Routine neonatal postextubation chest physiotherapy: a randomized controlled trial

OBJECTIVE

To test the effects of a neonatal postextubation programme on the incidence of postextubation collapse and adverse outcomes.

METHODS

A randomized controlled trial was carried out at the Mater Mothers' Hospital, Brisbane. Mechanically ventilated infants were randomized into one of two groups, physiotherapy group--which involved a regimen of chest wall percussion and oropharyngeal suctioning and control group - which involved suctioning without the percussion unless indicated. Chest X-rays were taken at 6 h and at 24 h postextubation. The primary outcome measure was postextubation collapse as determined by a paediatric radiologist blinded to the group allocation.

RESULTS

One hundred and seventy-seven neonates were enrolled in the trial between 1997 and 1999. After an interim analysis, the trial was stopped early. No statistically significant difference was shown in the rate of postextubation collapse (15 of 87 (17.2%) physiotherapy group and 17 of 86 (19.8%) control group (P = 0.85)). No differences were shown between the groups in the number of apnoeic or bradycardic events, duration of requirement for supplemental oxygen or the need for re-intubation within 24 h postextubation.

CONCLUSION

The results of this trial suggest that a routine neonatal postextubation chest physiotherapy programme for all infants is not indicated. There was no evidence that chest physiotherapy is associated with any adverse outcomes.

Classification of perinatal deaths: development of the Australian and New Zealand classifications

Classifications of perinatal deaths have been undertaken for surveillance of causes of death, but also for auditing individual deaths to identify suboptimal care at any level, so that preventive strategies may be implemented. This paper describes the history and development of the paired obstetric and neonatal Perinatal Society of Australia and New Zealand (PSANZ) classifications in the context of other classifications. The PSANZ Perinatal Death Classification is based on obstetric antecedent factors that initiated the sequence of events leading to the death, and was developed largely from the Aberdeen and Whitfield classifications. The PSANZ Neonatal Death Classification is based on fetal and neonatal factors associated with the death. The classifications, accessible on the PSANZ website (http://www.psanz.org), have definitions and guidelines for use, a high level of agreement between classifiers, and are now being used in nearly all Australian states and New Zealand.

Periextubation caffeine in preterm neonates: a randomized dose response trial

OBJECTIVE

To compare the effectiveness of three dosing regimens of caffeine for preterm infants in the periextubation period.

METHODS

A randomized double-blind clinical trial of three dosing regimens of caffeine citrate (3, 15 and 30 mg/kg) for periextubation management of ventilated preterm infants was undertaken. Infants born <32 weeks gestation who were ventilated for>48 h were eligible for the study. Caffeine citrate was given as a once daily dose for a period of 6 days commencing 24 h prior to a planned extubation, or within 6 h of an unplanned extubation. The primary outcome measure was extubation failure, defined as neonates who were unable to be extubated within 48 h of caffeine loading or who required reventilation or doxapram dose within 7 days of caffeine loading. Continuous recordings of oxygen saturation and heart rate were undertaken in a subgroup of enrolled infants.

RESULTS

A total of 127 babies were enrolled into the study (42, 40, 45, in the 3, 15, and 30 mg/kg groups, respectively). No statistically significant difference was demonstrated in the incidence of extubation failure between dosing groups (19, 10, and 11 infants in the 3, 15, and 30 mg/kg groups, respectively), however, infants in the two higher dose groups had statistically significantly less documented apnoea than the lowest dose group. Of the 37 neonates with continuous pulse oximetry recordings, those on higher doses of caffeine recorded a statistically significantly higher mean heart rate, oxygen saturations and less time with oxygen saturations <85%.

CONCLUSIONS

This trial indicated there were short-term benefits of decreased apnoea in the immediate periextubation period for ventilated infants born <32 weeks gestation receiving higher doses of caffeine. Further studies with larger numbers of infants assessing longer-term outcomes are necessary to determine the optimal dosing regimen of caffeine in preterm infants.

A longitudinal study of Streptococcus mutans colonization in infants after tooth eruption

We previously reported that, before tooth eruption, over one-half of infants aged 6 mos were already infected with Streptococcus mutans. The aim of this investigation was to determine the colonization of S. mutans after tooth eruption in the same cohort of 111 infants (35 pre-term, 76 full-term). Our results showed that S. mutans colonization increased with increasing age, so that by 24 mos of age, 84% harbored the bacteria (p < 0.01). The mean and median ages of S. mutans colonization in dentate infants were 15.7 mos and 16.0 mos, respectively. Factors associated with S. mutans colonization were sweetened fluids taken to bed (p < 0.01), frequent sugar exposure (p < 0.03) and snacking (p < 0.03), sharing of foods with adults (p < 0.03), and maternal S. mutans levels of > 10(5) CFU/mL (p < 0.02). In contrast, non-colonization of S. mutans was associated with toothbrushing (p < 0.03) and multiple courses of antibiotics (p < 0.001). Analysis of our data establishes the timing of S. mutans colonization in children from birth to 24 mos of age.

The effects of chlorhexidine gel on Streptococcus mutans infection in 10-month-old infants: a longitudinal, placebo-controlled, double-blind trial

PURPOSE

This study investigated the long-term effects of 0.2% chlorhexidine gel, used as a weekly brush-on gel, on Streptoccocus mutans infection in 10-month-old infants.

