Ponnusamy et al report on the availability of cooling equipment
within UK neonatal units in 2009 (1). They conclude that only 28% of all
units and 78% of level 3 units possess such equipment despite evidence
supporting therapeutic hypothermia. Whilst we agree with the authors in
supporting universal access to cooling for asphyxiated infants, the lack
of local availability of equipment need not equate to a lack of access...
Ponnusamy et al report on the availability of cooling equipment
within UK neonatal units in 2009 (1). They conclude that only 28% of all
units and 78% of level 3 units possess such equipment despite evidence
supporting therapeutic hypothermia. Whilst we agree with the authors in
supporting universal access to cooling for asphyxiated infants, the lack
of local availability of equipment need not equate to a lack of access to
therapeutic hypothermia.
From March 2009 the Scottish Cooling Group has cooperated to provide
therapeutic hypothermia within Scotland, supporting neonatal units whether
they choose to deliver cooling or not. Some level 3 units who anticipate
small numbers of asphyxiated infants have rightly had concern about
maintenance of expertise and have chosen to transfer out eligible infants.
Within Scotland there is now national provision of therapeutic
hypothermia delivered by six out of ten level 3 units and achieved through
cooperation, sharing of experience and outreach education. All non-cooling
units have clear referral criteria and guidance to undertake passive
cooling with strict temperature monitoring and the support of a cooling
centre whilst awaiting retrieval. The national transport service has
collaborated on the production of comprehensive cooling guidelines and is
able to initiate cooling at the referring centre and continue on transport
using servocontrol cooling systems.
We support the collection of national data but suggest that further
surveys should not focus solely on local availability of equipment but
should also investigate accessibility of hypothermia for asphyxiated
infants.
1. Ponnusamy V, Nath P, Bissett L, Willis K, Clarke P. Current
availability of cerebral function monitoring and hypothermia therapy in UK
neonatal units. Arch. Dis. Child. Fetal Neonatal Ed. 2010 95:F383-F384
Preer and Philipp have drawn attention to inadequate breastfeeding
and neonatal jaundice but omitted to mention the most important factor in
breastfeeding success: the let-down reflex.1
In addition to prolactin, oxytocin (the hormone associated with the
reflex) stimulates milk production: numerous oxytocin receptors on the
milk secreting cells of the breast alveoli mediate a massive release of
casein (milk protein) into...
Preer and Philipp have drawn attention to inadequate breastfeeding
and neonatal jaundice but omitted to mention the most important factor in
breastfeeding success: the let-down reflex.1
In addition to prolactin, oxytocin (the hormone associated with the
reflex) stimulates milk production: numerous oxytocin receptors on the
milk secreting cells of the breast alveoli mediate a massive release of
casein (milk protein) into the lumen of the alveoli.2 The let-down reflex
(via oxytocin) then transfers milk to the infant: in between the positive
pressure waves of the reflex milk flows back towards the breast alveoli,
away from the infant.3
Frequent feeding in the early postpartum period is associated with lower
bilirubin levels whilst jaundiced infants may be lethargic and feed
poorly.4 Good positioning and latching and relying on infant demand may,
of themselves, not be sufficient to ensure frequent feeding, good milk
production and transfer.
Mothers need to know how to institute a beneficial feeding pattern to
optimise the milk intake of their infant and avoid 'not enough breast
milk' jaundice.
References
1 Prier GL, Philipp BL. Understanding and managing breast milk jaundice.
Arch Dis Child Fetal Neonatal Ed August 5 2010 doi:10.1136/adc2010.184416
2 Lollivier V, Marnet PG, Delpal S, Rainteau D, Achard C, Rabot A et al.
Oxytocin stimulates secretory processes in lactating rabbit mammary
epithelial cells. J Physiol. 2006;570 (Pt 1):125-40.
3 Ramsay DT, Kent JC, Owens RA, Hartman PE. Ultrasound imaging of milk
ejection in the breast of lactating women. Pediatrics 2004; 113; 361-367
4 de Carvalho M, Klaus MH, Merkatz RB. Frequency of breast-feeding and
serum bilirubin concentration. Am J Dis Child 1982 Aug 136(8):737-8
I read this paper with interest and would like to comment on some of
the results and conclusions reached.
The authors have studied changes in regional cerebral saturation
(RSO2) using near infrared spectroscopy and used these to calculate
fractional tissue oxygen extraction (FTOE) in babies felt to require blood
transfusion and have made measurements before and after transfusion. They
describ...
