We were surprised at the results of the two studies published in your journal by Baumer[1] and Bersford et al[2]. Our experience with triggered ventilation over 10 years is shown in the table below:
We were surprised at the results of the two studies published in your journal by Baumer[1] and Bersford et al[2]. Our experience with triggered ventilation over 10 years is shown in the table below:
Complications of prematurity 1991-99
1991
1992
1993
1994
1995
1996
1997
1998
1999
<_1500 g="g" td="td"/>
n = 175
n = 190
n = 182
n = 184
n = 218
n = 169
n = 196
n = 203
n = 184
Retinopathy of prematurity Grade 3 or 4 (%)
2.2
5.2
6.5
4.8
5.5
7.1
3.2
Intraventricular haemorrhage Grade 3 or 4 (%)
13.1
2.5
16.4
12.3
12.8
11.8
7.6
9.3
3.2
Pneumothorax (%)
2.2
4.7
3.8
3.8
2.2
7
5
3.4
3.2
<_1250 g="g" td="td"/>
n = 130
n = 136
n = 133
n = 128
n = 162
n = 130
n = 154
n = 163
n = 134
Retinopathy of prematurity Grade 3 or 4 (%)
3
7.3
9
7
6.7
9.2
3.2
0.6
5.2
Intraventricular haemorrhage Grade 3 or 4 (%)
7.6
29.4
21
16.4
14.8
15.3
9.7
11.6
3.7
Pneumothorax (%)
3
4.4
5.2
4.6
3
5.3
3.5
3.6
3.7
In comparison to the outcome figures in the articles, our incidence of complications of pneumothoraces, intraventricular haemorrhage, and retinopathy of prematurity were significantly less.
As explained in our original article[3] and subsequently shown by others, pressure and flow triggered systems perform suboptimally in infants less than 1500 g. While bench testing may suggest an adequate response time, clinical practice indicates that these systems are compromised by the following:
(1) chest wall and lung compliance (2) airway resistance (3) leak around the endotracheal tube (4) endotracheal tube resistance (5) systems compliance.
The trigger delay may be aggravated by each of these factors, especially in the very low birth weight infants.
We believe that the inability of the patient to terminate the insufflation of gases at the onset of exhalation leads to increased intra thoracic pressure and even intra cranial pressure. Thus, if there is trigger delay as postulated above, the ventilator continues to force gases into the infant during the expiratory phase causing active exhalation and with consequent deleterious effects.
The system used in our unit is triggered by modified impedance technology. Peak detectors within the system detect onset of inspiration and exhalation with sensitivity and rapidly. Further, since the sensitivity depends on the rate of change of impedance, it is more sensitive when applied to very low birth weight infants or with increased rate of respiration. This may explain the marked difference in outcome, compared to the pressure triggered system, as shown by the application of the system in 1701 infants weighing less than 1500 g over 10 years. There were 1270 infants in the same group were less than 1250 g. The only problem we have encountered is that of some cardio respiratory monitors are incompatible with the triggering device. The signal processing through the monitors is crucial to the optimal performance of the respiratory analog input signal to the trigger/terminator. Prototypes of the system were used initially but since 1993 commercially available system (Sechrist SAVI) was utilized exclusively.
In large multicenter studies, derivation of consensus and consistent application of a standardized "conventional ventilation" protocol is very difficult. This may skew some of the outcome data. Perhaps the limitations of flow and pressure triggered systems need to be considered prior to abandoning triggered systems in the respiratory support of newborns. Active exhalation predisposes some of these infants to the complications cited. The incidence of ROP in our experience is less than that reported in the literature. Possibly the same mechanism described above also predisposes the infants to ROP.
Given all of the above, further studies and analysis may be prudent. Such studies of patient triggered ventilation should also incorporate the capability of patient terminated ventilation.
References
1. Baumer JH. International randomised controlled trial of patient triggered ventilation in neonatal respiratory distress syndrome. Arch Dis Child Fetal Neonatal Ed 2000;82:F5-F10.
2. Beresford MW, Shaw NJ, Manning D. Randomised controlled trial of patient triggered and conventional fast rate ventilation in neonatal respiratory distress syndrome. Arch. Dis Child Fetal Neonatal Ed 2000;82:F14-F18.
3. Visveshwara N, Freeman B, Peck M, Caliwag W, Shook S, Rajani K B. Patient-triggered synchronized assisted ventilation of newborns; report of a preliminary study and three years' experience. J Perinatol 1991;XI:347-354.
