eLetters

700 e-Letters

  • Its not just about the "lungs"

    All of these extubation-readyness tests assess respiratory drive / lungs. However, it may be for many preterms that they struggle to maintain their airway despite good drive and lungs that are relatively healthy. This aspect can't be tested and could explain why so many infants who seem able to breath don't do so once the ETT has been taken out.

  • Sedation during Therapeutic Hypothermia in Asphyxiated Newborns- Authors’ reply

    We thank Floris Gronendal et al. for their views on our sedation survey and highlighting their personal opinion about mandatory sedation during therapeutic hypothermia. They quote two seminal preliminary studies on preterm infants by Anand recruiting 16 and 30 babies each, but not the later definitive Neopain trial on 898 babies, that showed increased adverse outcome (death, intraventricular bleed, periventricular leukomalacia) with morphine, to support their views(1).

    Our survey was intended to examine the current practice of pre-emptive opioid sedation during therapeutic hypothermia in ventilated and non-ventilated infants (2). We have only highlighted the variation of sedation practices during therapeutic hypothermia and potentially toxic morphine doses used by some neonatal units in the UK and we have not made any recommendation about using or not routine sedation during therapeutic hypothermia. Such recommendations can only be based on scientific evidence, not on surveys or personal views, and this unfortunately is lacking. Clearly hypothermia in children and adults do require heavy sedation, but we do not feel that these data can be directly extrapolated to newborn infants.

    Preclinical studies on sedation during therapeutic hypothermia are conflicting. Thoresen et al. showed no reduction in neuropathology scores in a piglet model for hypoxic injury without general anaesthesia that were cooled for 24 hours compared with those that were not cooled(3),...

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  • Sedation during Therapeutic Hypothermia in Asphyxiated Newborns

    Sir,
    In their paper Montaldo et al. suggest that routine use of morphine in infants with perinatal asphyxia and therapeutic hypothermia (TH) is not useful and potentially harmful (Arch Dis Child Fetal Neonatal Ed. 2020:108-09). They rightfully suggest that morphine may accumulate during TH. However, in a recent study using multicentre data we have proposed novel dosing schedules for morphine and midazolam during TH thereby avoiding the risk of drug accumulation1.
    Montaldo et al. state that “… it is unclear if morphine suppresses the nociceptive cortical activity in babies…” referring to a study of oral morphine for acute procedural pain in preterm infants.
    Only since the late 1980s opioids are used during neonatal surgery following two classical papers by Anand showing that pre-emptive opioid analgesia following cardiac surgery in human infants dramatically decreased mortality and morbidity rates by suppressing pain and stress2 3.
    As written by Montaldo et al. the right of universal pain relief is undisputed, also in human infants, and it is generally accepted through many animal experiments that TH is stressful. Furthermore, sedation and analgesia during TH after cardiac arrest in adults is well tolerated and effective4.
    Therefore we are very reluctant to remove the mandatory use of sedatives including morphine from our international Dutch and Flemish guideline of TH, and we would like to stimulate others to use analgesia, while avoiding the...

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  • Sepsis and neurodevelopmental outcome in preterm neonates

    In their follow-up analysis of the PREMILOC trial, Baud et al.[1] found significantly better neurodevelopmental outcomes at 22 months postmenstrual age in those extreme preterm neonates of 24 and 25 weeks of gestation who had been treated with early hydrocortisone during the first ten days after birth. Improvements in global neurological assessments were most pronounced for moderate to severe neurodevelopmental impairment, with a prevalence of 2.1% in the hydrocortisone and 18.4% in the placebo group. In this context it has to be remembered that early hydrocortisone treatment had been associated with a significant increase in the late-onset sepsis rate before discharge for those most immature neonates of 24 and 25 weeks of gestation.[2]
    In their meta-analysis including seventeen observational studies, Alshaikh et al.[3] described “an increased risk of one or more long-term neurodevelopmental impairments … including cerebral palsy” in very-low-birth-weight infants who had suffered from culture-proven sepsis during the neonatal period. A follow-up analysis of extreme preterm neonates below 32 weeks of gestation found a significantly higher frequency of cerebral palsy at five years of age in those who had developed early- and/or late-onset sepsis.[4] Correspondingly, a positive association of Coagulase-negative staphylococcus sepsis and the risk of cognitive delay at a corrected age between 30 and 42 months has been reported in preterm neonates below 29 weeks of gestati...

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  • The value of C-Reactive Protein in treatment decisions for early onset neonatal sepsis

    Dear Editor
    We read with interest the letter by Sur et al in response to our article (1). It was very reassuring to note that our findings were replicated in their study confirming the potential scale of antibiotic reduction while identifying all ‘blood culture positive’ sepsis. We did not collect data on CRP in our study. The evidence does not support a single CRP measurement as a reliable tool to help decisions to initiate treatment in the context of early onset neonatal sepsis (EOS), particularly in asymptomatic infants[2]. Consistent normal values over first 48 hours are associated with absence of EOS; but abnormal values in an asymptomatic infant are unreliable to predict culture proven sepsis [2-5]. CRP concentrations increase in neonates in response to a number of non-infective inflammatory conditions such as asphyxia, meconium aspiration, tissue trauma and pneumothorax. Serial CRP trend is irrelevant in treatment initiation decisions, and in low incidence conditions such as EOS, its value in predicting true culture positive EOS is below that is expected of a good and reliable test (Likelihood ratio 3.0)[4,6). The American Academy of Paediatrics states that diagnosis of EOS cannot be made using CRP in the absence of positive blood or CSF culture [2]. For asymptomatic low / moderate risk infants (currently treated with presumptive antibiotics), a period of observation / serial physical examination may be used instead of invasive tests to identify at an early...

