Article Text

International practice patterns of IV magnesium in paediatric acute asthma
  1. Laura Simone1,
  2. Roger Zemek2,
  3. Damian Roland3,4,
  4. Mark D Lyttle5,
  5. Simon Craig6,
  6. Stuart R Dalziel7,
  7. Jocelyn Gravel8,
  8. Yaron Finkelstein9,
  9. Sarah Curtis10,
  10. Stephen B Freedman11,
  11. Amy C Plint12,
  12. Suzanne Schuh13
  13. on behalf of the Pediatric Emergency Research Network Group
    1. 1 Emergency Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
    2. 2 Pediatrics, CHEO, Ottawa, Ontario, Canada
    3. 3 Health Sciences, University of Leicester, Leicester, UK
    4. 4 Paediatric Emergency Medicine Leicester Academic (PEMLA) Group, University Hospitals of Leicester NHS Trust, Leicester, UK
    5. 5 Emergency Department, Bristol Royal Children's Hospital, Bristol, UK
    6. 6 Division of Pediatric Emergency Medicine, Monash Medical Centre Clayton, Clayton, Victoria, Australia
    7. 7 Emergency Medicine, Starship Children’s Hospital, Auckland, New Zealand
    8. 8 Department of Pediatrics, CHU SainteJustine, Montreal, Québec, Canada
    9. 9 Division of Emergency Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
    10. 10 University of Alberta, Edmonton, Alberta, Canada
    11. 11 Paediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada
    12. 12 Emergency Medicine, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
    13. 13 Division of Pediatric Emergency Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
    1. Correspondence to Dr Suzanne Schuh, Emergency Medicine, Hosp Sick Children, Toronto, ON M5G 1X8, Canada; suzanne.schuh{at}

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    Guideline recommendations about discharge of children with acute asthma treated with IV magnesium (IV-Mg) are disparate and inconclusive (see online supplemental material). The majority of children given IV-Mg in the emergency department (ED) are hospitalised, independent of asthma severity or degree of response to IV-Mg.1 The rationale for this practice is unknown but may be due to limited evidence whether children with a satisfactory response to IV-Mg can be safely discharged.2–4

    Supplemental material

    We conducted this international survey of three paediatric emergency research networks in Canada (Paediatric Emergency Research Canada), Australia/New Zealand (Paediatric Research in Emergency Departments International Collaborative) and the UK/Ireland (Paediatric Emergency Research United Kingdom and Ireland) belonging to the international Paediatric Emergency Research Network to determine the proportion of paediatric ED physicians who agree there is adequate evidence that children with acute asthma refractory to the initial corticosteroid and bronchodilator therapy, and who attain a satisfactory and sustained response to IV-Mg, can be safely discharged home. The modified Dillman’s method5 was used for participant contact from March to June 2021. Using network membership and email lists, we invited participants by email to click on a link to complete a web-based, 25-item, two-page Research Electronic Data Capture survey (online supplemental material). The first page asked screening and demographic questions; the second page contained the survey questions. Physicians not treating children and those in training were ineligible. Following best practices for survey studies,6 study authors performed item generation, reduction, pretesting and pilot testing. Physicians were asked to rate on a 4-point Likert scale (‘strongly agree’ to ‘strongly disagree’) the extent to which they agreed that children remaining in marked respiratory distress after stabilisation therapy with bronchodilators and steroids, who then have a satisfactory and sustained response to IV-Mg (mild asthma: PRAM 2/12 points for ≥3 hours post IV-Mg) can be safely discharged home. To detect a proportion of 40% (based on authors’ consensus) of physicians agreeing (strongly agree or agree) that the evidence of IV-Mg benefit is adequate with an error margin of 5%, 369 participants were needed. We used the χ2 test with 95% CIs for differences in relevant proportions, which included post hoc between-country outcome comparisons. Surveys without responses to the actual survey questions were not analysed.

    Supplemental material

    A total of 886 physicians were invited to participate; 657 (74.1%) responded, of whom 36 were ineligible, and 35 replied only to the first page, leaving 586 surveys for analysis (Canada 131, UK/Ireland 391 and Australia/New Zealand 64).

    A total of 104/586 participants (104 (17.7%, 95% CI 14.7% to 21.1%)) agree that current evidence of IV-Mg benefit about safe discharge after a satisfactory and sustained response to IV-Mg is adequate, with a significant difference between Canada and UK/Ireland (difference 52% (95% CI 44% to 61%)) vs Australia/New Zealand (difference 48.6% (95% CI 38% to 60%)), with a p value of <0.001 for both. The decision to use IV-Mg prompts Canadian physicians to hospitalise less frequently than those in UK/Ireland (difference −52% (95% CI −62% to −43%)) and Australia/New Zealand (difference −49% (−59% to −38%)), with a p value of <0.001 for both (table 1). Concern about inadequate evidence of benefit or discharge safety represents the main reason for routine hospitalisation after IV-Mg.

    Table 1

    Characteristics of participants and practice patterns with IV-Mg in acute asthma

    This study has several limitations. Survey responses may not accurately reflect actual practice and may not be generalisable to other countries. This study was not a priori powered for between-country comparisons.

    A minority of paediatric ED physicians consider the current evidence regarding the safety of discharge after IV-Mg in refractory acute asthma adequate and the majority routinely hospitalised after IV-Mg, irrespective of clinical response. There are significant differences in hospitalisation after IV-Mg across networks. Studies are needed to determine if patients can be safely discharged after IV-Mg, and future guidelines should be based on such research.