METHODS

The investigation followed the criteria of a placebo-controlled, double-blind, longitudinal clinical trial. Infants were recruited at birth and oral microbiological swabs were taken at 3 monthly intervals, together with medical, dental, dietary and brushing histories. Children who were found to be colonized with S. mutans were randomly assigned to either the chlorhexidine-gel group (N = 50) or placebo gel group (N = 46), and parents were instructed to brush the gel on the teeth once per week for 12 weeks. In another control group (N = 210), infants did not use either chlorhexidine or placebo gels. Saliva samples were cultured using S. mutans-selective tryptone-yeast extract-cysteine-sucrose-bacitracin (TYCSB) agar. The mean age of the children was 10.2 +/- 2.6 months at the start of the trial and subjects were followed until the ages of 18 months.

RESULTS

In the children with initial low S. mutans counts of < 300 CFU/mL, there was a significant percentage reduction in S. mutans counts in the chlorhexidine-gel group compared to the placebo gel and no-gel control groups after 3 months of weekly gel brushing. However, no significant differences with the placebo group were observed after 15 months of follow-up. There were 39 children (41%) who achieved reduction of their S. mutans to 0 CFU/mL. Compared to those who remained infected with S. mutans, these children had higher toothbrushing frequencies (P < .001) and toothpaste use (P < .001), as well as lower frequencies of daily feeds (P < .01), and lesser weekly frequencies of sweet solids and liquids (P < .001).

CONCLUSIONS

Children with relatively low initial S. mutans counts (< 300 CFU/mL) showed a reduction in S. mutans counts in the first 3 months when 0.2% chlorhexidine gel was brushed on the teeth weekly. No differences were observed when compared with the placebo and no-treatment groups at later follow-up periods.

Immunoglobulins in saliva of preterm and full-term infants

The aim of this longitudinal study was to determine salivary levels of total IgA, IgG and IgM in 84 preterm and 214 full-term infants, from birth to 18 months of age. Unstimulated whole saliva was collected from each infant at birth, and subsequently at 3-monthly intervals. Immunoglobulin levels were estimated using an ELISA technique. At birth, IgA was detected in 147/214 (69%) full-term infants but only 47/84 (56%) preterm infants (P < 0.01). In the case of IgG, 61% of full-term and 56% of preterm infants showed detectable levels, whereas IgM was found in 71% and 73%, respectively. Levels of IgA and IgG rose from birth to 18 months, whereas IgM levels did not change significantly. Increases in salivary levels of IgA were associated with introduction of solid foods (P < 0.001), as well as tooth eruption (P < 0.001). Our results indicate that the majority of full-term and preterm infants are orally immunocompetent at birth.

Non-anaemic iron deficiency identified by ZPP test in extremely premature infants: prevalence, dietary risk factors, and association with neurodevelopmental problems

INTRODUCTION

The aims of this study were to determine, in a cohort of extremely premature infants, the prevalence of iron deficiency identified by zinc protoporphyrin/heme ratio (ZPP) testing, and its association with neurodevelopmental problems and dietary risk factors for iron deficiency.

METHODS

Infants of less than 29 weeks' gestation or less than 1000 g birth weight were studied prospectively at a multidisciplinary follow-up clinic. Assessments were made at a corrected age of either 12 months (n=72) or 2 years (n=69). Physical examination, Griffiths Developmental Scale, and neurosensory-motor assessment were administered, information on diet and behaviour was obtained by questionnaire, and a fingerprick ZPP ratio was performed to identify iron deficiency.

RESULTS

18.4% of infants had positive ZPP tests. There was no significant association between a positive ZPP test result and dietary risk factors, or symptoms of lethargy, irritability or poor attention. In children without cerebral palsy, there was no difference on Griffiths scores or neurosensory-motor assessment between ZPP-positive and ZPP-negative groups. The diagnosis of cerebral palsy (n=12) was significantly associated with both a positive ZPP test and a lower Griffiths general quotient (GQ) score.

CONCLUSIONS

Iron deficiency occurs commonly in extremely low birth weight (ELBW) children in early childhood, and is not predicted by dietary risk factors. The prevalence of iron deficiency is increased in ELBW children with cerebral palsy. Non-anaemic iron deficiency (NAID) does not impair development or significantly affect behaviour of ELBW subjects who do not have cerebral palsy.

Oral colonization of Streptococcus mutans in six-month-old predentate infants

We hypothesize that S. mutans colonization occurs more frequently in pre-term children due to their relative immaturity. In this study of 172 predentate, six-month-old infants, we found that 50% of pre-term and 60% of full-term children harbored S. mutans. The colonization was confirmed by repeat sampling. Although there were minor differences, factors associated with S. mutans infection in pre-term and full-term infants were generally similar. In both groups, increased frequency of sugar was ranked the most important factor (p < 0.001), followed by breast-feeding (p < 0.001), and habits which allowed saliva transfer from mother to infant (p < 0.01). By contrast, non-colonization of S. mutans was associated with multiple courses of antibiotics (p < 0.001). Compared with pre-term children, there were higher percentages of full-term who had night feedings and consumed sugar during sleep times. Mothers with infected infants had S. mutans levels > 5 x 10(5) CFU/mL saliva (p < 0.001), poorer oral hygiene, more periodontal disease, and lower socio-economic status (p < 0.02) and snacked frequently (p < 0.001), compared with mothers with non-infected infants.

Clinical significance of quantitative blood cultures in newborn infants

AIM

To evaluate quantitative blood culture as a secondary test on a positive blood culture for the diagnosis of sepsis in newborn infants.

METHOD

A 15-month prospective study of colony forming units (CFU) on positive blood cultures from newborn infants clinically suspected of having bacterial sepsis. Growth of bacteria in peripheral blood cultures was quantified using the isolater 1.5 microbial tube lysis direct plating culture system. Colony forming units were evaluated against a clinical assessment of infection.

