I was interested to read this study looking at a question which is extremely important to mothers of preterm infants who need to exclusively express - "how frequently do I need to express?".
The conclusion that there is no difference in average yield of mothers expressing 5, 6, 7, 8, and 9 times a day will be very useful to mothers who are similar to those included in the study - that is mothers of preterm babies aged at least 10 days (but mostly 15-20 days old), who have good daily expressed milk yield (average yield clustered around 750ml/day for these expressing frequencies). Therefore mothers in this group may feel more confident in reducing their expressing sessions down to a more manageable 5 or 6 per day, which reduces their burden of expressing.
However it could be harmful to extrapolate outside of these characteristics, for example mothers attempting to establish their supply in the first 2 weeks of life. We know that this period may be a critical window to establish milk supply and this study cannot comment on the relationship of early expressing frequency to the establishment of adequate yield (which, to complicate matters further, is poorly defined in the context of prematurity, with a range of daily volume targets from 500-900ml suggested in the literature and by the Unicef Baby Friendly Initiative). Already I have seen the article summarised as "mothers of preterm infants should express milk at least 5 times a day" on social...
I was interested to read this study looking at a question which is extremely important to mothers of preterm infants who need to exclusively express - "how frequently do I need to express?".
The conclusion that there is no difference in average yield of mothers expressing 5, 6, 7, 8, and 9 times a day will be very useful to mothers who are similar to those included in the study - that is mothers of preterm babies aged at least 10 days (but mostly 15-20 days old), who have good daily expressed milk yield (average yield clustered around 750ml/day for these expressing frequencies). Therefore mothers in this group may feel more confident in reducing their expressing sessions down to a more manageable 5 or 6 per day, which reduces their burden of expressing.
However it could be harmful to extrapolate outside of these characteristics, for example mothers attempting to establish their supply in the first 2 weeks of life. We know that this period may be a critical window to establish milk supply and this study cannot comment on the relationship of early expressing frequency to the establishment of adequate yield (which, to complicate matters further, is poorly defined in the context of prematurity, with a range of daily volume targets from 500-900ml suggested in the literature and by the Unicef Baby Friendly Initiative). Already I have seen the article summarised as "mothers of preterm infants should express milk at least 5 times a day" on social media.
Overall this is a useful addition to the literature, but it will be important to ensure that the conclusions are not over-interpreted in clinical practice
Thank you for this interesting article, which really adds to our understanding of management of neonatal hypoglycaemia. However, your conclusion that a subset of babies should receive formula rather than breastfeed alongside gel, depending on their blood glucose level, is not supported by the evidence you have provided and ignores the potential harm associated with this approach.
Your data states that alongside the first use of gel, breastfed babies are more likely to require a second gel. There is no literature to support the idea that experiencing a second transient hypoglycaemia in a carefully monitored baby in the first 48 hours of life is harmful (indeed UK guidance uses a treatment threshold of 2mmol/l for the entire first 48 hours of life), and alongside the second gel breastfeeding is as effective as formula so there is no reason to suppose from the data provided that breastfed babies are more likely to go on to require intravenous dextrose.
Asking breastfeeding mothers to use formula instead of breastfeeding in the first hours of their baby's life is likely to undermine mothers' trust in breastfeeding, may impact on their milk supply through reduced stimulation in the critical time period and reduces the colostrum volume ingested, with its unique immune properties. It is not a recommendation to be made lightly.
As authors of the 2015 guidelines we read with interest the “UK neonatal resuscitation survey” [1]. Comparison with 2012 shows a rewarding positive effect of successive guidelines on newborn resuscitation practice.
However, we wanted to address this statement: “…updated guidelines have been criticised for failing to consider data from the Targeted Oxygen in the Resuscitation of Preterm Infants [To2rpido]”. To2rpido [2], published 2017, was unavailable for inclusion in 2015 ILCOR reviews of evidence. [3]. The analysis referred to was post-hoc and unprespecified. Clinicians were not blinded and recruitment was problematic. Enrolling only 5% of eligible infants, To2rpido was terminated after reaching 15% of targeted sample size due to loss of equipoise: ironically, clinicians were concerned about using high oxygen concentrations.
