Oxygen targeting in preterm infants using the Masimo SET Radical pulse oximeter

BACKGROUND

A pretrial clinical improvement project for the BOOST-II UK trial of oxygen saturation targeting revealed an artefact affecting saturation profiles obtained from the Masimo Set Radical pulse oximeter.

METHODS

Saturation was recorded every 10 s for up to 2 weeks in 176 oxygen dependent preterm infants in 35 UK and Irish neonatal units between August 2006 and April 2009 using Masimo SET Radical pulse oximeters. Frequency distributions of % time at each saturation were plotted. An artefact affecting the saturation distribution was found to be attributable to the oximeter's internal calibration algorithm. Revised software was installed and saturation distributions obtained were compared with four other current oximeters in paired studies.

RESULTS

There was a reduction in saturation values of 87-90%. Values above 87% were elevated by up to 2%, giving a relative excess of higher values. The software revision eliminated this, improving the distribution of saturation values. In paired comparisons with four current commercially available oximeters, Masimo oximeters with the revised software returned similar saturation distributions.

CONCLUSIONS

A characteristic of the software algorithm reduces the frequency of saturations of 87-90% and increases the frequency of higher values returned by the Masimo SET Radical pulse oximeter. This effect, which remains within the recommended standards for accuracy, is removed by installing revised software (board firmware V4.8 or higher). Because this observation is likely to influence oxygen targeting, it should be considered in the analysis of the oxygen trial results to maximise their generalisability.

The effectiveness of antenatal care programmes to reduce infant mortality and preterm birth in socially disadvantaged and vulnerable women in high-income countries: a systematic review

BACKGROUND

Infant mortality has shown a steady decline in recent years but a marked socioeconomic gradient persists. Antenatal care is generally thought to be an effective method of improving pregnancy outcomes, but the effectiveness of specific antenatal care programmes as a means of reducing infant mortality in socioeconomically disadvantaged and vulnerable groups of women has not been rigorously evaluated.

METHODS

We conducted a systematic review, focusing on evidence from high income countries, to evaluate the effectiveness of alternative models of organising or delivering antenatal care to disadvantaged and vulnerable groups of women vs. standard antenatal care. We searched Medline, Embase, Cinahl, PsychINFO, HMIC, CENTRAL, DARE, MIDIRS and a number of online resources to identify relevant randomised and observational studies. We assessed effects on infant mortality and its major medical causes (preterm birth, congenital anomalies and sudden infant death syndrome (SIDS)) RESULTS: We identified 36 distinct eligible studies covering a wide range of interventions, including group antenatal care, clinic-based augmented care, teenage clinics, prenatal substance abuse programmes, home visiting programmes, maternal care coordination and nutritional programmes. Fifteen studies had adequate internal validity: of these, only one was considered to demonstrate a beneficial effect on an outcome of interest. Six interventions were considered 'promising'.

CONCLUSIONS

There was insufficient evidence of adequate quality to recommend routine implementation of any of the programmes as a means of reducing infant mortality in disadvantaged/vulnerable women. Several interventions merit further more rigorous evaluation.

Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection

BACKGROUND

Observational studies of pregnant women in sub-Saharan Africa have shown that low serum vitamin A levels are associated with an increased risk of mother-to-child transmission (MTCT) of HIV. Vitamin A is cheap and easily provided through existing health services in low-income settings. It is thus important to determine the effect of routine supplementation of HIV positive pregnant or breastfeeding women with this vitamin on the risk of MTCT of HIV, which currently results in more than 1000 new HIV infections each day world-wide.

OBJECTIVES

We aimed to assess the effect of antenatal and or postpartum vitamin A supplementation on the risk of MTCT of HIV as well as infant and maternal mortality and morbidity.

SEARCH STRATEGY

In June 2010 we searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, AIDS Education Global Information System, and WHO International Clinical Trials Registry Platform; and checked reference lists of identified articles for any studies published after the earlier version of this review was updated in 2008.

SELECTION CRITERIA

We selected randomised controlled trials conducted in any setting that compared vitamin A supplementation with placebo in known HIV-infected pregnant or breastfeeding women.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed trial eligibility and quality and extracted data. We calculated relative risks (RR) or mean differences (MD), with their 95% confidence intervals (CI) for each study. We conducted meta-analysis using a fixed-effects method (when there was no significant heterogeneity between study results, i.e. P>0.1) or the random-effects method (when there was significant heterogeneity), and report the Higgins' statistic for all pooled effect measures.

