Septic shock resuscitation: what goals and how to achieve them?

Stephan M Jakob

doi:10.1186/cc7870

Abstract

The need to achieve adequate tissue oxygen delivery early in patients with septic shock is well established. However, it is less well recognized that tissue hypoperfusion can exist despite normalization of systemic hemodynamics. Efforts to resuscitate septic patients until adequate tissue perfusion has been achieved can potentially improve outcome. In a multicenter study, 130 patients with septic shock were resuscitated within 12 hours of diagnosis using a protocol including goals for mean arterial and pulmonary artery occluded pressures, urinary output, arterial pH, and hemoglobin goals. They were then randomly assigned to further resuscitation with either a cardiac index (≥ 3 l/minute per m2) or a gastric mucosal pH (≥ 7.32) target. The intensive care unit length of stay and 28-day mortality did not differ between groups, but more patients in the cardiac index group were in the target range, both at baseline and after resuscitation, as compared with the gastric mucosal pH group. In contrast to cardiac index, gastric mucosal pH at baseline and at 24 and 48 hours predicted mortality. Whether other targets for the chosen variables, or different and – in particular – earlier resuscitation efforts would have favored one group cannot be concluded from the data provided.

Highlights

The previous issue of Critical Care includes a report of a multicenter study in which cardiac index and gastric mucosal pH targets were compared during resuscitation of patients with septic shock [1]
It has been shown that persistent microcirculatory alterations are associated with organ failure and mortality in patients with septic shock [2]
In the study conducted by Palizas and coworkers [1], resuscitation to a pHi goal was not associated with better survival than resuscitation to a cardiac index target

Summary

Were the tested parameters relevant for survival?

Cardiac output determines tissue oxygen delivery and is certainly an important variable with respect to the resolution of septic shock. Other variables contribute to tissue oxygen transport, and the demands may vary. As the authors state themselves [1], a goal representing a presumed adequate relationship between oxygen delivery and consumption (for example, mixed venous oxygen saturation) would have been preferable. Its strong association with mortality makes pHi an ideal target variable for improving outcomes

Were the defined targets adequate?

Were other important targets achieved?