CVP vs. dynamic hemodynamic parameters as preload indicators in hemodynamically unstable patients after major surgery

Introduction. Adequate circulating blood volume is essential for the good outcome in postoperative patients. Therefore, the primary resuscitation question is how to assess the circulating volume. The aim of this study was to compare the central ve-nous pressure (CVP) and dynamic LIDCO parameters as markers indicating preload in surgical patients.

Materials and Methods. This prospective study included 24 patients hospitalized af-ter major surgery at the surgical intensive care unit of the University hospital Zagreb, Croatia. The patients were mechanically ventilated, without spontaneous breath-ing attempts and in sinus rhythm. Patients were divided into 2 groups, hemodynami-cally stable and hemodynamically unsta-ble. The CVP was measured as a static pa-rameter while the stroke volume variation (SVV) and pulse pressure variation (PPV) were measured as the dynamic parameters. Results. Study groups were comparable in terms of gender, age and body mass in-dex. The difference in the CVP between the hemodynamically stable (13,2±3,74 mmHg) and hemodynamically unstable group of patients (10,1±5,6 mmHg) was statistically insignificant (p=0,144). Differ-ences in SVV (10,2±6,48% in stable com-pared to 18,8±7,04% in unstable group) and PPV (11,5±6,65% in stable compared to 18±6,32% in unstable group) were both statistically significant with p values of 0,005 and 0,022 respectively. Conclusion. The study confirmed the inability of CVP to provide valid assessment of the preload as a reason for hemodynam-ic instability in comparison to dynamic LiDCOTMplus system parameters in me-chanically ventilated major surgical pa-tients.

Blood Volume, Central Venous Pressure, Stroke Volume, Pulse Pressure

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