I read this paper with interest and would like to comment on some of
the results and conclusions reached.
The authors have studied changes in regional cerebral saturation
(RSO2) using near infrared spectroscopy and used these to calculate
fractional tissue oxygen extraction (FTOE) in babies felt to require blood
transfusion and have made measurements before and after transfusion. They
describe that if the haemoglobin concentration (Hb) is low and the
cerebral FTOE is high before transfusion the FTOE tends to improve
afterwards leading them to conclude that cerebral oxygenation may be at
risk when the Hb is below 6g/dl. The authors used a restrictive
transfusion guideline and most of the babies studied therefore had quite
low haemoglobin concentrations. However I do not think that these
conclusions are completely supported by their data.
When transfusions are given the FTOE tends to decrease in all three
groups whether the Hb is low or higher. This result is surprising but is
consistent with the data from our study which was similar in design,
although slightly different methodology was used (1). Notably the babies
in our study had higher haemoglobin concentrations and yet still
demonstrated decreases in FTOE after transfusion (1).
FTOE represents the balance between oxygen delivery and consumption.
A decrease in FTOE implies either that oxygen delivery has increased or
oxygen consumption has fallen (or both). When giving a blood transfusion
one would expect consumption to remain constant unless other changes such
as changes in temperature or activity level have occurred. Cerebral
oxygen delivery is dependent on main three factors: the Hb, cerebral blood
flow (CBF) and the arterial oxygen saturation (SaO2). SaO2 should remain
constant within the monitored limits. Hb will obviously increase following
a transfusion. One might expect cerebral blood flow to decrease in
proportion to the increase in Hb so that delivery also remained constant,
a notion which is supported by clinical and animal studies (2-4). If this
occurred then FTOE should remain constant after transfusion. The decrease
in FTOE therefore implies that delivery increases with transfusion. CBF
may not therefore decrease as much as expected as a result of a
transfusion.
This result could suggest, as I think the authors imply, that
cerebral oxygen consumption is delivery dependent in these babies - in
other words the brain is dependent on the level of oxygen delivery and is
extracting oxygen at its maximum such that when oxygen delivery is
increased by transfusion FTOE decreases. This seems very unlikely in
clinical well babies. Changes in FTOE may therefore be more complex and a
decrease in FTOE after an intervention may not necessarily imply that
delivery was compromised before the intervention.
One factor which may be important could be the HbF fraction. Giving
a blood transfusion with adult red cells will increase the proportion of
HbA in most preterm babies. HbA has a lower affinity for oxygen and this
will therefore increase the availability of oxygen to the cells even
though delivery does not change and this may explain why FTOE decreases.
HbF was not measured in this study. Although we measured it in our study
(1) no correlation with FTOE was demonstrated but this may have been
because of other confounding factors and a larger sample with a wider
range of values might be more likely to demonstrate a relationship. There
is a relationship between HbF and FTOE measured in peripheral tissues (the
forearm) (5).
This question could be answered by measuring cerebral FTOE in two
groups of babies one with significant proportions of HbF and one group
with no HbF to see if there was a change in cerebral FTOE after
transfusion.
The authors seem to suggest that they expect a particular level of Hb
which would be associated with important changes in cerebral oxygenation.
In fact they suggest that 6g/dl is this value however this is not
supported by their data. A particular cut-off is also unlikely for
several reasons: preterm babies have varying abilities to compensate
depending on their cardio-respiratory status, they will have varying
amounts of HbF which might influence oxygen availability to the tissues
and finally the Hb does not accurately reflect the red cell volume (6).
For all of these reasons, as one observes clinically, anaemia may become
clinically important at different levels of Hb in different babies.
A better marker of significant anaemia is required and measurements
of tissue oxygenation either cerebral or peripheral made using NIRS may be
useful for this although the ideal measurement which best indicates at an
early enough stage when anaemia is starting to compromise tissue
oxygenation is not yet clear and more studies are required.
One factor which is missing is knowledge of what is 'abnormal'. How
high does the value of FTOE need to be to represent impaired cerebral
oxygenation? Although reference ranges are available in well infants it is
not clear when increases in cerebral FTOE are significant. What is
required is data which demonstrates whether some values of FTOE are
associated important clinical changes or morbidity so that changes or
values which are truly clinically important can be recognised. This sort
of data will clearly require much larger studies.
