 weeks gestation, chronic lung disease occurs in 57% to 70% of survivors, at 24 weeks in 33% to 89%, and at 25 weeks gestation in 16% to 71% of survivors. When compared to children born prior to the 1990's, the rates of neurodevelopmental disability have, in general, remained unchanged. Of 30 survivors reported at 23 weeks gestation nine (30%) are severely disabled. At 24 weeks gestation the rates of severe neurodevelopmental disability (including subnormal cognitive function, cerebral palsy, blindness and deafness) range from 17% to 45%, and at 25 weeks gestation 12% to 35% are similarly affected. In Cleveland, Ohio, we compared the outcomes of 114 children with birthweight 500-749 g born 1990-1992 to 112 infants born 1993-1995. Twenty month survival was similar (43% vs 38%). The use of antenatal and postnatal steroids increased (10% vs 54% and 43% vs 84%, respectively, P< 0.001), however the rates of chronic lung disease increased from 41% to 63% (P = 0.06). There was a significant increase in the rate of subnormal cognitive function at 20 months corrected age (20% vs 48%, P < 0.02) and a trend to an increase in the rate of cerebral palsy (10% vs 16%) and neurodevelopmental impairment. We conclude that, with current methods of care, the limits of viability have been reached. The continuing toll of major neonatal morbidity and neurodevelopmental handicap are of serious concern.

Brain Diseases↗
PubMed1999

Consideration of the use of health status, functional outcome, and quality-of-life to monitor neonatal intensive care practice.

Measures of health status, functional abilities, and quality-of-life are being used increasingly to evaluate health care practice, and to measure outcomes from the patient's perspective. There is thus a need to reassess the use of growth and neurodevelopmental status that have traditionally been used as measures of outcome after neonatal intensive care. The quality of neonatal intensive care constitutes only one factor among many that determine the functional health and quality-of-life of survivors of neonatal intensive care. These include genetic disposition, intrauterine events, the effects of sociodemographic factors on the health and development of the child, and on the parents' assessment of their child's functioning. To obtain health status, functional and quality-of-life measures, parents need to act as proxy for the child during infancy and childhood. The parents' cultural, social, and educational background and the specific experience of the parent with children may influence their responses. Furthermore, their perspective may differ from that of the child. Measures that have been used or have the potential to measure health status, functioning, and quality-of-life include the National Health Interview Survey, the National Health Insurance Study, the Functional Status II, the Multi-Attribute Health System, the Functional Independence Measure for Children, the Vineland Adaptive Behavior Scales, the Adolescent Child Health and Illness Profile, and the Child Health Questionnaire for children, infants, and toddlers. Knowledge of the validity of the use of these measures among survivors of neonatal intensive care is, however, sparse. Studies have shown that the collection of a standard core of data from various national sources with specific criteria for defining severe disability at 2 years of age is feasible in Great Britain. However, questionnaires or available national databases provide global and epidemiologic information on outcomes rather than identifying the specific pathogenesis or rates of impairments. To determine the possible deleterious effects of new therapies, specific diseases or impairments will need to be identified rather than the global effect on functioning or health related quality-of-life. Examination of the proximal neonatal impairments that predispose to later disability, such as rates of periventricular hemorrhage or retinopathy of prematurity, are probably better measures for evaluating quality of neonatal care rather than distal impairments such as cerebral palsy, growth impairments, or reactive airway disease. The ultimate goal of neonatal intensive care is to provide survival without impairment. Objective measures of specific impairments and their residual disability are thus better measures of the quality of neonatal intensive care than subjective assessments of children and their families.

Child↗
PubMed1998

Predictors of early school age outcomes in very low birth weight children.

The purpose of this study was to examine predictors of outcome in very low birth weight (< 1500 g) children. The very low birth weight sample consisted of 68 children weighing less than 750 g at birth and 65 children weighing 750 to 1499 g at birth who had been matched to the less than 750 g birth weight children in terms of hospital of birth, age, sex, and race. Mean ages for these two groups were 6.7 and 6.9 years, respectively. Outcomes were measured in terms of tests of cognitive function, neuropsychological abilities, and academic achievement and parent and teacher ratings of child behavior and school performance. A weighted sum of the number of major neonatal medical complications (Neonatal Risk Index) provided a composite measure of biological risk. Social risks were also assessed. Results indicated that the Neonatal Risk Index was the most consistent predictor of outcomes. Even after taking social risks into account, neonatal risk predicted overall cognitive ability and other achievement, neuropsychological, and behavior outcomes. Individual neonatal complications that predicted outcomes included severe cerebral ultrasonographic abnormality, chronic lung disease, necrotizing enterocolitis, and apnea of prematurity. Research and therapy to prevent or reduce neonatal complications and amelioration of social risks are of critical importance in improving outcomes of very low birth weight.