RESULTS

Of 137 positive blood cultures, 71 (51.8%) were taken from neonates with clinically defined infection and 66 (48.2%) were from non-infected infants. The clinical and biographical data in these two groups were similar. Coagulase negative staphylococci were the most commonly isolated organisms in each group (60.6% vs 93.9%). Eight deaths from sepsis occurred in the clinically infected group. Eighty-five per cent of sepsis was late onset. Although a CFU count > or = 30/mL predicted sepsis (sensitivity 83%, specificity 60%, positive predictive value 69%, negative predictive value 76%), a CFU count < 30/mL did not rule out serious sepsis. The higher the CFU count the greater the likelihood of sepsis.

CONCLUSION

Quantitative blood culture was not shown to be a sensitive secondary test on a positive blood culture to distinguish clinical sepsis from culture contamination. Although a positive threshold of > or = 30 CFU/mL proved to be optimal, improvement in test performance would be expected with a lower incidence of culture contamination.

The influence of growth on development outcome in extremely low birthweight infants at 2 years of age

OBJECTIVE

To determine if weight < 3rd and < 10th centile at 2 years in extremely low birthweight (ELBW) infants is associated with problems of development and motor skills, and whether this association is explained by perinatal risk status.

METHODOLOGY

One hundred and ninety-eight of 226 (88%) surviving ELBW infants born between January 1987 and December 1992 were assessed at 2 years corrected age. Children were classified as being at low perinatal risk (n = 128) or high perinatal risk (n = 70) for adverse developmental outcome based on perinatal risk factors. Weight at 2 years was classified as < 3rd, 3rd-9th or > or = 10th centile for age and gender. Development was assessed using the Griffiths Mental Developmental Scales and motor skills using the Neurosensory Motor Developmental Assessment (NSMDA).

RESULTS

For the total study group weight centile was strongly related to General Quotient (GQ) and motor abilities. For children < 3rd percentile (n = 48) mean (GQ) was 90.4 (SD, 15.9), for children between the 3rd-9th percentile (n = 49) 91.5 (SD, 17.9), and for children > or = 10th percentile (n = 99) mean GQ was 99.8 (SD, 8.6). The association with mean GQ and NSMDA category occurred for the high-risk subgroup and became non-significant in the low-risk subgroup if neurologically abnormal children were excluded. Other perinatal risk factors, exposure to breast milk, level of maternal education, marital status and history of feeding problems or infections over the 2 years did not confound this association.

CONCLUSION

Low weight percentile at 2 years was related to adverse developmental outcome in ELBW infants at high perinatal risk or with neurological impairment, though minimal association was present for neurologically normal infants at low perinatal risk.

Varicella-zoster virus infection in Australia

OBJECTIVE

To determine the epidemiology of varicella-zoster virus (VZV) infection in Australia using currently available data sources.

DESIGN

Analysis of national death data (23 years), congenital and neonatal cases (one year) and attendances at sentinel general practices (two years); hospital admissions in NSW and SA (six years); serological studies in 1995 involving antenatal clinics in Sydney and Brisbane and child-care centre staff and refugees in Sydney; and case-ascertainment in 1995 in South Western Sydney among public hospital staff, child-care centre staff and the community.

RESULTS

In Australia, there have been an average of 3.5 deaths from chickenpox (mostly children) and 11 from herpes zoster (mostly older people) each year since 1980. The crude death rate for chickenpox has declined (p > 0.05). In 1995, there were 14 cases of neonatal and two of congenital varicella. Average annual admission rates for NSW and SA showed 1,200 hospital bed-days used for chickenpox, more than 20% with complications, and more than 7,300 bed days for zoster; annually more than 880 in-patient admissions were complicated by VZV. Most people encounter the virus in their first 15 years, but some remain susceptible into their 20s; 25% of cases and 37% of hospital admissions for chickenpox occur in people > or = 15 years of age.

CONCLUSION

VZV infection involves people of all ages. It causes substantial morbidity and mortality, particularly at the extremes of life. The death rate from chickenpox but not zoster has fallen since the introduction of acyclovir in the 1980s. Surveillance of VZV infection must be given priority once vaccines become available, to monitor changes in morbidity and mortality.

Neonatal cranial ultrasound screening for intraventricular haemorrhage

The cost effectiveness of performing routine neonatal cranial ultrasound scans to diagnose intraventricular haemorrhage (IVH) on cohorts of high risk infants is in question. In the early 1980s cranial ultrasound scans were performed on preterm infants to expand knowledge of the incidence, aetiology, pathogenesis and evolution of IVH. In many neonatal units high risk infants are scanned on days 5-7 and 10-14 and prior to discharge for extremely low birthweight (ELBW) infants. Cranial ultrasound scanning is often used as a surrogate for assessment of neurodevelopmental outcome with information from meta analyses used to counsel parents about the likelihood of subsequent neurosensory disability.

Infants born to narcotic dependent mothers: physical growth patterns in the first 12 months of life

OBJECTIVES

To describe the physical growth patterns of infants born to narcotic dependent mothers (INDM) over a 12 months period and, if possible, to relate the growth to drug taking patterns during pregnancy.

METHODOLOGY

The growth of a cohort of 43 INDM was measured during the first 12 months of life. Weight and length measurements were compared with percentile charts and converted to Z scores. Questionnaire data about drug taking practices, demographic variables and the neonatal period (including withdrawal scores) were obtained.

