• Patients should determine their baseline and
personal best peak flow measurement.
• To obtain baseline, have patient perform maneuver 3 times in
morning and 3 times at night for 2 weeks and maintain a record.
• Personal best is the highest of these values over these 2 weeks.
• Normal peak flow values are greater than 80% of the
personal best, with mild values being 50–80% and
critical values < 50% of personal best.
• Predicted nomograms are also available based on patient height.
• Response to various triggers and exercise can be defined as a
decrease in peak flow of 15%, whereas a positive response
to bronchodilator therapy is an increase of 15% in peak
• Awareness of patient effort dependence and variations assists
in making clinical decisions based on peak flow measurements.