eLetters

1212 e-Letters

published between 2016 and 2019

  • Waveform capnography is reliable to ensure oxygenation

    I was interested to read the Archimedes article reviewing the structured question ‘in neonates who require ventilation, does waveform capnography give an accurate approximation of PaCO2?’ The findings such as the accuracy of ETCO2 decreases with the severity of lung disease (Grade B) adds to similar knowledge about waveform capnography when it was introduced in adults.

    Whenever capnography is discussed however it should always be remembered that the primary reason for its introduction into clinical practice was to reliably ensure patients oxygenation and reduce the incidence of hypoxic brain damage, which it did so dramatically. The presence of a capnography waveform is the gold standard to demonstrate the integrity and correct position of an airway and establish that the patient is being ventilated with the intended oxygen. This eureka moment discovering that waveform capnography is more about oxygenation than accuracy of PaCO2 estimation is crucial for patient safety. The exact value of PaCO2 is secondary.

    Unfortunately for over 20 years adult intensive care missed this eureka moment and consequently never started to use waveform capnography in adult ITUs when it was being universally introduced into operating theatres in the late 1980s [1].

    Despite waveform capnography continuing to save many patients lives in operating theatres the argument that the accuracy of ETCO2 decreased with the severity of lung disease predominated in intensive care and w...

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  • Response to Dr Whitaker's letter

    Dr Whitaker, in a letter in response to our Archimedes review of whether waveform capnography reliably approximates paCO2 in neonates, highlights two important questions which capnography seeks to address: Firstly, whether or not the endotracheal tube (ETT) is patent and correctly positioned in the trachea and secondly, whether the current ventilation strategy provides optimal CO2 clearance for the patient. The two questions are, of course, interlinked.
    To date, in our field of neonatal medicine, the ETCO2 provides a valuable adjunct to clinical examination in determining ETT position and patency both at the point of intubation and during ongoing mechanical ventilation. However, for reasons explained in the paper, the numerical approximations to alveolar pCO2 provided by the currently available techniques of wave form capnography in neonates are not accurate enough to guide ventilatory changes. Thus, to guide ventilator changes, many neonatal intensive care units currently use transcutaneous capnometry.
    In addition to the physiological properties, the waveform capnography sensors add extra weight and dead space to an infant’s ventilator circuit. This adds further complexity, like their still not fully assessed effect on volume-guarantee ventilation and potential for auto-triggering of ventilators. As volume guarantee is now considered the gold standard for ventilating preterm infants with respiratory distress syndrome, the value of waveform capnography, in addi...

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  • Prof Tim Cook

    Dear Editor
    We read with interest Dr Scrivens et al’s commentary [1]. The mother’s question - ‘should capnography be used for breathing tube monitoring?’ – captures the subject addressed in our ‘PICNIC survey’ [2]. Conversely, the authors examine a completely different question - ‘is capnography an optimum respiratory monitor in ventilated neonates?’
    A respiratory monitor detects whether the end-tidal CO2 value usefully measures pulmonary ventilation or PaCO2. Although not our focus here, we are surprised the review omitted Kugelman’s study which reported waveform capnography monitoring in neonatal ICU (NICU) improved ventilation accuracy and neurological outcomes [3].
    An airway monitor assesses ‘whether lung ventilation is taking place via a tracheal tube that is in the airway and is patent’. High rates of neonatal failed intubation, oesophageal intubation, accidental extubation and reports of associated patient harm all suggest the value of a reliable airway monitor in NICU. Waveform capnography rapidly detects correct intubation with few false positives and immediately detects displacement or disconnection, the evidence for which we have previously set out [4-6].
    Some neonatologists argue that continuous waveform capnography cannot be used in neonates. It is used routinely in neonatal anaesthesia. Others use it routinely during transfer of small neonates (eg 400g) (personal communication Dr James Tooley, Consultant, Bristol) sometimes only for it...

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  • Additional considerations for future modelling of paediatric intensive care retrieval teams in England and Wales

    We commend the DEPICT group for gathering evidence to support or refute the current set of performance standards for specialist paediatric intensive care retrieval teams (PICRTs), for which there is currently limited evidence base.

    A key tenet of ‘the paper’ was geographical distance as the sole reason for a breach in the 180 minute to bedside standard.[1] In our experience, the commonest reason to breach was ‘team availability’. In 2018 South Thames Retrieval Service (STRS) performed 824 emergency retrievals. In 4% of these, the team did not reach the bedside within 180 minutes. On 33/36 occasions, the reason for delay was lack of availability of retrieval team due to concurrent deployment.