RESULTS

Twenty-four (55.8%) of INDM had evidence of neonatal drug withdrawal requiring treatment with phenobarbitone. At birth, Z scores for weight and length indicated relative intrauterine growth retardation. By 12 months, there had been some catch up growth, but Z scores for weight and length were still below zero. Persistent weight retardation at 12 months was correlated with methadone dosage during pregnancy, but not the need for phenobarbitone therapy.

CONCLUSIONS

The growth patterns of INDM in the first 12 months of life indicated that at birth there was evidence of intrauterine growth retardation, but by 12 months the growth was little different from the rest of the community. There appears to be some influence of narcotic agents taken while pregnant on subsequent growth of INDM.

Characteristics at four months follow-up of infants born small for gestational age: a controlled study

This prospective study compared 65 small-for-gestational-age (SGA) (birth weight < 3rd centile) and 71 control infants at a corrected age of 4 months. It was hypothesised that differences would exist in growth, development, temperament and minor neurological signs and that these would be predicted by type (proportional/disproportional) of growth restriction at birth and maternal mood disturbance at birth or at 4 months. Infants had a Griffith's developmental test and neuromotor assessment. Maternal mood and infant temperament were surveyed. Few differences were found between SGA and control infants. SGA infants showed catch-up growth with 63% being above the third percentile and 43% being above the tenth percentile for weight. SGA infants had lower Griffith's GQ scores (97 vs. 102, P = 0.02) and they were rated in temperament as more manageable than controls. There were no differences in subtle neuromotor signs. Neither type of SGA nor maternal mood disturbance at birth had prognostic significance for infant catch up growth, neuromotor scores, or temperament though level of maternal stress and anxiety at 4 months were related to lower GQ scores in SGA infants.

Aetiology and classification of small for gestational age infants

OBJECTIVE

To determine important aetiological factors in small gestational age (SGA) infants and the effectiveness of anthropometric indexes in identifying patterns of growth retardation.

METHODOLOGY

Eighty-four SGA infants and 81 controls were enrolled. Maternal biological, lifestyle and psychosocial factors were compared for the total group and the term Caucasian subset. Anthropometric indexes were also examined in relation to growth patterns.

RESULTS

Decreased maternal size, poor weight gain, previous SGA infant and smoking were significantly associated with SGA status. Poor parental education and unemployment was increased in the study group. Mothers of SGA infants, especially the term Caucasian group, had a greater prevalence of hypertension and depressive and stress symptomatology. Ponderal index failed to identify discreet patterns of disproportionate/proportionate growth retardation.

CONCLUSION

Biological, lifestyle and psychosocial differences remain important aetiological factors of intrauterine growth retardation. Identification of specific patterns of growth retardation by ponderal index remains controversial.

Survival and neonatal and neurodevelopmental outcome of 24-29 week gestation infants according to primary cause of preterm delivery

A total of 189 infants of 24-29 weeks' gestation were born in a regional perinatal centre during a 2-year period. They were divided into groups according to the primary cause of preterm delivery: antepartum haemorrhage (n = 37, 20%), preeclampsia (n = 27), 14%), preterm premature rupture of membranes (n = 64, 34%), preterm labour (n = 27, 14%), chorioamnionitis (n = 16, 8%), other complications (n = 18, 10%). The perinatal mortality rate (PMR) was 286/1,000 of whom 44% were stillbirths. The 'other complication' group had the highest PMR due to a large number of intrauterine deaths, with no differences in neonatal mortality between the groups. Preeclampsia was associated with an increased risk of necrotizing enterocolitis and chorioamnionitis was associated with an increased risk of periventricular haemorrhage. Follow-up to at least 2 years was performed in 122 (97%) of survivors. Cerebral palsy occurred in 7%, while 18% had neurodevelopmental disability. No relationship was found between primary cause of preterm delivery and outcome. This information should be of value in counselling parents when preterm delivery is imminent.

Enamel hypoplasia and dental caries in very-low birthweight children: a case-controlled, longitudinal study

This longitudinal study investigated the sequelae of enamel defects in a group of 25 white, very-low birthweight (VLBW), preterm children (mean birthweight 969 +/- 218 g, mean gestational age 27 +/- 1.9 weeks). Twenty-five race-, age-, and sex-matched, full-term normal birthweight (NBW) control children born at the same hospital, were selected randomly from hospital records. The children were examined at approximate ages of 30, 44, and 52 months. At all examinations, VLBW children had significantly higher prevalence of enamel hypoplasia than did the NBW children. At the last recall examination, 96% of VLBW group, and 45% of the NBW group had at least one tooth with enamel defect, with a mean of 7.6 +/- 4.9 affected teeth per VLBW child, and only 1.0 +/- 1.3 affected teeth per control child (P < 0.001). A significant association of enamel defects with dental caries was observed only in the VLBW group on the second and third examinations (P < 0.001). The defect identified to be most significantly associated with dental caries was a variant showing both enamel hypoplasia and opacity. In spite of a high prevalence of enamel defects, the overall prevalence of dental caries in the VLBW children was not significantly different from that of NBW controls at all three examinations (P < 0.1). Other caries risk factors such as levels of Streptococcus mutans infection, fluoride supplementation, plaque scores, toothbrushing frequency, and daily sugar exposures were examined but none was found to be related significantly to development of dental caries.

