Department of Health

Bronchiolitis – Surviving the Season

  • 18 August 2016
  • Duration: 48:57
  • Dr David Armstrong

    Good afternoon, everyone, and welcome to Bronchiolitis - Surviving the Season, a webinar
    provided by the Victorian Paediatric Clinical Network. My name is David Armstrong. I'm a
    respiratory paediatrician at Monash Children’s Hospital and one of two clinical leads at the
    VPCN. It’s my pleasure this afternoon to welcome our speaker, Dr Tom Connell, who is a
    general paediatrician. He’s an infectious disease physician and head of general medicine at
    the Royal Children’s Hospital. Tom?

    Dr Tom Connell

    Thank you very much, David, and it’s a real pleasure to be here today to present on a topic
    that obviously is very important for all people and physicians. It’s great to have such a great
    audience here today, our nursing staff, allied health staff, and 175 registrants for the
    webinar today, which shows the interest that this topic has generated.

    What we’re planning to do today is, obviously bronchiolitis is a very large topic and we’re
    going to try to take it through about six or seven different areas as we go through. Please,
    as you know, obviously you can interact and you can ask questions, and we’ll try to get to
    some of these either during the course of the presentation if there’s a recurring theme for
    questions. There will be plenty of time for questions at the end, and what we’re hoping to
    do is take you through a bit about what – everyone knows what bronchiolitis is, but we want
    to take you through some of the evidence or lack of evidence for what we do currently in
    our practice, both in tertiary care hospitals like Monash and the Children’s and various
    hospitals around the city, and also our rural and regional colleagues where we all seem to
    manage bronchiolitis, probably if we’re really honest, in slightly different ways.

    The use of pulse oximetry is very topical at the moment and there’s been some recent very
    good trials come out on the use of pulse oximetry, and I’ll take you through some of the
    highlights about that before we go over to David who’s going to talk about treatment, high
    flow nasal cannula, and then thinking about opportunities how we with the network can
    lead to quality improvement activities and potential collaboration on how we might do
    some of these practical things.

    Bronchiolitis is caused by due to a viral infection. It’s lower respiratory tract infection in
    infants. It causes acute inflammation, oedema, and necrosis of epithelial cells lining the
    small airways, but subsequently it’s an increased mucus production, and therefore mucus
    plugging and potentially secondary infection. It typically begins with a runny nose or rhinitis
    and cough, which may progress to tachypnoea, wheezing, nasal flaring, decreased feeding,
    subsequent presentation to hospital. The most common cause is the respiratory virus,
    respiratory syncytial virus or RSV, and in order of frequency came secondary be rhinovirus,
    influenza, human metapneumovirus and parainfluenza. And if everyone is aware, people
    who use multiplex PCR testing for a viral will frequently get at least seven or eight panel
    multiplex, so you’ll frequently be able to tell which virus it is. Whether or not that matters
    or not is a topic for debate.

    Co-infection is common in up to one third of infants, and this guideline which is available
    recently with the updated guideline for the management of bronchiolitis, both for the
    diagnosis management and prevention, came out last year in 2015. We know that 95% of
    children are infected with RSV in the first two years of life, if you do sero-prevalence studies,
    and we know that you do not get immunity after infection as many of our patients ask us
    will this be the only time they will get it?

    What about, how common is bronchiolitis? Is it a common cause for admission? We know
    obviously in the tertiary hospital that bronchiolitis is a very common cause of admission,
    both in major centres and in the smaller centres. In fact it’s the most common cause of
    hospitalisation among infants less than 12 months, and approximately 100 000 admissions
    in the United States every year, and just from my own hospital in Melbourne, there’s about,
    of the admissions to general medicine, of which there are 7500 every year, approximately
    one seventh of those are for bronchiolitis, so 1 100 admissions every season. The typical
    season for RSV is, the winter with the high period of admissions to hospital, but you do see
    presentations any time from early February, March, April, all the way through the season.
    The cost is staggering, of hospitalisation for bronchiolitis. An estimated $1.7 billion a year,
    and, of course, the management can obviously lead to some of this cost and investigation
    and oximetry use. The highest rate of hospitalisations are between 30 days and 60 days of
    age where the rate of admission up to 25 per 1 000 children, approximately five or six times
    higher those who are older than that age group. This means that the variation in care is
    important, and may impact significantly given the overall number of patients that are
    investigated.

    If we were to do a straw survey of all the participants who are on the webinar tonight and
    ask you to put your hand up, we can’t do that obviously on a webinar, but what
    investigations should we order in infants presenting with bronchiolitis? Could any of us say
    none? I don’t think any of us could say none. Would we do a nasopharyngeal aspirate?
    We’ll all very comfortable when we get a nasopharyngeal aspirate result because we can
    give that information to the parents. But does it actually matter? And what about a chest
    X-ray? How many in your practice get a chest X-ray, or in your hospital? And we’d love to
    say that figure is also approach less single digits, but in all honesty we know that is not the
    case.

