Thread by @DurrantNiall

Okay so turns out that there is more work to be done regarding standardised salbutamol weaning plans, and SABA use in general, than I had thought. A 🧵regarding #asthma and weaning plans in the UK, the evidence, and what comes next. 1/17

https://twitter.com/DurrantNiall/status/1568950889381261312

What are salbutamol weaning plans? (WP) Children and young people are routinely discharged from the ward or ED with advice to gradually wean down salbutamol use over the coming days. WP may wean by time or doses (puffs) but start at 10 puffs every 4 hours 2/17

WP are commonly used across the UK and have been for years. They make clinicians and parents feel safe in the knowledge that the patient will continue to receive salbutamol, keeping the lungs open while they recover 3/17

However the dosing regime is in no BTS/SIGN guidance, Asthma UK personalised plan (PAAP) or GINA recommendation. Asthma UK PAAP actually recommends seeking urgent medical help if needing 10 puffs salbutamol. 4/17

This is likely because there’s no evidence that these WP are effective or safe. Indeed the National Review of Asthma Deaths (2014) found, in addition to UK’s v.poor asthma mortality, excessive use of high dose salbutamol was associated with worse mortality 5/17

Easy to assume this is because more severe patients use more salbutamol, but as 30% of asthma deaths occur in ‘mild’ asthmatics, it is probably more useful to think about poorly controlled than severe asthma. 6/17

High dose salbutamol may worsen outcomes for several reasons, psychological & pharmacological. First it is important to remember that salbutamol does not resolve asthma – it opens airways to an extent but does not reduce the inflammation or airway sensitivity. 7/17

Psychological – parents may rely high dose weaning plans thinking their child is safe, whereas continuing to require 10 puffs salbutamol 4hrly post-discharge is actually a sign of needing more steroids or alternative treatment. Clinicians may also be falsely reassured. 8/17

Sophie Holman's 2017 case highlighted the dangers of WPs. The coroners report noted the 10 yr old had regular 10 puffs 4 hourly in the 25 hours before her death. It condemned their use, especially given the NRAD recommendation all children receive a personalised asthma plan 9/17

As the coroner themselves noted, Sophie was not the only such case. judiciary.uk/wp-content/upl… 10/17

Pharmacological - Short term salbutamol may mask deterioration in those who respond well, but there are other risks. It is a racemic drug (50:50 isomers). The R-enantiomer causes the beneficial effects (and sympathetic activation, tremor, vomiting and tachycardia etc) 11/17

The S-enantiomer, long thought to be inert, appears to cause increased inflammation and airway reactivity, as well as possibly increase mucus production These effects are modified by co-administration of steroid – which is why GINA recommends it not be used on its own. 12/17

The S-enantiomer is metabolised 8 times slower than the R-molecule, so repeated high doses quickly causes a predominance of S over R. This may also reduce the response to inhaled salbutamol over repeated doses via competitive antagonism. 13/17

This may be behind the induction of tachyphylaxis with salbutamol. Certain individuals (Arg-16 homozygous beta-2 receptors) respond better to salbutamol but also experience more tachyphylaxis. Regular LABA use has also been shown to induce tolerance. 14/17

TLDR, Salbutamol standardised plans can:
Mask deterioration
Cause bronchospasm and inflammation
Be associated with mortality in excess use.
UK mortality and use of personalised plans remain poor, although slowly improving. 15/17

Salbutamol remains very useful! It's key in the management of asthma attacks. But we should all be using steroids to resolve attacks not repeated high doses of salbutamol. And asthma attacks are life threatening events, not a normal part of the disease 16/17

Next? Aim to improve early steroid prescribing in attacks, always prescribe a preventer. In the future we will likely move to Maintenance AS Reliever Therapy - inhaled steroid with a LABA (e.g formoterol) is used as the reliever inhaler, as per GINA 17/End

Links to some reading:
ginasthma.org/wp-content/upl…

bjgp.org/content/69/685…
ncbi.nlm.nih.gov/pmc/articles/P…

Oh also what am I suggesting instead?! I think the recent LALIG plan - PRN management at home, using up to 6 puffs every 4 hours, anything more prompting urgent review, is sensible.