SGEM#327: MAGNUM PA – Nebulized Magnesium for Pediatric Asthma

Date: April 16th, 2021 Guest Skeptic: Dr. Anthony Crocco is the Deputy Chief - McMaster Department of Pediatrics, Acting Head of Pediatric Cardiology, and creator of Sketchy EBM. Reference: Schuh et al. Effect of Nebulized Magnesium vs Placebo Added to Albuterol on Hospitalization Among Children With Refractory Acute Asthma Treated in the Emergency Department: A Randomized Clinical Trial. JAMA Nov 2020 Case: A four-year-old girl with a known history of asthma presents to your emergency department (ED) after a one-day history of runny nose and cough.  Her usual triggers are upper respiratory infections and cats.  You don the appropriate personal protective equipment (PPE) wondering if this is COVID.  On initial exam she has minimal air entry, has biphasic wheeze, is saturating 92% on room air and has suprasternal retractions.  You give her an initial Pediatric Respiratory Assessment Measure (PRAM) score of 8 - and consider her to be having a “severe” exacerbation.  You give her a dose of oral dexamethasone and start three back-to-back treatments of albuterol and ipatroprium bromide.  After one hour she is still working hard to breath and her PRAM has improved somewhat but is still 6 denoting “moderate” asthma.  You wonder whether magnesium is indicated now and rather than starting an IV to give it that way, you could just nebulize a dose instead. Background: Asthma is a common presenting complaint for children in the ED. We have covered asthma a few times on the SGEM: You mentioned the PRAM tool in the case scenario. Can you explain this further for those not familiar with the PRAM score? SGEM#52: Breakfast at Glenfield – Asthma, Social Media and Knowledge Translation SGEM#103: Just Breathe – Inhaled Corticosteroids for Asthma Exacerbations SGEM#142: We Need Asthma Education SGEM#194: Highway to the Dexamethasone – For Pediatric Asthma Exacerbations The PRAM score is a tool used to assess the severity of airway obstruction in pediatric patients. The PRAM was published in 2000 (Chalut et al) and validated in 2008 (Ducharme et al). The PRAM consists of five clinical elements: O2 saturation, suprasternal retractions, scalene muscle contraction, air entry and wheezing. A score of 0-3 is considered mild asthma, 4-7 is moderate and 8-12 is severe. The Canadian Pediatric Society (CPS) Guidelines  recommends the initial management of pediatric patients with severe asthma exacerbations consists of: keeping oxygen saturations >93%, inhaled beta agonists, inhaled ipatroprium bromide, oral steroids, consider IV steroids, consider continuous aerosolized beta-2 agonists, consider IV magnesium sulphate and keep NPO. For children with severe asthma, IV magnesium has been shown to significantly decrease hospitalization rates though practically these children are rarely sent home after this IV treatment (Cheuk et al 2005, Griffith et al 2016, Su et al 2018 and Liu et al 2016).  As IV magnesium requires an intravenous, a painful and often distressing procedure in of itself, and the magnesium itself given IV can cause hypotension, an alternate delivery system would be of benefit. Clinical Question: Does nebulized magnesium prevent hospitalization in children with moderate to severe asthma? Reference:  Schuh et al. Effect of Nebulized Magnesium vs Placebo Added to Albuterol on Hospitalization Among Children With Refractory Acute Asthma Treated in the Emergency Department: A Randomized Clinical Trial. JAMA Nov 2020 Population: Children 2 to 17 years of age with a previous diagnosis of asthma presenting to a pediatric ED with moderate to severe asthma after receiving one hour of treatments including 3 x inhaled albuterol treatments, 3 x inhaled ipatropium bromide treatments and oral corticosteroid. Moderate to severe asthma was defined by a PRAM score of greater than 4. Exclusions: Children less than 2 years of age, those requiring immediate airway management,