References
1. Wardle SP, Yoxall CW, Weindling AM. Cerebral Fractional Oxygen
Extraction Using Near Infrared Spectroscopy During Hypotension and Anaemia
in Preterm Infants. Journal of Cerebral Blood Flow and Metabolism
2000;20(2):272-279
2. Brown MM, Marshall J. Regulation of cerebral blood flow in response
to changes in blood viscosity. Lancet 1985; i:604-609.
3. Ramaekers VT, Casaer P, Marchal G, et al. The effect of blood
transfusion on cerebral blood-flow in preterm infants: a Doppler study.
Dev.Med.Child Neurol. 1988;30:334-341.
4. Younkin 1981) Younkin DP, Reivich M, Obrist WD, et al. Physiologic
responses of neonatal rCBF. J Cereb Blood Flow Metab 1981;1:S273-S274.
5. Peripheral Oxygenation and Anaemia in Preterm Babies. SP Wardle, CW
Yoxall, E Crawley, AM Weindling. Pediatric Research 1998;44(1):125-131
6. Hudson I, Cooke A, Holland B, Houston A, Jones JG, Turner T, Wardrop
CA 1990 Red cell volume and cardiac output in anaemic preterm infants.
Arch Dis Child 65:672-5
Sir,
The authors have rightly made a retrospective diagnosis of benign tonic
gaze in the three infants described. However, no mention is made of
whether or not tests for hypoglycemia and hypocalcemia were done at the
time of occurance as subtle seizures not picked up on later EEG may
present in this way and should be ruled out immedietely.
Sir,
The authors have rightly made a retrospective diagnosis of benign tonic
gaze in the three infants described. However, no mention is made of
whether or not tests for hypoglycemia and hypocalcemia were done at the
time of occurance as subtle seizures not picked up on later EEG may
present in this way and should be ruled out immedietely.
Dr. Mactier has done an excellent service by writing this article and
bringing this issue to the fore front. It is indeed a huge public health
problem and we do need many more studies to understand better treatment
for long term outcomes for children of opiate dependent mothers. However,
until such treatments and alternatives to methadone/buprenorphine are
available, we need to keep treating these women with
methadone/bu...
Dr. Mactier has done an excellent service by writing this article and
bringing this issue to the fore front. It is indeed a huge public health
problem and we do need many more studies to understand better treatment
for long term outcomes for children of opiate dependent mothers. However,
until such treatments and alternatives to methadone/buprenorphine are
available, we need to keep treating these women with
methadone/buprenorphine. Leaving them in the street and allowing them to
use heroin is not only a disservice to these patients but also to future
generation. People working in the field of addiction are not arguing that
methadone/buprenorphine is the best alternative but they are better than
using the heroin during pregnancy as use of heroin brings other lifestyle
issues and dangers to the pregnant mother as well as the fetus. NAS is an
important issue with respect to newborns, but proper management of NAS can
far minimize the adverse consequences. It is true that there are trans-
atlantic differences in attitude with regards to this population but this
is true in lot of other areas of health care. Having a comprehensive
system of primary care, UK can do better job of providing the adequate
care to these pregnant women. The essential thing is that we need to keep
an eye on the future generation. If these women are entered into a long
term comprehensive program with a support structure that is not only good
for their recovery but also provides a better future to these children,
the outcome will be drastically different. As the author has indicated,
the poor suffer from ongoing social deprivation. Right at the time of
their first encounter with the health care system, pregnant women can be
entered into a training/job/recovery program which will provide them
future support and lead to a better environment for growing children.
Lastly, since this article is focussed on pharmacotherapy, we do not need
to discuss much about behavior therapy/modification but one thing that has
proven extremely useful for this population is CM (contingency management)
and we should look to exploit the good effects of this very important tool
The key is to keep an eye on the future generation in spite of maternal
drug use.
The team from leed have highlighted a very important area of neonatal
practice that is still seeking clarification and enlightenment.
Neonates do have a high incidence of reflux due to physiologic and
iatrogenic causes. These have been clearly highlighted in this review. The
choice and rationale for treating these babies clearly shows that more
work still needs to done before we can be sure that the doctors and nurses
are u...
The team from leed have highlighted a very important area of neonatal
practice that is still seeking clarification and enlightenment.
Neonates do have a high incidence of reflux due to physiologic and
iatrogenic causes. These have been clearly highlighted in this review. The
choice and rationale for treating these babies clearly shows that more
work still needs to done before we can be sure that the doctors and nurses
are using appropriate measures to address the real problem and not just
propagating a placebo effect and using medications that are not only
unnecessary but potentially dangerous.
The following questions may help to concentrate the thinking about this
problem.
