Wheeze. It’s all in the timing…

You’ve just treated a 5-year-old with their second episode of wheeze this year. They’ve had burst therapy and are now one hour post-treatment with no work of breathing, scattered wheeze on auscultation and oxygen saturations of 95%. You contemplate giving them steroids and decide against it.

Authors warning – this is not a full critique of the papers referenced below. I hope to nudge readers to start questioning a standard practice in paediatrics…

You think that you could probably send them home in another hour or so, but your hospital guideline stretches these children to needing inhalers every four hours before discharge. You think that you might have to admit them as your Emergency Department-mandated attention span of four hours will be breached.

The paediatric team agrees they need admission ‘to stretch’ but will send them home at three hours. The paediatric consultant suddenly comes along and discharges them (one-hour post burst therapy), quoting a recent paper. You are very confused…

What is the current guidance?

This scenario likely plays out to varying degrees daily in paediatric healthcare.

The recent BTS/SIGN ‘British guideline on the management of asthma’ (July 2019) (page 111) states that ‘…children can be discharged home at 3-4 hourly inhalers’. The Australian Asthma Handbook (AAH) states, ‘…observe the patient for at least four hours’. This is (anecdotally) a mainstay of treatment practice in Australia, the USA, the UK and probably many other countries. BTS/SIGN references a paper for their recommendation, whereas the AAH states it ‘…based on clinical experience and expert opinion’.

So, what is the titanic study based on discharge at 4 hours post inhaler use? Well, BTS/SIGN quotes this paper. This was a randomised control study (so far, so good…) from 1999, used on 63 patients with asthma >18 months of age.

Based on a parental phone questionnaire two weeks post-discharge, they concluded children could be safely discharged home on three hourly nebulisers. I do not mean to belittle this study, as it was likely groundbreaking at the time and showed a novel approach. However, it was 20 years ago and is the only* study in the literature up to 2018. The study patients were discharged on nebulisers, and the length of stay had 95% confidence intervals between 42 and 67 hours. As any modern 21st-century paediatrician will tell you (and will be noted later), the average length of stay is rarely around these dizzy heights anymore.

But what does 3-4 hourly mean? Is it once a patient reaches three hours or four hours from their last inhaler for the first time? Is it reaching three hours or four hours twice between inhalers? Well, that’s where confusion reigns supreme.

At a recent UK conference, #PIER19, I conducted a survey that showed the following

Most said they send a child home when they reach four hourly inhalers for the first time, for which there is no evidence in the literature, but some said they wait twice for three or four hours (I personally call these the six—or eight-hour stretches…).

So why are some hospitals doing three hourly inhalers twice before discharge?

The most recent study is from 2018, when the Texas Children’s Hospital started a large quality improvement project in 2013, including discharging children on three-hour inhalers. Multiple interventions were used, including a streamlined care pathway, education, dexamethasone instead of prednisolone, a QI multidisciplinary team approach, and a detailed analysis of patient care.

I will not critique the study in its entirety. It suffices to say that the study showed no adverse outcomes and a shorter average length of stay (30 hours post-intervention vs 36 hours pre). This was coupled with many other interventions over the study period but was felt not to have had as large an impact as three hourly inhalers. How applicable this is to the ’real world’ is debatable, but the study is highly admirable as it’s only* the second prospective study in the literature for 20 years.

*There is a third study from 2003, but it’s retrospective and largely theoretical, so I have not dwelt upon it here.

Is one hour enough?

So, what about sending them home one hour post-therapy? This comes from a very recent study, which was a retrospective analysis of patients presenting to a major specialist children’s hospital in Australia over two weeks in the winter of 2014 compared with the winter of 2015. Between these winters, the hospital admission criteria were changed to an admission decision on medical review one hour post-initial therapy. This is based on studies (here and here) suggesting that the patient’s condition at one hour post-therapy highly predicts the need for admission/further therapy.

They looked at 105 patients (2014) vs 92 patients (2015). They showed that children who were ‘clinically well’ at one hour were likelier not to be admitted in 2015 vs 2014 (10% vs 40% p=0.001) and went home from ED faster in 2015 vs 2014. They also showed that any child with moderate symptoms (per new guidelines) was admitted each year at one hour post-therapy. This is a small study that was conducted over two weeks only and was based at a specialist children’s hospital with 75,000 ED attendances a year. How applicable this practice would be at a smaller hospital with just a few (or no) paediatricians is impossible to say.

Bottom line

The most recent published study with discharge at one hour post initial therapy supports what I, and others, probably already do (or we wish we had the courage to) when a child is so well after initial treatment – they are sent home. Is this confirming clinical gestalt?

As for discharging a patient home at 2, 3, 4, 6 or 8-hour inhalers (and whether that’s the first or second time round) – well I will leave that to you.

This author started a local quality improvement project around three hours (first time) and was discharged home. I just won’t be able to critique it here if it ever gets published…