Study finds, Reproducibility of Eucapnic Voluntary Hyperpnoe
Respiratory symptoms after exercise are frequently reported by asthmatics and exercise-induced bronchoconstriction (EIB) is a frequent cause which requires objective testing for diagnosis. Eucapnic voluntary hyperpnoea (EVH) is recommended as a surrogate stimulus for this purpose.

A Study was conducted to evaluate the short-term test-retest agreement and reproducibility of FEV1 changes after EVH in children & asthmatics.

Asthmatics aged between 10 and 20 years underwent EVH for EIB diagnosis on two occasions 2-4 days apart. FEV1 was measured at 5, 15 and 30 minutes after EVH with a target ventilation rate 21 times baseline FEV1. EIB was diagnosed as a decrease more than 10% in FEV1 from baseline.

--A total of 26 of 62 recruited individuals tested positive for EIB on both visits (positive group) and 17 on one visit only (divergent group), while 19 tested negative on both visits (negative group).

--The overall agreement was 72.5% and Cohen’s kappa coefficient of 0.452.

--Low bias (0.87%) and high intra-class correlation-coefficient (0.854) for FEV1 response between test days were found, but with wide limits of agreement (±20.72%).

--There were no differences in pre-challenge FEV1 or achieved ventilation rate between visits either between groups or within groups. There were no safety issues.

In children and young adolescents with asthma, more than one EVH test should be performed to rule out EIB and reduce misdiagnosis and maltreatment.