Nonetheless, To2rpido generated such interest that it led to the first neonatal review in ILCOR’s continuous evidence evaluation strategy. [4] Utilising GRADE methodology to rate quality of evidence and strength of recommendations, To2rpido’s impact was downgraded because of high risk of bias. This review [4] continues to recommend “starting with a lower oxygen concentration (21–30%) compared to higher oxygen concentration (60–100%)” whilst highlighting many gaps in our current knowledge.
The use of end-tidal CO2 (ETCO2) detection was not recommended because the guidelines, and Newborn Life Support (NLS) course, focus on airwa...
As authors of the 2015 guidelines we read with interest the “UK neonatal resuscitation survey” [1]. Comparison with 2012 shows a rewarding positive effect of successive guidelines on newborn resuscitation practice.
However, we wanted to address this statement: “…updated guidelines have been criticised for failing to consider data from the Targeted Oxygen in the Resuscitation of Preterm Infants [To2rpido]”. To2rpido [2], published 2017, was unavailable for inclusion in 2015 ILCOR reviews of evidence. [3]. The analysis referred to was post-hoc and unprespecified. Clinicians were not blinded and recruitment was problematic. Enrolling only 5% of eligible infants, To2rpido was terminated after reaching 15% of targeted sample size due to loss of equipoise: ironically, clinicians were concerned about using high oxygen concentrations.
Nonetheless, To2rpido generated such interest that it led to the first neonatal review in ILCOR’s continuous evidence evaluation strategy. [4] Utilising GRADE methodology to rate quality of evidence and strength of recommendations, To2rpido’s impact was downgraded because of high risk of bias. This review [4] continues to recommend “starting with a lower oxygen concentration (21–30%) compared to higher oxygen concentration (60–100%)” whilst highlighting many gaps in our current knowledge.
The use of end-tidal CO2 (ETCO2) detection was not recommended because the guidelines, and Newborn Life Support (NLS) course, focus on airway management without need for intubation. Both explain how, and when, ETCO2 might be used highlighting limitations to its use. The European guidelines, on which UK guidelines are based, state “detection of exhaled carbon dioxide in addition to clinical assessment is recommended as the most reliable method to confirm tracheal placement in neonates with spontaneous circulation”. [5] Given this, considered and careful use of ETCO2 detection best sits within the Advanced Resuscitation of the Newborn Infant (ARNI) course which teaches care, including intubation, beyond Newborn Life Support.
References:
1. Charles E, Hunt K, Murthy V, Harris C, Greenough A. UK neonatal resuscitation survey. Arch Dis Child Fetal Neonatal Ed 2019;104:F324–F325
2. Oei JL, Saugstad OD, Lui K, Wright IM, Smyth JP, Craven P, Wang YA, McMullan R, Coates E, Ward M, Mishra P, De Waal K, Travadi J, See KC, Cheah IG, Lim CT, Choo YM, Kamar AA, Cheah FC, Masoud A, Tarnow-Mordi W. Targeted Oxygen in the Resuscitation of Preterm Infants, a Randomized Clinical Trial. Pediatrics 2017;139:e20161452.
3. Wyllie J, Perlman JM, Kattwinkel J, Wyckoff MH, Aziz K, Guinsburg R, Kim HS, Liley HG, Mildenhall L, Simon WM, Szyld E, Tamura M, Velaphi S; Neonatal Resuscitation Chapter Collaborators. Part 7: Neonatal resuscitation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2015;95:e169–201.
4. Welsford M, Nishiyama C, Shortt C, Weiner G, Roehr CC, Isayama T, Dawson JA, Wyckoff MH, Rabi Y; International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Initial Oxygen Use for Preterm Newborn Resuscitation: A Systematic Review With Meta-analysis. Pediatrics 2019;143:e20181828.
5. Wyllie J, Bruinenberg J, Roehr CC, Rüdiger M, Trevisanuto D, Urlesberger B. European Resuscitation Council Guidelines for Resuscitation 2015: Section 7. Resuscitation and support of transition of babies at birth. Resuscitation 2015;95:249–63.
Dear Editor,
We read with great interest the network meta-analysis performed by Zeng et al [1]. The authors investigated the comparative efficacy and safety of different corticosteroids in the prevention of bronchopulmonary dysplasia in preterm infants. They included 47 RCTs with 6747 participants. We have several concerns about the study.