School performance of ELBW children: a controlled study

This paper examines the prevalence of learning difficulty in reading, spelling, mathematics and writing and the prevalence of attention deficit disorder (ADD) in extremely low-birthweight (ELBW) children at school compared to their peers. Parents of 87 eligible ELBW children completed an educational questionnaire and questionnaire for ADD. Teachers of the ELBW children completed a detailed educational and ADD questionnaire for the study child and two control children in the same class, matched for age and nearest in birth date to the study child. Parents reported that 4% of the ELBW children born between 1977 and 1986 were in a special education unit, 46% received remedial help and 21% repeated a grade. Teacher assessment of six aspects of reading and spelling and five aspects of mathematics and writing skills indicated that the ELBW children experienced marked problems in all areas compared to control children and were approximately 3 times more likely to be delayed by more than a year in all areas. Prevalence of ADD was not increased in the ELBW children compared to the control group, though males in both groups had a higher prevalence of symptoms. Early intervention and special education resources must be available for ELBW children attending school.

Which milk for the preterm infant?

The optimal diet for the low birthweight infant is one that supports a growth rate approximating that of the third trimester of intra-uterine life without imposing stress on the developing metabolic or excretory systems. Although preterm human milk does not meet the energy and nutrient needs of developing preterm infants, the benefits such as contributions to host defence and gastrointestinal trophic aspects, and the psychological benefits of maternal-infant bonding, make it the preferred diet.

Neonatal bacterial sepsis in a neonatal intensive care unit: a 5 year analysis

OBJECTIVE

To study the pattern of neonatal sepsis in a neonatal intensive care unit (NICU) during a 5 year period and assess the relationship between maternal risk factors and early onset sepsis (EOS).

METHODOLOGY

The study reported here was a retrospective analysis of 209 episodes of septicaemia and 5 episodes of bacterial meningitis in 198 newborn infants, 22 of whom died. Eighty-one infants had EOS (< or = 72 h) and 117 infants had late onset sepsis (LOS > 72 h). All infants had clinical evidence of sepsis, a computerized haematological score for sepsis of 4 or greater, and either treatment with antibiotics for 7 days or more or had earlier death due to sepsis. The organisms causing neonatal sepsis were analyzed according to the day of onset, gestational age, birthweight and year of infection.

RESULTS

Sepsis occurred in 5.6 per 1000 live births and 3.8% of NICU admissions. There were 81 episodes of EOS and 128 of LOS. Coagulase negative staphylococci (CONS) 38.8%, group B Streptococcus (GBS) 20.1% and Gram-negative bacilli (GNB) 20.1% were the common causes of sepsis; and GBS (50.6%) and CONS (60.9%) were the most common organisms in EOS and LOS, respectively. The mean gestational age and birthweight were higher in babies with EOS than compared with LOS. The higher likelihood of probable rather than definite infection in infants with EOS was related to more mothers in the EOS group receiving intrapartum antibiotics. GNB infection was more common in their babies.

CONCLUSIONS

GBS and CONS were the most common causes of EOS and LOS, respectively. The use of maternal intrapartum antibiotics interferes with neonatal blood culture results. Because blood cultures are not always positive in neonatal septicaemia, a combination of clinical, haematological and other microbiological evidence should be used when diagnosing neonatal septicaemia.

Prevalence and aetiology of neurological impairment in extremely low birthweight infants

OBJECTIVE

To determine the prevalence and perinatal predictors of cerebral palsy, intellectual impairment, visual impairment and deafness in a cohort of extremely low birthweight (ELBW) infants at two years of age.

METHODOLOGY

The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, between July 1977 and February 1990 and who survived to two years. The prevalence of cerebral palsy, intellectual impairment, blindness and deafness was measured by clinical,psychometric and audiological assessment and the association with 24 risk factors examined.

RESULTS

Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associated with ventricular dilatation, intraventricular haemorrhage, necrotizing enterocolitis and multiple birth, though only ventricular dilatation (OR 4.41; 95% CI 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and was independently associated with ventricular dilatation (OR 15.0; 95% CI 2.2-102.8), ventilation F(i)(2) > 80% (OR 3.4; 95% CI 1.01-11.5), vaginal delivery (OR 3.5; 95% Cl 1.09-11.4) and male sex (OR 6.1; 95% Cl 1.67-22.3). No perinatal predictor was statistically associated with risk of deafness. Retinopathy of prematurity (OR 36.9; 95% Cl 2.8-495.5) was associated with risk of later visual impairment.

CONCLUSIONS

Intellectual impairment was associated with a broad range of perinatal variables. Cerebral palsy was associated with fewer variables, all of which were also associated with intellectual impairment. Neurologic injury was associated with male sex and multiple birth, which are not biological insults themselves, but may be markers of susceptibility to injury.

Neonatal neutropenia and thrombocytopenia following maternal hypertension

OBJECTIVE

To assess the relationship between the subtypes of hypertension in pregnancy and subsequent neonatal haematology.

METHODOLOGY

Retrospective review of the haematology of newborns of hypertensive mothers at a tertiary neonatal unit.

RESULTS

Over a 2 year period, 249 infants had full blood examinations. Nineteen (7.6%) were neutropenic and 35 (14.1%) thrombocytopenic, including 11 (4.4%) who were both neutropenic and thrombocytopenic. Neutropenia occurred only in infants whose mothers had severe pre-eclampsia and eclampsia or pre-eclampsia with pre-existing hypertension, whereas thrombocytopenia complicated all maternal hypertension subtypes. Two (10%) of the neutropenic infants developed nosocomial infection while seven (20%) of the thrombocytopenic infants bled. Thirteen (68%) of the neutropenic infants compared with 15 (43%) of the thrombocytopenic infants developed their haematological abnormality within 24 h of birth. All but two infants developed the haematological abnormality by the 5th day of life.