Do we know if reflux in neonates is the
cause of apnoeas? If not why treat
If we believe there is an association in the
absence of aspiration, what is the mechanism?
It is agreed that the stomach of milk fed
neonate is unlikely to suffer from the effect of acid (buffering effect)
what then is the rationale for prescribing gaviscon? Could it be acting as
a thickening agent?
In the absence of proven oesophageal irritation
or inflammation why do we need to further reduce acid production by using
H2 blocker or even worse a proton pump inhibitor in the face of
significant side effects with this substance?
Is there a place for using ph study with
modified (acidified) feeds for testing to demonstrate acid reflux and how
significant is the position of non acid reflux in this group of patients?
Should positioning not be routinely adhered to
as part of routine neonatal care since gastro oesophageal reflux is common
in this age group?
Surgical intervention in my experience is mainly
offered for severe reflux especially in patients with neurological disease
or do the authors have a different experience?
Is contrast study underused in these patients?
And could this be a better test in this uncertain field? I concede that
reflux episde may be missed during this test but its presence can be noted
in addition to any anatomical defect.
Although I have raised a few questions, I appreciate the efforts of the
authors who have tried to highlight the clear difficulties with the
investigation and treatment of reflux in this age group. Neonatologists in
the front line have to deal with problems using best evidence and in most
cases extrapolate from management strategies of older children. It is how
ever the time to look again at the evidence and adjust practice
accordingly. I remember not long ago cisapride was the standard prokinetic
agent used to treat gastroesophageal reflux in neonatal units even when
the evidence was not there. Tertiary neonatal units had in their
formularies this dangerous medicine which was dished out routinely and
thanks to the responsible authorities for the withdrawal of this product
from the UK, meaning that neonates have been spared the dangers of
arrhythmias.
I have an interest in paediatric gastroenterology and have practised in a
DGH with sessions in gastroenterology at the
Children's hospital. In my practice I have
investigated neonates with symptoms suggestive of gastroesophageal reflux
and also suggested and advised on treatment regimes. Having looked at the
evidence, I still advice on ph studies with its flaws after initiation of
treatment which had failed to resolve the observed symptoms. In addition,
neonates with acute life threatening events in addition to Ph studies are
subjected to contrast studies to make sure no anatomical defect exists.
On the use of pharmacology agents, my emphasis is on the use of prokinetic
agents and less of H2 blockers or proton pump inhibitors unless evidence
of oesophagitis exists or the neonate is not enterally fed with milk while
symptomatic. In my experience, surgical intervention for managing
gastroesophageal reflux is only common with those neonates with
neurological problem with severe reflux disease.
The take home message for me after reading this article is that there is a
presumption by some medical practitioners that gastroesophageal Reflux
disease is associated with neonatal apnoes and bradcardias and also that
no reliable form of investigation exists to confirm this and that
pharmacological agents though lacking in evidence remain the mainstay of
treatment. It also tells me that more research is needed to provide the
necessary answers. I will be very willing to be a participant in any such
study.
Reference:
Peter CS, Sprodowski N, Bohnhorst B,et al Gastroesophageal reflux and
apnoea of prematurity: No temporal relationship. Pediatrics
2002;109:8-11
Birch JL; Newell SJ; Gastroesophageal reflux disease in preterm
infants: Current management and diagnostic dilemmas ; Arch Dis Child fetal
Neonatal Ed 2009;94:F379-F383 doi:10.1136/adc.2008.149112.
Dhillon AS, Ewer AK Diagnosis and management of gastroesophageal
reflux in preterm infants in neonatal intensive care units. Acta
Paediatrica 2004;93:88-93
Omari TI, Haslam RR, Lundborg P, et al Effect of omeprazole on acid
gastroesophageal reflux and gastric acidity in preterm infants with
pathological acid reflux. J Pedr Gastroenterol Nutr
2007;44:41-44.
The paper by Sarkar et al[1] addresses a question of considerable
practical and ethical importance for parents and clinicians caring for
asphyxiated newborn infants. Which infants are so severely affected that
they will not benefit from attempted neuroprotection with therapeutic
hypothermia?[2]
However, it is not clear that their paper answers this question. They
focus on risk of mortality...