Achievement↗
PubMed1998

Breastfeeding of very low birth weight infants.

This research examines the rate of breastfeeding among mothers of very low birth weight infants (VLBW, < 1500 grams), and the correlates of breast milk pumping and transition to nursing at the breast. Eighty-two mothers and their 69 singleton and 21 twin VLBW infants admitted to the Neonatal Intensive Care Unit (January 1-June 30, 1995) of an urban tertiary care hospital. Maternal demographic, infant birth, and neonatal data were compared according to breast or bottle feeding, and a telephone interview was administered retrospectively to mothers pumping breast milk at the time of the infant's discharge home. Of 39 mothers who chose to pump breast milk, 19 were still pumping at the time of the infant's discharge home. Only 8 made a successful transition to nursing at the breast. Mothers who continued pumping tended to be white, married, and older, and their infants had fewer neonatal complications. The rates of prolonged breast milk pumping and of nursing are very low. Specific interventions and better support might improve the success rates.

Adult↗
PubMed1998

Perinatal correlates of cerebral palsy and other neurologic impairment among very low birth weight children.

BACKGROUND AND OBJECTIVE: The etiology of neurologic impairments among very low birth weight (VLBW, <1.5 kg) children is poorly understood. We sought to investigate the perinatal predictors of major neurologic impairment, including cerebral palsy, among VLBW children. METHODS: Antenatal, intrapartum, and neonatal events and therapies were compared between 72 singleton inborn VLBW children born between 1983 to 1991 who had neurologic impairment at 20 months corrected age (including 50 with cerebral palsy and 22 with other neurologic impairments) and 72 neurologically normal VLBW children matched by birth weight, gestational age, race, and sex via a retrospective case-control method. Multiple logistic regression was conducted, entering only those variables found to be significant at the bivariate level. RESULTS: There were no significant differences in the rates of pregnancy-induced hypertension, maternal tocolytic use including magnesium, or antenatal steroid therapy. Higher rates of clinical chorioamnionitis were found among the mothers of the neurologically impaired children as compared with controls (31% vs 11%), but not among the subgroup of mothers of children with cerebral palsy (22% vs 12%). Significant differences in neonatal factors among the total neurologically-impaired group (n = 72) versus controls included oxygen dependence at 36 weeks (31% vs 15%), septicemia (53% vs 31%), severe cranial ultrasound abnormality (50% vs 17%), and hypothyroxinemia (43% vs 25%). In the subgroup with cerebral palsy (n = 50), significant differences included days on the ventilator (23 vs 14 days), septicemia (54% vs 33%), and severe cranial ultrasound abnormality (52% vs 12%). Multivariate analysis controlling for birth weight, gestational age, race, sex, and the birth period (before 1990 versus 1990 and after) revealed direct and independent effects of clinical chorioamnionitis [odds ratio (OR), 3. 79; confidence interval (CI), 1.34-10.78], severe cranial ultrasound abnormality (OR, 9.97; CI, 3.84-25.87), and septicemia (OR, 2.46; CI, 1.10-5.52) on total neurologic impairment. Consideration of the 50 cases with cerebral palsy revealed direct and independent effects of severe cranial ultrasound abnormality only (OR, 15.01; CI, 4.34-51. 93). CONCLUSIONS: Both antenatal and neonatal risk factors contribute to the development of severe neurologic impairment, including cerebral palsy among VLBW children. Because prevention of chorioamnionitis may not be feasible in the near future, attempts to decrease neonatal risk factors such as severe cranial ultrasound abnormalities and sepsis may be most feasible at this time.

Birth Weight↗
PubMed1998

Microsatellite instability in sporadic carcinomas of the proximal colon: association with diploid DNA content, negative protein expression of p53, and distinct histomorphologic features.