MAIN RESULTS

Five randomised controlled trials which enrolled 7,528 HIV-infected women (either during pregnancy or the immediate postpartum period) met our inclusion criteria. These trials were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005. We combined the results of these trials and found no evidence that vitamin A supplementation has an effect on the risk of MTCT of HIV (4 trials, 6517 women: RR 1.04, 95% CI 0.87 to 1.24; I(2)=68%). However, antenatal vitamin A supplementation significantly improved birth weight (3 trials, 1809 women: MD 89.78, 95%CI 84.73 to 94.83; I(2)=33.0%), but there was no evidence of an effect on preterm births (3 trials, 2110 women: RR 0.88, 95%CI 0.65 to 1.19; I(2)=58.1%), stillbirths (4 trials, 2855 women: RR 0.99, 95%CI 0.68 to 1.43; I(2)=0%), deaths by 24 months (2 trials, 1635 women: RR 1.03, 95%CI 0.88 to 1.20; I(2)=0%), postpartum CD4 levels (1 trial, 727 women: MD -4.00, 95% CI -51.06 to 43.06), and maternal death ( 1 trial, 728 women: RR 0.49, 95%CI 0.04 to 5.37).

AUTHORS' CONCLUSIONS

Current best evidence shows that antenatal or postpartum vitamin A supplementation probably has little or no effect on mother-to-child transmission of HIV. According to the GRADE classification, the quality of this evidence is moderate; implying that the true effect of vitamin A supplementation on the risk of mother-to-child transmission of HIV is likely to be close to the findings of this review, but that there is also a possibility that it is substantially different.

NeOProM: Neonatal Oxygenation Prospective Meta-analysis Collaboration study protocol

BACKGROUND

The appropriate level of oxygenation for extremely preterm neonates (<28 weeks' gestation) to maximise the greatest chance of survival, without incurring significant morbidity, remains unknown. Infants exposed to lower levels of oxygen (targeting oxygen saturations of <90%) in the first weeks of life are at increased risk of death, cerebral palsy, patent ductus arteriosus, pulmonary vascular resistance and apnoea, whilst those maintained in higher levels of oxygen (targeting oxygen saturations of >90%) have been reported to have greater rates of morbidity including retinopathy of prematurity and chronic lung disease. In order to answer this clinical dilemma reliably, large scale trial evidence is needed.

METHODS/DESIGN

To detect a small but important 4% increase in death or severe disability in survivors, over 5000 neonates would need to be recruited. As extreme prematurity affects 1% of births, such a project undertaken by one trial group would be prohibitively lengthy and expensive. Hence, the Neonatal Oxygenation Prospective Meta-analysis (NeOProM) Collaboration has been formed. A prospective meta-analysis (PMA) is one where studies are identified, evaluated, and determined to be eligible before the results of any included studies are known or published, thereby avoiding some of the potential biases inherent in standard, retrospective meta-analyses. This methodology provides the same strengths as a single large-scale multicentre randomised study whilst allowing greater pragmatic flexibility. The NeOProM Collaboration protocol (NCT01124331) has been agreed prior to the results of individual trials being available. This includes pre-specifying the hypotheses, inclusion criteria and outcome measures to be used. Each trial will first publish their respective results as they become available and the combined meta-analytic results, using individual patient data, will be published when all trials are complete. The primary outcome to be assessed is a composite outcome of death or major disability at 18 months - 2 years corrected age. Secondary outcomes include several measures of neonatal morbidity. The size of the combined dataset will allow the effect of the interventions to be explored more reliably with respect to pre-specified patient- and intervention-level characteristics.

DISCUSSION

Results should be available by 2014.

Routine educational outcome measures in health studies: Key Stage 1 in the ORACLE Children Study follow-up of randomised trial cohorts

OBJECTIVES

Statutory educational attainment measures are rarely used as health study outcomes, but Key Stage 1 (KS1) data formed secondary outcomes in the long-term follow-up to age 7 years of the ORACLE II trial of antibiotic use in preterm babies. This paper describes the approach, compares different approaches to analysis of the KS1 data and compares use of summary KS1 (level) data with use of individual question scores.

PARTICIPANTS

3394 children born to women in the ORACLE Children Study and resident in England at age 7.

METHODS

Analysis of educational achievement measured by national end of KS1 data (KS1) using Poisson regression modelling and anchoring of the KS1 data using external standards.

RESULTS

KS1 summary level data were obtained for 3239 (95%) eligible children; raw individual question scores were obtained for 1899 (54%). Use of individual question scores where available did not change the conclusion of no evidence of treatment effects based on summary KS1 outcome data.

CONCLUSIONS

When accessible for medical research purposes, routinely collected educational outcome data may have advantages of low cost and standardised definition. Here, summary scores lead to similar conclusions to raw (individual question) scores and so are attractive and cost-effective alternatives.

Has publication of the results of the ORACLE Children Study changed practice in the UK?

OBJECTIVE

  To investigate whether publication of the results of the ORACLE Children's Study, a 7-year follow-up of the ORACLE trial, changed practice with regard to the routine prescription of antibiotics to women with preterm rupture of membranes or spontaneous preterm labour (intact membranes).

DESIGN

  A comparative questionnaire survey of clinical practice in November 2007 (before publication) and March 2009 (after publication).

