Dr Simon Craig
An Australian study has found widespread variation in hospital management strategies for children with severe asthma who require escalated treatment beyond inhaled bronchodilators and oral corticosteroids.
The multicentre study of over 14,000 children presenting with acute severe asthma at 18 hospitals in Australia and New Zealand identified considerable inter-hospital differences in the frequency of treatment escalation and the choice of escalation treatments. It also found that many of the treatments were not supported by high quality evidence.
Overall, 7.3% children with acute severe asthma received some form of escalated treatment, with 4.2% receiving parenteral bronchodilators and 4.3% respiratory support. However, the use of parenteral treatment varied eight-fold between hospitals and the use of respiratory support varied ten-fold between hospitals.
The study investigators said that ‘remarkably’ nasal high-flow (NHF) therapy was used in nearly all patients (99%) who received respiratory support and accounted for nearly one-third of all escalation of asthma treatment.
While there is high-quality evidence supporting NHF therapy as a rescue treatment in children under one year old with bronchiolitis, there is little evidence to guide NHF therapy in children over one year of age with asthma and wheeze, they said.
The most common intravenous medication regimens were: magnesium alone (50.4%), magnesium and aminophylline (24.6%) and magnesium and salbutamol (10.0%).
The study authors said lack of high quality evidence for escalated treatments and inconsistencies with locals guidelines might explain the wide variations seen between hospitals
“While magnesium and salbutamol are listed as second-line and third-line bronchodilators for management of acute severe paediatric asthma in Australian national guidelines, some state-based guidelines prefer magnesium and aminophylline,” they noted
Paediatric respiratory physician and member of the National Asthma Council Australia Guidelines Committee Dr Louisa Owens said this was a critical study as children still die from acute asthma in Australia.
“The lack of evidence for some of these treatments is concerning and the study highlights areas which need more certainty and also some deviations from guidelines, for example, around nasal high-flow therapy,” she said.
“NHF therapy is widely used in the management of acute asthma, as was described in the study, and it likely has an important role, yet there is very little evidence behind this.
“Clearly the management of acute severe asthma in children should be a priority research area and the Australian Asthma Handbook guidelines are continually evolving to reflect the latest evidence regarding managing acute asthma in children,” said Dr Owens.
The study showed that children with treatment escalation had a longer length of stay than children without escalation (44.2 hours, vs 6.7 hours) and there was also considerable variation in length of stay between hospitals.
Severe outcomes were rare, with 243 children admitted to intensive care; 22 received non-invasive ventilation and only four were intubated.
Writing in BMJ Open Respiratory Research the study authors led by Dr Simon Craig said a major hurdle to determining effective management strategies was the lack of consistency in primary outcome measures.
Dr Craig, an Emergency Physician at Monash Medical Centre and Adjunct Clinical Professor, School of Clinical Sciences at Monash Health, said he is now working to establish a set of global standards for the way outcomes are measured in clinical trials involving children with acute severe asthma.
The study was supported by funding from the National Asthma Council Australia and the Thoracic Society of Australia and New Zealand (TSANZ).