Physiologic monitoring goals for the critically ill patient

Definition of the appropriate therapeutic goals for physiologic monitoring of patients postoperatively was approached by analyzing more than 50,000 values of the 20 most commonly monitored variables in a series of 113 critically ill patients throughout their immediate postoperative course. In general, normal values were poor criteria for monitoring, since normal values were restored in an average of 75 per cent of the survivors and 76 per cent of the nonsurvivors for the five most frequently measured variables; that is, arterial pressure, heart rate, central venous pressure, wedge pressure and cardiac output. Moreover, an average of 56 per cent of the 20 most commonly monitored variables of nonsurvivors was restored to the normal range. Furthermore, 34 per cent of all the nonsurvivors' values were within the normal range; this was only 2.4 per cent less than the percentage of normal values for the survivors. The empirically determined median value of the survivors taken in the late stage during periods remote from therapy was found to be a better criterion for therapeutic goals for most variables, including blood flow, oxygen transport and most intravascular pressures. However, normal values were satisfactory for arterial pressure, peripheral resistance, pH, mixed venous oxygen tension and arterial carbon dioxide tension, largely because of the biphasic patterns of these variables.