The role of central venous oximetry, lactic acid concentration and shock index in the evaluation of clinical shock: a review.

Initial therapy of shock in the emergency department emphasizes the normalization of hemodynamic variables e.g. heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP) rather than optimization of systemic and regional oxygenation. Central venous oximetry (ScvO2), arterial lactic acid concentrations (Lact) and the shock index (SI) were examined during initial hemodynamic stabilization of clinical shock in the emergency room. Although initial therapy normalized MAP, CVP and HR; ScvO2, Lact and SI continued to be abnormal indicating inadequate systemic oxygenation and left ventricular (LV) performance. Measurement of ScvO2, Lact and SI may provide valuable additional information on the adequacy of systemic oxygenation and LV function during initial therapy of shock. This may identify patients who require further monitoring and intervention to optimize systemic oxygen transport and cardiac performance and reduce their morbidity and mortality.