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Michael Wechsler, MD: Hello. I'm Dr Mike Wechsler. Welcome to Medscape's InDiscussion series on moderate to severe asthma. Today we'll be discussing emergency care of pediatric severe asthma with Dr Todd Florin. Dr Florin is associate professor of pediatrics in the Division of Pediatric Emergency Medicine at Lurie Children's Hospital in Chicago and Northwestern University Feinberg School of Medicine. He's also director of research for the Division of Emergency Medicine and director of the Grainger Research Program in Pediatric Emergency Medicine. He's hosted the Medscape InDiscussion podcast series on pediatric pneumonia. Todd, it's great to have you today. Welcome to our program. Tell us a little bit about yourself. What kind of research do you specialize in?
Todd A. Florin, MD, MSCE: Thanks so much, Mike. I'm a pediatric emergency medicine clinician-scientist. My research focus is risk stratification and improving management of kids with lower respiratory tract infections. These kids can present numerous different ways. Sometimes it can be hard to parse out which kids you have to worry about and which kids you can safely send home and feel like they can just be managed at home or in the community. Surprisingly, there are not that many evidence-based tools to help us. My research program focuses on using predictive analytics and biomarkers to improve our ability to risk-stratify these kids with lower respiratory tract infections at the bedside to help improve health outcomes and help them to be managed in the way most appropriate to their underlying risk.
Wechsler: That's relevant to our topic today because we're going to talk about severe asthma in the pediatric population. We've talked about severe asthma in adults. We've talked about pediatric asthma. We've talked about emergency management of asthma in adults. In this program, we're going to focus on emergency management of pediatric asthma. How many millions of kids in the United States have asthma?
Florin: Asthma is one of the most common conditions in children. There are approximately 4 million children in the United States who experience asthma exacerbations each year. That accounts for about 14 million missed days of school and more than 2 million emergency department visits each year. I think our listeners should know that respiratory conditions in general are the most common reasons why a child will visit the emergency department in the United States. This is our bread and butter and it's something that we all need to be aware of.
Wechsler: It's a serious problem in the pediatric population, just as it is in adults. Tell me a little bit more about what kids look like when they present with severe asthma. What are the telltale signs of when a parent or a primary care doctor or pediatrician should consider sending a kid to the emergency room?
Florin: Like with adults, there's a spectrum of disease, and most kids who present to primary care are going to have a mild exacerbation. In a child, mild exacerbation means they're slightly tachypneic. Their wheezing is intermittent; it's only in the expiratory phase and their expiratory phase is not significantly prolonged. Finally, they're not using accessory muscles. Generally, kids with mild exacerbation start with belly breathing and then they work upward in terms of their accessory muscle usage. At the mild exacerbation stage, their oxygen saturations are normal.
As you get more severe, the respiratory rate starts to go up. You have increasing tachypnea. Wheezing occurs throughout the entirety of the expiratory phase and in the most severe cases can start to involve the inspiratory phase. The inspiratory-to-expiratory ratio increases from 1:2 or greater.
We would have increased accessory muscle use as well. For example, you would see retractions, grunting, and nasal flaring. We have greater degrees of hypoxemia, with saturations ranging from 90% to 95% in children with moderate presentations, to less than 90% in kids with severe presentations.
One thing that can sometimes fool people is when a child has an inappropriately normal or low respiratory rate with low saturations and they're looking tired. That is really a key feature of impending respiratory failure. And that child needs to be taken very seriously; just because that respiratory rate is so-called "normal" does not mean that child is truly normal in their presentation.
Wechsler: It may be easy for a clinician to gauge some of these symptoms and signs. What do you tell parents to watch out for that is different from what you might tell a pediatrician?
Florin: I sit with parents and I show them the belly. I show them the ribs and I talk to them about what retractions look like. I teach them how to count a respiratory rate. Parents are amazingly accurate in their ability to count a respiratory rate if they're taught to do so. I talk to them about watching for things like persistently breathing fast, retractions, not taking at least half of what the child normally takes in terms of hydration, or not making at least two to three wet diapers in a 24-hour period. These are signs that I will talk to parents about, especially about either coming to the emergency room or coming back to the emergency room if I'm about to discharge them home.
Wechsler: There must be a huge component of anxiety, both in the kid as well as in the parent, when this is going on. What do you tell them to mitigate some of the stress and anxiety that they're experiencing? That could be contributing a fair amount to some of the presentation.
Florin: That's something we tell parents all the time: If they can stay calm, that will help their child stay calm. In pediatrics, we talk a lot about anticipatory guidance. This means telling parents what to expect and how to act appropriately if they encounter a child who is showing signs or symptoms of an asthma exacerbation.