POPULATION

  Lead obstetricians for labour wards of all maternity units in the UK.

METHODS

  Self-administered questionnaires requested information about the routine prescription of antibiotics to women with either preterm rupture of membranes or spontaneous preterm labour (intact membranes).

MAIN OUTCOME MEASURES

  Change in practice for prescription of antibiotics.

RESULTS

  The response rate was 166/214 (78%) in 2007 and 158/209 (76%) in 2009. In total, 120 maternity units responded on both occasions. For women with preterm rupture of membranes, 162/214 (98%) in 2007 and 151/158 (96%) in 2009 maternity units reported that they prescribed antibiotics, with the majority using erythromycin (98%). For women with spontaneous preterm labour (intact membranes), 35/166 (21%) in 2007 and 25/158 (16%) in 2009 maternity units reported that they routinely prescribed antibiotics. The findings from units who responded on both occasions are similar.

CONCLUSIONS

  There has been little change in the reported prescription of antibiotics to women with either preterm rupture of membranes or spontaneous preterm labour following publication of the ORACLE Children's Study. This suggests that current practice may require updated guidance.

Influenza A/H1N1v in pregnancy: an investigation of the characteristics and management of affected women and the relationship to pregnancy outcomes for mother and infant

BACKGROUND

In April 2009 a novel influenza A virus (AH1N1v) of swine origin (swine flu) emerged, spreading rapidly and achieving pandemic status in June 2009. Pregnant women were identified as being at high risk of severe influenza-related complications and as a priority group for vaccination against AH1N1v. Limited information was available about the maternal and fetal risks of AH1N1v infection or of antiviral drug or AH1N1v vaccine use in pregnancy.

OBJECTIVES

To assess rates of and risk factors for adverse outcomes following AH1N1v infection in pregnancy and to assess the adverse effects of the antiviral drugs and vaccines used in prevention and management.

METHODS

Prospective national cohort studies were conducted to identify pregnant women who were (1) suspected to be infected with AH1N1v or being treated with antiviral medication in primary care; (2) vaccinated against AH1N1v; and (3) admitted to hospital with confirmed AH1N1v. Characteristics of women with influenza-like illness (ILI) in primary care were compared with those of women without symptoms accepting or declining immunisation. Characteristics of women admitted to hospital with confirmed AH1N1v infection in pregnancy were compared with a historical cohort of over 1200 women giving birth in the UK who were uninfected with AH1N1v. Outcomes examined in hospitalised women included maternal death, admission to an intensive care unit, perinatal mortality and preterm birth. Risk factors for hospital and intensive care unit admission were examined in a full regression model.

RESULTS

The weekly incidence of ILI among pregnant women averaged 51/100,000 over the study period. Antiviral drugs were offered to 4.8% [95% confidence interval (CI) 4.0% to 5.9%] and vaccination to 64.8% (95% CI 64.7% to 68.9%) of registered pregnant women. Ninety pregnant women with ILI presenting in primary care were reported to the research team, 55 of whom were prescribed antiviral drugs and in 42 (76%) cases this was within 2 days of symptom onset. After comparison with 1329 uninfected pregnant women offered vaccination, pre-existing asthma was the only maternal factor identified as increasing risk of ILI presentation [adjusted odds ratio (OR) 2.0, 95% CI 1.0 to 3.9]. Maternal obesity and smoking during pregnancy were also associated with hospital admission with AH1N1v infection. Overall, 241 pregnant women were admitted to hospital with laboratory-confirmed AH1N1v infection. Eighty-three per cent of these women were treated with antiviral agents, but only 6% received antiviral treatment before hospital admission. Treatment within 2 days of symptom onset was associated with an 84% reduction in the odds of admission to an intensive therapy unit (OR 0.16, 95% CI 0.08 to 0.34). Women admitted to hospital with AH1N1v infection were more likely to deliver preterm; a three times increased risk was suggested compared with an uninfected population cohort (OR 3.1, 95% CI 2.1 to 4.5).

CONCLUSIONS

Earlier treatment with antiviral agents is associated with improved outcomes for pregnant women and further actions are needed in future pandemics to ensure that antiviral agents and vaccines are provided promptly to pregnant women, particularly in the primary care setting. Further research is needed on longer-term outcomes for infants exposed to AH1N1v influenza, antiviral drugs or vaccines during pregnancy.

Critical illness with AH1N1v influenza in pregnancy: a comparison of two population-based cohorts

OBJECTIVE

To compare admissions to intensive care units (ICUs) with confirmed AH1N1v influenza in pregnancy in Australia, New Zealand and the UK.

DESIGN

National cohort studies.

SETTING

ICUs in Australia, New Zealand and the UK.

POPULATION

Fifty-nine women admitted to ICUs in Australia and New Zealand in June-August 2009, and 57 women admitted to ICUs in the UK in September 2009-January 2010.

METHODS

Comparison of cohort data.

