When the initial PEFR is below 50% of predicted values, what should be administered after specific treatment?

When the peak expiratory flow rate (PEFR) is below 50% of predicted values, it indicates a significant degree of airway obstruction, which is common in acute asthma exacerbations or other respiratory distress situations. Administering corticosteroids in such cases is crucial because they help reduce airway inflammation and improve lung function over time.

Corticosteroids work by inhibiting the inflammatory response that contributes to airway swelling and mucus production. This therapeutic effect can take several hours to manifest, but it is essential for the long-term management of the underlying inflammation that can exacerbate an obstructive airway disorder. They address the root cause of the airway obstruction, leading to improved airflow as the inflammation decreases with ongoing treatment.

In contrast, while bronchodilators are effective for providing immediate relief of bronchospasm and can be the first-line immediate treatment, they do not address the underlying inflammation and are usually administered during the acute phase. Magnesium sulfate and aminophylline have specific roles in respiratory care but are typically reserved for more severe cases when other treatments may not be effective. Therefore, after immediate treatment with bronchodilators, corticosteroids are the appropriate next step for ongoing management when PEFR is significantly compromised.