Related Experiment Videos
[Airway challenge testing - accuracy of the interrupter technique]
1Medizin. Klinik Abt. Pneumologie, St. Vincentius-Kliniken Karlsruhe, Medizinische Klinik, Abteilung Pneumologie, Sudendstrasse, Germany. johannes.schildge@vincentius-ka.deInternet
Pneumologie (Stuttgart, Germany)
|September 6, 2001
Summary
The interrupter technique (Rint) for measuring airway resistance is not sensitive enough for airway challenge testing. Rint + 100 significantly underestimates airway hyperresponsiveness compared to FEV1 - 20 and Raw + 100.
Area of Science:
- Respiratory Physiology
- Pulmonary Function Testing
Context:
- Current recommendations for assessing bronchial sensitivity rely on FEV1 decrease or body plethysmography for airway resistance.
- The interrupter technique (Rint) offers a simpler method for measuring airway resistance but lacks established validation in challenge testing.
Purpose:
- To evaluate the efficacy of the increase in airway resistance by 100% (Rint + 100) using the interrupter technique compared to body plethysmography (Raw + 100) and FEV1 decrease (FEV1 - 20) in carbachol airway challenge testing.
- To determine the diagnostic accuracy of Rint + 100 in detecting airway hyperresponsiveness.
Summary:
- Significant correlations were observed between Rint and Raw measurements before and after carbachol challenge (p < 0.001).
- However, Rint systematically overestimated normal airway resistance and underestimated increases during challenge testing.
- Rint + 100 demonstrated low sensitivity (9%) for detecting airway hyperresponsiveness, unlike FEV1 - 20 (61%) and Raw + 100 (98%).
Impact:
- The interrupter technique (Rint + 100) is not a reliable substitute for FEV1 - 20 or Raw + 100 in airway challenge testing due to its low sensitivity.
- Findings suggest that Rint + 100 should not be used for diagnosing airway hyperresponsiveness in clinical settings.
- This study highlights the importance of validated methods for accurate assessment of bronchial sensitivity.