{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:43:59Z","timestamp":1785545039802,"version":"3.56.0"},"reference-count":69,"publisher":"JMIR Publications Inc.","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JMIR Res Protoc"],"abstract":"Abstract<\/jats:title>\n \n Background<\/jats:title>\n \n Intensive care unit\u2013acquired weakness (ICU-AW) research focuses predominantly on intrinsic muscle pathology rather than integrated systemic interactions, which are commonly studied in exercise science. Peak oxygen uptake (\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n \n ),\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n \n <\/mml:math>\n <\/jats:inline-formula>\n on\/off kinetics, and skeletal muscle oxygenation provide a quantitative evaluation of exercise capacity and are infrequently measured in intensive care unit (ICU) survivors. Routine cardiopulmonary exercise test (CPET) research separates\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n and\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n \n <\/mml:math>\n <\/jats:inline-formula>\n kinetics assessments into multiple sessions. Yet, a combined experimental approach may enhance diagnosis, follow-up retention, and mechanistic insight for patients with ICU-AW.\n <\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n \n This prospective cross-sectional observational study aims to develop a standardized, single-session CPET protocol for combined assessment of\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n ,\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n \n <\/mml:math>\n <\/jats:inline-formula>\n kinetics, and skeletal muscle microvascular oxygenation in ICU survivors, enabling quantitative and integrated assessment of ICU-AW.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n Adults mechanically ventilated for \u22657 days will be recruited to participate 6 months post-ICU discharge in a modified CPET exercise session on an upright cycle ergometer. The proposed standardization will involve (1) the estimation of\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n using a priori formulas with a\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n \n <\/mml:math>\n <\/jats:inline-formula>\n correction factor for the ICU population, (2)\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n on-kinetics (constant work rate) targeting relative 30%\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n r<\/mml:mi>\n e<\/mml:mi>\n s<\/mml:mi>\n e<\/mml:mi>\n r<\/mml:mi>\n v<\/mml:mi>\n e<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n , (3) an incremental ramp exercise based on self-reported functional status, and (4) a 10-minute recovery to quantify\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n off-kinetics. In addition, near-infrared spectroscopy will be placed on the vastus lateralis muscle to simultaneously collect tissue saturation index and deoxyhemoglobin during each phase of the protocol.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Recruitment is anticipated to begin in June 2026 and is expected to be completed in 2029\/2030. The anticipated sample size will be approximately 48 participants based on the feasibility of recruiting 1 participant per month and a sample size calculation based on Bland-Altman limits of agreement between predicted and measured\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n \n The intensive care unit combined assessment of cardiorespiratory exercise (ICU-CARE) CPET protocol will enable the quantitative evaluation of\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n p<\/mml:mi>\n e<\/mml:mi>\n a<\/mml:mi>\n k<\/mml:mi>\n <\/mml:mrow>\n <\/mml:msub>\n <\/mml:math>\n <\/jats:inline-formula>\n ,\n \n \n \n \n V<\/mml:mi>\n <\/mml:mrow>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n \n \n O<\/mml:mi>\n <\/mml:mrow>\n \n 2<\/mml:mn>\n <\/mml:mrow>\n <\/mml:msub>\n \n <\/mml:math>\n <\/jats:inline-formula>\n on\/off kinetics, and local microvascular skeletal muscle oxygenation during a single exercise session, facilitating the integrated physiological study of ICU-AW.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.2196\/92346","type":"journal-article","created":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T07:40:09Z","timestamp":1780386009000},"page":"e92346-e92346","source":"Crossref","is-referenced-by-count":0,"title":["Standardized Single-Session Cardiopulmonary Exercise Test for Measuring Peak Oxygen Uptake, Oxygen On\/Off Kinetics, and Skeletal Muscle Oxygenation in ICU Survivors\u2014ICU Combined Assessment of Cardiorespiratory Exercise (ICU-CARE) Study: Protocol for a Cross-Sectional Observational 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