On the Shoulders of Giants
A non-invasive approach to monitoring sepsis patients by using lactate clearance rather than central venous O2 saturation (ScvO2) was just as effective once central venous pressure (CVP) and mean arterial pressure (MAP) were optimized.
Why does this matter?
This study was in response to the early goal directed therapy (EGDT) paper we covered last Saturday. Part of EGDT is invasive monitoring of ScvO2, a measure of tissue oxygen delivery. A less invasive approach of measuring and trending lactate was favored by many, and this paper set out to show this was not inferior to EGDT.
It's clear which approach is favored.
This was a multi-center RCT including 300 patients with severe sepsis and hypoperfusion or septic shock randomized to early ED management to normalize CVP, MAP, and ScvO2 to 70% or greater; or to normalize CVP, MAP, and follow lactate clearance of at least 10%. Groups were well matched with randomization. Resuscitation with IV fluid, pressors, etc. was continued until the goals were reached or 6 hours elapsed. The admitting ICU team assumed care and managed per the usual ICU protocols and were not aware of group assignment. The lactate clearance group had 17% mortality; the ScvO2 group had 23% mortality. This 6% difference did not meet the pre-defined threshold of 10% for superiority. They could not blind group assignment, which is a potential weakness. The conclusion was that septic shock patients can be managed with lactate clearance and did not require placement of an invasive monitoring device.
Lactate clearance vs central venous oxygen saturation as goals of early sepsis therapy: a randomized clinical trial. JAMA. 2010 Feb 24;303(8):739-46. doi: 10.1001/jama.2010.158.