Estimates of length of neonatal stay for very premature babies in the UK

OBJECTIVE

To describe simple estimates of likely duration of stay for very premature babies born in the UK and discharged home.

DESIGN

Statistical modelling of data from thirty neonatal units in a geographically defined region of the UK.

PARTICIPANTS

All babies born at 23 to 32 completed weeks of gestation in 2005, 2006 and 2007 who were discharged home with the expectation that they would survive.

MAIN OUTCOME MEASURE

Total duration of stay in the neonatal service.

RESULTS

5528 babies were initially identified. 558 (10.1%) who died or who did not follow a normal care pathway were excluded. In a further 27, data were either missing or inadequate, leaving a study population of 4702 babies. As expected, gestation and birthweight exhibited strong influence on length of stay. Of the other variables tested, initial reason for admission (need for early respiratory support) showed the most consistent association. These factors were combined to produce predictive tables. The predictive performance of the tables was found to fit the data well for various groups, with the exception of multiple births who tended to have longer stays. However, when tested against individual units, much greater variation was seen independent of unit size and case mix.

CONCLUSION

The prediction tables should permit parents to make sensible estimates about the duration of their baby's stay in the neonatal service; however, there appear to be important differences between units. The variation noted in length of stay between otherwise similar units merits further investigation.

Prioritising neonatal medicines research: UK Medicines for Children Research Network scoping survey

Background

The dosing regimen and indications for many medicines in current use in neonatology are not well defined. There is a need to prioritise research in this area, but currently there is little information about which drugs are used in UK neonatal units and the research needs in this area as perceived by UK neonatologists.

Methods

The Neonatal Clinical Studies Group (CSG) of the Medicines for Children Research Network (MCRN) undertook a 2 week prospective scoping survey study to establish which medicines are used in UK neonatal units; how many babies are receiving them; and what clinicians (and other health professionals) believe are important issues for future research.

Results

49 out of 116 units responded to at least one element of the survey (42%). 37 units reported the number of neonates who received medicines over a 2 week period. A total of 3924 medicine-patient pairs were reported with 119 different medicines. 70% of medicine-patient pairs involved medicines that were missing either a license or dose for either term or preterm neonates. 4.3% of medicine-patient pairs involved medicines that were missing both license and dose for any neonate. The most common therapeutic gap in need of additional research identified by UK neonatologists was chronic lung disease (21 responding units), followed by patent ductus arteriosus and vitamin supplements (11 responding units for both)

Conclusion

The research agenda for neonatal medicines can be informed by knowledge of current medicine use and the collective views of the neonatal community.

Rates of very preterm birth in Europe and neonatal mortality rates

OBJECTIVE

To estimate the influence of variation in the rate of very preterm delivery on the reported rate of neonatal death in 10 European regions.

DESIGN

Comparison of 10 separate geographically defined European populations, from nine European countries, over a 1-year period (7 months in one region).

PARTICIPANTS

All births that occurred between 22(+0) and 31(+6) weeks of gestation in 2003.

MAIN OUTCOME MEASURE

Neonatal death rate adjusted for rate of delivery at this gestation.

RESULTS

Rate of delivery of all births at 22(+0)-31(+6) weeks of gestation and live births only were calculated for each region. Two regions had significantly higher rates of very preterm delivery per 1000 births: Trent UK (16.8, 95% CI 15.7 to 17.9) and Northern UK (17.1, 95% CI 15.6 to 18.6); group mean 13.2 (95% CI 12.9 to 13.5). Four regions had rates significantly below the group average: Portugal North (10.7, 95% CI 9.6 to 11.8), Eastern and Central Netherlands (10.6, 95% CI 9.7 to 11.6), Eastern Denmark (11.2, 95% CI 10.1 to 12.4) and Lazio in Italy (11.0, 95% CI 10.1 to 11.9). Similar trends were seen in live birth data. Published rates of neonatal death for each region were then adjusted by applying (a) a standardised rate of very preterm delivery and (b) the existing death rate for babies born at this gestation in the individual region. This produced much greater homogeneity in terms of neonatal mortality.

CONCLUSIONS

Variation in the rate of very preterm delivery has a major influence on reported neonatal death rates.

Spontaneous dipole alignment in films of N2O

Experimental data obtained using low energy electron beams are presented which show that films of N2O, of several hundred monolayers (ML), spontaneously acquire a positive potential of as high as 5 V. Films do not possess a dipole double layer but for >40 ML display a constant electric field within the material. This new phenomenon is attributed to dipole alignment. The phenomenon also shows a strong temperature dependence. This is revealed by the differing dependence of the surface potential on the film thickness at different temperatures and by electron transmission spectra which display marked structure at 62 K which is absent at 40 K.