We read with interest the excellent review by Dr Ng on the fetal and neonatal hypothalamic-pituitary-adrenal axis.(1) Although the issue of antenatal administration of steroids is addressed in a separate section of the paper it is practically restricted to their antenatal use for the prevention of respiratory distress syndrome and other complications of prematurity.
We read with interest the excellent review by Dr Ng on the fetal and neonatal hypothalamic-pituitary-adrenal axis.(1) Although the issue of antenatal administration of steroids is addressed in a separate section of the paper it is practically restricted to their antenatal use for the prevention of respiratory distress syndrome and other complications of prematurity.
We would agree that this is the commonest reason for giving steroids antenatally. However albeit rare there are other indications for their administration during pregnancy for purely maternal reasons. An example is the mother who has undergone renal transplantation, where steroids may be given for prolonged periods.
Some 20 years ago we reported 5 babies (2),whose mothers being recipients of of renal transplants had received 10 mg/day of prednisone throughout pregnancy. Umbilical cord plasma cortisol levels ranged from 12.8 microgram/dl to 16.3 microgram/dl. Synachthen test yielded normal adrenal response in all but one where there was no rise of cortisol level at 30 and 60 minutes. This baby received a 10 day ACTH course following which a new Synachthen test yielded a normal resonse. We mention this experience to draw attention to other situations where adminstration of steroids may be rquired during pregnancy. We think that Dr Ng should have addressed these issues too.
References
1. Ng PC. The fetal and neonatal hypothalamic-pituitary-adrenal axis. Arch Dis Child Fetal Neonatal Ed 2000;82:F250-F254
2. Dellagrammaticas HD, Parkin JM. Maternal renal Transplantation-complications in the newborn baby. Paediatriki 1980;43:364-373
Dr HD Dellagrammaticas MD, FRCPCH
Dr Nicoletta Iacovidou MD
NICU, 2nd Department of Paediatrics University of Athens Aglaia Kyriakou Children's Hospital Athens, Greece
The interest displayed in the trigger ventilation trial by Burmester
and Petros is welcome.(1) Their letter raises questions about the
interpretation of the performance of the Dr�ger babylog 8000, which was
used in a minority of infants in the study.
The trigger sensor device is different, and I agree with their
implied statement that as each trigger ventilator performs differently
results obtained...
The interest displayed in the trigger ventilation trial by Burmester
and Petros is welcome.(1) Their letter raises questions about the
interpretation of the performance of the Dr�ger babylog 8000, which was
used in a minority of infants in the study.
The trigger sensor device is different, and I agree with their
implied statement that as each trigger ventilator performs differently
results obtained using one ventilator cannot be extrapolated to another
ventilator. However, both ventilators were used in PTV mode (sometimes
referred to as Synchronised Intermittent Positive Pressure Ventilation,
Assist Control or Synchronised Assisted Ventilation in Infants), with the
ventilator set to trigger at each inspiratory effort. No infants in this
study were ventilated with SIMV (Synchronised Intermittent Mandatory
Ventilation) where the baby's breaths, selected during a 'time window',
trigger the ventilator with the preset number of breaths per minute.
The results were reported in the way that they were for a reason. The
original study design allowed a four-way randomisation between the two
makes of ventilator and the two modes of ventilation. As was reported,
only three centres had enough of both ventilators to allow this to occur.
Other centres ventilating infants with the Dr�ger babylog had a two-way
randomisation between PTV and IMV.
Therefore the possibility of confounding by differences in practice
between centres needed to be excluded. If the centres using the Dr�ger as
well as the SLE ventilator had different outcomes from those using only
one make of ventilator, this might lead to inappropriate conclusions being
drawn if all infants being ventilated with one ventilator were simply
compared to those being ventilated with another. A logistic regression
model was therefore used to allow for possible centre effects (as well as
other significant factors such as gestation).
With that caveat, I have extracted the following numbers from the
database giving details of the crude observed rates of pneumothorax in the
infants less than 28 weeks, separately reported for the two makes of
ventilator.