First, it looks that the authors are unfamiliar with the procedures of network meta-analysis because there were obvious mistakes. Figure 1 in the study was network plot of different corticosteroids. In Figure 1, the circle size should be proportional to the sample size randomised to each intervention [2]. The line width should be proportional to the study numbers of each direct comparison. However, the circle size was not proportional to the sample size in Figure 1. The line width between dexamethasone (high dose) and placebo also seems inadequate.
Second, various statistical methods or plots have been suggested to assist interpreting the results of network meta-analysis [3]. However, many of them were not performed or presented in this study. For example, since there were direct estimates (i.e., results of pairwise meta-analysis) and indirect estimates (i.e., results of network meta-analysis), the inconsistency between them should be assessed and explored because important inconsistency could threaten the validity of the results. Besides, the authors also didn’t assess small-study effects. Small-study effects could mat...
Dear Editor,
We read with great interest the network meta-analysis performed by Zeng et al [1]. The authors investigated the comparative efficacy and safety of different corticosteroids in the prevention of bronchopulmonary dysplasia in preterm infants. They included 47 RCTs with 6747 participants. We have several concerns about the study.
First, it looks that the authors are unfamiliar with the procedures of network meta-analysis because there were obvious mistakes. Figure 1 in the study was network plot of different corticosteroids. In Figure 1, the circle size should be proportional to the sample size randomised to each intervention [2]. The line width should be proportional to the study numbers of each direct comparison. However, the circle size was not proportional to the sample size in Figure 1. The line width between dexamethasone (high dose) and placebo also seems inadequate.
Second, various statistical methods or plots have been suggested to assist interpreting the results of network meta-analysis [3]. However, many of them were not performed or presented in this study. For example, since there were direct estimates (i.e., results of pairwise meta-analysis) and indirect estimates (i.e., results of network meta-analysis), the inconsistency between them should be assessed and explored because important inconsistency could threaten the validity of the results. Besides, the authors also didn’t assess small-study effects. Small-study effects could materially alter the relative effectiveness and ranking of treatments. The ‘comparison-adjusted’ funnel plot has been suggested to assess the presence of small-study effects. Model that adjusted for small-study effects should be performed if small-study effects was found.
References
1. Zeng L, Tian J, Song F, et al. Corticosteroids for the prevention of bronchopulmonary dysplasia in preterm infants: a networkmeta-analysis. Arch Dis Child Fetal Neonatal Ed. 2018 Nov;103(6):F506-F511.
2. Dias S, Caldwell DM. Network meta-analysis explained. Arch Dis Child Fetal Neonatal Ed. 2019 Jan;104(1):F8-F12.
3. Chaimani A, Higgins JP, Mavridis D, Spyridonos P, Salanti G. Graphical tools for network meta-analysis in STATA. PLoS One. 2013 Oct 3;8(10):e76654.
There seems to be a descrepency regarding the number of babies intubatec in two groups. 56 babies were intubated in high tidal volume group against 14 intubated in the low tidal volume group as per the article. I wondering whether it might have contributed to the high incidence of IVH in the high tidal volume group.
I congratulate Dr Thio and colleagues on their study of PEEP delivery in common neonatal resuscitation devices. This study is timely as clinicians look for more refined strategies to support the preterm lung at birth. Such strategies will require a reliance on equipment in the delivery room.
To allow for interpretation of the findings into the clinical context could the authors comment on the number, and characteristics, of lambs studied, and was this accounted for analysis in Table 1 (for example cluster analysis)? What was the pressure of medical gas supply?
We would like to thank Miller et al for their interest in our recently published review and their responding letter to the editor. The first concern is combining RCTs and cohort studies. We agree that classic Cochrane methods advocate combining only same study designs in a meta-analysis. However, there is also an alternative viewpoint. Appropriate integration of randomized and observational cohort studies may offer opportunities to provide more timely, comprehensive, and generalizable evidence about the medical intervention1. To date, the majority of human milk studies on bronchopulmonary dysplasia (BPD) have been observational cohort studies. Generalizing extensive perspective is motivation for combining randomized and non-randomized evidence in a meta-analysis2. In our review, to detect the possibility of incorporating randomized and observational cohort studies, we assessed the statistic heterogeneity between cohort studies and randomized studies. The test for subgroup differences has been shown in table 3, which demonstrated the statistic heterogeneity (I2 and P values) is generally low. This gave a plausible reason to pool observational and randomized studies in our review. In fact, combining observational and randomized studies has been also performed in a similarly themed review for preventing BPD, when authors compared raw mother’s own milk with pasteurized mother’s own milk3.
