Automated Calf Muscle Reactions in Blood Donors: A Systematic Review of Devices, Clinical Evidence, And Implementation Challenges Stimulation for the Prevention of Vasovagal

Abstract

Background: Vasovagal reactions (VVRs) are important adverse events associated with blood donation and may result in dizziness, presyncope, syncope, and donor injury. Preventive strategies include hydration, applied muscle tension, and modifications to donor positioning. Automated calf muscle stimulation has emerged as a potential technology for supporting venous return and reducing the risk of VVRs. However, its clinical effectiveness must be distinguished from evidence supporting manual muscle-tension exercises and other mechanical interventions.

Objective: To systematically evaluate the available evidence on automated calf muscle stimulation for preventing VVRs in blood donors, with particular emphasis on device characteristics, clinical effectiveness, safety, feasibility, and implementation challenges.

Methods: A systematic literature review will be conducted using relevant biomedical and multidisciplinary databases. Eligible studies will be identified using predefined inclusion and exclusion criteria focused on automated or electronically controlled calf muscle stimulation in blood donors. Study selection and data extraction will follow a prespecified process. Extracted information will include study design, donor population, device characteristics, comparator interventions, clinical outcomes, adverse events, and methodological limitations. Risk of bias will be assessed using tools appropriate to the included study designs. Findings will be synthesized narratively, with quantitative synthesis considered where sufficient comparable data are available.

Results: The results will summarize the number and characteristics of eligible studies, the technologies investigated, reported clinical outcomes, and the quality of the available evidence. Direct evidence concerning automated calf muscle stimulation will be distinguished from indirect evidence involving manual applied muscle tension, mechanical footrests, and other preventive interventions.

Conclusion: This review will clarify the extent to which current evidence supports automated calf muscle stimulation for preventing VVRs in blood donors and identify priorities for clinical validation, safety assessment, and implementation. Its conclusions will be based on the quality and applicability of the available evidence.