PTV mode�
IMV mode
Dr�ger without pneumothorax
19
20
Dr�ger with pneumothorax
5 (20.8%)�
4 (16.7%)
SLE without pneumothorax
154
114
SLE with pneumothorax
35 (18.5%)�
14 (10.9%)
The observed rate of pneumothorax was substantially (but not
significantly, chi-squared 2.8, p>0.05<_0.1 higher="higher" in="in" the="the" infants="infants" ventilated="ventilated" ptv="ptv" mode="mode" than="than" imv="imv" using="using" sle="sle" _2000.="_2000." although="although" numbers="numbers" are="are" small="small" observed="observed" pneumothorax="pneumothorax" rate="rate" was="was" those="those" with="with" drger="drger" babylog="babylog" _8000="_8000" ventilator.="ventilator." it="it" therefore="therefore" seems="seems" somewhat="somewhat" illogical="illogical" to="to" recommend="recommend" caution="caution" _2000="_2000" less="less" _28="_28" weeks="weeks" gestation="gestation" but="but" not="not" extend="extend" this="this" ventilating="ventilating" _8000.="_8000." given="given" that="that" none="none" of="of" these="these" differences="differences" were="were" statistically="statistically" significant="significant" no="no" clear="clear" recommendation="recommendation" can="can" be="be" given.="given." is="is" why="why" wording="wording" used="used" publication="publication" might="might" prudent="prudent" avoid.="avoid." p="p"/> As regards the number of infants departing from their assigned mode
of ventilation, several points should be emphasised. The study protocol
permitted changing the mode of ventilation at the discretion of the
attending clinicians. This was inevitably interpreted differently by each
clinical team. Departure from the assigned mode of ventilation was not an
intended outcome, and it is evident that this occurred more commonly in
the more immature infants and those that subsequently died. High rates of
departure from the assigned mode cannot therefore readily be interpreted
as evidence of failure of the assigned mode. The numbers of infants of all
gestations departing from the assigned mode of ventilation are shown
below.
PTV
IMV
Drager not departing
35
40
Drager departing
16 (31.4%)
15 (27.3%)
SLE not departing
303
274
SLE departing
�107 (26.1%)
�47 (14.6%)
There was therefore a higher crude rate of departure from the
assigned mode of ventilation in infants ventilated with the Dr�ger babylog
8000, with a similar proportion transferred for failure to trigger.
It would be difficult to interpret the pneumothorax rates for those
infants who were actually being ventilated with their assigned mode of
ventilation. Some infants were switched to another mode of ventilation
after sustaining their pneumothorax. Most of the pneumothoraces occurred
whilst infants were receiving their assigned mode of ventilation, and this
included infants being trigger ventilated using the Dr�ger ventilator.
Burmester and Petros ask whether centres contributing few patients
might have higher morbidity rates, correcting for potential confounding
factors by using a logistic regression model. The pneumothorax rate from
centres contributing less than 20 patients was the same as the centres
contributing more infants.
We have used a model to identify outcome differences in infants
randomised within 3 months of the first infant being entered into the
study, correcting for individual centre effects, gestation, birthweight
and mode of ventilation. There was no significant difference in rates of
death and chronic lung disease, abnormal cranial ultrasound scan or
duration of ventilation. However, a marked and statistically significant
difference was found for pneumothorax rates. The 139 infants randomised
within 3 months had a pneumothorax rate of 5% versus a rate of 13% for
those randomised more than 3 months into the trial (odds ratio 0.30, 95%
confidence intervals 0.12 to 0.74, p=0.009). This was seen equally for
both modes of ventilation.
This finding suggests that the initial educational visit by the trial
co-ordinator had a beneficial effect on ventilator management that
disappeared as infants continued to be enrolled.
In summary, there is no evidence from this study of any trend towards
better outcomes with the Dr�ger babylog 8000 ventilator, though the small
numbers enrolled make any conclusions less robust. There is evidence that
suggests there may have been a short term reduction of pneumothorax rates
from the educational package offered at the start of the trial.
In conclusion, there was no convincing evidence of a beneficial
effect of a policy of using PTV in preterm infants with RDS with the
ventilators used. Regular attention to staff education on ventilator
techniques is recommended.
I would like to use this opportunity to pay tribute to the two trial
co-ordinators (Sue Ellis and Tom Mill), to the trial statistician (David
Wright) and to the data monitoring committee (David Field and Diana
Elbourne), whose details were inadvertently omitted from the final paper,
and without whom, together with the trial collaborators, the study would
not have been possible.
