Search PubMed⌕ Search

Biomedical subjects

A D Rothberg

Publications and source records attributed to A D Rothberg.

At least 55 records · Page 3Linked to original sources
PubMed1991

Psychosocial support for maternal stress during pregnancy: effect on birth weight.

In a previous study we showed that moderate to severe stress during pregnancy was inversely related to infant birth weight. Using the same criteria for stress (according to the Social Readjustment Rating Scale of Holmes and Rahe), we studied 86 white mothers with singleton pregnancies and with no known medical or obstetric risk factors for reduced birth weight. After strict randomization, data were analyzed for 43 mothers who received psychosocial support between enrollment at +/- 20 weeks and delivery at +/- 38 weeks and for 43 control mothers who received standard care at the antenatal clinic. In the supported group seven infants weighed less than 3000 gm at birth versus 18 control infants (p = 0.008), and analysis revealed that this effect was more the result of improved intrauterine growth than of prolongation of pregnancy. These findings are of little clinical relevance as far as the neonate is concerned, but they do indicate that psychosocial support has a significant effect on birth weight. It is possible that previous studies that have looked only for an effect on low- or very-low-birth-weight rates might have missed this clinically measurable benefit of counseling.

Adult↗
PubMed1991

Six-year follow-up of early physiotherapy intervention in very low birth weight infants.

Eighty very low birth weight infants assigned to neurologically normal or at-risk groups on the basis of a neurodevelopmental score were previously described. Infants were assigned to physiotherapy or control groups, and the effect of physiotherapy was assessed at 1 year. At-risk infants had a significantly lower developmental quotient than the normal group and no beneficial effect of physiotherapy was shown. Of the original 80 subjects, 49 were reassessed at a mean age of 74.7 months. As observed previously, physiotherapy until 1 year did not influence subsequent outcome in either normal or at-risk children. At-risk and normal children had similar mean developmental quotients at 6 years, but the locomotor score of at-risk children was significantly below that of normal children. Cerebral palsy occurred in 6 of 24 at-risk vs 0 of 25 normal subjects (P less than .01) and remedial therapy was recommended in 17 of 24 at-risk subjects vs 6 of 25 normal subjects (P less than .001). These results confirm that the neurodevelopmental score predicts a risk for either cerebral palsy or soft neurological problems, and early physiotherapy is of questionable benefit in preventing such problems.

Central Nervous System↗
PubMed1990

Angiotensin-converting enzyme inhibitors in pregnancy may result in neonatal renal failure.

Oligohydramnios and neonatal renal failure is reported in a premature infant whose mother had used enalapril in weeks 32-35 of her pregnancy. The infant recovered adequate renal function after peritoneal dialysis. Review of the literature supports our view that angiotensin-converting enzyme inhibitors should not be used in pregnancy; if they are, both mother and fetus should be monitored with extreme care.

Acute Kidney Injury↗
PubMed1990

Short-term outcome for very-low-birth-weight infants with prolonged oxygen requirement.

Although Johannesburg Hospital's neonatal intensive care unit's survival rates are similar to those of First-World countries, it has been the impression of ward staff that ventilated very-low-birth-weight (VLBW) infants who cannot be weaned from high concentrations of oxygen and/or high inflation pressures within 7-10 days constitute a group with a poor prognosis. This study confirms previous studies showing that the early neonatal mortality rate is twice as high as the late neonatal mortality rate. It also confirms that mortality is related to birth weight and peak pressure and shows that VLBW infants with high oxygen and pressure requirements after 1 week do indeed constitute an extremely high-risk group with a short-term morbidity rate of 70-80% and a mortality rate of almost 50%.

Humans↗
PubMed1989

Measurement of the frequency response and common-mode gain of neonatal respiratory pressure and flow measurement systems. Part 1: Apparatus.

