A protocol to determine valid in young cystic fibrosis patients

Cystic fibrosis and physiological responses to exercise

“…With regard to treadmill versus cycling exercise, the consensus appears to be cycle-based protocols. Not only do these prevent falls and facilitate measurements such as electrocardiography during exercise, but also they are more pediatric-friendly and can enable testing of patients as young as 7 years of age [27,28].…”

“…Reliance has, therefore, traditionally fallen upon secondary verification criteria, encompassing subjective indicators of effort (sweating, facial flushing and hyperpnea) and objective physiological secondary criteria (heart rate, respiratory exchange ratio and/or blood lactate concentration). But adherence to these criteria has been shown to drastically under measure VO 2max in patients with CF [27].…”

Validity and Reliability Concerns Associated with Cardiopulmonary Exercise Testing Young People with Cystic Fibrosis

“…However, our research group recently demonstrated that the use of secondary criteria to confirm a maximal effort (e.g. RER >1.00 or 1.10, HR of 180 beats·min -1 or 95% age-predicted HR max ), in line with those recommended by Hebestreit et al [1], are invalid and can drastically underreport V˙O 2 max in some young people with CF [4], a finding consistent with healthy children and adolescents [5]. Accepting submaximal or rejecting ‘true' maximal values can distort the clinical application and interpretation of CPET, which is important given that V˙O 2 max is an indicator of prognosis [6,7], quality of life [8] and risk of hospitalisation for exacerbations [9] in people with CF.…”

“…This statement also provides a summary of the reliability of exercise tests for young people with CF; however, again published evidence has been ignored. We recently reported both the short- and medium-term reproducibility of a valid CPET protocol for young people with CF [4], which was shown to reduce the error of measurement when compared with an isolated incremental CPET to derived V˙O 2 peak [20]. To the best of our knowledge, we are not aware of any reproducibility or validity data for V˙O 2 max in young people with CF derived using the Godfrey protocol.…”

Increased daily activity in cystic fibrosis: time to break out the prescription pad?

“…To circumvent this, investigators have used field tests of sub-maximal exercise tests to estimate peak exercise capacity with shuttle tests [20]. Nonetheless, other investigators have questioned whether even a maximal exercise test in paediatric subjects with CF, using traditional criteria to verify maximal efforts, is as good as a subsequent exhaustive supramaximal exercise test [21,22]. Other investigators have used body size [23] and diffusing capacity of the lung for carbon monoxide [24] to predict V9O 2 peak, highlighting that estimated V9O 2 peak may be useful across the spectrum school-aged children for longitudinal evaluation if there is reasonable concordance between methods of calculating the figure.…”