Should Hemodynamic Profiling be a Sepsis Best Practice?
Hemodynamic profiles in critically ill patients are complex and change over the sepsis course.
Macro-circulatory and micro-circulatory factors contribute equally to the evolving disease state.
During the later stages of hemodynamic impairment, both factors must be considered.
In addition to source control and antimicrobial therapy, circulatory resuscitation is a key component of sepsis management.
Hypotension and impaired end organ perfusion are primarily driven by macro-circulatory and micro-circulatory disturbances.
Initially there is a linear relationship between macro-hemodynamics and end organ hypoxia. However, as sepsis progresses there is an uncoupling of: a. Macro-circulatory and micro-circulatory systems b. Micro-circulation and mitochondrial respiratory complexes.
With this uncoupling, maintaining macro-circulatory integrity alone (without considering micro-circulatory integrity), may not guarantee adequate tissue oxygen tension.
a. Mean Arterial Pressure (MAP)
MAP is usually driven above 65 mm Hg, but this may not provide additional benefit
Permissive hypotension (60-65 mm Hg) vs usual care demonstrated no difference in 90-day mortality.
Figure 1: Permissive Hypotension vs Usual Care MAP (Lamontagne et al JAMA 2020)
b. Cardiac Output Coupled with CVP
Provides parameters to fine tune fluid removal to match interstitial vascular fill rates
c. Tissue Perfusion
Venous Oxygen Saturation (either central ScvO2 or mixed)