Book of Abstracts - New Frontiers 2022

Abstracts of oral presentations

STROKE VOLUME VARIATION AS AN INDEX OF FLUID RESPONSIVENESS IN CONSCIOUS PATIENTS M. Javorka 1 , R. Wiszt 1 , B. Czippelová 2 , J. Čerňanová Krohová 2 , N. Mažgútová 1 , Z. Turianiková 1 1 Department of Physiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia; 2 Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia Cardiac stroke volume variation (SVV) measurement is an established technique to detect fluid-responsive hypovolemia in patients under mechanical ventilation. There is an ongoing effort to apply SVV for this purpose also in conscious patients. However, the effect of mental stress often occurring in conscious trauma patients as a potential confounding factor on SVV is not known. The aim of our study was to compare effect of simulated hypovolemia and mental stress on SVV in healthy volunteers in the context of potential confounders – breathing pattern, respiratory sinus arrhythmia magnitude and sex. We examined 102 young healthy volunteers (58 females), mean age 18.6 years. Finger arterial blood pressure was recorded by volume-clamp photoplethysmographic method (Finometer Pro, FMS, Netherlands). From the blood pressure curve, a built in ModelFlow algorithm calculated stroke volume values (SV) for each heart beat. Respiratory volume was recorded using calibrated respiratory inductive plethysmography (RespiTrace, NIMS, USA). During four phases of examination protocol (supine rest, head-up tilt – HUT, supine recovery, mental arithmetic task – MA) we analyzed SVV related to respiratory activity. While during HUT we found an expected increase in SVV together with mean SV decrease, SVV significantly decreased during MA. The observed changes during MA could be attributed to an increased respiratory rate and/or decreased respiratory sinus arrhythmia. Sex related differences in SVV responses to HUT and MA were observed. We conclude that mental stress together with respiratory sinus arrhythmia and respiratory pattern changes could significantly influence SVV as a potential index of fluid responsiveness in conscious patients. Sex differences and other confounding factors should be considered when interpreting SVV changes.

Keywords: stroke volume variation, fluid responsiveness, cardio-respiratory interactions, respiratory sinus arrhythmia, sex differences

Funding:The study was supported by grants VEGA 1/0117/17, VEGA 1/0200/19, VEGA 1/0283/21, Grant UK/71/2019 and ITMS project „Biomed Martin“ Nr. 26220200187.

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