Calculating the percentage of personal best
A written asthma action plan divides peak expiratory flow (PEF) readings into zones based on the client's personal best. This man's personal best is 450 L/min and today's reading is 355 L/min. His percentage is 355 ÷ 450 × 100 = 78.9%, which rounds to 79%. The green zone starts at 80% of personal best, which for him is 360 L/min. At 79%, he is just inside the yellow zone (50 to 79%). In the yellow zone, he uses his reliever, follows the steps in his action plan, and contacts his provider.
What each zone means
The green zone (80% or more) means good control: he continues his usual daily treatment. The yellow zone (50 to 79%) means asthma is worsening: he takes his reliever, usually inhaled salbutamol (albuterol), keeps taking his controller, follows the plan's specific instructions, and contacts his health provider. The red zone (below 50%, which for him is below 225 L/min) is a medical alert: he uses his reliever and seeks emergency care immediately. His cough and mild wheeze match the yellow-zone picture of early worsening.
| Zone | Percent of personal best | PEF for this client | Action |
|---|
| Green | 80% or more | 360 L/min or more | Continue usual treatment |
| Yellow | 50% to 79% | 225 to 359 L/min | Reliever, follow plan, contact provider |
| Red | Below 50% | Below 225 L/min | Reliever and emergency care |
Why the other answers are wrong
Green zone is tempting because 355 is close to 360, but the cut-off is fixed, and 79% is below 80%. Red zone overstates the problem; he is far above 50%. The option that places him correctly in the yellow zone but tells him to stop his controller is the most dangerous: the controller, usually an inhaled corticosteroid, treats the airway inflammation that drives the worsening, and it must never be stopped during an exacerbation. Watch out! An option can name the right zone and still be wrong because of the action attached to it; check both halves.
Teaching points for the nurse
Clients should know their personal best and the PEF numbers that mark each zone, written on the plan. The nurse reviews inhaler technique, reminds him to keep taking his controller daily even when he feels well, and explains when to move to the red-zone actions, such as a PEF below 225 L/min, breathlessness at rest, or difficulty speaking. Recording PEF readings in a diary helps the provider judge control at follow-up visits at the Barangay Health Station.