It is necessary, especially in neonatal work, for investigators to measure accurately the frequency response and common mode gain of respiratory pressure and flow transducers in air and other gas mixtures. Many of the systems designed for this task have been incompletely analysed and have unknown frequency responses themselves. We analyse aspects of systems employed previously and show that substantial amplitude and phase errors may have occurred. We describe a plethysmograph-based system which operates in any available gas mixture. A mathematical model of the acoustic microphone used as reference transducer, the microphone preamplifier, and the thermal behaviour of the plethysmograph, is developed to quantify the frequency response of the system. Maximum deviation from a perfect response is less than 1% in amplitude and 1 degree in phase for both pressure and flow measurements over the range 1-100 Hz. Measurements using a pressure transducer mounted on the tip of a catheter indicate that the error due to amplitude and phase variation in the plethysmograph is less than 0.1 dB and 0.4 degrees at 100 Hz.

Humans↗
PubMed1989

Measurement of the frequency response and common-mode gain of neonatal respiratory pressure and flow measurement systems. Part 2: Results.

We show that the technique of exciting a differential pressure transducer at one port to measure its differential gain yields incorrect results in the case of asymmetrical differential pressure transducers but is acceptable in the case of symmetrical transducers. We have measured the common-mode gain of a symmetrical and an asymmetrical differential pressure transducer from 1 Hz to 100 Hz, both directly and by computation from differential gain measurements. No compensation for common-mode error is necessary when a symmetrical transducer is used in mechanically ventilated neonates. We have also measured the frequency response of neonatal Fleisch and screen pneumotachographs connected to Validyne MP45 differential pressure transducers in air, 60% oxygen and 100% oxygen, and concluded that the effect of oxygen concentration is small below 40 Hz. However, the normalised frequency response of the flow transducer differs markedly from unity at frequencies inside the flow bandwidth generated by neonatal pressure cycled ventilators and dynamic correction is therefore necessary.

Humans↗
PubMed1989

Three-year growth and developmental follow-up of very low birth weight infants fed own mother's milk, a premature infant formula, or one of two standard formulas.

A cohort of 40 very low birth weight (VLBW) infants was followed until they reached 3 years of age. These infants were originally part of a feeding trial in the early postnatal period whereby they were fed either their own mother's milk, a standard whey-predominant formula, a casein-predominant formula, or a premature formula. Those fed the latter formula grew significantly better while in the hospital and had no biochemical derangements. At 3 years of age, there were no significant intergroup differences with respect to growth or development. There was a positive correlation between head growth in hospital and weight at 3 years, but there were no other significant relationships between early postnatal growth and growth parameters at 3 years. Socioeconomic status was the only predictor of developmental scores at 3 years of age. No adverse effects from early metabolic acidosis or alterations of amino acid profiles during the neonatal period were detectable at 3 years of age. However, the small sample size of this study may have missed true differences in outcome measures at 3 years, and larger studies are required to examine these questions further.

Cohort Studies↗
PubMed1989

Effects of temperature and composition on the viscosity of respiratory gases.

The steady-state sensitivity of resistance pneumotachographs is proportional to viscosity. Dynamic characteristics of pneumotachographs, pressure transducers, and mass spectrometers are also viscosity dependent. We derive linear equations to approximate the viscosities of O2, N2, CO2, H2O, He, N2O, and Ar for temperatures between 20 and 40 degrees C by using published viscosity data and a nonlinear extrapolation equation. We verify the accuracy of the extrapolation equation by comparison with published data. Our linear equations for pure gas viscosities yield standard errors less than 0.35 microP. We also compare a nonlinear equation for calculating the viscosities of mixtures of gases with published measured viscosities of dry air, humid air, and He-O2 and N2-CO2 mixtures. The maximum difference between published and calculated values is 1.3% for 10% CO2 in N2. All other differences are less than 0.38%. For saturated humid air at 35 degrees C, a linear concentration-weighted combination of viscosities differs from our nonlinear equation by 4.9, 2.1, and 1.7% at barometric pressures of 32, 83, and 100 kPa, respectively. By use of our method, the viscosity of normal respiratory gases can be calculated to within 1% of measured values.

Argon↗
PubMed1989

Dynamic skinfold measurements to assess fluid status in low birthweight infants. Part 1: Data acquisition and processing.

