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Biomedical subjects

R Brand

Publications and source records attributed to R Brand.

At least 109 records · Page 6Linked to original sources
PubMed1994

The use of an episiotomy in relation to the professional education of the delivery attendant.

In a group of 1272 primiparous women, who delivered spontaneously at the University Hospital of Leiden between 1 January 1988 and 31 December 1991, the relationship between the use of an episiotomy and the professional training of the delivery attendant has been studied, using multiple logistic regression (a random effects model to allow for patient-within-physician effects). The following factors were taken into account: birthweight, duration of the second stage of labour, supposed fetal distress, age and race of the mother, gestational age, duration of pregnancy and the year of the delivery. Based on the logistic regression model it is estimated that registrars and gynaecologists are 2.5 and 3.4 times, respectively, more likely than midwives to perform an episiotomy.

Cohort Studies↗
PubMed1994

School performance at nine years of age in very premature and very low birth weight infants: perinatal risk factors and predictors at five years of age. Collaborative Project on Preterm and Small for Gestational Age (POPS) Infants in The Netherlands.

To assess the impact of both perinatal disorders and developmental problems identified at preschool age on school performance, we followed a virtually complete birth cohort of very premature (< 32 completed weeks of gestation) and very low birth weight infants until they were 9 years of age. In 84% of the survivors (n = 813), data on school performance were available for analysis. At the age of 9 years, 19% of the children were in special education. Of the children in mainstream education, 32% were in a grade below the appropriate level for age and 38% had special assistance. After correction for other perinatal items, children of low socioeconomic status and boys had significantly higher adjusted odds ratios for special education. Logistic regression with a perinatal and a 5-year time category showed that the most predictive factors for special education were developmental delay, neuromotor and speech/language function, inattention and hyperactivity score, total problem score, and reported school results at the age of 5 years. When children with disabilities were left out of the analysis, the importance of neuromotor function and total problem score disappeared. Increased risks of any school failure in nondisabled children included mild or severe developmental delay and marginal or poor school performance at the age of 5 years. Long-term follow-up with specific attention to these predictors at 5 years of age, although time-consuming, is necessary.

Birth Weight↗
PubMed1994

Cerebral blood volume changes during exchange transfusions in infants born at or near term.

We investigated the effects on cerebral hemodynamics of blood pressure changes during exchange transfusions in infants born at or near term, using near infrared spectroscopy in eight stable infants (mean gestational age, 36.2 +/- 1.3 weeks) who underwent a total of 21 exchange transfusions for erythroblastosis fetalis (rhesus hemolytic disease). Changes in mean arterial blood pressure derived from an indwelling umbilical arterial catheter, transcutaneous arterial oxygen and carbon dioxide tension, as well as changes in cerebral oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HbR), and total hemoglobin (Hbtot = HbO2 + HbR), were recorded continuously from 15 minutes before until the completion of the exchange transfusion. Relative change(s) in cerebral blood volume (dCBV) were calculated as follows: dCBV = change in Hbtot x 0.89/Venous hemoglobin. Changes in mean arterial blood pressure and dCBV were observed during all exchange transfusions; a decrease was found during the withdrawal period and an increase during the infusion period. The mean response of dCBV to a change in mean arterial blood pressure was 0.011 ml.100 gm-1.mm Hg. Multivariate analysis showed that dCBV were primarily associated with changes in mean arterial blood pressure, followed by changes in arterial oxygen tension and in exchange cycle duration. We conclude that in stable term and near-term infants, hemorrhagically induced blood pressure changes provoke dCBV.

Blood Pressure↗
PubMed1994

Postnatal changes in plasma chain-breaking antioxidants in healthy preterm infants fed formula and/or human milk.