Dr Harry Baumer, on behalf of the trial collaborators
1. Burmester M, Petros A. Triggered ventilation in neonates. [Rapid Response] Arch Dis Child Fetal Neonatal Ed 9 May 2000
The rapid response from Dellagrammaticus and Iacovidou (17 May) provides
interesting information and further support to the conclusion of our
study (1): namely, that NICUs from Southern European countries (Italy, Spain
and, according to Dellagrammaticus, also Greece) adopt parental visiting
policies more restrictive than in Northern countries.
We agree that exploring the role of parents in deci...
The rapid response from Dellagrammaticus and Iacovidou (17 May) provides
interesting information and further support to the conclusion of our
study (1): namely, that NICUs from Southern European countries (Italy, Spain
and, according to Dellagrammaticus, also Greece) adopt parental visiting
policies more restrictive than in Northern countries.
We agree that exploring the role of parents in decision-making is
much more complex, and that data collected through a structured
questionnaire completed by the unit coordinator represent only that unit's
policy, "that is the intention and stance of each unit" towards the issue
at hand. In fact, this was precisely the aim of our study: to describe and
compare NICUs' policies in the various countries.
In a separate part of the EURONIC project we interviewed also
individual staff members (both doctors and nurses), asking for their views
and practices regarding parental involvement in decision-making: overall,
results match quite closely with findings from the NICUs policy study.
It would be certainly very interesting to obtain the parents'
views on the issue; however, results from interviews with parents carried
out by Unit's staff during a baby's hospital stay should be interpreted with
caution, given the understandable tendency of interviewed parents to
comply with perceived wishes and ideas of the staff caring for their baby.
References
(1) Cuttini et al. Parental visiting, communication and participation in
ethical decisions: a comparison of neonatal unit policies in Europe. Arch
Dis Child Fetal Neonatal Ed 1999;81:F84-91
The letter from Dr Mantadakis addresses the important issue of the
absence of randomised studies on the clinical effectiveness of the
interventions used to prevent the possible severe sequelae of fetal
alloimmune thrombocytopenia. Studies in small series are suggestive of
some benificial effect of the current interventions like high dose
intravenous immunoglobulin to the mother or intrauterine transfusion of
HPA compat...
The letter from Dr Mantadakis addresses the important issue of the
absence of randomised studies on the clinical effectiveness of the
interventions used to prevent the possible severe sequelae of fetal
alloimmune thrombocytopenia. Studies in small series are suggestive of
some benificial effect of the current interventions like high dose
intravenous immunoglobulin to the mother or intrauterine transfusion of
HPA compatible platelets. However, many in the field share concerns that
the quality of evidence available to the clinical community is not meeting
the standards required today. We therefore support her call for a multi-
centre study as the only way forward to achieve further improvements in
the management of this severe condition which is effecting 1 in 1000
neonates.
We read with interest the paper by Cuttini et al (1). Although policy
regarding parental visiting is a relatively easier issue to evaluate,
parental participation in decision making, particularly in decisions with
strong ethical overtones, is a much more complex issue. It is difficult to
evaluate with accuracy with accuracy and by its nature much more
controversial. The paper does not stress that data col...
We read with interest the paper by Cuttini et al (1). Although policy
regarding parental visiting is a relatively easier issue to evaluate,
parental participation in decision making, particularly in decisions with
strong ethical overtones, is a much more complex issue. It is difficult to
evaluate with accuracy with accuracy and by its nature much more
controversial. The paper does not stress that data collected from each
participating unit through a structured questionnaire completed by the
unit co- ordinator, represent policies, that is the intention and stance
of each unit towards the particular issue for evaluation. Data collected
through questionnaires and interviews involving both unit staff and
parents would have provided a better understanding of the actual practice
of each participating unit.
No unit from Greece took part in the study by Cuttini et al (1) but
Greece is briefly mentioned in the discussion, using results from a
previous study (2) where in a sample of 38 units from 11 European
countries it was shown that the 9 units imposing visiting restrictions
were in France, Greece, Italy and Portugal.
We would like to provide further information regarding visiting
policies in Greek NICUs. There are 15, two of which are private; twelve
attached to maternity hospitals and the remaining three are in children's
hospitals and accept distant referrals. In all but one (Aglaia Kyriakou
Children's Hospital) visiting restrictions are imposed. These allow
parents only and the usual practice is ½ -1 hour visiting time in the
morning and afternoon (excepting lactating mothers). The most common
reasons given for imposing restrictions are an increased danger of
infection and a disruptive effect on the unit.