The second concern from Miller et al was how to interpret the out...
We would like to thank Miller et al for their interest in our recently published review and their responding letter to the editor. The first concern is combining RCTs and cohort studies. We agree that classic Cochrane methods advocate combining only same study designs in a meta-analysis. However, there is also an alternative viewpoint. Appropriate integration of randomized and observational cohort studies may offer opportunities to provide more timely, comprehensive, and generalizable evidence about the medical intervention1. To date, the majority of human milk studies on bronchopulmonary dysplasia (BPD) have been observational cohort studies. Generalizing extensive perspective is motivation for combining randomized and non-randomized evidence in a meta-analysis2. In our review, to detect the possibility of incorporating randomized and observational cohort studies, we assessed the statistic heterogeneity between cohort studies and randomized studies. The test for subgroup differences has been shown in table 3, which demonstrated the statistic heterogeneity (I2 and P values) is generally low. This gave a plausible reason to pool observational and randomized studies in our review. In fact, combining observational and randomized studies has been also performed in a similarly themed review for preventing BPD, when authors compared raw mother’s own milk with pasteurized mother’s own milk3.
The second concern from Miller et al was how to interpret the outcome when the evidence from randomized and observational cohort studies were inconsistent. Miller et al stated that “the overall protective effect is driven by the cohort studies alone” in our review. However, this is not the case. In table 3, subgroup of RCT alone in all comparison showed a non-statistically significant trend towards protective effect of human milk on BPD. This meant the overall protective effect was not only driven by the cohort studies, but also attributed to the RCTs. RCTs undisputedly are on a higher level than observational studies. On the other hand, some of our most effective therapies are only supported by ‘lower-level’ observational studies, especially when the evidence from RCT is rare4. As conclusions in our review, we explicitly acknowledge the weakness of the evidence and that more RCTs are needed. A recent review for donor human milk on BPD also highlighted the benefit effect of human milk from observational studies, even though the effect from RCTs was not significant3.
Since neonates often received feeding with partial human milk due to a variety of reasons, paediatrician and parents pay close attention to the possible benefits of partial human milk feeding. One important aim of our review is to provide an overview of different portion/extent of human milk on BPD. In this setting, there are unavoidable overlaps in six categories: exclusive human milk (100% human milk), mainly human milk (50%≤human milk feeding<100%) and any human milk (0<human milk feeding≤100%); exclusive formula (100% formula feeding), mainly formula (50%≤formula feeding<100%) and any formula (0<formula feeding≤100%). A systematic review for human milk on retinopathy of prematurity also adopted the same method using replication of data 5.
We tried to avoid overlap by redefining two categories in our study to: any human milk (0<human milk feeding<50%) and any performed formula (0<human milk feeding<50%). Interestingly, our new meta-analysis only showed benefit from the comparision of exclusive human milk versus exclusive formula group [OR 0.78 (95% confidence interval 0.68 to 0.88)]. There was no statistical effect for other comparisons. Most comparisons included only one or two small studies. Overall, although we could not draw a definitive conclusion for maternal milk on BPD, limited evidence suggests further studies are necessary.
Competing interests None declared.
Reference
1. Cameron C, Fireman B, Hutton B, et al. Network meta-analysis incorporating randomized controlled trials and non-randomized comparative cohort studies for assessing the safety and effectiveness of medical treatments: challenges and opportunities. Systematic reviews 2015; 4: 147.
2. Verde PE, Ohmann C. Combining randomized and non-randomized evidence in clinical research: a review of methods and applications. Research synthesis methods 2015; 6: 45-62.
3. Villamor-Martinez E, Pierro M, Cavallaro G, et al. Donor human milk protects against bronchopulmonary dysplasia: a systematic review and meta-analysis. Nutrients 2018; 10: 238.
4. Verd S, Ginovart G. Human milk is perhaps the single most under-rated strategy to prevent bronchopulmonary dysplasia. Archives of disease in childhood Fetal and neonatal edition 2018 103: F599-f600.
5. Zhou J, Shukla VV, John D, et al. Human milk feeding as a protective factor for retinopathy of prematurity: a meta-analysis. pediatrics 2015; 136: e1576-86.