BACKGROUND: Microsatellite instability (MIN) seems to characterize a particular subset of sporadic colorectal adenocarcinomas with the studies indicating a better clinical outcome for patients with MIN-positive tumors than for those with MIN-negative ones. The goal of this study was to further clarify whether a genotype-specific histomorphology of the right-sided colonic carcinomas can be identified. METHODS: MIN status, DNA content, and p53 protein expression were evaluated in cryoconserved specimens from 20 adenocarcinomas of the proximal colon and correlated to stage, grade, and other histomorphologic features. The study was restricted to tumors of the proximal colon because approximately 90% of all MIN-positive tumors were found in the proximal colon, and differences between right- and left-sided tumors cannot be excluded a priori. RESULTS: By using four microsatellite markers, instability was detected in 35% of the tumors analyzed. The clinicopathologic features in the MIN-positive tumors were found to differ markedly from the MIN-negative tumors in their poorly differentiated histologic pattern, extracellular mucin production, and favorable lymph node and distant metastatic behavior. A marked association was found between MIN positivity and DNA diploid status, as well as negative p53 immunostaining. CONCLUSIONS: The MIN-positive colonic carcinomas were characterized by distinct histomorphologic features that are recognizable at routine diagnostic evaluation. Poorly differentiated adenocarcinomas of the proximal colon, with only a few lymph nodes and no distant metastases at presentation, and lack of p53 accumulation are highly suggestive of being MIN positive. These tumors should be discriminated from the other poorly differentiated carcinomas, because they seem to be associated with an improved prognosis compared with the tumors without microsatellite instability.

Adenocarcinoma↗
PubMed1998

Effects of intrauterine growth retardation on mental performance and behavior, outcomes during adolescence and adulthood.

Studies of the long-term effects of intrauterine growth retardation on mental performance and behavior are reviewed. The results of the majority of studies suggest that, if effects of prematurity and of other associated complicating factors are controlled for, effects of IUGR per se, that can sometimes be demonstrated at an earlier age, become diluted by socio-environmental conditions at later stages in life and no longer appear to have a detrimental effect on mental and behavioral outcomes in adolescence and adulthood.

Adolescent↗
PubMed1998

Placental lesions associated with neurologic impairment and cerebral palsy in very low-birth-weight infants.

OBJECTIVE: Systematic placental examination has the potential to shed light on poorly understood antenatal processes that may increase the risk of neurologic impairment and cerebral palsy. DESIGN: Using data from a retrospective case-control study, we analyzed placentas from 60 inborn, singleton, very low-birth-weight (<1.5 kg) infants delivered between 1983 and 1991 who had subsequent neurologic impairment at 20 months corrected age (42 with cerebral palsy and 18 with other neurologic abnormalities) and 59 control infants of comparable gestational age, birth weight, sex, and race. Three a priori hypotheses based on previous studies were that neurologic impairment would be increased with fetal vascular lesions with or without coexisting chorioamnionitis, decreased with chronic maternal vascular underperfusion, and increased when multiple placental abnormalities were seen in the same case. RESULTS AND CONCLUSIONS: We found 2 types of fetal placental vascular lesions to be associated with neurologic impairment, namely, recent nonocclusive thrombi of chorionic plate vessels (P < .04) and severe villous edema (P < .01). Chorionic plate thrombi were seen only with chorioamnionitis and accounted for the increased risk of neurologic impairment seen with chorioamnionitis. Maternal vascular lesions showed a biphasic relation to neurologic impairment in the subgroup of patients without chorioamnionitis. Mild lesions were increased in controls (inadequate vascular remodeling, P=.03, and accelerated maturation, P=.004). A more severe lesion, multiple villous infarcts, although not reaching significance, was increased in the neurologically impaired cases. Finally, in a test of 9 selected placental lesions, cases with cerebral palsy were more likely to have 2 or more lesions (P < .0001) and were less likely to have no lesions (P < .04) than control infants.

Case-Control Studies↗
PubMed1997

Neonatal morbidity after elective repeat cesarean section and trial of labor.