    Now that about the ubiquitous sort of blood gas analysis, frequently asked what is the cap
    gas show before considering escalation of therapy? The AAP clinical practice guideline
    again, and this came out last year, it makes for different gradings of evidence for people
    who are familiar with the aggregate evidence quality. This is level A to level D, to then
    exceptional situations, level X, and what these recommendations take into consideration,
    and these pdfs will be available to all participants after the webinar, so if you can’t keep up
    with this, you can take your time and read through the pdf documentation that we will
    provide.

    The level A, level B, level C essentially goes towards basically saying stronger evidence is
    level A, versus slight weaker evidence down to level D. And based on these, whether there
    is benefit or potential harm, so you can say that that’s a strong recommendation, versus a
    weaker, moderate recommendation, versus a weak recommendation, and then they
    balance it against harm and say that whether or not that’s actually a weak recommendation
    based on the balance of benefits to the patient versus the harm to the patient. And when
    you actually look at that, you look down and say that the NPA, there was very little evidence
    that actually impacts on the clinical management of the patient. There used to be the
    argument that that would help you cohort patients, but bronchiolitis is a clinical diagnosis.
    The NPA, it may detect prolonged viral shedding, and therefore you pick up RSV in NPAs
    multiple times during a presentation, or even after the patients may come back, they’ll viral
    shed for many weeks.

    It’s not recommended, yet it’s still done. There’s no real value to the patient, but as we
    know as parents and doctors, nice editorials on this. Parents ask us what causes the viral
    infection in their child, we frequently like to give the fact that they’ve been infected with
    one virus or possibly two viruses, because it gives us a label, but actually it’s a clinical
    diagnosis and the vast majority of patients have RSV.

    Chest X-rays are not routinely recommended and may lead to unnecessary antibiotic use.
    There is very good evidence for that, and that may lead to harm. So chest X-rays really
    should be reserved, and there’s good evidence for this, should be reserved for baby, infants
    and children that do not follow the typical course for bronchiolitis, like those that are
    admitted to an intensive care setting.

    A blood gas is not recommended. It should not be done, and there is no place for a blood
    gas or a capillary blood gas outside of an intensive care setting or a setting where a child
    presents in an extreme condition.

    So we think about pulse oximetry. This is where it gets really interesting. There are clinical
    practice guidelines of which many people who are familiar, which is an initiative from the
    Victorian Paediatric Clinical Network. This is an A to Z of all different guidelines for different
    conditions. We know they’re accessed very heavily, both in Australia and around the world,
    and it makes for an interesting heat map where you look at where these guidelines are
    accessed.

    If you go to bronchiolitis, it’s a slightly longer guideline than this, but it features – if we just
    look at the investigation, it’s a nasopharyngeal aspirate is not routinely recommended in
    children with typical bronchiolitis, yet we know that they’re done, and I know I'm guilty of
    that myself. And chest X-ray is not routinely recommended unless there’s diagnostic
    uncertainty.

    It’s costly. It exposes the child to radiation, and it’s not uncommon for children to have
    more than one chest X-ray throughout their stay. This data, and David’s going to show some
    further data later from some initiative that the network led about standardising care in
    bronchiolitis, is a result of a survey of adherence to the bronchiolitis clinical practice
    guideline at the Royal Children’s Hospital. This was done by a scholarly selective students of
    100 medical records, and you can see down here that the key finding is that a lot of patients
    didn’t have any documentation, whether their bronchiolitis was mild, moderate or severe,
    but also over one quarter of children had a chest X-ray and over half of the children had a
    nasopharyngeal aspirate for a condition that I’ve just told you there’s no evidence really for
    a chest X-ray outside of intensive care and a nasopharyngeal aspirate 50% is one in two
    patients out of the 1 100 that are admitted.

    Now, the devil is in the detail here. There is some detail to be got here in terms of whether
    or not these patients were admitted to the intensive care unit or not. It boils down to the
    question what’s driving the use of testing? And the costs of it roughly, conservatively, you
    could estimate just for testing alone is between 51 to $100 000 per year.

    So this brings us to variation. Variation in itself does not infer good or bad treatment, but
    variation can be warranted or it can be unwarranted, and this is a slide courtesy of Harriet
    Hiscock, who is the director of the health services research unit at the Royal Children’s
    Hospital and this is a slide from a Grand round we gave this year on variation and care. And
    that next slide, it states that warranted is expected, it reflects the population health and the
    need or burden of the disease, individual preferences and values of patients and on a small
    scale may reflect practice innovation. But unwarranted variation is not explained by need,
    by preferences and values, but it may signal inappropriate care, and provide both safety and
    quality issues. But it may also signal resource misallocation. So there’s a whole lot of
    questions we need to ask there, and within bronchiolitis this is an area that’s obviously ripe
    for research as we know the variation in care is quite significant.