We thank Ovali et al for their interest in our paper. They emphasise that BPD results from a multifactorial process and has wide variation in severity. We agree that basing the prediction of BPD solely on ventilatory requirement at one week of age would not identify all cases of BPD, as demonstrated by the low sensitivity of 67% demonstrated in our study.[1] The high sensitivity of ventilation at one week of age in predicting the development of BPD (99%), however, means that it could facilitate counselling of parents and act as a screening tool to identify candidates for future trials of therapeutic interventions to prevent BPD.
[1] Hunt K, Dassios T, Ali K, et al. Prediction of bronchopulmonary dysplasia development. Arch Dis Child Fetal Neonatal Ed 2018 [Epub ahead of print].
I wish to comment about the outcomes you have selected for your study on gastroschisis and in particular caution against the use of 'primary closure' as an outcome at all. There are a number of reasons for this. Firstly, implicit in the use of primary closure as an outcome is a belief that it is either a good or bad thing. The literature would not support that either delayed closure or primary closure is superior, therefore it is impossible to know how to interpret a higher (or lower) rate of primary closure following either Caesarian section or vaginal delivery. Is a higher rate of primary closure good or bad? Secondly, the increasing use by paediatric surgeons of the preformed silo to manage return of the visceral contents to the abdominal cavity means that the closure technique may be prescribed rather than one that is dependent on other factors (such as mode of delivery). Its relevance therefore as an outcome is highly questionable.
I note also that you encountered 'differences in definition of outcomes, choice of outcome measures and variation in reporting methods'. Such difficulties can be a real challenge in the context of a meta-analysis and preclude accurate evidence synthesis. One proposed way to address this challenge is the development and use of a Core Outcome Set. A Core Outcome Set is a set of outcomes that has been derived through consensus methodology across stakeholder groups as being the most important outcomes to measure in re...
I wish to comment about the outcomes you have selected for your study on gastroschisis and in particular caution against the use of 'primary closure' as an outcome at all. There are a number of reasons for this. Firstly, implicit in the use of primary closure as an outcome is a belief that it is either a good or bad thing. The literature would not support that either delayed closure or primary closure is superior, therefore it is impossible to know how to interpret a higher (or lower) rate of primary closure following either Caesarian section or vaginal delivery. Is a higher rate of primary closure good or bad? Secondly, the increasing use by paediatric surgeons of the preformed silo to manage return of the visceral contents to the abdominal cavity means that the closure technique may be prescribed rather than one that is dependent on other factors (such as mode of delivery). Its relevance therefore as an outcome is highly questionable.
I note also that you encountered 'differences in definition of outcomes, choice of outcome measures and variation in reporting methods'. Such difficulties can be a real challenge in the context of a meta-analysis and preclude accurate evidence synthesis. One proposed way to address this challenge is the development and use of a Core Outcome Set. A Core Outcome Set is a set of outcomes that has been derived through consensus methodology across stakeholder groups as being the most important outcomes to measure in research related to a condition. The concept being that if all studies of a condition use a core outcome set then it is much easier to perform meta-analysis reliably. Other benefits include being more certain that the most important outcomes (as defined by a range of stakeholder groups) are being measured and reported.
We have recently developed a core outcome set for gastroschisis (Allin et al Arch Dis Child Fetal Neonatal Ed 2018 doi: 10.1136/archdischild-2017-314560) and would like to bring this to your and other researchers' attention. We believe it may help with some of the difficulties you have encountered in evidence synthesis and will provide a framework for other researchers when selecting which outcomes to measure in future studies of infants with gastroschisis.
We would like to thank Dr. Hutchon for his considered letter and for highlighting a number of important points. We very much acknowledge his experience in the area of cord management at the time of delivery and his ongoing endeavours to advocate for appropriate cord management at the time of delivery(1). He correctly notes that there is no current formal policy for cord management at delivery for term newborn infants in our institution, which undoubtedly results in variability in practice. In a recently completed prospective study evaluating cardiac output in healthy term infants, we have noted that approximately one third of infants had early cord clamping and two thirds some form of placental transfusion, either as delayed or milking. Whilst we cannot be certain or draw any definitive inferences, it is likely that this same variability exits in our cohort of patients. The point related to ‘immediate transfer’ to the resuscitaire may be somewhat misleading. This relates to once the cord is clamped, and not that the cord was immediately clamped in each case(2). We acknowledge that this terminology may be confusing, and therefore cannot concur that our results relate to early cord clamping alone. It is also important to highlight that all our newborns were spontaneously breathing at delivery and did not require any assistance with adaptation.