We conducted a survey through a questionnaire and an interview of
parents whose baby has been cared for in another NICU imposing visiting
restrictions before transfer to our NICU and / or parents who had a
previous baby in another NICU imposing restrictions. The overwhelming
majority (98.6%) said they preferred the liberal policy we have adopted
with respect to visiting. One mother of preterm baby with bronchopulmonary
dysplasia said that 'if I had delivered at term I would be with my baby,
if I had not delivered prematurely I would also be with my baby (in my
womb), now that I have delivered prematurely why can't I be with my baby?
We conclude that in Greece there is a demand for unrestricted
parental visiting but most Greek NICUs do not meet this demand for reasons
which are not based on medical or sociological evidence.
It is worth noting that, in Greece, infants beyond the neonatal
period have been admitted to children's wards with their mothers for many
years.
Dr H D Dellagrammaticas MD, FRCPCH
Dr Nicoletta Iacovidou MD
NICU, 2nd Department of Paediatrics
University of Athens
Aglaia Kyriakou Children's Hospital
115 27 Athens, Greece
References
1. Cuttini M, Rebagliato M, Bortoli P, et al. Parental visiting, communication and participation
in ethical decisions: a comparison of neonatal unit policies in Europe.
Arch Dis Child Fetal Neonatal Ed 1999;81:F84 - F91
2. Reid M, Andersen E, EC Study Group of Parental Involvement in Neonatal
Care (Adam H, Cuttini M et al). Variations in family visiting policies in
neonatal intensive care units in eleven EC countries. Pediatr Perinat
Epidemiol 1994;8:41 - 52
Baumer reports the results of large multi-centre study comparing the
effects of patient triggered ventilation (PTV) with conventional
ventilation (IMV)1. There appears to be no benefit from PTV compared to
IMV in death rate, development of chronic lung disease, pneumothorax rates
and cerebral ultrasound abnormality. In addition, because of an increased
trend toward a higher pneumothorax rate, Baumer conc...
Baumer reports the results of large multi-centre study comparing the
effects of patient triggered ventilation (PTV) with conventional
ventilation (IMV)1. There appears to be no benefit from PTV compared to
IMV in death rate, development of chronic lung disease, pneumothorax rates
and cerebral ultrasound abnormality. In addition, because of an increased
trend toward a higher pneumothorax rate, Baumer concludes that at present,
PTV delivered with either the SLE 2000 or the Dräger babylog 8000
ventilators cannot be recommended for infants of less than 28 weeks
gestation with respiratory distress syndrome (RDS).
However, we are concerned that this may be a premature conclusion
given the significant difference in PTV delivered by the two main
ventilators used and the potential heterogeneity of clinical practice
within the different centres involved, despite agreed ventilation
protocols. Dimitriou et al2 demonstrated that neonates and infants trigger
a significantly lower proportion of breaths using the SLE 2000, an airway
pressure triggered ventilator, compared with the Dräger babylog 8000, an
airflow triggered ventilator that provides synchronised intermittent
positive pressure ventilation (SIPPV). Attempts to optimise the trigger
rate of the SLE 2000 ventilator by increasing pressure sensitivity often
results in auto triggering as discussed by Baumer. Therefore the PTV modes
of the two ventilators are substantially different. This prompts us to ask
whether the findings of this multi centre study are only applicable to PTV
provided by the SLE 2000? Would there have been a different outcome if all
the triggered babies had received SIPPV?
It is not known how many of the 40/213 babies of less than 28 weeks
gestation who had pneumothoraces were receiving SIPPV. As only 11%
(52/465) of all triggered babies ever received SIPPV, we surmise that very
few of the 40 were ventilated in this way. Is it fair to conclude that the
Dräger babylog 8000 has a trend to pneumothorax on SIPPV?
In a separate smaller study Baumer also reports 120 patients in three
centres randomly assigned to either the Dräger babylog 8000 or the SLE
2000 ventilator, and found a non-significant trend to higher pneumothorax
rate, chronic lung disease and death for the former group. But we are not
told how many of the babies were actually on trigger mode (PTV or SIPPV).
They could all have been receiving IMV on the Dräger babylog 8000.
Therefore is it possible that SIPPV is not being tested?
