The effect of passive mobilization associated with blood flow restriction and combined with electrical stimulation on cardiorespiratory safety, neuromuscular adaptations, physical function, and quality of life in comatose patients in an ICU: a randomized controlled clinical trial

BACKGROUND: Intensive care unit-acquired atrophy and weakness are associated with high mortality, a reduction in physical function, and quality of life. Passive mobilization (PM) and neuromuscular electrical stimulation were applied in comatose patients; however, evidence is inconclusive regarding atrophy and weakness prevention. Blood flow restriction (BFR) associated with PM (BFRp) or with electrical stimulation (BFRpE) was able to reduce atrophy and increase muscle mass in spinal cord-injured patients, respectively. Bulky venous return occurs after releasing BFR, which can cause unknown repercussions on the cardiovascular system. Hence, the aim of this study was to investigate the effect of BFRp and BFRpE on cardiovascular safety and applicability, neuromuscular adaptations, physical function, and quality of life in comatose patients in intensive care units (ICUs). METHODS: Thirty-nine patients will be assessed at baseline (T0–18 h of coma) and randomly assigned to the PM (control group), BFRp, or BFRpE groups. The training protocol will be applied in both legs alternately, twice a day with a 4-h interval until coma awake, death, or ICU discharge. Cardiovascular safety and applicability will be evaluated at the first training session (T1). At T0 and 12 h after the last session (T2), muscle thickness and quality will be assessed. Global muscle strength and physical function will be assessed 12 h after T2 and ICU and hospital discharge for those who wake up from coma. Six and 12 months after hospital discharge, physical function and quality of life will be re-assessed. DISCUSSION: In view of applicability, the data will be used to inform the design and sample size of a prospective trial to clarify the effect of BFRpE on preventing muscle atrophy and weakness and to exert the greatest beneficial effects on physical function and quality of life compared to BFRp in comatose patients in the ICU. TRIAL REGISTRATION: Universal Trial Number (UTN) Registry UTN U1111-1241-4344. Retrospectively registered on 2 October 2019. Brazilian Clinical Trials Registry (ReBec) RBR-2qpyxf. Retrospectively registered on 21 January 2020, http://ensaiosclinicos.gov.br/rg/RBR-2qpyxf/ SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05916-z.