To evaluate the measurement of fluid status in the premature neonate using dynamic skinfold thickness (DST) measurement, a pair of calipers were interfaced to a computer, and weight and digital DST at four sites were measured daily in 24 neonates in the postnatal weight loss period. A biexponential equation was fitted to each curve from the instant the rate of caliper closure fell below 2 mm/s, and the five constants obtained used in a search for a parameter that correlated with the percentage of weight loss. The percentage of fall in the DST from 0.4 to 30 seconds yielded highest mean of individual coefficients of determination (COD) (0.83); the percentage of fall from 0.7 to 35 seconds yielded highest COD in pooled data (0.56). Expected weight loss can be predicted with standard error of 2.9% with pooled regression but with standard error of 1.3% using individual correlations. We conclude that individuals lose fluid in a consistent manner during this period but that interindividual differences are large and require further investigation.

Algorithms↗
PubMed1989

Dynamic skinfold measurements to assess fluid status in low birthweight infants. Part 2: Correlation with postnatal weight changes.

Computerized recording of dynamic skinfold thickness measurements was performed on low birthweight infants. Four skinfold sites were measured daily for the first 7 days postnatally and then at intervals up to 4 weeks of age. The percentage of fall of the skinfold between 0.4 and 30 seconds after caliper application was shown to correlate best with postnatal weight loss until minimum weight was reached. Of the 24 infants studied in detail, only two had a correlation coefficient less than 0.75 between changes in the percentage of fall of the skinfold and postnatal weight changes. There was, however, marked individual variation in the amount of weight loss for a given reduction in the percent of the skinfold. Assuming that most of the postnatal weight loss of low birthweight infants is due to reduction of extracellular volume, dynamic skinfold thickness appears to be a good noninvasive measure thereof.

Data Collection↗
PubMed1988

Methylphenidate v. placebo--a randomised double-blind crossover study in children with the attention deficit disorder.

Fourteen pupils of the New Hope School in Pretoria who were considered to be responsive to methylphenidate were randomised to receive either the active drug or placebo in a double-blind trial for each of 4 weeks. Their behaviour was monitored by parents and teachers, who were required to complete a questionnaire (Conner's Abbreviated Teachers' Rating Scale) three times per week. After analysis of the data, only 2 children were identified as methylphenidate responders and 1 as a probable responder. One child showed significant deterioration on the drug while another showed deterioration that approached significance. The remaining 9 exhibited no significant response to methylphenidate.

Attention Deficit Disorder with Hyperactivity↗
PubMed1988

Provision of services for mentally handicapped children in the Witwatersrand area.

Childhood mental retardation is defined as significantly subaverage general intellectual functioning existing together with difficulty in adaptive behaviour, manifesting during the period from birth to 18 years. We addressed the issues of diagnosis, placement and management of the mentally handicapped child in the Witwatersrand area and surveyed facilities available for them. According to our calculations, facilities were adequate for 69.7% white, 26% Indian, 9.3% coloured and only 7.6% black children. Urgent attention must be given to providing more care for these children, especially those with profound mental retardation. A special class in a regular school is the most appropriate environment for the mildly to moderately retarded group.

Adolescent↗
PubMed1987

Prediction of intra-uterine growth retardation using maternal glucose tolerance and anthropometric data.

Maternal anthropometric data and the intravenous glucose tolerance test (IVGTT) were investigated as predictors of idiopathic intra-uterine growth retardation (IUGR). Eighty-three eligible subjects without known risk factors for IUGR were enrolled at 30.5 +/- 3.8 weeks' gestation and followed up until delivery at 39.3 +/- 1.9 weeks, at which stage the infants were assessed. There were no differences between the IVGTT profiles of mothers of infants which were appropriate for gestational age and those which were small for gestational age (SGA), irrespective of lenient or strict definitions of SGA. Third-trimester weight gain (grams per week) correlated well with both duration of pregnancy and birth weight (P less than 0.01). Correlations were also found between maternal weight and birth weight, between maternal height/weight ratio and birth weight, and between birth weight and maternal subscapular skinfold thickness.

Adult↗