    So what I'm going to talk about right now, again if we get a straw poll on is the value of
    pulse oximetry in influencing decisions whether to admit a child with bronchiolitis, what is a
    safe oxygen saturation? And when should we administer oxygen? So these questions are all
    interesting to ask, and again there is new research coming out from the US and also local
    research being done on this. Pulse oximetry is associated with a perceived need for
    hospitalisation. The severity of Bronchiolitis in itself as a disease has not really changed
    over decades. Yet the number of children admitted to hospital with bronchiolitis has more
    than tripled since around the 1990s. And one of the reasons for that that’s been proposed
    is the use of pulse oximetry.

    We know that we would like to say that pulse oximetry doesn’t interfere with our decision
    to admit a patient, to administer oxygen to a patient or to turn the oxygen off on a patient,
    yet we know in real terms, in practical terms on the wards on a day-to-day basis, that is just
    simply not true. The data from the oxyhaemoglobin disassociation curve, to bring you back
    to your nursing and medical undergraduate courses, show that a small increase in arterial
    partial pressures of oxygen are associated with marked improvement in oxygen saturation
    when it is below 90%. There is no evidence that increasing oxygen by administering oxygen
    above a saturation of 90% is associated with increasing the arterial partial pressure of
    oxygen.

    There are no studies until recently on the effect of brief episodes of hypoxaemia as occurs in
    bronchiolitis and indeed as occurs in normal children and in sleeping children and infants,
    and we know the accuracy of pulse oximetry is poor between 76 and 90%. CO2 level in
    blood has a much stronger influence on respiratory drive than is the oxygen level, and this
    graph here simply shows here that above 60mm above this, the curve starts to flatten out,
    so there’s no incremental gain of increase in saturations above a level about 90%. It’s just
    simply flat. There’s no benefit. Yet we’ve seen oxygen saturations on children on the
    wards, and I'm sure you have, where they have oxygen saturations of 93, 94% and they’re
    still in a half a litre of oxygen at that point. There is very little evidence on how to wean a
    patient from oxygen other than people switching it off and this leads to variation in care,
    and we know that.

    I'm going to take you through three studies now, before handing over to David, and these
    studies are nice, and this study here is a nice study from JAMA in 2014. This was an
    interesting study design, and I'm sure many of you are familiar with Suzanne’s work on this,
    a randomised control trial of oximetry on hospitalisation. So there’s the figures for how
    hospitalisation rates have increased over the last two decades, 12.9 to 31.2/1000. Although
    the virulence of bronchiolitis has not increased, the rates of admission have tripled. Why is
    that? It’s likely to be due to pulse oximetry, because as physicians and as parents, we seem
    look at the machine rather than the patient, so it’s become a surrogate of a marker for
    disease severity, more than the actual clinical presentation of the infant or the child under
    the age of 12 months in front of you. We know it alarms more often below 90% and
    therefore we believe we’ve got to intervene when the saturation is at 90% or lower, when
    the alarm is going off.

    There are data to show about alarm fatigue, it’s like we’re retro-fitting a diagnosis or retro
    fitting our management of patients based on a machine that was evolved to monitor pulse
    oximetry, not necessarily realising the impact that that might have had on hospitalisation.
    So what they did here was, an interesting ethical design, but safe to do, was they
    determined if increasing, artificially altering the oxygen saturation with a pulse oximeter
    that was sent off to be altered to 3% above the true value would result in a reduced rate of
    hospitalisation. Just giving an example, for instance if a patient’s true saturations were 92%
    and the machine was artificially set to read 95%, would that lead to a reduction in admission
    and a decision to admit that patient? The study design was double blind over five years from
    2008 to 2013. The children were aged 4 to 12 months, exactly the children that we would
    want the study in. And they excluded children with sats below 88% because no-one would
    really be game to randomise those kids, but true saturations less than 88% or those with
    relatively severe bronchiolitis. The RDAI is one index of severity in bronchiolitis, and there is
    no really validated scoring systems in my mind for assessing severity and none really
    implemented widely.

    They did a block randomisation of six, to try and minimise bias, with the true saturation or
    an altered saturation. They randomised in five centres. The ED physicians where these
    patients were randomised were informed that there was a 50% chance that there may be a
    variation in the saturation of the O2 of the child, about either way, weren’t told whether it
    would be up or down. Every patient had a concealed oximeter underneath the bed, which
    no-one could see and was said to alarm at 92%, where that would prompt reassessment of
    the baby. So quite a beautiful study design.

    So they randomised initially eligible patients at least, 1 800, excluded quite a significant
    number of those for not meeting eligibility criteria, so eventually got down to about 200
    patients.

    Now this table, which you can take your time on and read, but essentially the summary of
    the table would show you that there’s no difference in groups at baseline, so these patients
    were assessed to be the same in everything but their oxygen saturation rates, when the true
    oximeter versus the altered oximetry, and the crux of the study comes here, that the
    hospitalisation rates, that primary outcome of admission within 72 hours. You can see there,
    that the proportion of children who were admitted was higher in the true oximetry group
    versus the altered oximetry groups. Those were the true sats were 92% were more likely to
    be admitted compared to a similar patient that had an altered sat of 95% (really 92%). And
    the control factor, such as physician level, preference for doctor and baseline score, a
    variety of other things, suggesting that whether or not we like it or not, the evidence
    suggests an inconvenient truth that we do look at the pulse oximeter and attach more
    meaning to the sats that we actually should, and that’s important.

