Evaluation of Fluid Volume: Existing Indices and Our Newly Developed Method
Kensuke Nakamura1, Jun Oda2
1Emergency and Critical Care Medicine, Hitachi General Hospital, Japan
2Emergency and Critical Care Medicine, Tokyo Medical University, Japan
Fluid management is one of the most important factors of intensive care. In the recent critical care, fluid resuscitation is the important and first approach for the shock resuscitation, whereas fluid overload would worsen the patients’ prognosis and we should avoid unnecessary fluid load. Therefore, some kind of indices to evaluate fluid responsibility hase been needed. Various techniques are proposed and studied for evaluating the fluid volume. Central venous pressure, which has been used as gold standard for fluid volume through the ages, was demonstrated poor relationship to fluid responsiveness. In contrast, dynamic indices such as stroke volume variation have gained attentions for better assessment for predicting fluid responsiveness. But these assessments require some invasions and preparation to indicate. The respiratory variation of inferior venous cava IVC or internal jugular vein IJV by ultrasound echography has been once again appreciated as a fluid responsiveness marker. However, echography measurements entail some subjective problems. The evaluation results are affected to some degree by the subjective views of sonographers. We developed and analyzed the automatic analysis of IJV and IVC with the software and showed that the cardiac variation of IJV and IVC were also associated with fluid status and fluid responsibility. The automatic analysis with software is expected to evaluate them shortly, easily and objectively. As there is no absolute index to predict fluid responsibility, we should evaluate with as many methods as possible, and development of new predictor and technique is important in this field. We would like to introduce our efforts to evaluate fluid responsibility in clinical practice and studies.