Targets for resuscitation from shock.

Resuscitation from circulatory and respiratory failure represent mainstays of emergency and critical care management. Importantly, no amount of resuscitative effort will be successful in promoting patient survival if the primary reason for the shock state is not identified and treated, independent of resuscitation. Having said that, aggressive resuscitation to normal functional levels of blood flow and organ perfusion pressure during the first 6 hours following the development of shock improves outcome both in patients with trauma or sepsis. However, clinical studies have demonstrated that restoration of total blood flow to supranormal levels in subjects with established shock that has been present for over 6 hours does not improve survival. Still, some defined clinical targets are essential in these patients as well to prevent further organ injury due to ischemia and its associated inflammatory response. Thus, the rapid restoration of normal hemodynamics by conventional means, including fluid resuscitation and surgical repair, results in a better log term outcome than inadequate or delayed resuscitative efforts. Clear initial targets for resuscitation are a mean arterial pressure > 60 mm Hg, and a cardiac output and O(2) transport to the body adequate enough to prevent tissue hypoperfusion. The level of cardiac output needed to achieve this goal is probably different among subjects and within subjects over time. Indirect signposts of adequate perfusion, such as venous O2 saturation, mentation, urine output and local measures of tissue blood flow are useful in monitoring this response.