MAIN OUTCOME MEASURES

Incidence of ICU admission, comparison of characteristics and outcomes.

RESULTS

There was a significantly higher ICU admission risk in Australia and New Zealand than in the UK (risk ratio 2.59, 95% CI 1.75-3.85). Indigenous women from Australia and women with Maori/Pacific Island backgrounds from New Zealand had the highest admission risk (29.7 admissions per 10 000 maternities, 95% CI 17.9-46.3). Women admitted in Australia and New Zealand were significantly more likely to have a pre-existing medical condition (51% versus 21%, P = 0.001), but were less likely to receive antiviral treatment (80% versus 93%, P = 0.038) than women admitted in the UK. Women admitted in the UK had a longer length of hospital stay (median 21 days, range 3-128 days) than women admitted in Australia and New Zealand (median 12 days, range 3-66 days), but there were no other differences in maternal or pregnancy outcomes.

CONCLUSIONS

The difference in admission risk may reflect a second phase effect from successful clinical and public health interventions, as well as differences in population characteristics between the countries. The overall severity of the AH1N1v influenza infection in pregnancy is evident, and emphasises the importance of an ongoing immunisation programme in pregnant women in both northern and southern hemispheres.

Evidence into practice: evaluating a child-centred intervention for diabetes medicine management. The EPIC Project

BACKGROUND

There is a lack of high quality, child-centred and effective health information to support development of self-care practices and expertise in children with acute and long-term conditions. In type 1 diabetes, clinical guidelines indicate that high-quality, child-centred information underpins achievement of optimal glycaemic control with the aim of minimising acute readmissions and reducing the risk of complications in later life. This paper describes the development of a range of child-centred diabetes information resources and outlines the study design and protocol for a randomized controlled trial to evaluate the information resources in routine practice. The aim of the diabetes information intervention is to improve children and young people's quality of life by increasing self-efficacy in managing their type 1 diabetes.

METHODS/DESIGN

We used published evidence, undertook qualitative research and consulted with children, young people and key stakeholders to design and produce a range of child-centred, age-appropriate children's diabetes diaries, carbohydrate recording sheets, and assembled child-centred, age-appropriate diabetes information packs containing published information in a folder that can be personalized by children and young people with pens and stickers. Resources have been designed for children/young people 6-10; 11-15; and 16-18 years.To evaluate the information resources, we designed a pragmatic randomized controlled trial to assess the effectiveness, cost effectiveness, and implementation in routine practice of individually tailored, age-appropriate diabetes diaries and information packs for children and young people age 6-18 years, compared with currently available standard practice.Children and young people will be stratified by gender, length of time since diagnosis (< 2 years and > 2 years) and age (6-10; 11-15; and 16-18 years). The following data will be collected at baseline, 3 and 6 months: PedsQL (generic, diabetes and parent versions), and EQ-5 D (parent and child); NHS resource use and process data (questionnaire and interview). Baseline and subsequent HbA1c measurements, blood glucose meter use, readings and insulin dose will be taken from routine test results and hand-held records when attending routine 3-4 monthly clinic visits.The primary outcome measure is diabetes self-efficacy and quality-of-life (Diabetes PedsQL). Secondary outcomes include: HbA1c, generic quality of life, routinely collected NHS/child-held data, costs, service use, acceptability and utility.

TRIAL REGISTRATION

ISRCTN17551624.

Cost-effectiveness of therapeutic hypothermia to treat neonatal encephalopathy

OBJECTIVE

To estimate the cost-effectiveness (CE) of total body hypothermia plus intensive care versus intensive care alone to treat neonatal encephalopathy.

METHODS

Decision analytic modeling was used to synthesize mortality and morbidity data from three randomized controlled trials, the Total Body Hypothermia for Neonatal Encephalopathy Trial (TOBY), National Institute of Child Health and Human Development (NICHD), and CoolCap trials. Cost data inputs were informed by TOBY, the sole source of prospectively collected resource utilization data for encephalopathic infants. CE was expressed in terms of incremental cost per disability-free life year (DFLY) gained. Probabilistic sensitivity analysis was performed to generate CE acceptability curves (CEACs).

RESULTS

Cooling led to a cost increase of £3787 (95% confidence interval [CI]: -2516, 12,360) (€5115; 95% CI: -3398-16,694; US$5344; 95% CI: -3598, 26,356; using 2006 Organisation for Economic Co-operation and Development (OECD) purchasing power parities) and a DFLY gain of 0.19 (95%CI: 0.07-0.31) over the first 18 months after birth. The incremental cost per DFLY gained was £19,931 (€26,920; US$28,124). The baseline CEAC showed that if decision-makers are willing to pay £30,000 for an additional DFLY, there is a 69% probability that cooling is cost-effective. The probability of CE exceeded 99% at this threshold when the throughput of infants was increased to reflect the national incidence of neonatal encephalopathy or when the time horizon of the economic evaluation was extended to 18 years after birth.