The paper by Sarkar et al[1] addresses a question of considerable
practical and ethical importance for parents and clinicians caring for
asphyxiated newborn infants. Which infants are so severely affected that
they will not benefit from attempted neuroprotection with therapeutic
hypothermia?[2]
However, it is not clear that their paper answers this question. They
focus on risk of mortality, but do not provide any data on the mechanism
of demise in dying infants. What proportion of infants died despite full
attempts to save their lives, and what proportion died following
withdrawal or withholding of life-sustaining treatment? This is critically
important since in previous studies of infants with HIE the majority of
deaths followed treatment limitation decisions.[3]
The problem is that if a significant proportion of deaths did follow
treatment limitation decisions, the statistical association between an
Apgar score of 0 and death may reflect a self-fulfilling prophecy.[4]
Given the recommendation by the Neonatal Resuscitation Program and
previous evidence of poor outcome in infants with such Apgar scores, it
would not be surprising if an Apgar score of 0 at 10 minutes made
clinicians more pessimistic about outcome and more likely to subsequently
limit treatment.
Secondly, the authors suggest that infants surviving with Apgar
scores of 0 at 10 minutes are "likely to have severe disability". They
base this claim on the finding that there were no non-disabled survivors
in the cohort. However, the absence of an event does not provide good
evidence of its rarity in the presence of small sample sizes.[5]
The authors note in passing that their results differ from those of
the NICHD sub-study.[6] But they understate the significance of those
results. In that study there were 13 survivors with an Apgar score of 0 at
10 minutes, of whom 6 (46%) had mild or no disability.[6] Although that
report did not distinguish between cooled and non-cooled infants, if the
two reports are combined they suggest a 38% chance of favourable outcome
among surviving infants, with a confidence interval of 18-61%.
Further follow-up data of infants with HIE treated with cooling may
help clarify which infants do not benefit from therapeutic hypothermia.
But at present it would be premature to deny infants treatment based
solely on their Apgar score at 10 minutes of age.
Dr Dominic Wilkinson, Neonatologist, Nuffield Medical Research
Fellow, The Ethox Centre, University of Oxford
REFERENCES
1. Sarkar S, Bhagat I, Dechert RE, Barks JD. Predicting death despite
therapeutic hypothermia in infants with hypoxic-ischaemic encephalopathy.
Arch Dis Child Fetal Neonatal Ed. 2010; [published Online First
doi:10.1136/adc.2010.182725].
2. Wilkinson DJ. Cool heads: ethical issues associated with
therapeutic hypothermia for newborns. Acta Paediatrica. 2008;98:217-20
doi: 10.1111/j.1651-2227.2008.01127.x [published Online First 28/11/2008].
3. Pierrat V, Haouari N, Liska A, et al. Prevalence, causes, and
outcome at 2 years of age of newborn encephalopathy: population based
study. Arch Dis Child Fetal Neonatal Ed. 2005;90:F257-61 doi:
10.1136/adc.2003.047985.
4. Wilkinson D. The self-fulfilling prophecy in intensive care. Theor
Med Bioeth. 2009;30:401-10 doi: 10.1007/s11017-009-9120-6.
5. Eypasch E, Lefering R, Kum CK, Troidl H. Probability of adverse
events that have not yet occurred: a statistical reminder. BMJ.
1995;311:619-20.
6. Laptook AR, Shankaran S, Ambalavanan N, et al. Outcome of term
infants using apgar scores at 10 minutes following hypoxic-ischemic
encephalopathy. Pediatrics. 2009;124:1619-26.
In their retrospective observational study of 1960 preterm infants
over a 7-year period, Aralikatti et al reported an increased risk of
developing threshold retinopathy of prematurity (ROP) in Asian and black
infants compared to white infants [1]. The proportion of small for
gestational age (SGA), by standard growth charts, was also higher in Asian
(36.19%) than in white (29.45%) and black infants (...
In their retrospective observational study of 1960 preterm infants
over a 7-year period, Aralikatti et al reported an increased risk of
developing threshold retinopathy of prematurity (ROP) in Asian and black
infants compared to white infants [1]. The proportion of small for
gestational age (SGA), by standard growth charts, was also higher in Asian
(36.19%) than in white (29.45%) and black infants (27.81%) and the authors
speculated that this might explain the increased risk of ROP in Asian
infants. They also adjusted for birthweight and gestational age through
logistic regression analysis and reported that the results still supported
the increased risk of ROP in non-white infants.
