What is the significance of a peak flow reading that is significantly lower than a child's personal best?

A peak flow reading significantly lower than a child's personal best indicates worsening asthma symptoms. The peak flow meter measures the maximum speed of expiration, providing a practical assessment of lung function. When a child's reading falls below their personal best, it typically signals an increase in airway obstruction or inflammation, indicating that the asthma is not well-controlled at that moment.

Monitoring peak flow readings allows parents and caregivers to detect changes in a child's asthma status early. A decreased reading should prompt further evaluation of asthma control and possibly lead to interventions, such as medication adjustments or a doctor's visit, to prevent an exacerbation. This proactive approach is essential for effective asthma management, emphasizing the need to maintain readings close to the child's personal best for optimal control of the condition.