International Anesthesia Research Society 2024 Annual Meeting

Introduction: Exertional dehydration correlates with decreased athletic performance and can lead to systemic collapse and death. Therefore, appropriate hydration monitoring is important, but unfortunately, it is under-investigated (1). While various «hydration» monitoring technologies are available on the market, few have been critically examined, with measurement of body weight the only viable practice for monitoring hydration and exertional dehydration (2). Non-invasive Venous Waveform Analysis (NIVA) has recently been described in adults as a non-invasive method for monitoring volume status, both in congested states and during acute blood loss (3,4). This study investigated how NIVA monitors hydration in relation to the established practice of total body water monitoring in track athletes at Miami University, Oxford, Ohio. Methods: Fifteen athletes performed routine cardiovascular aerobic exercises varying in duration from 45 minutes to 120 minutes, resulting in a total of 43 pre- and post-exercise assessments. NIVA measurements were obtained by applying a device containing a piezoelectric sensor to the volar aspect of the wrist 10 minutes prior to the start of exercise, and after a 15-minute rest period following exercise. All athletes were allowed to hydrate as desired/needed, and intake volumes were recorded. Venous waveform signals were analyzed to provide a quantitative value [Volume Index Analysis (VIA)] Score. Body weights and percent body water were concurrently measured using a TANITA in-body scale (Tanita Corporation of America, Inc., Arlington Heights, IL, USA). Results: The change ( ) in VIA Score from pre-exercise to post-exercise demonstrated a significant linear correlation with the change in total body water percentage ( total body water %; r=0.32, p< 0.05, n=41). Conclusions: NIVA represents a non-invasive, individualized approach to hydration monitoring and management in athletes. The VIA Score demonstrated a significant correlation with the total body water percentage. Further studies are needed to assess the use of the NIVA device in monitoring and modulating dehydration in performance athletes and to evaluate the impact of using the VIA Score on athlete performance and health.