Concentrations of chain-breaking antioxidants were studied in the first 6 postnatal weeks in 29 healthy preterm infants (gestational age 30-35 wk). Vitamin C, uric acid, and sulfhydryl groups declined, whereas vitamin E rose and bilirubin followed its typical biphasic postnatal course. The influence of these changes on the plasma peroxyl radical trapping capacity was assessed in vitro (TRAP assay). The trapping capacity decreased postnatally and this appeared to be related to the coincident fall in uric acid concentrations. Results did not differ between babies fed with only preterm formula (n = 12) and those fed predominantly with human milk (n = 6), except for higher bilirubin and TRAP values in the breast-fed infants. There are major postnatal changes in the concentrations of the plasma chain-breaking antioxidants and this may influence the susceptibility of the preterm baby to oxygen toxicity.

Aging↗
PubMed1994

Does training on an anaesthesia simulator lead to improvement in performance?

We have used the Leiden anaesthesia simulator, which makes use of a standard anaesthesia machine and monitors, and realistically simulates the anaesthesia work place. After obtaining informed consent, 28 anaesthetists and anaesthesia trainees in one hospital took part in the study. All participants were exposed to a pre-scripted simulated "control" scenario of anaphylactic shock (phase 1). The sessions were videotaped and the performances of individual participants were evaluated using a standardized scoring scheme. During phase 2, the participants were allocated randomly to undergo training in the management of either anaphylactic shock (group A, n = 13) or malignant hyperthermia (group B, n = 15) on the simulator. After 4 months, each participant underwent a blinded evaluation session with a pre-scripted "test" scenario of malignant hyperthermia (phase 3). These sessions were also videotaped and evaluated as for phase 1. The participants in group B responded more quickly, treated better and deviated less from the accepted procedure during phase 3 than those in group A. The total performance of participants in group B during phase 3 was significantly better than those in group A. We conclude that training on an anaesthesia simulator does improve the performance of anaesthetists in dealing with emergencies during anaesthesia.

Anaphylaxis↗
PubMed1994

Otitis media, respiratory tract infections and hearing loss in pre-term and low birthweight infants.

In 1983, 1338 liveborn infants with a gestational age of less than 32 weeks and/or a birthweight of less than 1500 g, were enrolled in a national follow-up study in The Netherlands. At the age of 5 years, 966 children were alive. Of these, 927 (96%) were assessed on a home visit 2-6 weeks after their fifth birthday by three specially trained paediatricians. An assessment of ENT morbidity was made and compared with ENT morbidity in full-term children of the same age group. Markedly preterm birth or very low birthweight does not seem to be a risk factor for developing middle ear disease in childhood, however, the rate of ENT problems seems to be higher than in the general population of Dutch pre-school children.

Child, Preschool↗
PubMed1994

No beneficial effect of low-dose fetal intravenous gammaglobulin administration in combination with intravascular transfusions in severe Rh D haemolytic disease.

Recent observations have shown that treatment with high-dose intravenous gammaglobulin (IVIgG) given to the mother may improve fetal outcome in cases of severe Rh D alloimmunization. Unfortunately, the costs of this new method of treatment are too high for routine use. Therefore, we decided to apply this treatment to the fetus and to investigate whether the effect of IVIgG might be attributable to blockade of the fetal mononuclear phagocyte system. We have performed a randomized study in which 20 fetuses with severe Rh D-haemolytic disease (HDN) were treated with intrauterine intravascular red cell transfusions (IUT). In 10 of these 20 cases transfusions were followed by administration to the fetus of low-dose IVIgG (85.7 +/- 11.6 mg/kg by ultrasound-estimated fetal weight because of fetal vascular volume considerations). We compared the number of IUTs, postnatal exchange transfusions, haematocrit (Ht) and haemoglobulin (Hb) values before and after transfusion (s) needed by the newborns of the two groups. No significant differences in the transfusion requirements of the fetuses and in the clinical outcome could be demonstrated. However, the 95% confidence interval for the difference in the improvement of cord blood Ht was too wide for any conclusions. The 95% confidence interval for the difference in the improvement of Hb levels suggests that any clinically relevant advantage of IVIgG on Hb is unlikely.

Blood Transfusion↗
PubMed1994

The use of ultrasonography and Doppler in the prediction of fetal haemolytic anaemia: a multivariate analysis.

