Which device is used to measure a patient’s peak expiratory flow rate?

A peak flow meter is a simple and portable device specifically designed to measure a patient's peak expiratory flow rate (PEFR), which is the maximum speed at which a person can exhale air. This measurement is critical in assessing and monitoring conditions like asthma, as it can help to determine how well the lungs are functioning and whether the condition is exacerbating.

The peak flow meter works by having the patient take a deep breath and then exhale forcefully into the device. The reading indicates the flow rate of the exhaled air, which can be compared against established normal values. Monitoring PEFR regularly can help in managing asthma and adjusting medications based on lung function.

In contrast, a pulse oximeter measures oxygen saturation in the blood, a thermometer assesses body temperature, and a blood pressure cuff measures arterial pressure. None of these devices are designed to evaluate the airflow or expiratory strength of a patient’s lungs like the peak flow meter does. Hence, the peak flow meter is the appropriate device for measuring peak expiratory flow rate effectively.