Open Access Highly Accessed Research article

Non-invasive detection of hypovolemia or fluid responsiveness in spontaneously breathing subjects

Éva Zöllei1*, Viktória Bertalan1, Andrea Németh1, Péter Csábi1, Ildikó László2, József Kaszaki2 and László Rudas1

Author Affiliations

1 Department of Anaesthesiology and Intensive Therapy, University of Szeged, Semmelweis u. 6, Szeged 6725, Hungary

2 Institute of Surgical Research, University of Szeged, Pécsi u. 6, Szeged 6720, Hungary

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BMC Anesthesiology 2013, 13:40  doi:10.1186/1471-2253-13-40

Published: 5 November 2013

Abstract

Background

In the assessment of hypovolemia the value of functional hemodynamic monitoring during spontaneous breathing is debated. The aim of our study was to investigate in spontaneously breathing subjects the changes in hemodynamic parameters during graded central hypovolemia and to test whether slow patterned breathing improved the discriminative value of stroke volume (SV), pulse pressure (PP), and their variations (SVV, PPV). In addition, we tested the alterations in labial microcirculation.

Methods

20 healthy volunteers participated in our study. Central hypovolemia was induced by lower body negative pressure (LBNP). Continuous signals of ECG, non-invasive blood pressure and central venous pressure were recorded. During baseline and each stage of LBNP the labial microcirculation was investigated by orthogonal polarization spectral imaging, 3 minute periods of patterned breathing at 6 and 15/min respiratory rate were performed, and central venous blood gas analysis was done. Data from baseline and those of different LBNP levels were compared by analysis of variance and those of different breathing rates by t-test. Finally, we performed ROC analysis to assess the discriminative values of SV, PP, SVV and PPV.

Results

Moderate central hypovolemia induced by LBNP caused significant, clinically relevant falls in PP (p < 0.05) and SV and central venous oxygen saturation (ScvO2) (p < 0.001). The proportion of perfused vessels (p < 0.001) and microvascular flow index decreased (p < 0.05). PPV increased (p < 0.001), however the magnitude of fluctuations was greater during slow patterned breathing (p < 0.001). SVV increased only during slow patterned breathing (p < 0.001). ROC analysis confirmed the best predictive value for SV (at 56 ml cut-off AUC 0.97, sensitivity 94%, specificity 95%). Slow patterned breathing improved the discriminative value of SVV (p = 0.0023).

Conclusions

Functional hemodynamic monitoring with slow patterned breathing to control spontaneous respiration may be worthy for further study in different populations for the assessment of hypovolemia and the prediction of volume responsiveness.

Keywords:
Hypovolemia; Functional hemodynamic monitoring; Spontaneous breathing; Microcirculation