Which device should NOT be used with a face mask for respiratory therapy?

Using a peak flow meter with a face mask is not appropriate because a peak flow meter is specifically designed for measuring airflow through the mouth and requires a tight seal around the lips. It assesses how well air moves out of the lungs by measuring peak expiratory flow rate. When a patient uses a face mask, the airflow being measured can be compromised due to several factors including improper sealing around the mask, which can lead to inaccurate readings and inconsistent results.

On the other hand, devices like NPPV (Non-Invasive Positive Pressure Ventilation), CPAP (Continuous Positive Airway Pressure), and Wright's respirometer can effectively function with a face mask. NPPV and CPAP are both used to assist breathing by providing positive pressure to keep the airways open and can be applied with a face mask designed for that purpose. Wright's respirometer, while primarily a flow measuring device, can accommodate a face mask for certain types of respiratory assessments, making it suitable in this context.