CONCLUSION

Although haematological abnormalities in infants born to hypertensive mothers are uncommon, serious neonatal complications can occur and therefore early haematological screening of these infants is recommended.

Neurodevelopmental outcome of preterm infants with bronchopulmonary dysplasia

The neurodevelopmental outcome of 78 infants with bronchopulmonary dysplasia (BPD) was compared with that of 78 control infants matched for birthweight. To determine the effect of the severity of BPD, 62 infants requiring oxygen at 36 weeks' postmenstrual age (sBPD) were compared with their matched controls. Infants were followed up to 2 years of age, corrected for prematurity, and were classified for neurological impairment, developmental delay, and neurodevelopmental disability. Seventy six (98%) BPD infants and 71 (91%) controls had follow up data available to two years. Neurological impairment, developmental delay, and neurodevelopmental disability occurred more frequently in infants with BPD than in controls but this was not significant. For infants with sBPD, the increased incidence of neurological impairment and definite developmental delay was not significant when compared with the controls, though neurodevelopmental disability occurred more frequently (odds ratio (OR) 3.6: 95% confidence intervals (CI) 1.1-11.8). Predictors of disability in infants with sBPD included periventricular haemorrhage (OR 19.4: 95% CI 4.3-86.6), ventricular dilatation (OR 12.8: 95% CI 2.9-57.3), and sepsis (OR 5.0: 95% CI 1.3-19.4). Adjusting for the presence of these factors, the association between BPD and disability was no longer apparent (OR 0.9: 95% CI 0.2-3.6). The findings suggest that BPD is not independently associated with adverse neurodevelopmental outcome.

Systemic bacterial and fungal infections in infants in Australian neonatal units. Australian Study Group for Neonatal Infections

OBJECTIVE

To examine the pattern and incidence of sepsis occurring in neonatal units in Australia.

DESIGN

A one-year prospective study of babies with systemic sepsis within 48 hours of birth (early-onset sepsis) or after this time (late-onset sepsis) in seven Australian neonatal units. Systemic sepsis was defined as clinical sepsis, plus either positive bacterial or fungal culture of blood and/or cerebrospinal fluid, or group B streptococcal antigen detected in the urine.

RESULTS

There were 241 episodes of sepsis, affecting 234 babies. One quarter (61) were early-onset, a rate of 2.2 per 1000 live births. Group B streptococcus (GBS) was the commonest cause of early-onset sepsis, with a rate of 1.3 per 1000 live births. The incidence of early-onset GBS sepsis was lower at a hospital which screened for maternal carriage and used intrapartum antibiotic prophylaxis for all carriers. The rate of late-onset sepsis was 4.4 per 1000 live births and coagulase-negative staphylococci were the commonest cause. Meningitis occurred in 23% of babies with early-onset and in 10% with late-onset sepsis. The mortality from early-onset sepsis was 15%, and from late-onset sepsis was 9%. There were no major regional variations, other than for GBS.

CONCLUSIONS

The incidence of and mortality from neonatal sepsis is comparable to other countries, and shows no major regional variation. The use of intrapartum antibiotics may reduce the incidence of neonatal GBS sepsis. There are no previous comparable data on neonatal infections in Australia.

Extremely low birth weight and control infants at 2 years corrected age: a comparison of intellectual abilities, motor performance, growth and health

A 2-year cohort of 63 surviving extremely low birth weight (ELBW) infants was prospectively studied and 60 of these infants, together with 44 normal birth weight control infants, were assessed at 2 years of age for intellectual abilities, motor skills, growth and health. The total ELBW group differed significantly from controls on overall Griffiths developmental quotient (99.3 vs. 103.8 P = 0.02) and in the personal/social subscale (100.7 vs. 106.7 P = 0.01). A subset of 43 of the ELBW infants was identified as low risk at discharge. No statistically significant differences were present between the low risk ELBW subset and controls in intellectual abilities though both the total ELBW group and the low risk ELBW subset differed from controls in fine and gross motor abilities, and in weight at 2 years. The total ELBW group also experienced more frequent ill health and hospital readmission.

Outcome of resuscitated apparently stillborn infants: a ten year review

This study addresses the dilemma of whether to attempt resuscitation of the previously undiagnosed fresh stillborn infant and evaluates factors predictive of survival and long-term outcome. We reviewed the clinical spectrum, immediate complications and long-term outcome of 45 successfully resuscitated apparently stillborn infants (34 term, 11 preterm) who were admitted to the Intensive Care Nursery. Significant obstetric and intrapartum events were identified in 34 (75%) infants while 11 (25%) had no apparent risk factors. Of the 39 infants with neonatal complications, 37 had hypoxic-ischaemic encephalopathy (HIE: Sarnat stage 1 in 5, stage 2 in 15, stage 3 in 17); 12 (27%) had oliguria, 10 (22%) had hypotension, 7 (16%) experienced hypoglycaemia, 4 (9%) had disseminated intravascular coagulopathy (DIC) and 1 (2%) had persistent pulmonary hypertension of the newborn (PPHN). Fourteen infants (31%) died in the neonatal period and four (9%) died during infancy. Risks of death and adverse neurodevelopment were significantly increased in infants with stage 2 or 3 HIE (P < 0.005). Follow-up assessment of 24 of the 27 surviving infants revealed a normal outcome in 15 (63%), severe disability in six (25%), moderate disability in two (8%) and mild disability in one (4%) infant. The positive predictive value of stage 2 or 3 HIE was 70% for mortality and 80% for morbidity. One-third (15/45) of successfully resuscitated apparently stillborn infants were normal at follow-up assessment and the outcome for these infants was predicted with complete accuracy by the stage of HIE present during the neonatal period.

