PEAK EXPIRATORY FLOW AND PEAK FLOW METER
Peak Expiratory Flow (PEF) is the maximum speed at which an individual can forcefully exhale air from the lungs in a single breath, serving as an indicator of airway openness. Normal PEF values are influenced by age, gender, size, and lung condition. While PEF remains relatively consistent in healthy individuals, asthmatics may experience a decrease during asthma attacks or when medication is ineffective. Daily monitoring of PEF is crucial for asthmatics to assess respiratory deterioration and predict potential attacks, especially when comparing several readings. This practice allows for timely adjustments in medication dosage, aligning with the doctor’s plan of action outlined in the ACTION PLAN FOR PERSONS WITH ASTHMA handout published by Vigilance Santé.
PEF is measured using a peak flow meter, a small device equipped with a mouthpiece and a sliding pointer on a graded scale. Proper usage involves standing, ensuring unrestricted clothing, and following specific steps:
- Ensure the sliding marker is at zero.
- Take a deep breath.
- Close lips tightly around the mouthpiece and blow forcefully in one breath.
- Record the result.
- Repeat the process two more times, ensuring the sliding marker is at zero each time.
- Record the highest of the three readings in the asthma diary.
Maintaining the peak flow meter involves cleaning it in warm soapy water for 5 minutes, rinsing under clean running water, and allowing it to air dry on a clean towel. The mouthpiece can be removed and cleaned separately.