ATS Pulmonary Function Laboratory Manual

chapter  13

Test Procedure for Mannitol Challenge Test (7)

(Continued from previous page)

Step Action 10.

Administer third 160-mg dose (4 × 40-mg capsules) 10.1. Administer the third 160-mg dose following the directions in Step 8.

End of challenge 11.1. following completion of the mannitol challenge test with a positive result or significant respiratory symptoms (e.g., wheezing, dyspnea, cough), administer a short-acting inhaled beta-agonist and monitor patient until fully recovered to within baseline. In the case of a negative outcome, if the patient has significant respiratory symptoms, administer a short- acting inhaled beta-agonist.

11.

Calculations Positive responses are determined by a change in FEV 1

from the post–0-mg dose, or if there is a fall of at least 10%

in FEV 1 between consecutive doses. Below is the formula to calculate the percent change for mannitol challenges using the 0-mg and 5-mg doses as an example. % change = Post 0-mg FEV 1 − Post 5-mg FEV 1 Post 0-mg FEV 1 × 100 If: Post 0-mg FEV 1 = 3.30 L Post 5-mg FEV 1 = 3.10 L The % change = −6.1% Reporting of Test Results The response for the mannitol challenge is expressed as the cumulative dose and a provocative dose (PD) causing a 15% reduction in FEV 1 (PD 15 ) value is reported. The PD 15 is determined by linear interpolation in a similar manner as used to calculate PC 20 for the methacholine challenge. Reactivity to mannitol is expressed as percent decrease in FEV 1 at the end of the challenge divided by the cumu- lative dose of mannitol administered to induce that decrease in FEV 1 (1, 3). Pediatric Considerations The Mannitol challenge test should not be performed in children under 6 years of age according to the product infor- mation page. There is limited information on the use of Mannitol in patients 6 to 18 years of age (9), and children under age 6 may not be able to perform acceptable and repeatable spirometry to conduct the challenge properly. Procedure Notes 1. The inhaler is for single patient use (i.e., one inhaler per challenge test). 2. Pierce the capsule only once by fully depressing both piercing buttons on the sides of the inhaler simultane- ously. A second puncture may cause the capsule to split or fragment. 3. Using rubber/latex gloves when administering the test and handling mannitol capsules may increase static and inhibit capsule movement within the inhaler.

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