In assessing and managing patients presenting with acute, life-threatening asthma, if the exacerbation does not resolve relatively quickly, clinicians need to start looking for other causes of the patient’s respiratory distress, a review of the literature suggests.
“I think one of the most important points of this review is that asthma is a self-limiting disease, and it’s important to understand that with appropriate treatment and immediate response to it, exacerbations will get better with time,” Orlando Garner, MD, Baylor College of Medicine, Houston, said in an interview.
“So I think one of the key points is, if these exacerbations do not resolve within 24-48 hours, clinicians need to start thinking: ‘This could be something else,’ and not get stuck in the diagnosis that this is an asthmatic patient who is having an exacerbation. If the distress doesn’t resolve within 48 hours, it’s time to look for other clues,” he stressed.
The study was published online in the journal CHEST®.
Appropriate triage is key in the management of acute asthma, Dr. Garner and colleagues pointed out. A simplified severity score for the evaluation of asthma in the ED can help in this regard. Depending on the presence or absence of a number of key signs and symptoms, patients can be readily categorized as having mild, moderate, or severe asthma. “Static assessments and dynamic assessments of acute asthma exacerbation in the ED can also help triage patients,” the authors added.
Static assessment involves assessing the severity at presentation, which in turn determines the aggressiveness of initial treatment. Objective static assessments include the measurement of peak expiratory flow (PEF) or forced expiratory volume in 1 second (FEV1). A severe exacerbation is usually defined as a PEF or an FEV1 of less than 50%-60% of predicted normal values, the authors noted.
Dynamic assessment is more helpful than static assessment because it gauges response to treatment. “A lack of improvement in expiratory flow rates after initial bronchodilator therapy with continuous or worsening symptoms suggests need for hospitalization,” Dr. Garner and colleagues observed. The main treatment goals for patients with acute asthma are reversal of bronchospasm and correction of hypoxemia.
These are achieved at least initially with conventional agents, such as repeated doses of inhaled short-acting beta2-agonists, inhaled short-acting anticholinergics, systemic corticosteroids, and occasionally intravenous magnesium sulfate. If there is concomitant hypoxemia, oxygen therapy should be initiated as well. Patients who have evidence of hypercapnic respiratory failure or diaphragmatic fatigue need to be admitted to the intensive care unit, the authors indicated.
For these patients, clinicians need to remember that there are therapies other than inhalers, such as epinephrine and systemic terbutaline. During a life-threatening asthma episode, airflow in the medium and small airways often becomes turbulent, increasing the work of breathing, the researchers pointed out.
Heliox, a combination of helium and oxygen, reduces turbulent flow, they noted, although FiO2 requirements need to be less than 30% in order for it to work. “Heliox can be used in patients with severe bronchospasm who do not respond to the conventional therapies,” the authors noted, “[but] therapy should be abandoned if there is no clinical improvement after 15 minutes of use.”
Although none of the biologics such as dupilumab (Dupixent) has yet been approved for the treatment of acute exacerbations, Dr. Garner predicts they will become the “future of medicine” for patients with severe asthma as well.