PediatricsA randomized trial of magnesium in the emergency department treatment of children with asthma*
Introduction
In the United States, 4.8 million children have asthma, the most prevalent chronic disease of childhood.1 The self-reported prevalence rate for asthma increased 75% from 1980 to 1994, with an increase of 160% among children from birth to 4 years.2 This increased prevalence has been accompanied by increasing morbidity and mortality. From 1980 to 1994, the national hospitalization rate for asthmatic children from birth to 4 years increased 47%, while the national death rate for asthma among children and adults has more than doubled from 1975 to 1995.2
For patients in the emergency department with a moderate to severe asthma exacerbation, the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health recommends aggressive use of β2-agonists and systemic corticosteroids.3 However, several clinical trials have shown that patients with this degree of illness treated with β2-agonists and corticosteroids alone typically have an incomplete response and frequently (19% to 50%) require hospitalization.4, 5, 6, 7, 8 In each of 2 separate trials, 31% of children in the ED with moderate to severe exacerbations treated with prednisone and frequent, intermittently nebulized albuterol for 4 hours required hospitalization.4, 5 Therefore, it would seem that many patients with a moderate to severe exacerbation might benefit from therapy with additional medications.
Reports of the use of magnesium sulfate to treat acute asthma first appeared in the literature more than 60 years ago.9, 10 However, there are no specific recommendations provided by the NHLBI guidelines for the use of magnesium to treat status asthmaticus, and although it has been shown to be effective for asthmatic patients with the most severe disease, it has not been well studied among those with more moderate illness. The early literature reports on magnesium therapy consisted mostly of small case series.11, 12, 13, 14, 15, 16, 17, 18, 19 To date, there have been few prospective, randomized studies assessing the efficacy of magnesium for acutely ill asthmatic patients in the ED.20, 21, 22, 23, 24 Ciarallo et al20 found that the administration of 25 mg/kg of magnesium to asthmatic children with poor response to initial β2-agonist therapy resulted in significant improvements.20 Skobeloff et al21 found similar effects among very ill, β2-agonist–unresponsive adults, and Bloch et al22 demonstrated a magnesium benefit among a small subset of severely ill adults. However, Green and Rothrock23 found that the routine early administration of magnesium to a more mildly ill population of adults with acute asthma did not alter outcome.
We hypothesized that the routine early administration of high-dose magnesium would benefit moderate to severely ill children with asthma, irrespective of the response to initial β2-agonist therapy. The primary study outcome in this randomized, double-blind, placebo-controlled clinical trial was the change in a clinical asthma score over time. Secondary outcome measures included hospitalization rates and time required to meet discharge criteria.
Section snippets
Materials and methods
Candidates eligible for the study were patients between 1 and 18 years with a past history of at least 1 episode of wheezing who presented to the ED with a moderate to severe asthma exacerbation (defined as a Pulmonary Index [PI] score of 8 to 13, Table 1).Score Respiratory Rate (breaths/min)* Wheezing† Inspiratory/Expiratory Ratio Accessory Muscle Use Oxygen Saturation (%) 0 ≤30 None 2:1 None 99–100 1 31–45 End expiration 1:1 + 96–98 2 46–60 Entire expiration 1:2 ++ 93–95 3 >60 Inspiration and
Results
Sixty-two children were examined by investigators and met eligibility criteria. Of these, 8 refused to participate, leaving 54 study subjects. Twenty-four children were treated with magnesium and 30 with placebo. At entry, there were no significant differences between the 2 treatment groups with respect to sex or race, although subjects treated with magnesium were older (P =.04, Table 2).Variable Group Magnesium Placebo No. of patients 24 30 Mean age, mo (±SD) 81
Discussion
This study found that the routine administration of high-dose magnesium to moderate to severely ill asthmatic children, early in the course of their ED care and irrespective of their response to albuterol, did not result in additional clinical improvement. There were no significant differences found between the magnesium and control groups with respect to change in PI score from baseline, and the study had adequate power to minimize the risk of a type II error. Similarly, there were no
References (28)
- et al.
Nebulized dexamethasone versus oral prednisone in the emergency treatment of asthmatic children
Ann Emerg Med
(1995) - et al.
Intravenous versus oral corticosteroids in the management of acute asthma in children
Ann Emerg Med
(1997) - et al.
A trial of nebulized magnesium sulfate to reverse bronchospasm in asthmatic patients
Ann Emerg Med
(1992) - et al.
Intravenous magnesium therapy for moderate to severe pediatric asthma: results of a randomized, placebo-controlled trial
J Pediatr
(1996) - et al.
Intravenous magnesium sulfate as an adjunct in the treatment of acute asthma
Chest
(1995) - et al.
Intravenous magnesium for acute asthma: failure to decrease emergency treatment duration or need for hospitalization
Ann Emerg Med
(1992) - et al.
Current estimates from the National Health Interview Survey, 1994
Vital Health Stat
(1995) - et al.
Surveillance for asthma–United States, 1960-1995
MMWR CDC Surveill Summ
(1998) Guidelines for the Diagnosis and Management of Asthma (report no. 97-4051)
(1997)- et al.
Controlled trial of oral prednisone in the emergency department treatment of children with acute asthma
Pediatrics
(1993)
Methylprednisolone therapy for acute asthma in infants and toddlers: a controlled clinical trial
Pediatrics
A controlled trial of methylprednisolone in the emergency treatment of acute asthma
N Engl J Med
Blood serum magnesium in bronchial asthma and its treatment by administration of magnesium sulfate
J Lab Clin Med
Sulfato de magnesio en la crisis de asma
Presna Med Argentina.
Cited by (0)
- *
Address for reprints: Richard J. Scarfone, MD, Division of Emergency Medicine, The Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104; 215-590-1944, fax,215-590-4454; E-mail [email protected].