Treatment strategies in shock: use of oxygen transport measurements

Shock has traditionally been categorized according to its cause. Shock can result from hemorrhage, primary cardiac failure, central nervous system failure, trauma, or sepsis. Therapeutic principles have been developed for each etiologic type. End points for such therapy have included optimization of pulmonary capillary wedge pressure, cardiac output, blood pressure, and urine output. Recent investigators agree that the common denominator in each of the shock syndromes is a reduction in the amount of oxygen consumed by the cell. The logical therapeutic approach would be to increase oxygen delivery to support the increased metabolic demand of the cells. The end point of resuscitation should be optimization of oxygen delivery and oxygen consumption. These variables are easily calculated by using data obtained from pulmonary artery catheter and laboratory measurements. The physician or nurse caring for critical ill patients should have a thorough understanding of the rationale for the use of oxygen transport calculations and the methods of manipulating oxygen delivery. A simple explanation of these principles including the importance of hemoglobin, cardiac index, and percent saturation of hemoglobin and suggested treatment strategies are presented.