[The histamine provocation test: are 1 second capacity and specific conductance competing or complementary...

Area of Science:

• Respiratory Medicine
• Pulmonary Function Testing
• Diagnostic Criteria

Background:

• Histamine provocation testing is used to diagnose airway hyperresponsiveness.
• Conventional criteria for interpreting histamine challenges, such as percentage change in specific airway conductance (PC-sGaw) or forced expiratory volume in 1 second (PC-FEV), can yield contradictory results.
• There is a need for more reliable criteria to assess positive histamine provocation challenges.

Purpose of the Study:

• To evaluate a new combined criterion for determining a positive histamine provocation challenge.
• To overcome the limitations and contradictions associated with existing diagnostic criteria.

Main Methods:

• The study involved histamine provocation challenges.
• Pulmonary function was assessed using spirometry and bodyplethysmography.
• A novel criterion was tested: specific airway conductance (sGaw) less than or equal to 0.04 times the provocative concentration of FEV1 (PC-FEV).

Main Results:

• The proposed combined criterion (sGaw ≤ 0.04 x PC-FEV) demonstrated effectiveness in resolving ambiguities.
• This method provides a more consistent interpretation compared to traditional criteria like PC-FEV ≥ 20% or PC-sGaw ≥ 50%.

Conclusions:

• The combination of spirometry and bodyplethysmography offers a superior method for interpreting histamine provocation tests.
• This refined diagnostic approach enhances the accuracy and reliability of identifying airway hyperresponsiveness.