CONCLUSIONS

The probability that cooling is a cost-effective treatment for neonatal encephalopathy is finely balanced over the first 18 months after birth but increases substantially when national incidence data or an extended time horizon are considered.

Gastroschisis: a national cohort study to describe contemporary surgical strategies and outcomes

BACKGROUND

Information on adoption of newer surgical strategies for gastroschisis and their outcomes is largely limited to hospital-based studies. The aim of this study was to use a new UK national surveillance system to identify cases and thus to describe the contemporary surgical management and outcomes of gastroschisis.

METHODS

We conducted a national cohort study using the British Association of Paediatric Surgeons Congenital Anomalies Surveillance System to identify cases between October 2006 and March 2008.

RESULTS

All 28 surgical units in the United Kingdom and Ireland participated (100%). Data were received for 95% of notified cases of gastroschisis (n = 393). Three hundred thirty-six infants (85.5%) had simple gastroschisis; 45 infants (11.5%) had complex gastroschisis. For 12 infants (3.0%), the type of gastroschisis could not be categorized. Operative primary closure (n = 170, or 51%) and staged closure after a preformed silo (n = 120, or 36%) were the most commonly used intended techniques for simple gastroschisis. Outcomes for infants with complex gastroschisis were significantly poorer than for simple cases, although all deaths occurred in the simple group.

CONCLUSIONS

This study provides a comprehensive picture of current UK practice in the surgical management of gastroschisis. Further follow-up data will help to elucidate additional prognostic factors and guide future research.

A novel use of a classification system to audit severe maternal morbidity

OBJECTIVE

obstetric haemorrhage remains a significant cause of maternal morbidity and mortality worldwide and is significant in terms of patient safety and quality of care. One drastic outcome of haemorrhage is the need for peripartum hysterectomy. A classification system that can be used to audit severe events such as peripartum hysterectomy would be a useful adjunct to patient safety systems, but it would need to account for pre-existing risk factors, such as previous caesarean section. One system that accounts for important risk factors is the Robson Ten Group Classification System (TGCS). The aim of this study was to examine whether the TGCS could be extended in a novel way to classify who required peripartum hysterectomy.

SETTING

population-based matched case-control study data from the UK Obstetric Surveillance System was used. All eligible UK hospitals participated.

PARTICIPANTS

women who underwent peripartum hysterectomy between February 2005 and February 2006 and their matched controls.

METHODS

cases and controls were categorised using the TGCS. The odds of having a peripartum hysterectomy in each classification group were calculated using logistic regression. An adjusted analysis was undertaken controlling for potential confounders.

FINDINGS

307 of the 315 women who had a peripartum hysterectomy were classified into one of the 10 groups; 606 of the 608 control women were classified. Women who underwent a peripartum hysterectomy were predominantly from the more complex classification groups. After adjusting for age, ethnicity and socio-economic status, the groups with an increased odds of peripartum hysterectomy were those who had a previous caesarean section.

CONCLUSIONS

the TGCS can be used in a novel way, that is, to examine an outcome other than caesarean section, and could be part of a new system to monitor patient safety. Population-based data were used as an example of how an existing classification system could be used in a different way from that for which it was created, and could make comparisons across institutions and countries while adjusting for case mix in a simple manner. The TGCS may not necessarily be a useful way to monitor other events in childbirth. Further work is needed to develop other classification systems which could be used as a benchmarking tools to monitor patient safety in maternity care.

Neonatal ECMO Study of Temperature (NEST)--a randomised controlled trial

BACKGROUND

Existing evidence indicates that once mature neonates with severe cardio-respiratory failure become eligible for Extra Corporeal Membrane Oxygenation (ECMO) their chances of intact survival are doubled if they actually receive ECMO. However, significant numbers survive with disability. NEST is a multi-centre randomised controlled trial designed to test whether, in neonates requiring ECMO, cooling to 34 degrees C for the first 48 to 72 hours of their ECMO course leads to improved later health status. Infants allocated to the control group will receive ECMO at 37 degrees C throughout their course, which is currently standard practice around the world. Health status of both groups will be assessed formally at 2 years corrected age.

METHODS/DESIGN

All infants recruited to the study will be cared for in one of the four United Kingdom (UK) ECMO centres. Babies who are thought to be eligible will be assessed by the treating clinician who will confirm eligibility, ensure that consent has been obtained and then randomise the baby using a web based system, based at the National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit. Trial registration.Babies allocated ECMO without cooling will receive ECMO at 37 degrees C +/- 0.2 degrees C. Babies allocated ECMO with cooling will be managed at 34 degrees C +/- 0.2 degrees C for up to 72 hours from the start of their ECMO run. The minimum duration of cooling will be 48 hours. Rewarming (to 37 degrees C) will occur at a rate of no more than 0.5 degrees C per hour. All other aspects of ECMO management will be identical.