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  • Target range 90-95% vs. 91-95%

    We were impressed by the conduct and results of Reynolds et al.’s randomised controlled cross-over trial comparing Vapotherm’s IntellO2 device with manual control of inspired oxygen, showing improvement in the proportion of time spent within the target oxygen saturation range (automated arm mean 80% of time in 90-95% range vs. manual 49%). The findings are consistent with a meta-analysis referenced within their paper [1].

    The Neonatal Oxygenation Prospective Meta-analysis (NeOProM) shows that targeting oxygen saturations of 91–95% with an oximeter with a correctly configured algorithm, carries a 38% survival advantage [2]. The co-ordinator of the NeOProM collaboration has stated that the “Infants born extremely preterm … should have their oxygen saturation levels targeted between 91% and 95%” [3].

    The difference between the saturation targeting approach adopted by Reynolds et al., and NeOProM may appear small but, on account of the sigmoidal shape of the haemoglobin–oxygen dissociation curve, significant hypoxic shifts will occur with small changes in oxygen saturation.

    Given the rigor of the NeOProM findings, would Reynolds et al. agree that targeting oxygen saturations of 91-95% is an important first step, whilst we wait for products which will allow improved titration of oxygen delivery?

    References:
    [1] Mitra S, Singh B, El-Naggar W, McMillan DD. Automated versus manual control of inspired oxygen to target oxygen saturation in prete...

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  • Not necessarily aortic perofration

    Thank you for an interesting case but the position of the arterial catheter after the perforation suggests to me that this was from an umbilical artery rather than the aorta (compare the path on the abdominal wall on the 2 x-rays).

    This may therefore be why you were able to successfully manage this conservatively.

  • Thrombosis after umbilical venous catheterisation

    We kindly thank Da Lozzo et al. for their reaction to our paper. Indeed, many variables may be of influence on the incidence of thrombosis in our study group.
    The authors are correct that the incidence of necrotizing enterocolitis in our study group (12.5%, 5/40) is higher than expected based on literature. As shown by Battersby et al. comparing NEC incidences internationally is challenging (1). The incidence of NEC in our study group does not reflect the NEC incidence of last 15 years at our department (which was 3.7% (98/2626) in infants with a gestational age <32 weeks). Possibly, the higher incidence of NEC led to a higher incidence of thrombosis in our study. However, care should be taken when interpreting our results due to the small sample size (n=40).
    Da Lozzo et al. make a valuable point about the diameter of central venous catheters. Most (25/40) umbilical venous catheters (UVCs) used in our study-group were 4Fr Vygon catheters, single or double lumen, with an external diameter of 1.5 and 1.4 mm, respectively (strange enough double lumen is smaller than single lumen). In 3/40 infants 5Fr Vygon catheters (external diameter 1.7 mm) were used and in 10/40 infants 3.5Fr Vygon catheters (external diameter 1.16 mm). In 2/40 infants the size of the catheter was not registered. We found no association between the risk of thrombosis and the size of the catheter (p=0.59). However, as stated in the discussion of our paper, the sample size of our group is too...

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  • Umbilical venous catheterisation and risk of thrombosis

    We appreciated the paper by Dubbink-Verheij et al. evaluating the incidence of thrombosis in newborns who underwent umbilical catheterization in comparison with a control group of infants without umbilical venous catheter (UVC). While the paper highlights specific issues about UVC-related thrombosis in NICU, regarding the sites, the time of onset and the outcomes of this condition, we suggest that some relevant variables have not been taken fully in account.
    Some of the comorbidity rates of the patients in the study group are not consistent with data from literature and might have had a role in the unusual high rate of thrombosis and poor outcome in the study group. The reported rates of necrotizing enterocolitis (NEC; 12.5% in the study group, 10% in the total population of the study) is significantly higher compared with that of the Vermont Oxford Network (VON); VLBW infants between 2000 and 2009 based on the VON showed a NEC incidence of 4.6-6.1%. (1)
    The study reported 30 thrombotic episodes in defined locations but, remarkably, the type and the diameter of catheter utilized was not stated by the Authors. Neonates, and especially preterm neonates, have an unfavorable catheter-to-vessel diameter ratio, which is a recognized risk factor for the development of catheter-related thrombosis in CVCs. In a in vitro model Nifong and McDevitt (2) quantified the impact of the catheter to vein size ratio on fluid flow unraveling the mechanism by which risk of catheter-...

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  • Lack of data/evidence to back recommendations for significant change of practice

    I read with interest this review by Dr Padidela et al.

    I would like the authors to comment on the following issues:

    1. The review is suggesting significant change to current UK practice but does not review any data to suggest that current practice is causing secondary hyperparathyroidism ( apart from an anecdotal case discussed). While the recommendations may have merit based on physiology , it seems suboptimal to recommend a significant change of practice without any data to clearly show that current practice is causing a problem.

    2. The review recommends measurement of plasma parathromone as a critical initial step and most of the subsequent practice is dictated by this. The authors state " measurement of plasma PTH both for screening and diagnosis is crucially important". In the very next line they however state "the reference range of plasma PTH in neonates is not well established" They then go to talk about a very small study of 20 preterm neonates.
    It does not make much sense to recommend a major change of practice without any data to back it up and then highlight plasma PTH as a critical investigation for decision making when we don't really have any robust normative data.
    Should we not instead be generating prospective data based on current practice and if there is evidence of secondary hyperparathyroidism to change treatment accordingly? Also should we not be generating normative data for various gestati...

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