Post-processing of peak oxygen uptake data obtained during cardiopulmonary exercise testing in individuals with spinal cord injury: A scoping review and analysis of different post-processing strategies

Objectives: To review the evidence regarding the most common practices adopted with cardiopulmonary exercise testing (CPET) in individuals with spinal cord injury (SCI), with the following specific aims to: (1) determine the most common averaging strategies of peak oxygen uptake (V̇O_2peak), (2) review the endpoint criteria adopted to determine a valid V̇O_2peak, and (3) investigate the effect of averaging strategies on V̇O_2peak values in a convenience sample of individuals with SCI (between the fourth cervical and sixth thoracic segments).

Data Sources: Searches for this scoping review were conducted in MEDLINE (PubMed), EMBASE, and Web Science.

Study Selection: Studies were included if (1) were original research on humans published in English, (2) recruited adults with traumatic and non-traumatic SCI, and (3) V̇O_2peak reported and measured directly during CPET to volitional exhaustion. Full-text review identified studies published before April 2021 for inclusion.

Data Extraction: Extracted data included authors, journal name, publication year, participant characteristics, and comprehensive information relevant to CPET.

Data Synthesis: We extracted data from a total of 200 studies involving 4,928 participants. We found that more than 50% of studies adopted a 30-sec averaging strategy. A wide range of endpoint criteria were used to confirm the attainment of maximal effort. In the convenience sample of individuals with SCI (n=30), the mean V̇O_2peak decreased as epoch (i.e., time) lengths increased. Reported V̇O_2peak values differed significantly (P <.001) between averaging strategies, with epoch length explaining 56% of the variability.

Conclusions: The adoption of accepted and standardized methods for processing and analyzing CPET data is needed to ensure high-quality, reproducible research, and inform population-specific normative values for individuals with SCI.