    STRS is commissioned to staff two teams on every shift. In 2018 32% of retrievals were performed concurrently. STRS is the second busiest PICRT in the UK, however on 29 % of shifts, no retrieval team was launched. STRS is a fully integrated retrieval service –all staff are based in the intensive care unit, and when not on retrieval work clinically in the PICU. This allows flexible staffing and in times of high demand, helps support increased PICU bed capacity. In 2018, 98.8% of patients were kept within region.

    The authors highlight the importance of mobilisation time. Despite the integration of our service within a busy PICU, STRS recorded the highest national compliance with the mobilisation standard for 2017.[2]

    In our region 90% of intubations are p...

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  • Paediatricians support national epidemiological surveillance.

    We welcome the comments made by Professor Andrew Williams, who has been a great supporter of our UK-wide study of children with progressive intellectual and neurological deterioration (PIND). The PIND Study uses the mechanism provided by the British Paediatric Surveillance Unit (BPSU), which is based in the Royal College of Paediatrics and Child Health. Since 1986 the BPSU has provided paediatricians in the United Kingdom with the means of investigating rare disorders of childhood. As Professor Williams points out there is a need to make research central to good paediatric practice and the BPSU continues to facilitate that.
    The PIND Study is funded by the National Institute for Health Research (NIHR) Policy Research Programme to look for cases of variant Creutzfeldt-Jakob disease (vCJD) among the many neurodegenerative diseases of childhood. Since the PIND Study started in 1997 we have identified children with more than 190 of these rare disorders - that number constantly increases as new diseases and new genetic variants of known diseases are discovered. Thus our study not only provides the sole means of systematically searching for vCJD in children but also gives a unique oversight of the changing pattern of childhood neurodegenerative disease in the UK. We work closely with the National Creutzfeldt-Jakob Disease Research and Surveillance Unit which carries out surveillance for vCJD in adults.
    Professor Williams highlights the fact that our work could not be...

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  • Response to e-letter regarding Primary Care screening tool

    We thank Luamar Dolfini and Gabriella Williamson for noting the sepsis screening tool that we developed in Leeds. Our tool was based on the NICE guidance, but used local early warning scores (PAWS) to simplify the assessment risk for sepsis. At Leeds Children's Hospital our tool is used on all acute paediatric admissions and in any child that deteriorates on the paediatric wards. Since our initial letter was published in 2018, our team have further amended our screening tool in response to human factors work, and have introduced the acronym LEEDS (Look for sepsis is all acute admissions or children who deteriorate: Evaluate the risk of sepsis by completing the sepsis screening tool; Escalate to a senior decision maker to consider the risk of sepsis; Decide whether there is a high/medium/low risk of sepsis using clinical assessment and investigations such as lactate; Start antibiotics in under 60 minutes if sepsis is a possibility). Our team have found the paper by Roland and Snelson ("So why didn't you think this baby was ill?" Decision-making in acute paediatrics, Arch Dis Educ Pract Ed 2019; 104:43-48) invaluable in educating our team about making decisions and assessing risk and this e-letter highlights that all parts of the puzzle (e.g. a full and comprehensive set of observations) are essential in being able to appropriately risk stratify patients, including for sepsis.

  • Re: letter Meningococcal meningitis presenting postinfant group B meningococcal immunisation. doi: 10.1136/archdischild-2018-316341

    M Nadeem
    1. Department of Paediatrics, Tallaght University Hospital, Dublin 24, Ireland
    2. Trinity College Dublin

    Corresponding author: M Nadeem, Department of Paediatrics, Tallaght University Hospital, Dublin 24, Ireland

    So et al1 reported a case of meningococcal group W meningitis in an infant who presented within 24 hours of receiving group B meningococcal vaccine (4CMenB). Fever and focal seizure, which required two doses of intravenous lorazepam, have been reported at the time of presentation. Intravenous ceftriaxone was commenced for suspected sepsis. CSF PCR was positive for capsular group W meningococcus. With respect to the focal seizure in a febrile infant, whether viral encephalitis was excluded and whether antiviral was commenced pending the exclusion of herpes simplex encephalitis (HSE) are questions that were not addressed in the present case.