PRIMARY OUTCOME

Cognitive score from the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) at age of 2 years (24 - 27 months).

DISCUSSION

For the primary analysis, children will be analysed in the groups to which they are assigned, comparing the outcome of all babies allocated to "ECMO with cooling" with all those allocated to "ECMO" alone, regardless of deviation from the protocol or treatment received. For the primary outcome the analysis will compare the mean scores for each group of surviving babies. The rationale for this choice of primary analysis is to give a fair representation of the average ability of assessable children, accepting the limitation that excluding deaths might impose.The consistency of the effect of cooling on the group of babies recruited to the trial will be explored to see whether cooling is of particular help, or not, to specific subgroups of infants, using the statistical test of interaction. Therefore pre-specified subgroup analyses include: (i) whether the ECMO is veno-arterial or veno-venous; (ii) whether the child's oxygenation index at the time of recruitment is <60 or > or = 60; (iii) initial aEEG pattern shown on the cerebral function monitor, and (iv) primary diagnostic group.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN72635512.

Neurological outcomes at 18 months of age after moderate hypothermia for perinatal hypoxic ischaemic encephalopathy: synthesis and meta-analysis of trial data

OBJECTIVE

To determine whether moderate hypothermia after hypoxic-ischaemic encephalopathy in neonates improves survival and neurological outcome at 18 months of age.

DESIGN

A meta-analysis was performed using a fixed effect model. Risk ratios, risk difference, and number needed to treat, plus 95% confidence intervals, were measured.

DATA SOURCES

Studies were identified from the Cochrane central register of controlled trials, the Oxford database of perinatal trials, PubMed, previous reviews, and abstracts. Review methods Reports that compared whole body cooling or selective head cooling with normal care in neonates with hypoxic-ischaemic encephalopathy and that included data on death or disability and on specific neurological outcomes of interest to patients and clinicians were selected. Results We found three trials, encompassing 767 infants, that included information on death and major neurodevelopmental disability after at least 18 months' follow-up. We also identified seven other trials with mortality information but no appropriate neurodevelopmental data. Therapeutic hypothermia significantly reduced the combined rate of death and severe disability in the three trials with 18 month outcomes (risk ratio 0.81, 95% confidence interval 0.71 to 0.93, P=0.002; risk difference -0.11, 95% CI -0.18 to -0.04), with a number needed to treat of nine (95% CI 5 to 25). Hypothermia increased survival with normal neurological function (risk ratio 1.53, 95% CI 1.22 to 1.93, P<0.001; risk difference 0.12, 95% CI 0.06 to 0.18), with a number needed to treat of eight (95% CI 5 to 17), and in survivors reduced the rates of severe disability (P=0.006), cerebral palsy (P=0.004), and mental and the psychomotor developmental index of less than 70 (P=0.01 and P=0.02, respectively). No significant interaction between severity of encephalopathy and treatment effect was detected. Mortality was significantly reduced when we assessed all 10 trials (1320 infants; relative risk 0.78, 95% CI 0.66 to 0.93, P=0.005; risk difference -0.07, 95% CI -0.12 to -0.02), with a number needed to treat of 14 (95% CI 8 to 47).

CONCLUSIONS

In infants with hypoxic-ischaemic encephalopathy, moderate hypothermia is associated with a consistent reduction in death and neurological impairment at 18 months.

Neurological outcomes at 18 months of age after moderate hypothermia for perinatal hypoxic ischaemic encephalopathy: synthesis and meta-analysis of trial data

OBJECTIVE

To determine whether moderate hypothermia after hypoxic-ischaemic encephalopathy in neonates improves survival and neurological outcome at 18 months of age.

DESIGN

A meta-analysis was performed using a fixed effect model. Risk ratios, risk difference, and number needed to treat, plus 95% confidence intervals, were measured.

DATA SOURCES

Studies were identified from the Cochrane central register of controlled trials, the Oxford database of perinatal trials, PubMed, previous reviews, and abstracts. Review methods Reports that compared whole body cooling or selective head cooling with normal care in neonates with hypoxic-ischaemic encephalopathy and that included data on death or disability and on specific neurological outcomes of interest to patients and clinicians were selected. Results We found three trials, encompassing 767 infants, that included information on death and major neurodevelopmental disability after at least 18 months' follow-up. We also identified seven other trials with mortality information but no appropriate neurodevelopmental data. Therapeutic hypothermia significantly reduced the combined rate of death and severe disability in the three trials with 18 month outcomes (risk ratio 0.81, 95% confidence interval 0.71 to 0.93, P=0.002; risk difference -0.11, 95% CI -0.18 to -0.04), with a number needed to treat of nine (95% CI 5 to 25). Hypothermia increased survival with normal neurological function (risk ratio 1.53, 95% CI 1.22 to 1.93, P<0.001; risk difference 0.12, 95% CI 0.06 to 0.18), with a number needed to treat of eight (95% CI 5 to 17), and in survivors reduced the rates of severe disability (P=0.006), cerebral palsy (P=0.004), and mental and the psychomotor developmental index of less than 70 (P=0.01 and P=0.02, respectively). No significant interaction between severity of encephalopathy and treatment effect was detected. Mortality was significantly reduced when we assessed all 10 trials (1320 infants; relative risk 0.78, 95% CI 0.66 to 0.93, P=0.005; risk difference -0.07, 95% CI -0.12 to -0.02), with a number needed to treat of 14 (95% CI 8 to 47).