Handedness in extremely low birth weight infants: aetiology and relationship to intellectual abilities, motor performance and behaviour at four and six years

Hand preference was measured in a total group of 71 ELBW children to determine patterns of hand preference at 4 and 6 years, possible aetiological factors leading to handedness, and whether left or non right hand preference were markers for intellectual, motor, temperament or behavioural differences. At both 4 and 6 years the prevalence of left handedness was increased, though this prevalence changed over the period of the study. Results supported brain injury as one mechanism leading to increased left hand preference, though this process did not adequately explain this increase. Possible reasons for this and the apparent change in prevalence with time are examined. Mixed handedness at 4 years was associated with lower intellectual abilities though otherwise children were similar in motor skills, temperament and behaviour independent of hand preference category.

The prevalence and origins of left hand preference in high risk infants, and its implications for intellectual, motor and behavioural performance at four and six years

This study investigates the origins of hand preference at 4 years in a cohort of 115 high risk and premature infants; the relationship between patterns of hand preference and intellectual, motor, temperament and behavioural status at 4 and 6 years; and evidence for brain injury in mediating the relationship between hand preference and development disorder. Increased left hand preference was independently associated with extreme prematurity, high neonatal risk, increased numbers of minor physical anomalies, lowered intellectual and motor abilities, and more difficult temperament. These findings supported the presence of intrauterine and neonatal pathological mechanisms leading to left hand preference in a small number of children. Neither poor function of the non dominant hand nor absence of a family history of left handedness could further define this pathological subgroup. Support for pathological mechanisms producing left handedness was found predominatly in the infants of high birth weight, whereas prevalence of left handedness was increased mainly among the extremely low birth weight infants. In this latter group the prevalence of left handedness was also increased among children of normal intelligence, suggesting that mechanisms other than brain damage lead to left hand preference in very premature infants.

Perinatal hypoxic-ischaemic brain injury: prediction of outcome

Twenty-six term babies with hypoxic-ischaemic brain injury were studied during the neonatal period to evaluate the prediction of outcome to at least one year of age by means of ultrasonography, CT scanning and Doppler ultrasound assessment of cerebral palsy blood flow velocity (CBFV). Adverse outcome was defined as the occurrence of cerebral palsy, developmental delay or death. At follow-up, 17 infants had an adverse outcome (seven died, 10 had disability); the remainder had no detectable impairment. Abnormalities on cranial ultrasound were not, but generalised decreased tissue density on CT scan was, associated with adverse outcome. Abnormal mean CBFV in the middle cerebral artery had no association with outcome, but abnormal mean CBFV in the anterior cerebral artery and a low resistance index in both arteries were significantly associated with adverse outcome. Such information may be used for appropriate counselling of parents of asphyxiated infants.

Hematologic scoring system in early diagnosis of sepsis in neutropenic newborns

The hematologic profiles of 1000 newborns were prospectively examined to identify infants with neutropenia (N = 170) according to the system of Manroe et al. (J Pediatr 1979;95:89-98) and to evaluate a hematologic scoring system (Rodwell et al. J Pediatr 1988;112:761-7) as a screening test for sepsis. Neutropenia was more commonly of noninfectious than infectious origin (83.5% vs. 16.5%; P < 0.001). On the initial test a positive screen (scores > or = 3) identified 26 of 28 infants with sepsis or probable infection (sensitivity 93%; specificity 82%; positive and negative predictive values 50 and 98%, respectively). Corresponding values for an elevated immature:total neutrophil ratio were 100, 75, 43 and 100%. Overall mortality with neutropenia was 15% and was higher with an infectious than a noninfectious etiology (39% vs. 11%, P < 0.001) despite early antibiotic therapy. The combination of a neutrophil count < or = 500/mm3 and scores > or = 3 or an elevated immature:total neutrophil ratio identified a poor prognostic group: 67% (8 of 12) and 70% (7 of 10) infants, respectively, with these findings died, 6 in the infected group. The hematologic scoring system or immature:total neutrophil ratio in combination with the degree of neutropenia provides valuable diagnostic and prognostic information which could be applied to identification of possible candidates for granulocyte transfusions or other experimental treatments.

Assessment of bioelectrical impedance for individualizing gentamicin therapy in neonates

The use of bioelectrical impedance (BI) analysis as a non-invasive approach for individualizing gentamicin therapy in newborn infants has been investigated in a two phase study. In Phase I, 1/impedance and length were identified as statistically significant predictors of the distribution volume of gentamicin (Adj R2 = 0.78, CV = 12.42%), and length/impedance and post-conceptual age were predictors of total systemic clearance (Adj R2 = 0.83, CV = 14.5%), following the administration of 2.5 mg.kg-1 gentamicin to 17 neonates (gestational age (GA) 27 to 36 weeks). In a prospective validation of these relationships in an independent (Phase II) group of 27 infants (GA 26 to 41 weeks), predicted serum gentamicin concentrations were close to those achieved. Several instances of high prediction errors (predicted minus achieved levels) were observed in infants with known or suspected renal impairment and they caused significant (P < 0.05) perturbation in the bias and accuracy of the models. Daily BI measures over a four to five day period were able to detect individual changes in the fat-free body compartments, which were translated into alterations in gentamicin regimens. This simple, non-invasive and relatively inexpensive bedside technique provides a potentially valuable means to individualize gentamicin therapy without relying on the measurement of serum gentamicin concentration.

