Author: Nikki Abela / Editor: Liz Herrieven/ Reviewer: Lizzie Binham / Codes: A2 / Published: 14/11/2016 / Reviewed: 22/10/2024
And with that comes a new season.
This blog is a bit of an update and some serves as revision of our good practice, because as, Damian Roland reminds us, the child with respiratory distress is challenging, especially in those under 5 years who dont have a formal diagnosis of asthma.
In children, intermittent wheezy episodes are usually secondary to viral infection and not necessarily combined with underlying atopy, so response to medication may be inconsistent.
At the back of your mind you should always be considering differentials such as bronchiolitis (which is more likely in the under 1s), aspiration pneumonitis, pneumonia and cystic fibrosis. Rarely, wheeze can be a sign of heart problems: LVF in babies and myocarditis in the over 1 year olds.
Remember that prematurity and low birth weight are risk factors for recurrent wheezing.
Telling the difference between viral wheeze and bronchiolitis can certainly be difficult, but don’t let it paralyse you. If unsure, it can be worth giving a child 5-10 puffs of salbutamol as a trial and having a second listen to their chest a few minutes after to see if there was any improvement. There are ways to tell the difference though, and there is a whole blog about this that might help. If you ask ten doctors about this subject, you’ll get 10 opinions!
For the purposes of this blog, we’ll talk about the acute management of asthma or viral wheeze. Thankfully you don’t need to tell these two apart in order to crack on and get acute treatment started as its the same either way. (Bronchiolitis treatment is very different).
As soon as you assess the child, try to figure out their severity score. Most EDs will have printed algorithms for a visual aid, which unless you have a mind like Sheldon Cooper, I would suggest you use.
Plan A
Give the first line treatment. This is easy enough, but I do find that I sometimes second guess myself sometimes. The BTS/SIGN guidance has answered a few of these clinical dilemmas, which I will share with you.
If the child has mild/moderate symptoms give a salbutamol inhaler via a spacer and check their technique. Dose is not only age dependent but needs to be tailored according to symptoms so check your local protocol. The number of puffs of salbutamol you give varies depending on your local guidelines, so make sure you have checked these and are adhering to local policy. For most places, once children are managing with inhalers every 3-4 hours, they can go home on this regimen and tail it down when symptoms start improving a few days down the line.
If the patient has severe or life-threatening asthma with Sats <92%, then reach for the nebulized salbutamol. If there is poor response to the first neb, consider adding ipratropium bromide to make a combined nebuliser which can be repeated every 20-30minutes and adjusted according to response. Again local guidelines may vary as to when you should be mixing your nebulisers so make sure you’ve checked your local policy.
Add in a steroid early in both moderate or more severe exacerbations. Hold the IV hydrocortisone for those who can’t retain oral therapy as the evidence shows that the oral and IV routes have similar efficacy.
However, do repeat the dose of steroid if it is vomited up it soon after.
There is good evidence that single dose dexamethasone is as effective as a 3 day course of prednisolone, so many places have switched to this regime. As always, you should adhere to your local guidelines when choosing which steroid to give.
There is low level poor evidence for nebulised magnesium sulphate in the treatment of severe asthma, but BTS/SIGN say you can consider it.
OK, so youve done all that but the patient isn’t showing sign of getting better, so time to resort to plan B.
Plan B
Your options now are all IV, so when giving the back-to-back nebs, put on topical anaesthetic cream in anticipation of needing a cannula. A capillary blood gas may be of use here, but dont let a normal gas prevent escalation of treatment in a child who is clinically deteriorating (remember youd expect a low PaCO2 with tachypnoea, so anything normal or high is bad).
There are three options for IV treatment. Most guidelines will have a specified order. You will find most clinicians experienced in dealing with severe wheeze have a preferred agent. You will also find the preferences, and reasons for those choices, are hugely variable. In essence, you need to identify your patient is in need of escalation of treatment and get on with escalating.
- IV magnesium sulphate has the lowest side-effect profile and has been proven to work the fastest. However, most clinicians will tell you that it doesnt always work. A wise PED consultant once told me that although there is no harm in giving it, there is harm in waiting for it to work and thereby delaying subsequent treatment. So, start thinking of (and probably drawing up) your next option.
- IV salbutamol can be given as a bolus or a continuous infusion, especially in those with refractory symptoms. Do, however, check your potassium and ECG before starting treatment and have the patient on an ECG monitor.
- IV aminophylline is usually given as a loading dose followed by a continuous infusion (omit the loading dose in those already on oral theophyllines). Place the child on an ECG monitor.
The Next Step
Critical care input is the next step for children with severe asthma not responding to treatment or with any life-threatening features. There are a number of ongoing trials on the use of other agents, but the evidence is currently lacking so theyre not recommended by BTS/SIGN.
Discharge planning – When Plan A works well
Children can be discharged when stable with Sats >94% and on 34 hourly inhaled bronchodilators that can be continued at home. PEF can be useful in assessment, although its use is dependent on the childs age and ability to comply.
Deciding on who can be safely discharged is easy when the child responds well to the first puffs of salbutamol. Some children who need more can also be safely discharged, but that decision requires experience.
Before discharge make sure you:
- Check inhaler technique.
- Consider the need for preventer treatment or optimising/adjusting previously prescribed preventer treatments.
- Provide written advice for subsequent asthma attacks.
- It is good practice to advise patients to try and arrange a review with their GP within the next couple of days.
- For patients with multiple attendances, severe symptoms, or evidence of ongoing poorly-controlled symptoms you can consider referral for outpatient paediatric review.
Remember: many children with recurrent episodes of wheeze triggered by viruses do not go on to develop atopic asthma.
Viral induced wheeze is not a benign illness though. Although they probably wont benefit from steroid preventers, children still need to have good inhaler technique taught and access to salbutamol at home. Inevitably, the next attack will happen at 2am so youll see them again if they werent given a spray to help them stay away!
Big thanks to Edward Snelson who added much wisdom to this blog.
References and further reading
- The Rolobot Rambles: The Sounds of Winter: An audio-visual review of Paediatric Respiratory Disease. by Prof Damian Roland. 2015.
- BTS/SIGN British Guideline on the Management of Asthma. 2021.
- Paediatrics for Primary Care (and anyone else). Why bronchiolitis doesn’t get better with inhalers and how understanding “why?” is better than “do that!”, 2016.