CONCLUSIONS

In infants with hypoxic-ischaemic encephalopathy, moderate hypothermia is associated with a consistent reduction in death and neurological impairment at 18 months.

Effect of a collector bag for measurement of postpartum blood loss after vaginal delivery: cluster randomised trial in 13 European countries

OBJECTIVE

To evaluate the effectiveness of the systematic use of a transparent plastic collector bag to measure postpartum blood loss after vaginal delivery in reducing the incidence of severe postpartum haemorrhage.

DESIGN

Cluster randomised trial.

SETTING

13 European countries.

PARTICIPANTS

78 maternity units and 25 381 women who had a vaginal delivery.

INTERVENTIONS

Maternity units were randomly assigned to systematic use of a collector bag (intervention group) or to continue to visually assess postpartum blood loss after vaginal delivery (control group).

MAIN OUTCOME MEASURES

The primary outcome was the incidence of severe postpartum haemorrhage in vaginal deliveries, defined as a composite of one or more of blood transfusion, intravenous plasma expansion, arterial embolisation, surgical procedure, admission to an intensive care unit, treatment with recombinant factor VII, and death.

RESULTS

Severe postpartum haemorrhage occurred in 189 of 11 037 of vaginal deliveries (1.71%) in the intervention group compared with 295 of 14 344 in the control group (2.06%). The difference was not statistically significant either in individual level analysis (adjusted odds ratio 0.82, 95% confidence interval 0.26 to 2.53) or in cluster level analysis (difference in weighted mean rate adjusted for baseline rate 0.16%, 95% confidence interval -0.69% to 1.02%).

CONCLUSION

Compared with visual estimation of postpartum blood loss the use of a collector bag after vaginal delivery did not reduce the rate of severe postpartum haemorrhage.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66197422.

Assessment of brain tissue injury after moderate hypothermia in neonates with hypoxic-ischaemic encephalopathy: a nested substudy of a randomised controlled trial

Background

Moderate hypothermia in neonates with hypoxic–ischaemic encephalopathy might improve survival and neurological outcomes at up to 18 months of age, although complete neurological assessment at this age is difficult. To ascertain more precisely the effect of therapeutic hypothermia on neonatal cerebral injury, we assessed cerebral lesions on MRI scans of infants who participated in the Total Body Hypothermia for Neonatal Encephalopathy (TOBY) trial.

Methods

In the TOBY trial hypoxic–ischaemic encephalopathy was graded clinically according to the changes seen on amplitude integrated EEG, and infants were randomly assigned to intensive care with or without cooling by central telephone randomisation. The relation between allocation to hypothermia or normothermia and cerebral lesions was assessed by logistic regression with perinatal factors as covariates, and adjusted odds ratios (ORs) were calculated. The TOBY trial is registered, number ISRCTN 89547571.

Findings

325 infants were recruited in the TOBY trial between 2002 and 2006. Images were available for analysis from 131 infants. Therapeutic hypothermia was associated with a reduction in lesions in the basal ganglia or thalamus (OR 0·36, 95% CI 0·15–0·84; p=0·02), white matter (0·30, 0·12–0·77; p=0·01), and abnormal posterior limb of the internal capsule (0·38, 0·17–0·85; p=0·02). Compared with non-cooled infants, cooled infants had fewer scans that were predictive of later neuromotor abnormalities (0·41, 0·18–0·91; p=0·03) and were more likely to have normal scans (2·81, 1·13–6·93; p=0·03). The accuracy of prediction by MRI of death or disability to 18 months of age was 0·84 (0·74–0·94) in the cooled group and 0·81 (0·71–0·91) in the non-cooled group.

Interpretation

Therapeutic hypothermia decreases brain tissue injury in infants with hypoxic–ischaemic encephalopathy. The predictive value of MRI for subsequent neurological impairment is not affected by therapeutic hypothermia.

Funding

UK Medical Research Council; UK Department of Health.

ADEPT - Abnormal Doppler Enteral Prescription Trial

BACKGROUND

Pregnancies complicated by abnormal umbilical artery Doppler blood flow patterns often result in the baby being born both preterm and growth-restricted. These babies are at high risk of milk intolerance and necrotising enterocolitis, as well as post-natal growth failure, and there is no clinical consensus about how best to feed them. Policies of both early milk feeding and late milk feeding are widely used. This randomised controlled trial aims to determine whether a policy of early initiation of milk feeds is beneficial compared with late initiation. Optimising neonatal feeding for this group of babies may have long-term health implications and if either of these policies is shown to be beneficial it can be immediately adopted into clinical practice.

