Abstract
Background Asthmatic patients frequently suffer cold-weather-associated respiratory symptoms. The sensitivity, specificity, accuracy and diagnostic value of isocapnic hyperventilation of cold air(IHCA) using a multistep method was investigated in patients suspected to have asthma. Method One hundred and 29 adult patients who had an IHCA performed between july 1999 and December 2000, had an methacholine bronchoprovocation test because of a clinical suspicion of asthma. Results According to strict criteria, 50 were defined as asthmatics and 79 as symptomatic nonashmatics. There were no differences in age, sex and smoking state between the asthmatic and symptomatic nonasthmatic groups. There was a significant decrease in the percentage reduction in the forced expiratory volume in 1 second(FEV1) after the IHCA between the asthmatics(-10.0±6.8%) and the symptomatic nonasthmatics(-2.3±2.5%). The factors associated with a reactivity to IHCA were FEV1/FVC, FEF25-75/FVC and FEV1(% of predicted). The accuracy was highest using a 7% fall in FEV1; the sensitivity was 76% and the specificity 96%. Conclusion IHCA is a specific, although not a sensitive, test for diagnosing asthma in adult patients. Furthermore, the diagnostic cut-off value of the different methods of IHCA need to be determined.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
