Peak Nasal Inspiratory Flow (PNIF)

• Accuracy is + 10 % of the reading or 10 L/min.

• Decongestion will show an average of 16% increase in flow.

• The normal value for PNIF differs according to age, gender, and height.

• There is no clinical need to measure Peak Oral Inspiratory Flow when measuring nasal patency/function.

• There is no clinical need to calculate the nasal patency index during evaluation.

• Research shows hormonal influences on the nasal mucosa affecting nasal obstruction, especially during puberty, menopause, and during use of oral contraceptives.

• PNIF readings strongly depend on pulmonary function.

• PNIF readings correlate with the NOSE scale or subjective patient perception of nasal breathing.
  

• Studies show statistically significant differences between men and women.

• Studies show a correlation between PNIF readings and height due to growth and development.

• PNIF variability may be found in the differences in nasal anatomy.

• PNIF is a great adjunct objective measurement to rhinomanometry, especially in telemedicine.
  

1. Before each use, the cursor (red dial) on the Peak Flow Meter is reset to the zero [0] mark. To reset the dial, gently tap the bottom of the meter to have the magnetic weight dislodged, returning to the starting position.
   
2. Have the patient clear/blow their nose. If it's a baseline test for congestion, do not use sprays or rinses.
3. In a standing position, have the patient fully exhale.
   
4. Hold the meter horizontally.
   
5. With the lips sealed and an airtight seal between the nose and mask, inhale forcibly through the nose.
   
6. The PNIF technique should be a short and quick inspiratory flow lasting about 1 second in duration.

Notes

• A low resistance antiviral filter may be placed between the meter and the mask to minimize risk of cross-contamination.

• There are 5 sizes of reusable and disposable masks available to accommodate different facial shapes and sizes.

• Between patients, the mask should be disinfected according to the manufacturer to avoid the risk of cross- infection.

• The PNIF can be sent home with the patient.

• In clinical trials and research, it is common for one meter to be used with each patient receiving their own mask.

• The PNIF, in its most basic form, measures the flow and patency like rhinomanometry, but lacks the pressure variable to measure resistance.