    Most infants had sats well above 88%, and that’s where the true limitations are in this study
    in my mind, that most of these children wouldn’t have been administered oxygen in much
    sense anyway, so it’s this question, if we got it more around the ball park, around the 92,
    93% mark, that would be a much more meaningful study. But overall the study nicely shows
    the over reliance on information provided by a medical device.

    Next study is the intermittent use of continuous versus pulse oximetry. Anybody who
    managed bronchiolitis, and I'm thinking of all our nursing colleagues on the wards who look
    at the patients of bronchiolitis, will be well used to the continuous pulse oximeter going off.
    We know that this causes a frequently inappropriate call for medical attention, and
    potentially increasing oxygen, or putting oxygen on a baby because the oxygen pulse
    oximeter has alarmed.

    The American Academy of Paediatrics recommends that continuous pulse monitoring is not
    required if there is improvement clinically. But we’re tied to these machines. We
    frequently cannot just simply look away from the machine. The hypothesis here was that
    intermittent monitoring will reduce length of stay of a patient. A nice hypothesis, with the
    primary outcome being length of stay. The primary outcome of length of stay in
    bronchiolitis is quite a difficult end point, as there are many factors that influence length of
    stay. The authors of this study powered their study to detect a difference in length of 18
    hours. In the introduction they indicated that at their hospital they had a medium length of
    stay of about 40 hours, therefore I questioned straight away how they would recruit enough
    patients to show a difference of 18 hours.

    This is an RCT, a parallel, superiority trial of 161 infants, 80 continuously monitored and 81
    intermittently monitored. Four children’s hospitals, Monday to Friday recruitment. The
    randomisation in this study was well described and the intermittent arm was, until their sats
    were 90% or greater, got intermittent oximetry. There was a variety of safety mechanisms
    built into the trial.

    This shows here that the patients were fairly similar in terms of baseline, although the
    continuous were slightly younger than the intermittent. Everything else was pretty much
    standard apart from some therapies which were questionably given beforehand.
    This is the Kaplan Meier curve, which shows straight away when you look at this, if you’re
    used to looking at these curves, there’s no difference between the groups, and in fact all
    they showed was a mean difference of 2.7 hours between the groups. So you look at that,
    you think, this is disappointing. That was a disappointing study, but it still showed there was
    no difference between monitoring continuously or intermittently, at least in that
    population, but I’d argue their population was slightly different than the ones potentially we
    see where the mean length of stay in some patients attending hospital will be around 3
    days, sometimes 3.5 days a difference of 18 hours is much easier to detect in that group of
    patients rather than a difference of 18 hours in a medium stay of 40 hours.

    Interestingly here in this study, even though the AAP guidelines have come out well before
    this study saying that there’s no need for RSV testing or chest X-rays, you can see here that
    again, very similar to the findings from our study at the Children’s Hospital, 40% of patients
    had RSV respiratory PCR testing, chest radiograph in at least four to five patients out of
    every ten. So potentially confirming the fact that we are a lot of doctors and nurses and
    we’re all the same. We’re trying frequently to change our need to see diagnostic tests in
    front of us and go back to clinical baseline, there’s a need for a paradigm shift in care.
    What they showed was they would have needed over 2 000 in each arm rather than 161
    total patients to show the difference that they actually showed. This study was only done in
    non-hypoxemic babies, we need to repeat this study on obviously babies who are in oxygen
    because they have much more relevance when we talk about intermittent monitoring.
    The last study I'm going to do very quickly before I hand over to Dave. This is a nice study
    showing the effect of oxygen desaturation on subsequent medical use. We always worry
    about babies going home with transient desaturations on what effect that may have on
    some infants. Again we retro fitted clinical management to pulse oximeters, because we
    feel that that is indicative of severity. Desats equates to bad disease in a lot of people’s
    minds. So what this group did is a tag-on to the previous study. Whilst they looked at
    babies who were discharged from the ED, not needing oxygen, they then actually monitored
    them for ~ 2 days to see whether or not they desaturated to 90% or less for more than a
    minute. A minor desaturation was 90% for at least a minute, a major desaturation was
    three of them or 10% on the time on the monitor less than 90% or greater and less than
    90% for three minutes continuously. The parents weren’t able to see the readout because
    we wouldn’t send anyone home with a monitor that was displaying a pulse oximeter
    reading, but this data was then couriered to the respiratory unit at the hospital to analyse.
    They did some very nice analysis and the details in the study.

    Essentially there were 1 119 patients screened, of which 118 patients were analysed .Of
    these there were 75 patients with desaturation both minor and major and no desaturation
    of 43. Keep those figures in your mind, because that’s a significant amount of babies. There
    was no difference in those representing to a hospital, a GP, a primary practitioner in those
    who had subsequently proven to have desats, or no desats and the frequency of
    presentation, suggesting that parents were looking at their babies clinically. If this was in a
    hospital setting we would have been putting oxygen onto these babies straight away
    because they had a desaturation less than 90% for one minute.