He makes a very valid comparison with oxygen saturation values in term infants highlighti...
We would like to thank Dr. Hutchon for his considered letter and for highlighting a number of important points. We very much acknowledge his experience in the area of cord management at the time of delivery and his ongoing endeavours to advocate for appropriate cord management at the time of delivery(1). He correctly notes that there is no current formal policy for cord management at delivery for term newborn infants in our institution, which undoubtedly results in variability in practice. In a recently completed prospective study evaluating cardiac output in healthy term infants, we have noted that approximately one third of infants had early cord clamping and two thirds some form of placental transfusion, either as delayed or milking. Whilst we cannot be certain or draw any definitive inferences, it is likely that this same variability exits in our cohort of patients. The point related to ‘immediate transfer’ to the resuscitaire may be somewhat misleading. This relates to once the cord is clamped, and not that the cord was immediately clamped in each case(2). We acknowledge that this terminology may be confusing, and therefore cannot concur that our results relate to early cord clamping alone. It is also important to highlight that all our newborns were spontaneously breathing at delivery and did not require any assistance with adaptation.
He makes a very valid comparison with oxygen saturation values in term infants highlighting the differences in oxygen saturation values between the Australian (3)and Leiden studies(4), attributing this difference to the impact of delayed cord clamping. It is interesting to note that there was a higher degree of bradycardia less than 80bpm in the Leiden cohort who received delayed cord clamping(4). A recent single centre study performed in Melbourne by Blank et al provides even greater clarity on respiratory adaptation(5). They evaluated similar respiratory variables to our measurements in a cohort of term infants, delivered both vaginally and by caesarean section. They did not identify any difference in respiratory variables between spontaneously breathing term infants based on mode of delivery. This is interesting when one considers that their hospital policy mandates caesarean delivered babies have immediate clamping and vaginally delivered have delayed clamping performed. This would suggest that in healthy term infants who do not require any respiratory support at birth, the timing of cord clamping results in no obvious difference in immediate respiratory variables over the first 10 mins of life. However this does not imply that delayed cord clamping has no immediate benefits on babies who may need support during this period of adaptation, and future work in this area is certainly warranted.
Eugene Dempsey and Daragh Finn
References
1. Hutchon D, Bettles N. Motherside care of the term neonate at birth. Matern Health Neonatol Perinatol. 2016;2:5.
2. Finn D, De Meulemeester J, Dann L, Herlihy I, Livingstone V, Boylan GB, et al. Respiratory adaptation in term infants following elective caesarean section. Arch Dis Child Fetal Neonatal Ed. 2018;103(5):F417-F21.
3. Dawson JA, Kamlin CO, Vento M, Wong C, Cole TJ, Donath SM, et al. Defining the reference range for oxygen saturation for infants after birth. Pediatrics. 2010;125(6):e1340-7.
4. Smit M, Dawson JA, Ganzeboom A, Hooper SB, van Roosmalen J, te Pas AB. Pulse oximetry in newborns with delayed cord clamping and immediate skin-to-skin contact. Arch Dis Child Fetal Neonatal Ed. 2014;99(4):F309-14.
5. Blank DA, Gaertner VD, Kamlin COF, Nyland K, Eckard NO, Dawson JA, et al. Respiratory changes in term infants immediately after birth. Resuscitation. 2018;130:105-10.
I was interested to read this study looking at a question which is extremely important to mothers of preterm infants who need to exclusively express - "how frequently do I need to express?".
The conclusion that there is no difference in average yield of mothers expressing 5, 6, 7, 8, and 9 times a day will be very useful to mothers who are similar to those included in the study - that is mothers of preterm babies aged at least 10 days (but mostly 15-20 days old), who have good daily expressed milk yield (average yield clustered around 750ml/day for these expressing frequencies). Therefore mothers in this group may feel more confident in reducing their expressing sessions down to a more manageable 5 or 6 per day, which reduces their burden of expressing.
