BackgroundIn 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.Methods20 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.ResultsModerate 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).ConclusionsFunctional 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.
Persistent GI symptoms and general patient dissatisfaction is a rather common finding after EST in patients with SOD, and correlated with the presence of predominant dyspeptic symptoms at the initial presentation, but does not depend on the technical and functional success of EST.
GTN and CCK10 coadministration induces a significant improvement of the GBEF in patients with GB dyskinesia. The application of this new pharmacologic test during QHBS permitted the noninvasive separation of those patients with secondary impaired GB-emptying as a result of GB dyskinesia from those with primary forms of GB hypokinesia.
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