    This suggests that transient desaturation are common but the question is whether or not we
    should even act on these in a hospital setting, and we know we do. We know we do. The
    babies are put on oxygen for another few hours. So this creates a tension that we sort of
    talk about the use of an oximeter from those three studies that have started to have the
    dialogue about the use of pulse oximetry to influence management decision. Hand over to
    David.

    Dr David Armstrong

    Alright, Tom, thank you very much. I’m going to briefly run through – although we’re 5:27,
    we can finish at 5:40 but I’ve been assured by the moderator that if we go a few minutes
    over the world will not stop spinning on its axis, so please do feel free to send us a question.
    We can see your question as you type it and your question is only seen by us. It’s not seen
    by any of the other participants, so feel free to type your questions in. We can answer them
    as I go through or the few minutes at the end.

    So Tom’s very nicely led into some of the controversies that surround the treatment of
    bronchiolitis, surprising for such a common condition that we see so often. I’m going to talk
    a little about respiratory support, a little bit more about oxygen and high flow nasal cannula
    therapy which has become much more popular over recent years. I’m going to talk a little
    bit about fluid support and then the evidence base for a lot of other medications and other
    strategies.

    So low flow oxygen, from 0 to 2 litres per minute, is very commonly prescribed to infants
    with bronchiolitis. You’re taught as a medical student, time, oxygen and minimal handling is
    the management of bronchiolitis. It may or may not surprise you to know that the evidence
    base for the use of oxygen in bronchiolitis is very limited and the provision of oxygen and
    the level of oxygen that we provide at the saturation we provided as indicated by Tom is
    really based on first principles and the oxyhaemoglobin dissociation curve. So guidelines
    vary in the cut off to start and stop oxygen, varying from 90 to 94% In Australia as a general
    rule we recommend starting oxygen if a sat is below 92 and ceasing it when the oxygen rises
    to 92% or above.

    As indicted by Tom, the provision of oxygen definitely has an effect on both the decision to
    admit and length of stay, but we’re thinking now perhaps in the wrong direction that overdependence
    on oxygen saturation monitoring may lead us to admit patients who don’t need
    to be in the hospital, may stay longer than if they were not so monitored.

    High flow nasal cannula therapy, the indication for that is a patient with bronchiolitis who is
    hypoxic as defined by a saturation less than 92% and with increased work of breathing.
    At the moment there’s fairly low-level evidence that the provision of high-flow nasal
    cannula therapy reduces work of breathing, reduces length of stay and decreases the rate of
    transfer to the ICU.

    So nasal cannula have been used for many years, low flow up to 2 litres for minute. It’s very
    easy to administer and it’s well tolerated. Higher flows at 1 to 2 litres per kilo per minute
    can deliver continuous distending pressure, or CDP, but this is dependent on the size of the
    cannula, the gas flow, the anatomy, leak around the nose and body weight. Potential
    problems of high flow, mucosal dryness and thickened nasal secretions due to inadequate
    humidification.

    So what is it? High flow nasal cannula therapy delivers high flow, 1 to 2 litres per kilo per
    minute, of air mixed with oxygen that’s heated and humidified, and this heating and
    humidification prevents cooling and water loss from the airway, and prevents impairment of
    muco-ciliary transport. All of you watching this webinar, I presume, will be familiar with
    now the portable devices used to deliver high flow and the heated nasal cannula shown in
    the picture.

    How does it work? Well, there are various theories on why nasal flow therapy works. It can
    certainly wash out naso-pharyngeal dead space, and that improves ventilation efficiency. It
    attenuates upper airway resistance, and thereby decreases work of breathing, and the
    warmed humidified air also improves lower airway conductance and compliance, the ease
    with which air can enter and leave the lungs. Additionally, the provision of warmed and
    humidified gas reduces the metabolic work associated with gas conditioning, that is the job
    of the nose, which is to heat and humidify the air, and high flow through the nasopharynx in
    certain circumstances can be titrated to provide as I said to positive a distending pressure
    which helps overcome consolidation or atelectasis associated with bronchiolitis.

    This ventilation mode first became popular in neonates, weaning from ventilation. These
    are some of the issues around and doubts and problems around this therapy and the
    evidence that high flow nasal cannula could consistently assist ventilation, babies with
    bronchiolitis or a neonate, the evidence base up until now has not been great.

    High flow nasal cannula therapy has also been used in the ICU which has been shown in
    small studies to improve respiratory distress and oxygen saturation, the COMFORT scale, a
    global scale of improvement in respiratory and cardiovascular status has also been shown to
    improve in association with high flow therapy, and measurement of oesophageal balloon
    pressure has shown that a high flow does generate a mild positive airway pressure and
    improves lung volume recruitment.