OBJECTIVE: To evaluate neonatal outcomes after an elective repeat cesarean section (ERCS) compared with a trial of labor (TOL). POPULATION AND METHOD: All mothers who underwent previous cesarean section and delivered singleton infants at term gestation were identified during a 1-year period. Neonatal outcomes were compared between infants delivered by ERCS (n = 497) and those delivered by TOL (n = 492), and between infants delivered by a successful (n = 336) and a failed (n = 156) TOL. A cohort of mothers and their term infants delivered by routine vaginal delivery were also identified. RESULTS: Infants delivered by ERCS had an increased rate of transient tachypnea compared with infants born by TOL (6% vs 3%). Compared with routine vaginal deliveries, the adjusted odds ratio of developing any respiratory problem after an ERCS was 2.3 (95% confidence interval [CI]: 1.4, 3.8), and for developing transient tachypnea was 2.6 (CI: 1.5, 4.5). In addition, two infants delivered by ERCS developed respiratory distress syndrome. Infants delivered after a TOL had increased rates of suspected and proven sepsis (5% vs 2% and 1% vs 0.1%, respectively). Compared with a successful TOL, the infants delivered by cesarean section after a failed TOL had more neonatal morbidity and had a longer hospital stay (4.8 +/- 2 vs 3.1 +/- 2 days). The odds ratio for developing any respiratory illness after a failed TOL was 2.1 (95% CI: 1.1, 4.1), for suspected sepsis was 4.8 (95% CI: 2.6, 9.0), and for proven sepsis was 19.3 (95% CI: 2.0, 187). Neonatal outcomes after a successful TOL were similar to routine vaginal births. CONCLUSION: Infants born by ERCS are at increased risk for developing respiratory problems compared with those born by TOL. However, TOL is associated with increased rates of suspected and proven sepsis. This appears to be limited to infants delivered by cesarean section after a failed TOL.

Cesarean Section, Repeat↗
PubMed1996

Catch-up growth during childhood among very low-birth-weight children.

OBJECTIVES: To examine growth attainment and correlates of catch-up growth at 8 years of age in a cohort of very low-birth-weight (VLBW) children (< 1500 g), including appropriate and small-for-gestational-age children, and to compare their growth with normal-birth-weight (NBW) children. DESIGN: Eight-year longitudinal follow-up of a cohort of VLBW children. A geographically based, randomly selected sample of NBW children was recruited at 8 years of age. SETTING: Tertiary perinatal center. PARTICIPANTS: Two hundred forty-nine VLBW children born between January 1, 1977, and December 31, 1979 (78% of survivors), of whom 199 were born appropriate for gestational age and 50 were small for gestational age (< -2 SD). The NBW population included 363 children. MAIN OUTCOME MEASURES: For the VLBW population, rates of subnormal weight (below the third percentile) and height were obtained at birth, at 40 weeks (term), and at 8 and 20 months. For the VLBW and NBW populations, mean weight, height, and percentile distribution at 8 years were derived from the National Center for Health Statistics standards. RESULTS: Catch-up growth to above the third percentile occurred between 40 weeks and 8 months, 8 and 20 months, and up to 8 years of age among the VLBW children. At 40 weeks, 54% were subnormal in weight and 60% were subnormal in height; at 8 months, 33% and 22%, respectively, and at 8 years, 8% were subnormal in weight and height. Small-for-gestational-age children had lower rates of catch-up growth. Multivariate analyses disclosed maternal height, race, birth weight, and neurologic abnormality to predict percentile distribution of height; and maternal height, small for gestational age, and neurologic abnormality to predict subnormal height. CONCLUSIONS: Catch-up growth occurs during childhood among VLBW children. These results have implications when counseling parents about the potential growth attainment of their children.

Child↗
PubMed1996

Hospitalization as a measure of morbidity among very low birth weight infants with chronic lung disease.

