Reliability of maximum oxygen uptake in cardiopulmonary exercise testing with continuous laryngoscopy

• Published in: ERJ open research 2021-01, Vol.7 (1), p.825
• Main Authors: Engan, Mette, Hammer, Ida Jansrud, Bekken, Marianne, Halvorsen, Thomas, Fretheim-Kelly, Zoe Louise, Vollsæter, Maria, Bovim, Lars Peder Vatshelle, Røksund, Ola Drange, Clemm, Hege
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 2312-0541; 2312-0541
• DOI: 10.1183/23120541.00825-2020

A cardiopulmonary exercise test (CPET) is the gold standard to evaluate symptom-limiting exercise intolerance, while continuous laryngoscopy performed during exercise (CLE) is required to diagnose exercise-induced laryngeal obstruction. Combining CPET with CLE would save time and resources; however, the CPET data may be distorted by the extra equipment. We therefore aimed to study whether CPET with CLE influences peak oxygen uptake ( ' peak) and other gas exchange parameters when compared to a regular CPET. Forty healthy athletes without exercise-related breathing problems, 15-35 years of age, performed CPET to peak exercise with and without an added CLE set-up, in randomised order 2-4 days apart, applying an identical computerised treadmill protocol. At peak exercise, the mean difference (95% confidence interval) between CPET with and without extra CLE set-up for ' peak, respiratory exchange ratio (RER), minute ventilation ( ' ) and heart rate (HR) was 0.2 (-0.4 to 0.8) mL·kg ·min , 0.01(-0.007 to 0.027) units, 2.6 (-1.3 to 6.5) L·min and 1.4 (-0.8 to 3.5) beats·min , respectively. Agreement (95% limits of agreement) for ' peak, RER and ' was 0.2 (±3.7) mL·kg ·min , 0.01 (±0.10) units and 2.6 (±24.0) L·min , respectively. No systematic or proportional bias was found except for the completed distance, which was 49 m (95% CI 16 to 82 m) longer during CPET. Parameters of gas exchange, including ' peak and RER, obtained from a maximal CPET performed with the extra CLE set-up can be used interchangeably with data obtained from standard CPET, thus preventing unnecessary additional testing.