SGA, as defined by standard growth standards, is a known risk factor
for ROP in the preterm infant [2-5]. When looking for an association
between ethnicity and the risk of ROP in a logistic regression model which
adjusts for birthweight and gestational age, the model calculates the odds
ratio of ROP for each ethnicity by adjusting separately for each unit
increment in birthweight and for each unit increment in gestational age,
while maintaining the other factor constant. The classification of each
infant as SGA or AGA is totally ignored in the model used, as the
birthweight and the gestational age of each infant are separately taken
into account, without any indication whether each infant's birthweight is
appropriate for his/her gestational age or not. We believe that this
deficiency in the model they used prevented the authors from reliably
studying whether the relationship they found between ethnicity and the
risk of ROP was not confounded by growth retardation.
Furthermore, the observed ethnic differences in foetal growth are
often physiologic rather than pathologic [6]. Customised birth weight
percentiles, by adjusting for the variables found to be associated with
normal variation in birth weight, such as maternal height, weight, parity,
ethnic origin and the baby's gender, better distinguish growth-restricted
from constitutionally small but healthy neonates and have been proven to
be superior to standard growth charts in detecting foetal and neonatal
complications associated with poor foetal growth [7-8]. Using these
customised birth weight percentiles [9], we found that, regardless of
gestational age, SGA infants identified exclusively by the customised
method, and therefore missed by the standard growth charts, accounted for
50% of all infants diagnosed with ROP in a cohort of 6125 neonates. We
also found that, after adjusting for prematurity, SGA infants exclusively
identified by the customised method, still had a higher risk of
complications, including an increased risk for all grades of ROP,
confirming previous reports that morbidities associated with preterm
delivery, including ROP [2-5], are compounded by foetal growth restriction
[10].
We therefore believe that adding a classification of birthweight as
SGA (or not) in their regression model, even using the standard growth
charts, was needed, and would have allowed the authors to reliably confirm
if the role of ethnicity in the risk of ROP is not confounded by SGA.
Better still, using the customised growth percentiles instead of standard
growth charts to classify infants' growth in their model would have been
more appropriate, as maternal ethnicity is already integrated in the
customised classification of the infant's birth weight.
Hassib Narchi, Alyson Skinner
References
1. Aralikatti AKV, Mitr A, Denniston AKO, Haque MS, Ewer AK, Butler
L. Is ethnicity a risk factor for severe retinopathy of prematurity? Arch
Dis Child Fetal Neonatal Ed 2010;95:F174-F176.
2. Zaw W, Gagnon R, da Silva O. The risks of adverse neonatal outcome
among preterm small for gestational age infants according to neonatal
versus fetal growth standards. Pediatrics 2003;111 (Part 1):1273-1277.
3. 26. Slidsborg C, Olesen HB, Jensen PK, Jensen H, Nissen KR,
Greisen G, Rasmussen S, Fledelius HC, la CM. Treatment for retinopathy of
prematurity in Denmark in a ten-year period (1996-2005): is the incidence
increasing? Pediatrics 2008; 121:97-105.
4. Allegaert K, Vanhole C, Casteels I, Naulaers G, Debeer A, Cossey
V, Devlieger H. Perinatal growth characteristics and associated risk of
developing threshold retinopathy of prematurity. J AAPOS 2003;7:34-37.
5. Regev RH, Lusky A, Dolfin T, Litmanovitz I, Arnon S, Reichman B.
Excess mortality and morbidity among smallfor- gestational-age premature
infants: a population-based study. J Pediatr 2003;143:186-191.
6. Kierans WJ, Joseph KS, Luo ZC, Platt R, Wilkins R, Kramer MS. Does
one size fit all? The case for ethnic-specific standards of fetal growth.
BMC Pregnancy Childbirth 2008;8:1.
7. Gardosi J. New definition of small for gestational age based on
fetal growth potential. Horm Res 2006;65 (Suppl 3):15-18.
8. Reddy UM. Prediction and prevention of recurrent stillbirth.
Obstet Gynecol 2007;110:1151-1164
9. Narchi H, Skinner A, Williams B. Small for gestational age
neonates- are we missing some by only using standard population growth
standards and does it matter? J Matern Fetal Neonatal Med. 2009; 29:1-7.
10. Pallotto EK, Kilbride HW. Perinatal outcome and later
implications of intrauterine growth restriction. Clin Obstet Gynecol
2006;49:257-269
We congratulate Sehgal and colleagues for their study (1) that found
prophylactic surfactant causes major haemo-dynamic changes in preterm
babies. This publication follows close on the heels of a study in the NEJM
that found that prophylactic surfactant was no better than continuous
positive airway pressure (CPAP)ventilation (2). It is significant that
both these papers (1,2) quote a Cochrane meta-analysis in there
intro...