The INNOVO multicentre randomised controlled trial: neonatal ventilation with inhaled nitric oxide versus ventilatory support without nitric oxide for severe respiratory failure in preterm infants: follow up at 4-5 years

BACKGROUND

Trials of inhaled nitric oxide (iNO) used short term in preterm infants with severe respiratory failure have to date shown no evidence of benefit, and there have been no trials reporting follow-up to 4 years of age. The INNOVO trial recruited 108 infants (55 iNO arm and 53 controls) from 15 neonatal units. By 1 year of age 59% had died, and 84% of the survivors had signs of impairment or disability.

OBJECTIVE

This paper reports the long-term clinical effectiveness and costs of adding NO to the ventilator gases of preterm infants with severe respiratory failure.

PATIENTS AND METHODS

Children were assessed at age 4-5 years by interview, examination, cognitive and behavioural assessments. The outcome data were divided into seven domains and were described as normal, impaired or disabled (mild, moderate or severe) by the degree of functional loss.

RESULTS

38 of the 43 survivors had follow-up assessments. In the iNO group 62% (34/55) had died or were severely disabled, compared to 70% (37/53) in the no iNO group (RR 0.89, 95% CI 0.67 to 1.16). There was no evidence of difference in the levels of impairment or disability between the two groups in any of the domains studied, or of cost differences, amongst the survivors.

CONCLUSION

For this group of babies with severe respiratory failure there was no evidence of difference in the longer-term outcome between those babies allocated to iNO and those who were allocated to no iNO. The challenge is to identify those premature babies who are able to respond to NO with clinically important health improvements.

TRIAL REGISTRATION NUMBER

17821339.

Geographically based investigation of the influence of very-preterm births on routine mortality statistics from the UK and Australia

BACKGROUND

Comparisons of national perinatal and neonatal mortality often neglect the underlying causes.

OBJECTIVE

To assess effects of very-preterm births in the UK and Australia.

SETTING

Two geographically defined populations: the former Trent Health Region of the UK and New South Wales (NSW)/the Australian Capital Territory (ACT), Australia.

METHOD

All births 22(+0) to 31(+6) weeks in 2000, 2001 and 2002 were identified by established surveys of perinatal care. Rates of birth and death were compared.

RESULTS

The population of NSW/ACT was 35% higher and there were 66% more births than in Trent (273 495 vs 164 824). The proportion of liveborn infants between 22 and 31 weeks gestation was about 25% higher in Trent (NSW/ACT 2945, rate per 1000 live births 10.82 (95% CI 10.43 to 11.22); Trent 2208, rate per 1000 live births 13.47 (95% CI 12.92 to 14.05)). The proportion of these infants admitted to a neonatal unit was also higher in Trent (91.2% vs 94.4%; OR 1.63 (95% CI 1.30 to 2.05)). Unadjusted mortality in infants admitted to a neonatal unit was similar: NSW/ACT 332/2686 (12.4%); Trent 284/2085 (13.6%); unadjusted OR 1.12 (95% CI 0.94 to 1.33; p = 0.21).

CONCLUSIONS

The higher rates of very premature birth and more ready admission to neonatal intensive care for infants in the UK may help to explain why perinatal and neonatal mortality are higher there than in Australia. Efforts to understand why the rate of premature birth in the UK is so high should be a national priority.

Referral pattern of neonates with severe respiratory failure for extracorporeal membrane oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) remains the mainstay of management in neonates with severe but potentially reversible respiratory failure. In the UK, ECMO is available only as a supraregional service at four centres.

OBJECTIVE

To explore regional variations in ECMO referrals and neonatal deaths due to severe respiratory failure in England, Wales and Northern Ireland.

METHODS

In this retrospective study, data regarding ECMO referrals due to neonatal respiratory failure from January to December 2002 were obtained from the four UK ECMO centres and then subdivided according to the Government Office Regions. Anonymised data regarding neonatal deaths was obtained from Confidential Enquiry into Maternal and Child Health. Neonatal deaths were classified into four groups (group 1: deaths potentially avoidable by ECMO; group 2: deaths where it was unclear whether ECMO would have been of benefit; group 3: neonates not eligible for ECMO; and group 4: data inadequate to classify deaths).

RESULTS

There was significant regional variation in the rates of both ECMO referral (0.10 to 0.46 per 1000 live births; (p<0.001)) and neonatal deaths (groups 1 and 2) (0.09 to 0.32 per 1000 live births; (p<0.001)). Regions with high referral rates for ECMO tended towards having higher group 1 plus group 2 neonatal death rates (correlation coefficient = 0.75).

CONCLUSION

It is possible that there are significant regional variations in the uptake of ECMO and in neonatal mortality due to severe respiratory failure. A confidential prospective study may further clarify these observations and identify the factors that might lead to these variations.