OBJECTIVE: To assess the value of ultrasonography and Doppler to predict the severity of fetal haemolytic anaemia. DESIGN: Ultrasonographic measurements of the fetal liver, spleen, umbilical vein and placenta, and Doppler measurements of umbilical venous and fetal aorta flow velocities were performed before the first intrauterine blood transfusion. Multivariate regression models for the prediction of the fetal haemoglobin level were derived from the measurements. SETTING: National referral centre for management of alloimmunised pregnancies. SUBJECTS: Forty fetuses in 39 severe red cell alloimmunised pregnancies. RESULTS: A logistic regression model, incorporating the two Doppler parameters only, predicted the presence or absence of severe anaemia in nonhydropic fetuses with an accuracy of 90%. Positive predictive value was 89% and negative predictive value was 100%. CONCLUSION: In severe red cell alloimmunised pregnancies, Doppler blood flow velocity studies can be used to predict the severity of fetal anaemia. This may lead to a reduction of invasive diagnostic tests, to more accurate timing of intrauterine transfusions, and thus to a higher survival rate.

Anemia, Hemolytic↗
PubMed1994

Comparison of mortality and rates of cerebral palsy in two populations of very low birthweight infants.

Comparisons of mortality and rates of cerebral palsy in different populations can be confusing. This is illustrated by comparing two populations of very low birthweight infants born in the 1980s, one from the Netherlands, the other from the UK (Oxford region). Although a number of biases were controlled for while comparing two large geographically defined populations, by assessing the survivors at similar ages and describing their health status in a standard way, some problems in interpretation of outcome remained. Differences in registration practice of live births at early gestational ages, as well as differences in withholding or withdrawing treatment, which occurred in about half of the cases of neonatal death in the Netherlands and in about one third of those in the Oxford region, may have influenced the incidence of registered live births, neonatal mortality, and the rate of cerebral palsy.

Blindness↗
PubMed1994

Comparing mortality and morbidity in hospitals: theory and practice of quality assessment in peer review.

The incidence of mortality in a specific hospital depends on many risk factors. These risk factors may be divided roughly into two categories. The intake category, consists of those risk factors for which the hospital has hardly any influence upon their incidence; and the care category being those for which the incidence depends partly or completely on the treatment policy of the hospital. A hospital with a high incidence of risk factors in the intake category will have a higher mortality rate than a hospital with a low incidence, even if their care is exactly the same (i.e., if they treat their infants equally well). Therefore, a fair comparison between one hospital and a reference cohort, or among several hospitals (using a national registry) should adjust e. g. correct for those risk factors belonging to the intake category. A practical method is proposed, based on logistic regression, to effectuate such a "fair" judgment. The regression technique enables to compare "observed" and "expected" rates in a specific hospital and to test whether a difference between these rates is statistically significant. Both clinical and statistical aspects of the method are discussed, as well as the actual implementation of an automated annual reporting system. The method has been implemented in the Netherlands as an annual peer review and quality assessment system in obstetric care.

Cause of Death↗
PubMed1994

Changes of respiratory system mechanics in ventilated lungs of preterm infants with two different schedules of surfactant treatment.

We investigated the time course of changes in the static respiratory system compliance and resistance in relationship to surfactant administration by means of single-breath and multiple-occlusion techniques. The study comprised 12 infants receiving a high-dose schedule (200 mg/kg, maximum 600 mg/kg) and 13 infants receiving a low-dose schedule (100 mg/kg, maximum 300 mg/kg) of porcine surfactant. Eight healthy preterm infants served as a comparison group. Respiratory mechanics were studied before and at 1.5, 8, and 72 h after surfactant administration. Results were related to changes in gas transfer, including an estimate of venous admixture. Static compliance improved after surfactant instillation, and changes were similar in the two treatment groups during the first eight h (0.8 In.(hour + 1) mL.kPa-1). The compliance values remained below the values of the healthy comparison group during the whole study period, but resistance remained at the same level. There was a considerable delay in changes of respiratory mechanics in relationship to the rapid fall of the venous admixture, from 27 to 19%, and the rapid increase of the transcutaneous oxygen pressure/fraction of inspired oxygen ratio from 13 to 27 kPa within the hour. There were no clues that short-term changes in compliance were masked by breathing at a higher and flatter portion of the pressure-volume curve. Both treatment schedules resulted in a similar improvement of compliance within 72 h and the two groups benefited similarly in terms of venous admixture.