    At the time of presentation, it may not be possible to clinically differentiate encephalitis from meningitis, as either syndrome may have common features including fever, headache and meningism.2 Children with encephalitis may present with fever, seizures and focal neurological signs.2 3 Moreover those with HSE may experience a progressively deteriorating level of consciousness with fever, focal seizures or focal neurological abnormalities in the absence of any other cause.2 4 However the absence of fever2 5 or the lack of altered states of consciousness5 at presentation does not exclude...

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  • Comment to Response by M Nadeem to Letter ‘Meningococcal Meningitis Post-Infant Group B Meningococcal Immunisation’

    Dear Sir,

    We thank Dr Nadeem, for highlighting that the clinical features of drowsiness and infant focal seizures in our case report indicates that early treatment for viral/herpes encephalitis was an imperative.

    We would like to reassure Dr Nadeem that our infant did indeed receive a combination of early intravenous antiviral treatment (acyclovir) and antibiotics (cefotaxime and amoxicillin) and this was continued until final viral/bacterial PCR and CSF culture results were obtained. The use of acyclovir and amoxicillin was omitted from the original report due to word count limitations.

    Viral PCR tested was negative for a range of viruses including herpes simplex (HSV). Although PCR assay is an important diagnostic modality for viral encephalitis HSV, we would add that due to focal seizures, our infant case received investigations and treatment as per national (1) and local guidelines: immediate brain CT imaging was performed to exclude neurosurgical conditions, and a later cranial MRI scan did not show selective damage to the mesial temporal lobe structures or the hippocampus. In addition, an early electroencephalogram (EEG) was normal. The EEG severity and the presence of epileptic seizures at the initial presentation would be significant indicators for predicting the 6-month clinical outcome in patients with HSE.

    The seriousness of HSV CNS infections suggests that clinicians maintain a high index of suspicion to initiate evaluation under s...

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  • Failing to consider Virtual Academic Units within UK infrastructure for research that benefits infants, children and young people

    I was deeply surprised that this leading paper in citing the 2018 ‘Turning the tide 5 years on’ does not mention ‘virtual Biomedical Research Units and Centres’ (1,2). The establishment of such centres had been specifically recommended in the seminal 2012 RCPCH Report ‘Turning the Tide: Harnessing the power of child health research’ (3).
    We in Northampton established a Virtual Academic Unit (VAU) in 2004, and published our experience of its first 10 years experience in Archives in 2015 (4).
    Among the articles published through the VAU there is ‘Ethical Research Involving Children.’ (2013) UNICEF, which predates the College own Children’s and Young People’s Child Health Research Charter. (5)

    The Virtual Academic Unit is continuing to collaborate on and publish in clinical child health research to this day. (6) However, it has remained totally unfunded with no allocated research time in spite of every possible endeavour to address this.

    We have to be pragmatic and recognise that with present and future increasing pressures within the NHS having any research time within a job plan is seen by most NHS managers as an unproductive luxury given the immediate pressing necessities of delivering a clinical service.

    As my 2015 article relates

    ‘A VAU has its place and in a present and future environment where resources are continuing to be constrained, a method of working that allows something meaningful to be produced, from where previousl...

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  • Response to: Failing to consider Virtual Academic Units within UK infrastructure for research that benefits infants, children and young people

    Dear Editor,

    Re: Professor Andrew N Williams’ letter to ADC “Failing to consider Virtual Academic Units within UK infrastructure for research that benefits infants, children and young people”

    We were pleased to hear the success of the Virtual Academic Unit and invited Professor Andrew Williams to contribute to the RCPCH research bulletin of March 2019.

    At the RCPCH, we know from our research and from speaking to our membership, that paediatricians around the country have little or no allocated funding or designated research time. We, therefore, applaud all those paediatricians who continue to go above and beyond to undertake research to achieve better health outcomes for children and young people.

    The RCPCH is fully committed to strengthening basic science and clinical research and the development of devices, medicines and technologies that address the needs of children. Furthermore, our committment includes supporting our members and growing and promoting opportunities for research within paediatrician’s careers.

    We will continue to work with our partners across the UK to influence, promote and grow child health research.

     

    Lindsey Hunter, Research Development Manager, RCPCH

    Professor Anne Greenough, immediate past Vice President Science and Research, RCPCH and Professor of Neonatology and Clinical Respiratory Physiology, King's College London

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