How much albuterol are they to give? How often are they going to give that albuterol? How long will it take for the albuterol to work? Ultimately, we're empowering them with information in terms of when to seek additional care beyond what they feel comfortable with at home.
Wechsler: Do you give any guidance in terms of specific thresholds? Are there any objective criteria? Do you tell them to keep on taking albuterol? Do people check peak flows? What sort of criteria might you consider in the pediatric population?
Florin: If we're talking to parents specifically, I'm telling them to monitor if the child is breathing faster than 50 to 60 breaths per minute and they're starting to see those retractions in the ribs. We're also monitoring if they're taking less than 50% of their usual hydration, fluid intake, and if they're making fewer than two to three wet diapers in a 24-hour period. Those are the thresholds that I generally tell a parent in terms of heading to the emergency department.
In regard to clinicians, there are several validated scores that clinicians can use to help gauge asthma severity. The three most popular are the PRAM, or the Pediatric Respiratory Assessment Measure; the PASS, the Pediatric Asthma Severity Score; and the PIS, or the Pulmonary Index Score. All three of these have been validated to predict the need for hospitalization, and they all contain similar variables — just in different combinations. We look at wheezing, prolonged expiration, air entry, retractions, and oxygen saturation. These are the components of these scores. In general, what I tell clinicians is that it's better to use some validated score to help gauge both the disposition of a child to the emergency department, but also to gauge that child's risk of needing hospitalization. These scores have been validated for predicting the need for hospitalization by gauging the response after initial therapy in the acute care setting.
Wechsler: Are there different strategies in terms of managing kids in the office of the pediatrician vs in the emergency room?
Florin: Yes. Most primary care pediatricians have albuterol or a short-acting beta agonist available in the office in addition to some glucocorticoid, whether that's prednisone or dexamethasone. We can certainly talk about which one is preferred in the emergency department setting. Most pediatricians can give albuterol if the child is saturating well and if they look like they have a mild exacerbation. They can give them glucocorticoid. But beyond that, most pediatricians don't have access to things like ipratropium, magnesium, and things that we would use in the emergency department for more moderate or severe exacerbations. Give a proper dose of albuterol and glucocorticoid, and watch the child for a little bit. If you're not seeing a response or if the child worsens, which can sometimes happen after you give albuterol and you increase some V/Q mismatch, then that child needs to be referred to the emergency department.
Wechsler: Now we're at the emergency room. First, what are the goals of emergency room care?
Florin: There are three key goals in the acute care of a child with asthma. The first is quickly reversing their airflow obstruction. Second, you need to correct any hypoxemia or, in severe cases, hypercapnia. The third is reducing that kid's chance of being hospitalized. You also want to reduce that child's chance of having to come back to the emergency department if you send them home.
Wechsler: Those sound like important goals for these patients. When the patient comes in, what's the initial management upon arrival in the emergency room?
Florin: After doing an initial triage and severity assessment using a validated score, you first go to your glucocorticoids. These include things like prednisone, prednisolone, and dexamethasone. Generally, the effects are noted about 2-4 hours after you give these medications. There have been multiple studies that have demonstrated in meta-analyses that you want to administer glucocorticoids as early as possible. This is defined as within an hour of presenting to the emergency department. If you provide early glucocorticoids, you're going to reduce your admission rates.
There have been emergency departments that have started giving glucocorticoids in triage because of that data. Dexamethasone is our steroid of choice. It has a prolonged half-life compared with prednisolone and prednisone as well as similar efficacy. That can be given intramuscularly in patients who are not tolerating oral intake. The second hallmark of therapy is bronchodilators. Things like albuterol in the US. You can give these either nebulized or with a metered-dose inhaler (MDI). And MDI with a spacer can be given intermittently or continuously, depending on the presentation of the child.
Wechsler: Is it better to give a nebulized therapy or an MDI? Are there differences there?
Florin: When I was training 15 years ago, every kid got a nebulizer because the thought was that the nebulized steam forces the medicine in. Since that time, there have been multiple clinical trials and meta-analyses that have looked at giving short-acting beta agonists via nebulizer or via an MDI with spacer. The MDI has been shown to be at least as effective as a nebulizer. It may be even better at reversing bronchospasm compared with a nebulizer. Honestly, the choice depends on the availability and the frequency of dosing. A nebulized therapy ensures that you're complying with national treatment guidelines. It gives you the ability to simultaneously deliver oxygen and ipratropium. With the nebulizer, 90% of the drug remains either in the machine or out in the atmosphere and not down in the kid's lungs.
An MDI with spacer ensures that the medicine is going where it needs to go. I would approach a child with a mild to moderate exacerbation, who I think is going to go home, with an MDI. They can also then take that MDI home with them after the emergency department visit. If a child is looking more moderate to severe, I will go to a nebulizer because I'm going to want to ensure that they get oxygen. I'm going to want to ensure that they get ipratropium, and it's likely that they're going to need to be on that therapy continuously for a longer period of time.