However it could be harmful to extrapolate outside of these characteristics, for example mothers attempting to establish their supply in the first 2 weeks of life. We know that this period may be a critical window to establish milk supply and this study cannot comment on the relationship of early expressing frequency to the establishment of adequate yield (which, to complicate matters further, is poorly defined in the context of prematurity, with a range of daily volume targets from 500-900ml suggested in the literature and by the Unicef Baby Friendly Initiative). Already I have seen the article summarised as "mothers of preterm infants should express milk at least 5 times a day" on social...
Show MoreThank you for this interesting article, which really adds to our understanding of management of neonatal hypoglycaemia. However, your conclusion that a subset of babies should receive formula rather than breastfeed alongside gel, depending on their blood glucose level, is not supported by the evidence you have provided and ignores the potential harm associated with this approach.
Your data states that alongside the first use of gel, breastfed babies are more likely to require a second gel. There is no literature to support the idea that experiencing a second transient hypoglycaemia in a carefully monitored baby in the first 48 hours of life is harmful (indeed UK guidance uses a treatment threshold of 2mmol/l for the entire first 48 hours of life), and alongside the second gel breastfeeding is as effective as formula so there is no reason to suppose from the data provided that breastfed babies are more likely to go on to require intravenous dextrose.
Asking breastfeeding mothers to use formula instead of breastfeeding in the first hours of their baby's life is likely to undermine mothers' trust in breastfeeding, may impact on their milk supply through reduced stimulation in the critical time period and reduces the colostrum volume ingested, with its unique immune properties. It is not a recommendation to be made lightly.
As authors of the 2015 guidelines we read with interest the “UK neonatal resuscitation survey” [1]. Comparison with 2012 shows a rewarding positive effect of successive guidelines on newborn resuscitation practice.
However, we wanted to address this statement: “…updated guidelines have been criticised for failing to consider data from the Targeted Oxygen in the Resuscitation of Preterm Infants [To2rpido]”. To2rpido [2], published 2017, was unavailable for inclusion in 2015 ILCOR reviews of evidence. [3]. The analysis referred to was post-hoc and unprespecified. Clinicians were not blinded and recruitment was problematic. Enrolling only 5% of eligible infants, To2rpido was terminated after reaching 15% of targeted sample size due to loss of equipoise: ironically, clinicians were concerned about using high oxygen concentrations.
Nonetheless, To2rpido generated such interest that it led to the first neonatal review in ILCOR’s continuous evidence evaluation strategy. [4] Utilising GRADE methodology to rate quality of evidence and strength of recommendations, To2rpido’s impact was downgraded because of high risk of bias. This review [4] continues to recommend “starting with a lower oxygen concentration (21–30%) compared to higher oxygen concentration (60–100%)” whilst highlighting many gaps in our current knowledge.
The use of end-tidal CO2 (ETCO2) detection was not recommended because the guidelines, and Newborn Life Support (NLS) course, focus on airwa...
Show MoreDear Editor,
Show MoreWe read with great interest the network meta-analysis performed by Zeng et al [1]. The authors investigated the comparative efficacy and safety of different corticosteroids in the prevention of bronchopulmonary dysplasia in preterm infants. They included 47 RCTs with 6747 participants. We have several concerns about the study.
First, it looks that the authors are unfamiliar with the procedures of network meta-analysis because there were obvious mistakes. Figure 1 in the study was network plot of different corticosteroids. In Figure 1, the circle size should be proportional to the sample size randomised to each intervention [2]. The line width should be proportional to the study numbers of each direct comparison. However, the circle size was not proportional to the sample size in Figure 1. The line width between dexamethasone (high dose) and placebo also seems inadequate.
Second, various statistical methods or plots have been suggested to assist interpreting the results of network meta-analysis [3]. However, many of them were not performed or presented in this study. For example, since there were direct estimates (i.e., results of pairwise meta-analysis) and indirect estimates (i.e., results of network meta-analysis), the inconsistency between them should be assessed and explored because important inconsistency could threaten the validity of the results. Besides, the authors also didn’t assess small-study effects. Small-study effects could mat...
There seems to be a descrepency regarding the number of babies intubatec in two groups. 56 babies were intubated in high tidal volume group against 14 intubated in the low tidal volume group as per the article. I wondering whether it might have contributed to the high incidence of IVH in the high tidal volume group.
I congratulate Dr Thio and colleagues on their study of PEEP delivery in common neonatal resuscitation devices. This study is timely as clinicians look for more refined strategies to support the preterm lung at birth. Such strategies will require a reliance on equipment in the delivery room.