OBJECTIVE: To examine the spectrum of hospitalization and rehospitalization among very low birth weight (VLBW, <1500 gm) infants with severe chronic lung disease during the first 2 years of life. POPULATION: All 124 VLBW infants admitted to our center from October 1988 to September 1990 who were oxygen and ventilator dependent at 21 days of age. One hundred infants survived to discharge, of whom two subsequently died. The 98 surviving infants are the subject of this report. METHODS: The duration of the neonatal stay, the use of a long-term care facility, and rehospitalizations were recorded to a postnatal age of 24 months. The duration of these hospitalizations and the total duration of hospitalization during the first year of life were correlated with demographic and perinatal risk factors and 20-month outcome. RESULTS: The 98 infants spent a median of 125 days (range, 44 to 365) of their first year hospitalized; the neonatal stay accounted for 85% of this time. Forty-nine of the infants (50%) were rehospitalized in their first year (median stay, 14 days), and 36 (37%) were rehospitalized in their second year (median stay, 7 days). Long-term care facility stay and rehospitalizations accounted for 6% and 9% of the first-year hospitalizations, respectively. A median of 9 days (range, 1 to 365) of the second year of life were spent in hospital. The infants rehospitalized during their first year of life did not differ significantly from those not requiring rehospitalization with regard to maternal demographic descriptors, birth data, severity of chronic lung disease, or measures of 20-month outcome. Both duration of neonatal stay and total hospital stay during the first year were significantly associated with all measures of chronic lung disease severity and with 20-month neurodevelopmental outcome measures, whereas the duration of rehospitalization was associated only with duration of oxygen dependence. CONCLUSION: Among infants with severe chronic lung disease, the total duration of hospitalization during the first year of life provides a better index of morbidity than the number or duration of rehospitalizations alone.

Chronic Disease↗
PubMed1996

Radiation exposure from diagnostic radiographs in extremely low birth weight infants.

OBJECTIVE: We sought to examine radiation doses received by infants of less than 750 g birth weight from radiographs. METHODS: We examined the radiology records, including radiograph films, of all 25 surviving infants with birth weight less than 750 g admitted to our center during 1991. The standard method of neonatal radiation dose calculation was modified to consider the body size, postnatal growth, and extramedullary hematopoiesis of the extremely low birth weight infant. To determine overall radiation exposure, we calculated an effective dose equivalent, which is the sum of weighed organ dose equivalents. RESULTS: The infants had a mean of 31 radiographys performed, including 17 chest radiographs, 5 babygrams, and 9 abdominal radiographs. The majority of chest radiographs and babygrams were performed in the first month, whereas abdominal radiographs increased during the second month of life. Total-body radiation dose and total effective dose equivalent by the standard and modified methods, respectively, for single exposures ranged from 0.01 to 0.02 millisieverts (mSv) for a chest radiograph, from 0.02 to 0.04 mSv for a babygram, and from 0.02 to 0.03 mSv for an abdominal radiograph. Surface organs icluding the skin, breast, and thyroid received the largest radiation doses. The effective dose equivalent per infant for all radiographs was 0.72 mSv according to the modified method, compared to a total-body dose of 0.40 mSv using the standard method. However, infants with chronic lung disease or necrotizing enterocolitis received up to 1.5 mSv total-body dose, including 3.3 mSv to the breast, 2.5 mSv to the thyroid, and 2.3 mSv to the testes. CONCLUSIONS: Radiation doses received by infants of less than 750 g birth weight are small in comparison with the range of doses that form the basis of risk estimates for cancer.

Body Constitution↗
PubMed1996

Outcomes of extremely low birth weight infants.

BACKGROUND: Our goal was to determine the effects of recent changes in delivery room and neonatal care, including surfactant and dexamethasone therapy, on survival, neonatal morbidity, and 20-month neurodevelopmental outcome of infants with birth weights of less than 750 g. METHODS: We compared the outcomes of 114 infants of 500 to 750 g birth weight delivered at our perinatal center between January 1990 and December 1992 (period II), when surfactant and postnatal dexamethasone were used, with the outcomes of 166 such infants born between July 1982 and June 1988 (period I). RESULTS: The rate of cesarean section increased from 17% to 27% and delivery room intubation increased from 54% to 72% during periods I and II, respectively. Survival increased from 23% during period I to 43% during period II. The increase in survival was significant at birth weights of 600 to 700 g and at 24 weeks' gestation and greater. During period II fewer infants died at less than 24 hours of age and more died at more than 28 days of life. Neonatal morbidity did not change appreciably; neither did 20-month neurodevelopmental outcomes. Twenty percent of the infants had subnormal cognitive function (Mental Development Indices < 70) and 10% had cerebral palsy during period II. CONCLUSIONS: Despite an increase in survival during 1990 to 1992, the neonatal and early childhood outcomes of the survivors were unchanged. Physicians and parents anticipating the delivery of extremely low birth weight infants must be aware of these outcomes to make informed decisions as to the advisability of aggressive care at birth and thereafter.

Cause of Death↗