At what peak flow rate can hospital discharge be considered for an asthma patient?

From the Guidelines

Hospital discharge for an asthma patient can typically be considered when their peak expiratory flow rate (PEFR) reaches at least 70% of their personal best or predicted value, as recommended by the National Asthma Education and Prevention Program Expert Panel report 3 guidelines for the management of asthma exacerbations 1. This threshold indicates that the acute exacerbation is resolving and the patient's airway obstruction has significantly improved. The decision to discharge should not be based solely on peak flow measurements but should also consider other clinical factors such as:

• Symptom improvement
• Oxygen saturation above 90% on room air
• Decreased work of breathing
• The patient's ability to use their inhalers correctly Before discharge, patients should have a clear follow-up plan, including appropriate medications like a short course of oral corticosteroids, a rescue inhaler such as albuterol, and possibly an inhaled corticosteroid. Peak flow monitoring is valuable because it provides an objective measure of airflow limitation that correlates with the degree of bronchospasm and inflammation in the airways, helping clinicians make more informed decisions about when a patient has recovered sufficiently to manage their condition at home. Other guidelines, such as those from the British Thoracic Society 1, also support the consideration of peak flow rate in discharge decisions, but the most recent and highest quality study 1 provides the most relevant guidance.

From the Research

Hospital Discharge Criteria for Asthma Patients

• The decision to discharge an asthma patient from the hospital is based on several factors, including peak expiratory flow rate (PEFR) 2.
• According to the study by 2, patients with a PEFR of ≥ 70% of predicted have a lower relapse rate after discharge without glucocorticoids.
• However, another study by 3 suggests that using a patient's reported "personal best" PEF may not be accurate, and discharge decisions should be based on other factors as well.
• A study by 4 found that discharging patients with acute asthma after they have responded clinically to intensive anti-asthma treatment, regardless of PEFR, may not be associated with increased risk of early relapse.

Peak Flow Rate and Discharge

• The study by 2 suggests that patients with a PEFR between 40% and 70% of predicted after initial inhalant therapy may be responsive to steroids, but require close monitoring.
• Another study by 5 found that discharging asthmatics from hospital until the diurnal variation in their peak flow is below 20% may reduce the risk of further severe attacks of asthma requiring re-hospitalisation.
• However, a study by 6 found no significant difference in outcomes between peak flow monitoring and symptom monitoring in older adults with asthma, suggesting that peak flow rate may not be the only factor to consider when making discharge decisions.

Discharge Considerations

• Other factors to consider when deciding to discharge an asthma patient from the hospital include the duration of bronchospasm, frequency of visits, history of previous endotracheal intubation, pulse rate, and accessory muscle use 2.
• Patients with complicating disease, poor access to medications, poor educability, and prominent psychiatric difficulties may require longer hospital stays or closer monitoring after discharge 2.