We congratulate Sehgal and colleagues for their study (1) that found
prophylactic surfactant causes major haemo-dynamic changes in preterm
babies. This publication follows close on the heels of a study in the NEJM
that found that prophylactic surfactant was no better than continuous
positive airway pressure (CPAP)ventilation (2). It is significant that
both these papers (1,2) quote a Cochrane meta-analysis in there
introduction to suggest that prophylactic surfactant reduces mortality
(3). This is a misinterpretation of the Cochrane report. The meta-analysis
had found that there was no difference in the in-hospital deaths, after
use of surfactant (Risk Ratio: 0.70, 95% C.I. 0.47 - 1.06). It however
found that surfactant reduces incidence of deaths in the first 30 days of
life and this was then reported as a reduction in neonatal mortality (Risk
Ratio: 0.80, C.I. 0.72 - 0.88). The Cochrane meta-analysis was revised
recently (4) but this misleading statement in the abstract has survived
into the new version also. The fact that leading researchers working with
surfactant carry this wrong impression from the Cochrane report suggests
that the report needs to be revised for clarity.
We hope that this letter will in a small way, add to the results of newer
studies on surfactant(1,2), to clarify the issue that prophylactic
surfactant is not useful in reducing mortality.
References
1. Haemodynamic changes after delivery room surfactant administration
to very low birth weight infants Arvind Sehgal, Wendy Mak, Michael Dunn,
Edmond Kelly, Hilary Whyte, B McCrindle, Patrick J McNamara Arch. Dis.
Child. Fetal Neonatal Ed. published 10 June 2010, 10.1136/adc.2009.173724
2. SUPPORT Study Group of the Eunice Kennedy Shriver NICHD Neonatal
Research Network. Early CPAP versus Surfactant in Extremely Preterm
Infants. N Engl J Med. 2010 May 16. [Epub ahead of print] PMID: 20472939
3. Soll RF. Prophylactic natural surfactant extract for preventing
morbidity and mortality in preterm infants. Cochrane Database Syst Rev
2000;2:CD000511.
4. Soll R, Ozek E. Prophylactic animal derived surfactant extract for
preventing morbidity and mortality in preterm infants. Cochrane Database
of Systematic Reviews 1997, Issue 4. Art. No.: CD000511. DOI:
10.1002/14651858.CD000511
With great interest we read the article by Sehgal et al describing
the hemodynamics of surfactant administration in the delivery room. The
authors found a low RVO, low LVO, low to normal SVC flow and an increasing
RVO:LVO ratio in the first 60 minutes after surfactant administration.
Surprisingly, SVC flow is responsible for 62% of RVO in the pre-surfactant
measurement and up to 79% of LVO at 1 hour...
With great interest we read the article by Sehgal et al describing
the hemodynamics of surfactant administration in the delivery room. The
authors found a low RVO, low LVO, low to normal SVC flow and an increasing
RVO:LVO ratio in the first 60 minutes after surfactant administration.
Surprisingly, SVC flow is responsible for 62% of RVO in the pre-surfactant
measurement and up to 79% of LVO at 1 hour after surfactant. This combined
with a large duct and exclusive left-to-right shunting would mean there is
very little blood flow to the lower body. However, this was not reflected
by the arterial pH. The authors provide hemodynamic explanations, but do
not discuss methodological issues surrounding Doppler-derived cardiac
output measurements. Delivery room hemodynamics are not extensively
studied, but some information is available for healthy term newborns.
Agata et al. measured 34 healthy term infants at 1 hour of age and found a
LVO of 327 /- 66 ml/kg/min, followed by a decrease.1 Walther et al.
showed comparable findings in a group of 32 term infants starting at 30
minutes after birth.2 We re-analysed a previously published cohort of
preterm infants who were studied during lung recruitment.3 There were 9
infants who were measured within 1 hour after birth immediately after the
change to high frequency ventilation. In this group the median (range) RVO
and SVC flow was 325 (251-541) and 74 (48-126) ml/kg/min respectively. The
ductal diameter was 2.9 (1.7-3.6) mm with total ductal shunting always
left-to-right.
We suggest that differences in methodology may explain the differences in
findings. Detailed information on where LVO and RVO diameters were
determined was not provided. The Pa Vmax is suggestive of an expected RVO
of 150-300 ml/kg/min 4 so it is possible that a reduced diameter
measurement could explain the low RVO and LVO compared to values found
using other referenced methodology.5 Further investigations into whether
the low-normal SVC flow is caused by the early surfactant administration
and if this coincides with low peripheral blood flow will be required to
establish the full picture and potential consequences of these
observations.