Wechsler: Is there a specific age below which it's hard for kids to use an MDI, in general? When do you consider that specific issue? Are kids coordinated when they're 5 or 4 or 6 or 8? What is that age? Obviously, it's going to differ from kid to kid.
Florin: Absolutely — development is a part of that. But the great thing about the spacer is that it gets made with different mask sizes. As long as you are leaving that spacer over the kid's nose and mouth for at least five breaths — we say five to 10 breaths — the kid doesn't need to coordinate anything. You puff the medicine into the spacer, you allow the kid to go through five to 10 breaths, and that medicine is going to go where it needs to go. We can use MDIs with spacers all the way down into the infant age range with good success. For the youngest kids, where the mask is not going to fit, I may do a nebulizer. The other thing to consider is that 10 breaths with a mask on is easier in a squirmy child than trying to keep that mask on for a 15-minute nebulizer session.
Wechsler: Is there a role for levalbuterol vs albuterol in this patient population?
Florin: That's a great question. Generally we use racemic albuterol; levalbuterol is more expensive. There are data that suggest that it is not any more beneficial in terms of avoiding the side effects of racemic albuterol in the pediatric population. We generally tend to use levalbuterol in patients with either congenital heart disease or physiologically significant cardiac disease. In those cases, we may want to try to avoid the resultant tachycardia that happens with racemic albuterol. For the most part, racemic albuterol is cheaper, it's more easily available, and the results are generally about the same.
Wechsler: You mentioned anticholinergics and antimuscarinic agents. What's the added value of giving a drug like ipratropium, and do you just give that as part of a nebulizer or do you give a separate inhalation via MDI?
Florin: Ipratropium is widely available via nebulizer. We generally do not give it via MDI. There have been multiple randomized trials and multiple meta-analyses that show that if you combine two to three doses of ipratropium with inhaled albuterol into a single nebulized chamber and allow that to run, the number-one benefit is a substantial reduction of hospital admissions. It does improve lung function when you compare it to a beta agonist alone. Our go-to dose, if someone weighs less than 20 kg, is 250 µg per dose. If someone weighs more than 20 kg, it's 500 µg per dose. You just mix it together. It has become standard of care to reduce hospital admission for kids with moderate to severe asthma who present to the emergency department.
Wechsler: What about using magnesium sulfate? Is that used at all in pediatrics?
Florin: It has been used more and more frequently over the past 5-10 years. When I was first starting 15 years ago, we used it only for the most severe cases. I think there have been data that have shown that adding that bronchial smooth muscle contraction actually helps kids. It also helps avoid hospitalization if it's given early in the course. There have been meta-analyses that have looked at this, finding that for every four kids treated with magnesium, one avoids hospitalization. There's a reduced risk for hospitalization in kids who receive magnesium sulfate via IV in the emergency department.
Generally, we'll give magnesium in kids who are older than 4 years of age with moderate exacerbation that is not responding to the initial therapies that we talked about. Or we use it to treat kids who have severe presentations, and usually the dose is right at 50 mg/kg, given over 20 minutes. We generally give that piggyback with a normal saline bolus to prevent clinically significant hypotension, which is rare, although I have seen it occur. If it does occur, it's really hard to chase it down. I always piggyback with a normal saline bolus with my magnesium, if I'm going to give it.
Wechsler: What are the current guidelines and recommendations in terms of giving antibiotics in the emergency room in the context of pediatric asthma exacerbations? I know that in adults, there have been studies showing that giving drugs like azithromycin can be beneficial, or other macrolide antibiotics. What about in kids?
Florin: One of my areas of focus is antimicrobial stewardship for lower respiratory tract infections in kids. This is a perfect question for me. Macrolides, if given unnecessarily, select for resistant organisms on the mucosal surfaces. We generally want to avoid macrolides, even with their anti-inflammatory properties, if there are no signs of a bacterial illness.
We've done studies of radiographic pneumonia in kids who present with an asthma exacerbation. Of kids who presented, 30% of them got an x-ray. Only 2% of them had a radiographic pneumonia. The risk factors for when we are going to consider antibiotics for a potential pneumonia are going to be things like fever greater than 39 °C. We would also consider it for an older kid, older than 5, or an oxygen saturation less than 91%. Those may be risk factors where that kid may have a concomitant pneumonia. But giving macrolides alone for non-pneumonia for the anti-inflammatory properties — there's been no evidence to show that that is helpful in a child with asthma exacerbation. We do not routinely do that.