METHODS AND DESIGN

Babies with gestational age below 35 weeks, and with birth weight below 10th centile for gestational age, will be randomly allocated to an "early" or "late" enteral feeding regimen, commencing milk feeds on day 2 and day 6 after birth, respectively. Feeds will be gradually increased over 9-13 days (depending on gestational age) using a schedule derived from those used in hospitals in the Eastern and South Western Regions of England, based on surveys of feeding practice. Primary outcome measures are time to establish full enteral feeding and necrotising enterocolitis; secondary outcomes include sepsis and growth. The target sample size is 400 babies. This sample size is large enough to detect a clinically meaningful difference of 3 days in time to establish full enteral feeds between the two feeding policies, with 90% power and a 5% 2-sided significance level. Initial recruitment period was 24 months, subsequently extended to 38 months.

DISCUSSION

There is limited evidence from randomised controlled trials on which to base decisions regarding feeding policy in high risk preterm infants. This multicentre trial will help to guide clinical practice and may also provide pointers for future research.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN: 87351483.

Moderate hypothermia to treat perinatal asphyxial encephalopathy

BACKGROUND

Whether hypothermic therapy improves neurodevelopmental outcomes in newborn infants with asphyxial encephalopathy is uncertain.

METHODS

We performed a randomized trial of infants who were less than 6 hours of age and had a gestational age of at least 36 weeks and perinatal asphyxial encephalopathy. We compared intensive care plus cooling of the body to 33.5 degrees C for 72 hours and intensive care alone. The primary outcome was death or severe disability at 18 months of age. Prespecified secondary outcomes included 12 neurologic outcomes and 14 other adverse outcomes.

RESULTS

Of 325 infants enrolled, 163 underwent intensive care with cooling, and 162 underwent intensive care alone. In the cooled group, 42 infants died and 32 survived but had severe neurodevelopmental disability, whereas in the noncooled group, 44 infants died and 42 had severe disability (relative risk for either outcome, 0.86; 95% confidence interval [CI], 0.68 to 1.07; P=0.17). Infants in the cooled group had an increased rate of survival without neurologic abnormality (relative risk, 1.57; 95% CI, 1.16 to 2.12; P=0.003). Among survivors, cooling resulted in reduced risks of cerebral palsy (relative risk, 0.67; 95% CI, 0.47 to 0.96; P=0.03) and improved scores on the Mental Developmental Index and Psychomotor Developmental Index of the Bayley Scales of Infant Development II (P=0.03 for each) and the Gross Motor Function Classification System (P=0.01). Improvements in other neurologic outcomes in the cooled group were not significant. Adverse events were mostly minor and not associated with cooling.

CONCLUSIONS

Induction of moderate hypothermia for 72 hours in infants who had perinatal asphyxia did not significantly reduce the combined rate of death or severe disability but resulted in improved neurologic outcomes in survivors. (Current Controlled Trials number, ISRCTN89547571.)

Comparing methods of analysing datasets with small clusters: case studies using four paediatric datasets

Studies of prematurely born infants contain a relatively large percentage of multiple births, so the resulting data have a hierarchical structure with small clusters of size 1, 2 or 3. Ignoring the clustering may lead to incorrect inferences. The aim of this study was to compare statistical methods which can be used to analyse such data: generalised estimating equations, multilevel models, multiple linear regression and logistic regression. Four datasets which differed in total size and in percentage of multiple births (n = 254, multiple 18%; n = 176, multiple 9%; n = 10 098, multiple 3%; n = 1585, multiple 8%) were analysed. With the continuous outcome, two-level models produced similar results in the larger dataset, while generalised least squares multilevel modelling (ML GLS 'xtreg' in Stata) and maximum likelihood multilevel modelling (ML MLE 'xtmixed' in Stata) produced divergent estimates using the smaller dataset. For the dichotomous outcome, most methods, except generalised least squares multilevel modelling (ML GH 'xtlogit' in Stata) gave similar odds ratios and 95% confidence intervals within datasets. For the continuous outcome, our results suggest using multilevel modelling. We conclude that generalised least squares multilevel modelling (ML GLS 'xtreg' in Stata) and maximum likelihood multilevel modelling (ML MLE 'xtmixed' in Stata) should be used with caution when the dataset is small. Where the outcome is dichotomous and there is a relatively large percentage of non-independent data, it is recommended that these are accounted for in analyses using logistic regression with adjusted standard errors or multilevel modelling. If, however, the dataset has a small percentage of clusters greater than size 1 (e.g. a population dataset of children where there are few multiples) there appears to be less need to adjust for clustering.