To allow for interpretation of the findings into the clinical context could the authors comment on the number, and characteristics, of lambs studied, and was this accounted for analysis in Table 1 (for example cluster analysis)? What was the pressure of medical gas supply?
In Reply
We would like to thank Miller et al for their interest in our recently published review and their responding letter to the editor. The first concern is combining RCTs and cohort studies. We agree that classic Cochrane methods advocate combining only same study designs in a meta-analysis. However, there is also an alternative viewpoint. Appropriate integration of randomized and observational cohort studies may offer opportunities to provide more timely, comprehensive, and generalizable evidence about the medical intervention1. To date, the majority of human milk studies on bronchopulmonary dysplasia (BPD) have been observational cohort studies. Generalizing extensive perspective is motivation for combining randomized and non-randomized evidence in a meta-analysis2. In our review, to detect the possibility of incorporating randomized and observational cohort studies, we assessed the statistic heterogeneity between cohort studies and randomized studies. The test for subgroup differences has been shown in table 3, which demonstrated the statistic heterogeneity (I2 and P values) is generally low. This gave a plausible reason to pool observational and randomized studies in our review. In fact, combining observational and randomized studies has been also performed in a similarly themed review for preventing BPD, when authors compared raw mother’s own milk with pasteurized mother’s own milk3.
The second concern from Miller et al was how to interpret the out...
Show MoreWe thank Ovali et al for their interest in our paper. They emphasise that BPD results from a multifactorial process and has wide variation in severity. We agree that basing the prediction of BPD solely on ventilatory requirement at one week of age would not identify all cases of BPD, as demonstrated by the low sensitivity of 67% demonstrated in our study.[1] The high sensitivity of ventilation at one week of age in predicting the development of BPD (99%), however, means that it could facilitate counselling of parents and act as a screening tool to identify candidates for future trials of therapeutic interventions to prevent BPD.
[1] Hunt K, Dassios T, Ali K, et al. Prediction of bronchopulmonary dysplasia development. Arch Dis Child Fetal Neonatal Ed 2018 [Epub ahead of print].
I wish to comment about the outcomes you have selected for your study on gastroschisis and in particular caution against the use of 'primary closure' as an outcome at all. There are a number of reasons for this. Firstly, implicit in the use of primary closure as an outcome is a belief that it is either a good or bad thing. The literature would not support that either delayed closure or primary closure is superior, therefore it is impossible to know how to interpret a higher (or lower) rate of primary closure following either Caesarian section or vaginal delivery. Is a higher rate of primary closure good or bad? Secondly, the increasing use by paediatric surgeons of the preformed silo to manage return of the visceral contents to the abdominal cavity means that the closure technique may be prescribed rather than one that is dependent on other factors (such as mode of delivery). Its relevance therefore as an outcome is highly questionable.
I note also that you encountered 'differences in definition of outcomes, choice of outcome measures and variation in reporting methods'. Such difficulties can be a real challenge in the context of a meta-analysis and preclude accurate evidence synthesis. One proposed way to address this challenge is the development and use of a Core Outcome Set. A Core Outcome Set is a set of outcomes that has been derived through consensus methodology across stakeholder groups as being the most important outcomes to measure in re...
Show MoreWe would like to thank Dr. Hutchon for his considered letter and for highlighting a number of important points. We very much acknowledge his experience in the area of cord management at the time of delivery and his ongoing endeavours to advocate for appropriate cord management at the time of delivery(1). He correctly notes that there is no current formal policy for cord management at delivery for term newborn infants in our institution, which undoubtedly results in variability in practice. In a recently completed prospective study evaluating cardiac output in healthy term infants, we have noted that approximately one third of infants had early cord clamping and two thirds some form of placental transfusion, either as delayed or milking. Whilst we cannot be certain or draw any definitive inferences, it is likely that this same variability exits in our cohort of patients. The point related to ‘immediate transfer’ to the resuscitaire may be somewhat misleading. This relates to once the cord is clamped, and not that the cord was immediately clamped in each case(2). We acknowledge that this terminology may be confusing, and therefore cannot concur that our results relate to early cord clamping alone. It is also important to highlight that all our newborns were spontaneously breathing at delivery and did not require any assistance with adaptation.
He makes a very valid comparison with oxygen saturation values in term infants highlighti...
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