    Supplemental material

    Ethics statements

    Patient consent for publication

    Ethics approval

    This study involves human participants and was approved by REB number: 1000073768 (The Hospital for Sick Children). The participants gave informed consent to participate in the study before taking part.


    Thank you to the following Paediatric Emergency Research United Kingdom and Ireland collaborators for acting as site leads for obtaining local approvals, and distributing the survey and reminders: Meriel Tolhurst-Cleaver (Alder Hey Children’s Hospital NHS Foundation Trust); Caroline Ponmani (Barking, Havering & Redbridge University Hospitals NHS Trust); Stuart Hartshorn (Birmingham Children’s Hospital); Catherine Williams (Bolton NHS Foundation Trust); Andora Webster (Bristol Royal Hospital for Children); Rhea D’Arcy (Chelsea and Westminster NHS Foundation Trust); Michael Barrett (Children’s Health Ireland at Crumlin); Sheena Durnin (Children’s Health Ireland at Tallaght); Thomas Waterfield (Children’s Health Ireland at Temple Street); Stephen Brearey (Countess of Chester NHS Foundation Trust); Darren Ranasinghe (Croydon University Hospital); Martin Laque (Evelina London Children’s Hospital); Patrick Aldridge (Frimley Park Hospital); Elizabeth Herrieven (Hull Royal Infirmary); David Hartin (Ipswich Hospital); Arshid Murad (James Cook University Hospital Middlesbrough); Ellie Clegg (Leeds General Infirmary); Damian Roland (Leicester Royal Infirmary); Clare Dieppe (Morriston Hospital Swansea); Katie Knight (North Middlesex Hospital); Richard Freeman (Northumbria Healthcare NHS Foundation Trust); Lauren Fraser (Northwick Park Hospital); Chris Gough (Nottingham University Hospitals NHS Trust); Sharryn Gardner (Ormskirk & District General Hospital); David Patel (Queen Alexandra Hospital Portsmouth); Gareth Patton (Royal Aberdeen Children’s Hospital); Emily Walton (Royal Alexandra Children’s Hospital, Brighton); Julie-Ann Maney (Royal Belfast Hospital for Sick Children); Gisela Robinson (Royal Derby Hospital); Andy Appelboam (Royal Devon and Exeter Hospital); Jen Browning (Royal Hospital for Children & Young People, Edinburgh); Steven Foster (Royal Hospital for Children Glasgow); Emma Jenkinson (Royal Wolverhampton NHS Trust); Seb GrayGrey (Salisbury NHS Foundation Trust); Shammi Ramlakhan (Sheffield Children’s NHS Foundation Trust); Lisa Kehler (Shrewsbury & Telford NHS Trust); Niall Mullen (South Tyneside & Sunderland NHS Foundation Trust); Jane Bayreuther (Southampton Children’s Hospital); Victoria Worsnop (St George’s University Hospitals NHS Foundation Trust); Neil Thompson (St Mary’s Hospital, Imperial College Healthcare NHS Trust); Katy Rose (University College Hospital London); Mary Wilson (University Hospital Crosshouse, Kilmarnock); Lorraine Wicksey (University Hospital Lewisham); Jeff Morgan (University Hospital of Wales, Cardiff); Jason Palman (Watford General Hospital); Sarah Wilson (Wexham Park Hospital); and Amutha Anpananthar (Whipps Cross Hospital).


    Supplementary materials


    • Handling editor Steve Rothrock

    • Twitter @damian_roland, @mdlyttle

    • Collaborators Pediatric Emergency Research Network Group Co-Authors: Naveen Poonai, MD, MSc (Division of Pediatric Emergency Medicine, Children’s Hospital of Western Ontario, Departments of Pediatrics, Internal Medicine, Epidemiology & Biostatistics, Schulich School of Medicine & Dentistry, London, Ontario, Canada); Franz E Babl (Emergency Department, Royal Children’s Hospital, Melbourne, Australia; Murdoch Children’s Research Institute; Melbourne, Australia; Departments of Paediatrics and Critical Care, University of Melbourne, Melbourne, Australia), MD, MPH; Graham Thompson (Departments of Pediatrics and Emergency Medicine, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada), MD, MSc; Francine M Ducharme (Department of Pediatric Emergency Medicine, CHU Sainte-Justine, Montreal, Université de Montréal, Qc, Canada; Department of Pediatrics and of Social and Preventive Medicine, Université de Montréal, Montreal, Qc, Canada), MD, MSc; David W. Johnson (Departments of Pediatrics, Emergency Medicine, and Physiology & Pharmacology, Alberta Children's Hospital, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada), MD; Terry P Klassen (Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada; Children’s Hospital Research Institute of Manitoba, Winnipeg, MB Canada), MD, MSc; Bethany Lerman (Division of Pediatric Emergency Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada), BA; Bryan Maguire (Department of Clinical Research Services, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada), MSc; Rebecca Emerton (Departments of Pediatrics and Emergency Medicine, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada), BA.

    • Contributors LS and SS conceptualised and designed the study, drafted the initial manuscript, and reviewed and revised the manuscript for important intellectual content. RZ, DR, MDL, SCr, SRD, YF, SCu, SBF, ACP, NP, FEB, GT, FMD, DWJ and TPK designed the study and revised the manuscript for important intellectual content. JG designed the study, translated the survey into French and revised the manuscript for important intellectual content. BL and RE coordinated and supervised the data collection and reviewed the manuscript for important intellectual content. BM conducted the statistical analysis and revised the manuscript for important intellectual content. All authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.

    • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

    • Competing interests None declared.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.