A further finding was a significantly higher rate (124/463) of
triggered babies that departed from their assigned mode of ventilation, 45
of these failing to trigger their ventilator. Were they all on the SLE
2000 ventilator, as Dimitriou2 would predict?
Finally, we note that 10 of the 22 neonatal units each recruited less
than 20 patients over the four year period, one contributing only 1
patient. Could the technique of PTV ventilation in units contributing so
few numbers be different to those enrolling 60-136 neonates over the same
period, despite prior visits from the trial co-ordinator? Would a logistic
regression for morbidity against number of patients contributed from each
unit reveal that the greatest morbidity occurred in units which
contributed fewer patients, rather than those using PTV or SIPPV modes?
Given the heterogeneity of the units involved and the significant
difference in ventilators used, we think that it is premature to dismiss
SIPPV on the Dräger babylog 8000 in neonates less than 28 weeks gestation
with RDS. We agree with Baumer that further studies are required, and
extend his conclusion by saying that PTV with the SLE 2000 (n=411) rather
than SIPPV from the Dräger babylog 8000 ventilator (n=52), cannot be
recommended in this group.
MARGARITA BURMESTER, ANDY PETROS
Intensive Care Units, Great Ormond Street Hospital London WC1N 3JH, UK
1. Baumer JH. International randomised controlled trial of patient
triggered ventilation in neonatal respiratory distress syndrome. Arch Dis
Child Fetal Neonatal Ed 2000;82:F5-10.
2. Dimitriou G, Greenough A, Laubscher B, Yamaguchi N. Comparison of
airway pressure triggered and airflow triggered ventilation in very
immature infants. Acta Paediatrica 1998;87:1256-60.
We were interested to read the article of Vyas et al (1) on the
incidence of severe retinopathy of prematurity (ROP) in 11 neonatal units
(NUs) from five cities in England in 1994. We have published similar data
from 8 NUs in New South Wales (NSW) Australia in 1993 and 1994.(2)
These data were prospectively collected in the NSW Neonatal Intensive Care
Unit's data collection and is stored and maintai...
We were interested to read the article of Vyas et al (1) on the
incidence of severe retinopathy of prematurity (ROP) in 11 neonatal units
(NUs) from five cities in England in 1994. We have published similar data
from 8 NUs in New South Wales (NSW) Australia in 1993 and 1994.(2)
These data were prospectively collected in the NSW Neonatal Intensive Care
Unit's data collection and is stored and maintained in the NSW Centre for
Perinatal Health Services Research, University of Sydney, NSW.
For infants <_29 weeks="weeks" gestation="gestation" there="there" was="was" no="no" significant="significant" difference="difference" in="in" severe="severe" rop="rop" greater="greater" than="than" or="Stage" _3="_3" between="between" the="the" _5="_5" cities="cities" england="england" and="and" nsw="nsw" australia="australia" table.="table." p="p"/> Table: Incidence of severe ROP in the 5 cities in England and NSW,
Australia.
Gestation
5 cities in England
NSW, Australia
Significance
< 27 weeks
20/95 (21%)*
44/157 (28%)
ns
27-28 weeks
5/162 (2.6%)
15/269 (5.6%)
ns
*= Number with severe ROP/number examined and the percent in
parenthesis.
Unlike Vyas et al (1) we could not find an association between
improved survival and the development of severe ROP. In 6 of the NUs in
our study survival
in infants <_27 weeks="weeks" gestation="gestation" ranged="ranged" from="from" _51.3="_51.3" to="to" _68.8="_68.8" two="two" nus="nus" have="have" been="been" excluded="excluded" this="this" analysis="analysis" as="as" they="they" are="are" childrens="childrens" hospitals="hospitals" and="and" very="very" few="few" small="small" premature="premature" infants.="infants." the="the" percent="percent" with="with" severe="severe" rop="rop" for="for" lowest="lowest" highest="highest" survival="survival" was="was" _15.1="_15.1" _3="_3" _20="_20" _23.8="_23.8" _5="_5" _21="_21" respectively="respectively" while="while" range="range" of="of" in="in" _6="_6" _36.0="_36.0" _9="_9" _25.="_25." infants="infants" _27-28="_27-28" _85.1="_85.1" _96.7="_96.7" _7.1="_7.1" _4="_4" _56="_56" _3.4="_3.4" _2="_2" _58="_58" respectively.="respectively." group="group" _2.01="_2.01" _50="_50" unpublished="unpublished" observations.="observations." we="we" also="also" shown="shown" that="that" despite="despite" an="an" increase="increase" preterm="preterm" following="following" introduction="introduction" surfactant="surfactant" there="there" no="no" significant="significant" impact="impact" on="on" incidence="incidence" or="or" severity="severity" rop.3="rop.3" p="p"/> In infants 29-31 weeks' gestation, 6 of 443 (1.4%)
developed severe ROP and one infant required Cryo/Laser therapy.(2)
This infant was 30 weeks' gestation with a birth weight of 1305 grams. We
therefore agree with Vyas et al (1) that there should be no reduction in
the upper limit of gestation or birth weight for screening for ROP.