Wechsler: What else do people need to think about in terms of differential diagnosis? Not everyone who comes in with what looks like an asthma flare has an asthma flare. Kids choke on marbles and other foreign objects. There are viral infections. How do you distinguish between, or how do you manage differently, bronchiolitis vs asthma?
Florin: I feel like we could do a whole podcast series on bronchiolitis alone. Bronchiolitis is not asthma. Sometimes they are difficult to tease apart. They're related, especially in an older infant or toddler in the 12- to 24-month age range. We call it "asthmalitis," where you're not sure: Is it bronchiolitis or is it asthma? Generally, with bronchiolitis you get wheezing because you get obstruction secondary to mucus production, or secondary to viral illness. This is distinct from the pathophysiology of asthma, where you're dealing with a chronic inflammatory condition. Some clues that can help you are if a child is less than 2 years old and they haven't wheezed before, and they've got significant upper respiratory tract symptoms that then progress to the lower tract. Those kids are generally not going to respond to short-acting beta agonists, and that's one clue that can help you in making that distinction.
We think about croup. Croup is inspiratory stridor with no wheezing. Sometimes that can get mistaken for wheezing or for bronchiolitis. It's very important to differentiate that, because clearly, short-acting beta agonists are not going to work in croup. Dexamethasone is really the go-to for viral croup. You talked about foreign body. That will usually present initially with stridor. If that foreign body makes its way into the lower airways, that can present as wheeze. Typically, there's a choking episode that's associated with that. Asking if the child has ever wheezed before is really, really critical in helping to tease that distinction apart as well.
Pneumonia, of course, shows up in the differential, and kids can have viral pneumonia, which is more frequent, or bacterial pneumonia. The kids with bacterial pneumonia tend to look a little bit sicker. For those kids, you're going to want to look for things like focal rales on exam, significant hypoxemia, higher fevers. Those are going to be the things that are going to take you down the pneumonia route.
Wechsler: All right, last question for you. I get very nervous when any kid gets really sick or when any adult gets really sick. What are the criteria that you utilize to decide whether you need to engage in some type of ventilatory support, whether it's a noninvasive or more invasive ventilatory support?
Florin: That's a great question, and we deal with that every day in the emergency department. We generally reserve respiratory support for kids who have severe exacerbations that are not responding to initial therapy. If they're able to maintain their respiratory drive, if they're talking to you and you've given them albuterol, ipratropium, steroid, magnesium, you could try subcutaneous or intramuscular epinephrine to open them up.
If you've tried all of these therapies and they're not getting better or their work of breathing is getting worse, or if their mental status is declining and their respiratory drive is declining, those are going to be reasons to try positive pressure ventilation. In kids, we generally try to avoid intubating if at all possible, because you can actually increase airflow obstruction during the intubation, and these kids are notoriously difficult to ventilate. Our initial go-to for kids that we think require positive pressure is noninvasive positive pressure — things like CPAP (continuous positive airway pressure) or BiPAP (bilevel positive airway pressure). We do a trial of that to see if they'll tolerate it. Oftentimes that's enough to avoid having to progress to intubation and all of the challenges that go along with that.
Wechsler: This has been a really comprehensive review of the management of pediatric asthma in the emergency room. I feel like even I could manage a kid in the emergency room at this point. We've talked a lot about how to gauge severity. We've talked about the treatment goals. We've talked about the treatment strategies, including bronchodilators vs MDIs; antibiotics; magnesium; ventilatory support; and the key components of the management of the pediatric patient in the emergency room. This has been a great discussion.
Todd, I want to thank you so much for your insight today. I hope that we get to chat again about this topic and many others as they evolve in the coming years.
Thanks so much for joining us. Today we had Dr Todd Florin discussing emergency management of pediatric asthma. I would like to thank you, the audience, for joining us today. This is Dr Mike Wechsler for InDiscussion.
Listen to additional seasons of this podcast.
Resources
Medscape InDiscussion: Pediatric Pneumonia Podcast
Medscape InDiscussion: Team Effort: A Multidisciplinary Approach to Severe Asthma Control
Medscape InDiscussion: Emergency! Managing Asthma in the ER
Pediatric Acute Asthma Scoring Systems: A Systematic Review and Survey of UK Practice
PRAM Score for Pediatric Asthma Exacerbation Severity
Pediatric Asthma Severity Score Is Associated With Critical Care Interventions
The Pulmonary Index Score as a Clinical Assessment Tool for Acute Childhood Asthma
Role of Inhaled Corticosteroids for Asthma Exacerbation in Children: An Updated Meta-Analysis
Pneumonia in Children Presenting to the Emergency Department With an Asthma Exacerbation
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Cite this: Pediatric Asthma: When Is It an Emergency? - Medscape - Nov 14, 2023.
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