    As far as fluid therapy goes for bronchiolitis, we know that both nasogastric and IV routes
    are acceptable. A large trial published by the PREDICT Emergency Network has shown that
    in a randomised controlled trial comparing nasogastric with IV fluid, the mean length of stay
    was not different. There was some advantage to nasogastric tube placement in that this
    was more likely to be successful the first time round, rather than insertion of an intravenous
    cannula.

    In terms of intravenous fluids in bronchiolitis, there’s insufficient evidence currently to
    recommend a specific proportion of maintenance fluid, so we’re often told that in severe
    bronchiolitis, or bronchiolitis of any kind, that we should not fluid overload these patients,
    they should be on two thirds or three quarters or half maintenance, but really there’s no
    evidence to support any of those proportions, and this is an example of the significant
    variation in care of bronchiolitis. This is a prime example of where there’s very wide
    variation in practice in fluids from restricted to liberal.

    What we do know is that if we’ve using the intravenous fluid route, it’s very important that
    we use an isotonic intravenous fluid rather than a hypotonic fluid because of the risk of
    hyponatraemia.

    So here’s just a summary of the evidence for or against some other therapies that have
    been tried in bronchiolitis. There is no evidence to support the use of antibiotics, including
    azithromycin, short-acting beta agonists should not be used as they’re ineffective and have
    the risk of significant side effects. The same goes for systemic or local glucocorticoids, or
    adrenaline, either with or without steroids. Now the story on hypertonic saline is
    interesting. The evidence for this is it’s undergoing some evolution. At the time that we’re
    speaking today there does seem to be some evidence of benefit from an inhalation of 3%
    hypertonic saline. Aggregated studies which show that if the child presents to an
    emergency department and is administered 3% hypertonic saline, there’s about a 20%
    reduction in the risk of admission. For patients admitted to hospital with bronchiolitis,
    there’s about a half a day, the patients who are treated get discharged about half a day
    sooner, and as Tom mentioned the current mean duration of stay of bronchiolitis in
    Australia is about 3.4 days, so that is rather significant.

    As to other therapies outside of medication, chest physiotherapy, nasal suction are not
    recommended.

    Just to go back to high flow nasal cannula for a moment, a study that has, well, an
    international study in Australia and New Zealand in 17 centres, there’s a randomised control
    trial called the PARIS study, the Paediatric Acute Respiratory Intervention Study, which is
    randomising children presenting to EDs with bronchiolitis and hypoxia. It’s a low flow or
    high flow nasal cannula therapy. This study is being done in 17 centres as I said across
    Australia and New Zealand and will provide the largest study in the best evidence base for
    the use of high flow nasal cannula therapy in children.

    Finally, to sum up, or to finish off, as Tom has indicated, wide variation in care, so plenty of
    opportunity for us to improve our standard of care or our care of infants with bronchiolitis,
    so the VPCN sponsored a state-wide bronchiolitis project last year based upon the evidence
    based clinical practice guidelines. The RCH partnered with five smaller paediatric health
    services and used the Plan-Do-Study-Act methodology. So a number of charts were audited,
    the gap in evidence-based treatment was identified and intervention was put in place to
    address those gaps and a post study audit was done.

    This is just a summary of some of the data that was collected, but I hope you will be inspired
    by the fact that we were able to show quite significant improvements in the evidence-based
    care of these children, so this is a summary of all of the five health services, including the
    RCH, a chest X-ray was avoided, pre-audit in only 55%, but that increased to 97% in the
    post-audit. Similar figures for a nasopharyngeal swab being avoided or must all patients
    avoid it, and nasopharyngeal swab post-audit, and one which goes back to some stuff that
    Tom was talking about, we are very wedded to the oximetry number, so we had zero
    patients discharged within six hours of oxygen being ceased, as the clinical practice
    guideline recommends, and we increased that to a massive 27% in the post-audit. I’m being
    facetious, I don’t think 27% is massive and there’s plenty of scope to improve.
    So I see we’ve got some questions coming through. This is just a summary of what we’re at,
    so I think we should avoid routine investigations and treatments in patients with typical
    bronchiolitis. The PDSA methodology certainly works to improve practice. Don’t use
    hypotonic IV fluids, there’s a little evidence to support use of continuous oximetry, and
    we’re waiting for the outcome of the PARIS trial to actually tell us the place of high flow
    nasal cannula therapy versus low flow.

    So, we’ve got a couple of minutes left and we’ve got quite a few questions coming up, so
    the first question is would the webinar be available later to view? The answer to that is
    yes.

    Next question – the next question is can you comment on the use of antibiotic therapy in
    febrile infants with bronchiolitis for prevention of secondary infection. I might, I have a
    view on this, but Tom’s the man.

    Dr Tom Connell

    Yes.

    Dr David Armstrong

    And I’ll tell you if I disagree with him.