Airway Resistance↗
PubMed1994

Sex difference in disability and handicap at five years of age in children born at very short gestation.

OBJECTIVE: The objective of this study was to examine the relationship between sex and disabilities or handicaps at 5 years of age in infants born at less than 32 weeks gestation. DESIGN: From the nationwide collaborative survey starting in 1983, including perinatal data obtained during routine perinatal care and follow-up assessments by the attending pediatricians, data from 1008 infants fulfilling the criteria were used. At age 5 years, a detailed assessment was performed by three specially trained pediatricians in 96% surviving infants (n = 648), of which 345 were boys. Each child was categorized as disabled or handicapped, using World Health Organization definitions. RESULTS: The prevalence of handicaps was three times greater in boys than in girls (21% vs 7%, odds ratio 3.2). Adjustment for gestational age and birth weight (logistic regression analysis) did not change this (odds ratio 3.5). Further adjustment by including perinatal variables such as idiopathic respiratory distress syndrome did not alter the odds ratios. The male excess in handicaps was not related to lower mortality, and therefore was not a mere consequence of a higher survival rate. The excess in handicaps was found in all assessed areas. CONCLUSIONS: Infants' sex seems to be an important determinant of handicaps. The perinatal variables used in the present study do not explain the difference in handicaps. These findings emphasize the need to include the sex distribution of a study population more systematically in analyses in future studies concerning long-term outcome of very preterm birth or low birth weight.

Child, Preschool↗
PubMed1993

[Underreporting of first-week mortality in premature childbirth in the National Obstetrics Register].

The reliability of the perinatal mortality as recorded in the Perinatal Database of the Netherlands (LVR), was studied over 1983. For this year is was possible to make a comparison between preterm infants in the LVR and the same infants recorded by paediatricians in the database of the Project on Preterm and Small for Gestational Age Infants in the Netherlands 1983 (POPS). The comparison between the recorded mortality of the same infants in these two anonymous databases was realised by a simple matching procedure. For the premature infants a 30% lower first week mortality was found in the LVR than in the POPS-group, which means that 10% of the total perinatal mortality (stillbirths and first-week deaths together) has not been registered in the LVR for this group, due to lack of adaptation of data after later deaths. The mortality in the LVR should be interpreted with caution while it is not yet possible to match the obstetric data to the data of the National Neonatology Registration.

Data Interpretation, Statistical↗
PubMed1993

Hearing loss in very preterm and very low birthweight infants at the age of 5 years in a nationwide cohort.

In a geographically defined population of very preterm and very low birthweight infants (gestational age < 32 weeks and/or birthweight < 1500 g) hearing was evaluated in 890 children by pure-tone audiometry at the age of 5 years. Hearing loss was conductive/unspecified in 123 (13.8%) and sensorineural in 13 (1.5%) children. The prevalence of sensorineural hearing loss was 15 times as high as in 5-7 year old children in the Dutch population at large. The sensorineural hearing loss prevalence in very low birthweight and extremely low birthweight infants was similar. On account of communication disorders 10 (1.1%) children were classified as disabled and 6 (0.7%) as handicapped, following the definitions of the International Classification of Impairments, Disabilities, and Handicaps of the World Health Organisation. Children with conductive hearing loss had a higher risk of impairments, disabilities and handicaps of language and speech development, than children with normal hearing, the difference being statistically significant. The same holds for children with sensorineural hearing loss; moreover they had a significantly higher risk of impairments, disabilities and handicaps of mental development. Overall comparison of children with and without sensorineural hearing loss proved that the children with sensorineural hearing loss had a significantly less favourable outcome, based on 15 perinatal factors simultaneously. The age at which sensorineural hearing loss in very preterm and/or very low birthweight infants is detected has to be improved.