1. Agata Y, Hiraishi S, Oguchi K, Misawa H, Horiguchi Y, Fujino N,
Yashiro K,
Shimada N. Changes in left ventricular output from fetal to early neonatal
life.
J Pediatr. 1991;119(3):441-5
2. Walther FJ, Benders MJ, Leighton JO. Early changes in the neonatal
circulatory transition. J Pediatr. 1993;123(4):625-32
3. de Waal K, Evans N, van der Lee J, van Kaam A. Effect of lung
recruitment on
pulmonary, systemic, and ductal blood flow in preterm infants. J Pediatr.
2009;154(5):651-5
4. Evans N. Support of the preterm circulation: keynote address to
the Fifth Evidence vs Experience Conference, Chicago, June 2008. J
Perinatol. 2009;29 Suppl 2:S50-7
5. Evans N, Kluckow M. Early determinants of right and left
ventricular output in ventilated preterm infants. Arch Dis Child Fetal
Neonatal Ed. 1996;74(2):F88-94
Ponnusamy et al report on the availability of cooling equipment within UK neonatal units in 2009 (1). They conclude that only 28% of all units and 78% of level 3 units possess such equipment despite evidence supporting therapeutic hypothermia. Whilst we agree with the authors in supporting universal access to cooling for asphyxiated infants, the lack of local availability of equipment need not equate to a lack of access...
Preer and Philipp have drawn attention to inadequate breastfeeding and neonatal jaundice but omitted to mention the most important factor in breastfeeding success: the let-down reflex.1 In addition to prolactin, oxytocin (the hormone associated with the reflex) stimulates milk production: numerous oxytocin receptors on the milk secreting cells of the breast alveoli mediate a massive release of casein (milk protein) into...
Dear Sir,
I read this paper with interest and would like to comment on some of the results and conclusions reached.
The authors have studied changes in regional cerebral saturation (RSO2) using near infrared spectroscopy and used these to calculate fractional tissue oxygen extraction (FTOE) in babies felt to require blood transfusion and have made measurements before and after transfusion. They describ...
Sir, The authors have rightly made a retrospective diagnosis of benign tonic gaze in the three infants described. However, no mention is made of whether or not tests for hypoglycemia and hypocalcemia were done at the time of occurance as subtle seizures not picked up on later EEG may present in this way and should be ruled out immedietely.
Conflict of Interest:
None declared...
Dr. Mactier has done an excellent service by writing this article and bringing this issue to the fore front. It is indeed a huge public health problem and we do need many more studies to understand better treatment for long term outcomes for children of opiate dependent mothers. However, until such treatments and alternatives to methadone/buprenorphine are available, we need to keep treating these women with methadone/bu...
The team from leed have highlighted a very important area of neonatal practice that is still seeking clarification and enlightenment. Neonates do have a high incidence of reflux due to physiologic and iatrogenic causes. These have been clearly highlighted in this review. The choice and rationale for treating these babies clearly shows that more work still needs to done before we can be sure that the doctors and nurses are u...
Dear Editor,
The paper by Sarkar et al[1] addresses a question of considerable practical and ethical importance for parents and clinicians caring for asphyxiated newborn infants. Which infants are so severely affected that they will not benefit from attempted neuroprotection with therapeutic hypothermia?[2]
However, it is not clear that their paper answers this question. They focus on risk of mortality...
Dear Editor,
In their retrospective observational study of 1960 preterm infants over a 7-year period, Aralikatti et al reported an increased risk of developing threshold retinopathy of prematurity (ROP) in Asian and black infants compared to white infants [1]. The proportion of small for gestational age (SGA), by standard growth charts, was also higher in Asian (36.19%) than in white (29.45%) and black infants (...
We congratulate Sehgal and colleagues for their study (1) that found prophylactic surfactant causes major haemo-dynamic changes in preterm babies. This publication follows close on the heels of a study in the NEJM that found that prophylactic surfactant was no better than continuous positive airway pressure (CPAP)ventilation (2). It is significant that both these papers (1,2) quote a Cochrane meta-analysis in there intro...
Dear editor,
With great interest we read the article by Sehgal et al describing the hemodynamics of surfactant administration in the delivery room. The authors found a low RVO, low LVO, low to normal SVC flow and an increasing RVO:LVO ratio in the first 60 minutes after surfactant administration. Surprisingly, SVC flow is responsible for 62% of RVO in the pre-surfactant measurement and up to 79% of LVO at 1 hour...
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