A 14-year-old boy who had previously been diagnosed with mild persistent asthma has a PEFR of 100 L/min. This indicates which of the following?

a. Increased airway resistance
b. Heart failure
c. Increased lung compliance
d. Inability to take in a deep breath and cough

ANS: A
For patients with acute asthma, the PEFR is the most frequently used parameter to assess airway resistance.

Peak expiratory flow rate (PEFR) (L/min) 350-600 (normal) 75-100 (critical value)