    Dr Tom Connell

    Yes, so that’s a good question. Thank you for that one, and I think the answer to that
    question is that there are in fact probably no evidence of randomised control trials to give
    antibiotics or not, but we know that typically bronchiolitis causes a low grade fever and I
    have a low threshold for prescribing antibiotics and narrow-base antibiotics such as benzo
    penicillin or amoxicillin to infants who are febrile in the context of bronchiolitis for the
    reason we know that they get airway necrosis and things like that. But I give it for a short
    course and I don’t do a chest X-ray before showing that they’ve got some reactive changes
    in that chest X-ray because we could all almost report what the chest X-ray says in children
    with bronchiolitis. So I have a, I don’t give antibiotics in the typical course of bronchiolitis
    presentation and a very typical presentation, but in a continuously febrile child I have a low
    threshold for administering antibiotics.

    Dr David Armstrong

    Look, I obviously see a slightly different population of children, or as at the Children’s, as at
    Monash, the vast majority of children with bronchiolitis were admitted under the general
    paediatricians. I tend to see them if they come to the intensive care unit, if they’re very
    unwell. They may well have been started on intravenous antibiotics, but the next day if we
    get the NPA back showing RSV and they’ve improved, then those antibiotics are not
    continued.

    Our next question is we are a 16 bed med and surgical unit and do NPAs to cohort patients
    as we’re limited single rooms. What are your thoughts? I think, Tom, you alluded to this.

    Dr Tom Connell

    So I think that’s purported to be, in various hospitals purported to be useful for cohorting
    patients, but my counter to that would be to say that babies who are admitted during
    bronchiolitis season have a clinical, bronchiolitis is a clinical diagnosis, but children can be
    cohorted based on clinical diagnosis, rather than the use of an RSV, whether or not your
    hospital infection control policies that you may have may have guidelines suggest you need
    an RSV resort to cohort patients is debatable in some institutions. I’ve heard that happening
    but we don’t do, obviously we only have the luxury now of 85% single rooms in the
    Children’s, so we don’t need to do our free testing for isolating patients, so we within the
    old hospital when we had multiple rooms, there was a bit of a practice or a bit of a scope
    creep to using NPA to cohort patients, but if it’s a clinical diagnosis you can cohort in a
    season with a typical presentation of bronch, they’ve got RSV, or they’ve got something like
    par-influenza, you can cohort in the base of clinical signs.

    Dr David Armstrong

    Okay, thanks, Tom. So the next question is can children still be diagnosed with
    bronchiolitis beyond the age of 12 months, and is there an overlap with bronchiolitis and
    viral induced wheeze in children between the age of 12 and 24 months? Look, that’s
    another great question. Certainly we wanted to emphasise that in Australia and New
    Zealand, our definition of bronchiolitis really is limited to the infant age group of 0 to 12
    months, however there is an overlap and we do know that in patients who are subsequently
    diagnosed with asthma, admission to hospital with RSV bronchiolitis is an independent risk
    factor for the development of asthma, so there is certainly an overlap and I think that in
    patients who are older than 12 months with pronounced wheeze are strong family history
    of asthma, other atopic illnesses then you may well be dealing with an infant asthma. But
    really what we’re talking about is the typical age group presenting with an acute illness
    which is characterised by crackles hypoxemia in respiratory distress.

    Dr Tom Connell

    I might comment in addition to that, David. There’s been some lovely editorials after the
    release of the latest guidelines for the management of bronchiolitis and it’s stimulated a
    lively discussion in the US, particularly from emergency physicians who see these patients
    straight up, who are really against not trialling a use of a SABA and potentially in some of
    the patients over the age of 1, but some of the risk factors that Dave has already alluded to.
    So if you go from a hub, from recommending that, from a guideline that says that we would
    use these testing or trialling SABA in select groups to say that we don’t need to do it in
    anybody, and you’re kind of basically moving, it’s a paradigm shift in practice, so they’re
    going to be people coming, kicking and screaming to that guideline or that change in
    practice, and particularly our colleagues in the emergency room who see these patients
    before we do a lot of the time. And that’s a really important thing.

    So I would watch that space in terms of the use of that because there is that overlap group
    is where it really gets quite difficult and in terms of the viral induced wheeze versus those
    patients who may benefit from a trial of a SABA therapy. So that’s a kind of “watch this
    space” and that’s the group that is the most controversial in the latest guideline with the
    management of bronchiolitis.

    Dr David Armstrong

    Okay, great. We probably have another couple of minutes, so we’ve got, just before we
    take the last two questions, can I please ask all of the people who have dialled in to note
    that at the end when we’ve finished there’ll be a very short survey on the right hand side of
    your screen that‘s going to appear shortly. We would be very grateful if you could fill that
    out because this is as Tom found out when he walked in today, this is the first webinar
    we’ve ever done and we’re pretty clear, we probably aren’t perfect, but we certainly will
    look to improve our webinars in the future. We plan to make these regular, so your honest
    feedback will be very gratefully received. Thank you.

    Okay, I think we’re down to the last couple of questions, so what are the specific
    indications for an NPA? Well, I think we’ve covered a little bit of that. I would say a sick
    patient with bronchiolitis in the intensive care unit on a ventilator where we’re thinking
    does the child need antibiotics or not, from my perspective an NPA showing RSV the next
    morning when the child’s improving will change my management, will make me discontinue
    antibiotic treatment. Tom?