Capillary plasma elastase alpha 1-proteinase inhibitor in infected and non-infected neonates

Capillary heel prick plasma elastase alpha 1-proteinase inhibitor (E alpha 1-PI) measured by an immunoassay (using commercially available reagents) was examined as an early indicator of neonatal sepsis. Fifty five infants were studied within 24 hours of birth; 60 (including 10 studied on the first day of life) were examined between two and 30 days after birth. Reference ranges for the neonatal period were developed. Raised E alpha 1-PI concentrations (range 440-2600 micrograms/l) were found at the outset of each of the 24 infectious episodes including five with concomitant neutropenia. On the first day of life, obstetric and neonatal complications were also associated with high concentrations (range 190-2400 micrograms/ml). In infants who survived infection, E alpha 1-PI normalised with antibiotic treatment. It is concluded that capillary heel prick plasma is suitable for E alpha 1-PI testing and raised concentrations provide a sensitive but non-specific index of infection in the first 24 hours after birth. Sequential testing may provide early warning of infectious complications and serve as a guide to the cessation of antibiotic treatment.

Cystic encephalomalacia and intrauterine herpes simplex virus infection

Cystic encephalomalacia occurred in two preterm infants who had proven intrauterine herpes simplex virus type 2 infection. Calcification was evident in the basal ganglia. Follow-up scans indicated that the cysts had resolved over a period of two months in one infant, while in the case of the other, the cysts became progressively larger with significant ventricular dilatation developing. While cystic changes in the brain of preterm infants are usually due to periventricular leukomalacia, intrauterine infection needs to be considered as a possible cause. Antiviral treatment may be of benefit to infants with herpes simplex virus infection.

Alloimmune neonatal neutropenia in Australian aboriginals: an unrecognized disorder?

Alloimmune neonatal neutropenia (ANN) is reported for the first time in two Australian aboriginals. Both infants displayed the typical clinical features of ANN with profound neutropenia which persisted for 7 weeks and only minor infectious episodes. However, management strategies differed for the two infants because in one case (complicated by uncertain paternity) serological confirmation of ANN was not obtained until after recovery of the infant's neutrophil count. The maternal antibodies could not be assigned to known neutrophil antigen specificities and a new antigen may be involved. The antibodies were reactive with > 99% of neutrophils in a Caucasian population. Aboriginals comprise 1% of the total population of Australia and 1-2% of the obstetric population at our institution. Thus, ANN may be an unrecognized disorder in this ethnic group and a possible cause of neonatal infection and mortality.

Mineral deficiency in the pathogenesis of enamel hypoplasia in prematurely born, very low birthweight children

Although it is well known that enamel hypoplasia commonly is observed in prematurely born, very low birthweight (VLBW) children, its pathogenesis is not understood clearly. One likely mechanism may be related to mineral deficiency, which may be diagnosed as radiological demineralization of the long bones. In this study, we compared the cortical area of the humerus as measured from neonatal radiographs in 31 VLBW children with enamel hypoplasia and 14 VLBW children without enamel hypoplasia. The results showed that children with enamel hypoplasia had a lower mean cortical area of 10.1 +/- 1.9 mm2 compared with 13.9 +/- 1.4 mm2 in children without enamel hypoplasia (P less than 0.001). It was also found that intubated children with a lower cortical mass may be more predisposed to develop localized enamel hypoplasia caused by the laryngoscope (P less than 0.001).

Early identification of cerebral palsy in high risk infants

This study of high risk infants aimed to identify which signs at the corrected ages of 1, 4 and 8 months were important for distinguishing those infants who later developed hypertonic cerebral palsy (CP). From a total cohort of 450 infants (350 of birthweight less than 1500 g and 100 of birthweight greater than 1500 g), 26 infants were later diagnosed as having CP and formed the study group. A control group of 26 infants from the same initial cohort who did not develop CP was matched to the study group. Both groups were followed for a minimum of 2 years. At each assessment (1, 4, 8, 24 months corrected age), all children were assessed using a standard medical examination and a detailed neurosensorimotor developmental scale that evaluated neurological signs, motor attainments, primitive reflexes and postural reactions. Each test response was graded as normal, suspect or abnormal and the results for the two groups were compared. Assessment at 1 month failed to identify a number of the CP infants whereas at 4 months there was some overidentification. At 8 months, assessment was highly predictive of cerebral palsy. Individual signs of abnormality were found to be of limited value but the presence of three or more abnormal signs at 8 months was highly predictive of CP.

Cost-analysis of neonatal intensive and special care

In the present economic climate and with increasing expenditure on neonatal intensive care, there has been a demand for economic evaluation and justification of neonatal intensive care programmes. This study assesses the inhospital costs of neonatal intensive care. Fixed and variable costs were calculated for services and uses of an Intensive/Special Care Nursery for the year 1985 and corrected to 1987 Australian dollar equivalents. Establishing a new neonatal intensive care unit of 43 costs in an existing hospital with available floor space including operating costs for a year were estimated in Australian dollars for 1987 at $6,408,000. Daily costs per baby for each were $1282 ventilator, $481 intensive, $293 transitional and $287 recovery, respectively. The cost per survivor managed in the Intensive/Special Care Nursery in 1985 showed the expected inverse relationship to birthweight being $2400 for greater than 2500 g, $4050 for 2000-2500 g, $9200 for 1500-1999 g, $23,900 for 1000-1499 g and $63,450 for less than 1000 g. Further analysis for extremely low birthweight infants managed in 1986 and 1987 demonstrated costs per survivor of $128,400 for infants less than 800 g birthweight and $43,950 for those 800-999 g. This methodology might serve as a basis for further accounting and cost-evaluation exercises.