Authors: Pinsky M et al.
Anesthesiology 144(4):759–760, April 2026
Summary:
This editorial challenges the traditional reliance on mean arterial pressure (MAP) and cardiac output as primary indicators of adequate resuscitation in septic shock. While these global parameters are commonly used to guide therapy, the author argues they do not fully reflect true tissue perfusion—the ultimate goal of resuscitation.
The article introduces the concept of tissue perfusion pressure (TPP), defined as the difference between MAP and critical closing pressure (Pcc). Unlike MAP, which is easily measured, Pcc represents the downstream resistance within small vessels and arterioles that can limit or even stop blood flow despite adequate systemic pressures. In septic shock and other vasoplegic states, elevated or dysregulated Pcc can create “choke points” that impair microcirculatory flow, meaning that normal or even elevated MAP does not guarantee adequate tissue perfusion.
Using large cohort data from septic patients, the referenced study demonstrates that both higher TPP and higher Pcc are associated with improved outcomes, including lower rates of acute kidney injury and better survival. Patients with both high TPP and high Pcc had the best outcomes, while those with low values for both had the worst. These findings suggest that microcirculatory dynamics—rather than just systemic hemodynamics—play a critical role in determining patient outcomes.
The article also discusses emerging methods to estimate Pcc and mean systemic filling pressure (Pmsf) using bedside data such as pulse pressure and heart rate, though these techniques remain imperfect and require further validation. Importantly, the study does not establish treatment targets but instead provides a framework for future research into more precise resuscitation strategies.
Ultimately, the author emphasizes that effective resuscitation must move beyond simply normalizing MAP and cardiac output toward a more nuanced understanding of microcirculatory flow and tissue-level perfusion.
Key Points:
- MAP and cardiac output alone do not adequately reflect tissue perfusion in septic shock
- Tissue perfusion pressure (TPP = MAP − Pcc) is a more physiologically relevant measure
- Critical closing pressure (Pcc) represents microvascular resistance that can limit flow
- Higher TPP and Pcc are associated with improved outcomes in septic patients
- Future resuscitation strategies may need to target microcirculatory function, not just systemic hemodynamics
What You Should Know:
We’ve been treating numbers, not perfusion. Just because the MAP looks good doesn’t mean the tissues are getting blood. This shifts the focus toward microcirculation—and if this holds up, it could fundamentally change how we manage septic shock at the bedside.
We would like to thank Anesthesiology for allowing us to summarize and share this article.