    Dr Tom Connell

    Yes, I agree with that. I think outside of an intensive care unit there probably is no use at all
    for an NPA, but when I was preparing this and thinking a bit about it, I think I thought
    people might counter and say what about influenza? And influenza is treatable. We have a
    drug for influenza. Of course we do, but in reality the use of oseltamivir for treating flu has
    been, with severe flu, and usually within the first 72 hours of presentation, so it’s debated
    whether or not oseltamivir would make any difference, but that’s why companies now are
    coming out with rapid flu kits that you can do point to care testing on, rather than the
    multiplex expensive PCR testing that we do and it gives us the very comfortable 8 vial panel
    so we can actually talk to parents about it, but we don’t need an 8 vial panel for an RSV
    diagnosis, for a diagnosis of bronchiolitis. So outside of intensive care I don’t even deal with
    these.

    Dr David Armstrong

    Okay. Right, thanks, Tom. I can partially see one question, but the one I can see is do you
    advocate continuous SP O2 monitoring versus intermittently high flow nasal cannula
    therapy has been instigated, or can we still just monitor intermittently. Well, as I
    indicated before, at the moment there’s a large clinical trial that has started and that clinical
    trial is the PARIS study, and continuous monitoring has been advocated in that particular
    study, so we can gather the most data possible. So I don’t think we’ve got enough
    information at the moment on whether we should be monitoring patients on high flow
    nasal cannula therapy intermittently or continuously. I suspect we can monitor them
    intermittently just as we can the low flow, but we don’t have the evidence for that yet.
    And then the next question is, sorry, Tom? Did you have something, sorry?

    Dr Tom Connell

    Yes, I just want to say but the PARIS, one of the big reasons I think for a lot of people to
    potentially partake in the PARIS trial was actually there is a weaning protocol and one of my
    big bug bears about is switching off oxygen and the timing or how long we need to do that.
    There is a weaning protocol in PARIS which will give us some evidence. Something that
    might hypothesise at the use of the babies we recruit to PARIS might actually increase]
    length of stay potentially the high flow nasal cannula, because that actually may increase
    length of stay when we think about we’re not increasing the severity of the condition, we’re
    using more high flow. But the proof of that will be in the pudding when we get the results
    forward.

    Dr David Armstrong

    Glen has asked, what are your thoughts on nebulised saline in the hospital setting as a
    form of humidification in the oxygen? Do you have any advice for paramedics in the prehospital
    setting? Glen, I don’t think, to my knowledge, there’s any evidence in support of
    nebulised, if you’re talking about normal saline, 0.9%, there’s no evidence for that, there’s
    no evidence for nasal saline drops, there’s no evidence for deep suction. So I think my
    advice for paramedics in the pre-hospital setting is as we’ve discussed, that the child has
    increased work of breathing and certainly it’s hypoxic with saturations below 90% apply low
    flow oxygen. I’m not aware of any high flow oxygen being administered by ambulance
    personnel.

    Dr Tom Connell

    But it won’t do any harm. It certainly won’t do any harm, but there’s no evidence to
    support, it might work.

    Dr David Armstrong

    Clinton’s asked a question about why is nasal suction not recommended? Because there’s
    no evidence that it is effective in length of stay oxygenation work of breathing or any other
    significant parameter. Terese, last question to Terese. We still have consultants teaching
    junior doctors to do NPAs on babies under 3 months with bronchiolitis in case it might be
    whooping cough. Oh, this is definitely a Tom Connell question.

    Dr Tom Connell

    Yes, so I think the answer to that one is obviously unimmunised babies, we know
    unimmunised babies can develop whooping cough. It’s the one diagnosis that certainly you
    don’t want to miss. It’s a very characteristic clinical diagnosis board to tell if it’s whooping
    cough. Yes, there is a degree of overlap for children with proven pertussis have very
    characteristic clinical syndrome and you can do, you can ask for a chest for border tell a
    pertussis PCR on its own without asking for a respiratory panel. So that’s doable. So
    essentially it’s a clinical diagnosis, pertussis, but of course you want to confirm that for the
    point of view of contact tracing and a whole range of other things, but you can ask for that
    chest individually without asking for the panel.

    Dr David Armstrong

    Great. Thank you, Tom. We have gone significantly over our time and unfortunately we’re
    going to have to draw to a close there. Can I just before we close say for any questions that
    we’ve missed that appear on our screen, we will provide written answers to those questions
    on the VPCN website. Can I also remind everyone that the slides for this presentation have
    been already uploaded onto the VPCN website and can be viewed, you can send us in your
    questions over the next 24 hours and we will answer them as soon as possible.
    Could I just finish by reminding people once again if you could please fill in the survey that
    would be great, and I’d really like to thank Tom for coming in. Terrific presentation and
    we’ve really enjoyed giving this talk and I hope you have enjoyed it too. So thank you and
    goodbye from us.

Victorian Paediatric Clinical Network Webinar 

Bronchiolitis - Surviving the Season

Reviewed 18 August 2016

Health.vic

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