David A Todd
Neonatal Unit
The Princess Anne Hospital
Coxford Road
Southampton, Hants, UK
John Kennedy
Ophthalmology Department
Westmead Hospital
Sydney, NSW
Australia
1. Vyas J, Field D, Draper ES, Woodruff G, Fielder AR, Thompson J, Shaw NJ, Clark D, Gregson R, Burke J, Durbin G. Severe retinopathy of prematurity and its association with different rates of survival in infants less than 1251 g birth weight. Arch Dis Child Fetal Neonatal Ed 2000;82:F145-F149.
2. Todd DA, Cassell C, Kennedy J, John E and the NSW Neonatal
Intensive Care Unit's study group. Retinopathy of prematurity in infants
<_32 weeks="weeks" gestation="gestation" at="at" birth="birth" in="in" new="new" south="south" wales="wales" _1993="_1993" and="and" _1994.="_1994." j="j" paediatr="paediatr" child="child" health="health" _199935355-357.="_199935355-357." p="p"/> 3. Kennedy J, Todd DA, Watts J, John E. Retinopathy of prematurity
in infants less than 29 weeks' gestation: 3 1/2 years pre- and
postsurfactant. J Pediatr Ophthalmol Strabismus 1997;34:289-292.
This review on alloimmune thrombocytopenic purpura (ATP) by OUWEHAND et al is excellent and describes the current
knowledge on ATP. Regarding the management of this condition, since no
randomised trials have been performed using IVIg or intravenous
corticosteroids during pregnancy, no evidence-based guidelines for the use
of either treatment exist. I believe it is necessary for a
multi-institutuional trial on the preventio...
This review on alloimmune thrombocytopenic purpura (ATP) by OUWEHAND et al is excellent and describes the current
knowledge on ATP. Regarding the management of this condition, since no
randomised trials have been performed using IVIg or intravenous
corticosteroids during pregnancy, no evidence-based guidelines for the use
of either treatment exist. I believe it is necessary for a
multi-institutuional trial on the prevention of ATP to be performed. Since
ATP is relatively rare, with an estimated incidence of 1 in 1100 births,
it is rather difficult even for hospitals with 10,000-15,000
deliveries/year to have enough patients for study. On the other hand, a
multi-institutional comparison of the two preventive modalities, in women
whose previous pregnancies were affected by ATP, is feasible and will
provide firm evidence of efficacy (or lack of) for IVIg or
corticosteroids.
Neonates are exposed to many procedures, including intubation, IV
access, central line placement, chest tube insertion, lumber puncture,
catheterisation, suprapubic aspiration etc. These procedures are
associated with pain and stress. No clear guidelines are available for
alleviating the distress by premedication before such procedures.
Researchers are looking for methods to minimise the pain and distre...
Neonates are exposed to many procedures, including intubation, IV
access, central line placement, chest tube insertion, lumber puncture,
catheterisation, suprapubic aspiration etc. These procedures are
associated with pain and stress. No clear guidelines are available for
alleviating the distress by premedication before such procedures.
Researchers are looking for methods to minimise the pain and distress in
neonates during these procedures.
Examples include the use of thiopental as premedication before
intubation,(1) local anaesthetics before heel prick,(2) and response to
cutaneous stimulus.(3) In the recent issue of the journal three articles (1,3,4) were on the issue of
premedication before procedures in neonates. However, there is no
consensus regarding the policy and protocol for use of premedication
before procedures in neonates. The issue of is not so simple. In the
present era of evidence medicine, more
randomised control trials are needed so that the experts can reach to a
consensus. The questions need research are: the type of drug (analgesic,
sedative or anaesthetics), the mode of administration (IM, IV, ET) and the
dose to be used.