Audiometry, Pure-Tone↗
PubMed1993

A polymerase chain reaction method adapted for selective amplification and cloning of 3' sequences of potyviral genomes: application to dasheen mosaic virus.

'Universal' degenerate oligonucleotide primers were used to amplify cDNA sequences containing the 3' untranslated region (3' UTR) and a portion of the coat protein gene sequence of dasheen mosaic potyvirus (DMV). These primers were based on the conserved WCIEN and QMKAAA 'boxes' of the potyviral coat protein and the poly-A tail found at the 3' end of the genome. The forward genome-sense primers were designed taking into consideration the codon degeneracy of the WCIEN and QMKAAA residues for several potyviruses. The anti-sense reverse primer has 21 T residues followed by either A, C or G at the 3' end to ensure specific priming at the end of the 3' UTR and beginning of the poly-A tail. The specificity of amplification was verified using the known potyviruses (watermelon mosaic 2 and soybean mosaic viruses). To demonstrate the applicability of this method, the 3' UTR of the unsequenced DMV was amplified, cloned and sequenced. Sequence comparisons with other potyviral 3' UTRs revealed DMV to be quite distinct: nucleotide sequence similarities of only 34% to 44% were found with sequenced viruses indicating no close affinities with any other potyvirus. The potyvirus 3' sequence amplification procedure is simple and rapid, is potentially useful in developing virus specific probes and may be used to differentiate strains and species of potyviruses on the basis of the 3' UTR sequences.

Amino Acid Sequence↗
PubMed1993

Breech delivery in very preterm and very low birthweight infants in The Netherlands.

OBJECTIVE: To study the relation between various perinatal factors and the sequelae of very preterm birth, applying logistic regression analysis. DESIGN: In a nationwide collaborative study in the Netherlands, perinatal and follow up data were collected on 899 liveborn singleton nonmalformed infants with gestational age less than 32 weeks or birthweight less than 1500 g born in 1983. MAIN OUTCOME MEASURES: Neonatal mortality rate and total handicap rates (minor and major) in surviving children at two years and five years of age. RESULTS: Comparing breech with vertex presentation, the odds ratio for neonatal mortality (adjusted for duration of pregnancy, birthweight, maternal hypertension and prolonged rupture of membranes) is 1.6 (P < 0.05). Comparing abdominal versus vaginal delivery, the odds ratio indicates equal risks. When breech and vertex presentation are analysed separately it appears that breech presenting infants have a significantly lower mortality risk when born by caesarean section compared with vaginal delivery. However, comparing abdominal versus vaginal delivery in breech presentation, the odds ratio for handicap at five years (0.9) is not significantly different from 1. CONCLUSION: The data presented suggest a reduced neonatal mortality rate in breech presenting infants born by caesarean section but because of the observational design of the study the statistical analysis described only identifies a possible trend and cannot prove the issue.

Breech Presentation↗
PubMed1993

Prediction of height achievement at five years of age in children born very preterm or with very low birth weight: continuation of catch-up growth after two years of age.

To predict height at five years in a cohort of 565 very preterm and/or very low-birth-weight children, hypothesized growth determinants were subjected to discriminant analysis. Many neonatal parameters were not significantly associated with short stature at five years of age. A correct classification of stature (smaller/larger than the 10th percentile at five years of age) could be obtained in 85% of children, using the following variables: height at two years of age; total (or mid) parental height; parental level of education; length at one year of age; hypertension during pregnancy; sex; weight at two years of age; length percentile at one year of age. However, when compared to actual longitudinal data, the false-positive rate was 37%. The survey also demonstrated the continuing catch-up growth in very preterm and very low-birth-weight infants after two years of age.

Biometry↗