Yours sincerely,
Dr.Shabih Manzar,FAAP
Assistant Professor, Department of Pediatrics
King Fahd University Hospital
P.O.Box 40211, Al-Khobar 31952
Saudi Arabia
References:
1. Bhutada A, Sahni R,Rastogi S, Wung JT. Randomised controlled trial
of thiopental for intubation in neonates. Arch Dis Child Fetal Neonatal Ed
2000;82:F34-F37
2. Barker DP, Rutter N. Lignocaine ointment and anaesthesia in
preterm infants. Arch Dis Child Fetal Neonatal Ed 1995;72:F203-4
3. Jain A, Rutter N. Local anaesthetic effect of topical amethocaine
gel in neonates: randomised controlled trial. Arch Dis Child Fetal
Neonatal Ed 2000;82:F42-F45
4. Whyte S, Birrell G, Whyllie J. Premedication before intubation in
UK neonatal units. Arch Dis Child Fetal Neonatal Ed 2000;82:F38-F41
We were surprised at the results of the two studies published in your journal by Baumer[1] and Bersford et al[2]. Our experience with triggered ventilation over 10 years is shown in the table below:
Complications of prematurity 1991-99
We read with interest the excellent review by Dr Ng on the fetal and neonatal hypothalamic-pituitary-adrenal axis.(1) Although the issue of antenatal administration of steroids is addressed in a separate section of the paper it is practically restricted to their antenatal use for the prevention of respiratory distress syndrome and other complications of prematurity.
We would agree that this is the commonest...
The interest displayed in the trigger ventilation trial by Burmester and Petros is welcome.(1) Their letter raises questions about the interpretation of the performance of the Dr�ger babylog 8000, which was used in a minority of infants in the study.
The trigger sensor device is different, and I agree with their implied statement that as each trigger ventilator performs differently results obtained...
Dear Editor,
The rapid response from Dellagrammaticus and Iacovidou (17 May) provides interesting information and further support to the conclusion of our study (1): namely, that NICUs from Southern European countries (Italy, Spain and, according to Dellagrammaticus, also Greece) adopt parental visiting policies more restrictive than in Northern countries.
We agree that exploring the role of parents in deci...
The letter from Dr Mantadakis addresses the important issue of the absence of randomised studies on the clinical effectiveness of the interventions used to prevent the possible severe sequelae of fetal alloimmune thrombocytopenia. Studies in small series are suggestive of some benificial effect of the current interventions like high dose intravenous immunoglobulin to the mother or intrauterine transfusion of HPA compat...
Editor,
We read with interest the paper by Cuttini et al (1). Although policy regarding parental visiting is a relatively easier issue to evaluate, parental participation in decision making, particularly in decisions with strong ethical overtones, is a much more complex issue. It is difficult to evaluate with accuracy with accuracy and by its nature much more controversial. The paper does not stress that data col...
Editor,
Baumer reports the results of large multi-centre study comparing the effects of patient triggered ventilation (PTV) with conventional ventilation (IMV)1. There appears to be no benefit from PTV compared to IMV in death rate, development of chronic lung disease, pneumothorax rates and cerebral ultrasound abnormality. In addition, because of an increased trend toward a higher pneumothorax rate, Baumer conc...
Dear Editor,
We were interested to read the article of Vyas et al (1) on the incidence of severe retinopathy of prematurity (ROP) in 11 neonatal units (NUs) from five cities in England in 1994. We have published similar data from 8 NUs in New South Wales (NSW) Australia in 1993 and 1994.(2) These data were prospectively collected in the NSW Neonatal Intensive Care Unit's data collection and is stored and maintai...
This review on alloimmune thrombocytopenic purpura (ATP) by OUWEHAND et al is excellent and describes the current knowledge on ATP. Regarding the management of this condition, since no randomised trials have been performed using IVIg or intravenous corticosteroids during pregnancy, no evidence-based guidelines for the use of either treatment exist. I believe it is necessary for a multi-institutuional trial on the preventio...
Editor,
Neonates are exposed to many procedures, including intubation, IV access, central line placement, chest tube insertion, lumber puncture, catheterisation, suprapubic aspiration etc. These procedures are associated with pain and stress. No clear guidelines are available for alleviating the distress by premedication before such procedures. Researchers are looking for methods to minimise the pain and distre...
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