So finally got around to corralling Physiology Jedi Master Jon-Emile Kenny for a chat, which is always a tremendous learning opportunity. And this time was no different. Jon breaks down some of the mysteries around arteriolo-capillary coupling and shock flow, and brings up some really interesting potential uses of the critical collapse pressure of small arterioles, and hints at how we may be able to use some POCUS techniques to clinically assess tissue perfusion.
So I got to have a chat with ER doc extraordinaire Korbin Haycock today, reasserting my belief that tissue perfusion is not proportional to blood pressure. I am again including the article discussed, and here is the graph in question:
Here is our talk:
And the paper – which is definitely worth a read, as it clearly supports individualizing therapy!
Discussing with Rory is always awesome, because he manages to distill things to the most important stuff. In this one he basically says sure Phil, it’s fun to think up all kinds of semi-theoretico-imaginary hemodynamic stuff, but you gotta make sure you control the source!
Love to hear comments and criticisms!
Here is the open access paper I was talking about, graph on page 2.
So I’m in the process of putting together my resus handbook, and the really good thing about writing something up is that it forces one to beef up the entire mental database and fill in blanks that may sometimes be filled by belief, habit, culture or leaps of faith. So part of my process will involve discussing stuff with the brightest guys I know. Who happen to be pretty bright. So I figured it might be stuff worth sharing!
Here, Segun and I discuss the possible uses of Pmsa, of resuscitation philosophy, and touch on the issue of blood pressure vs perfusion. (please skip to 0:30 – sorry can’t cut out!)
Love to hear some additions to our discussion!
Here is the paper I was referring to, with the graph on page 2:
It’s really exciting to be at the outer frontier, trying to figure out some new clinical areas. Now these have all been described, however the ability of clinicians to properly identify certain pathophysiological findings has been limited prior to POCUS. Following the trail being blazed by Dr. Andre Denault, we are also working on expanding the applications, particularly in resuscitation/deresuscitation and CHF/AKI. There are more questions than answers, but that’s exactly why it’s interesting.
So for those unfamiliar with the topic here is a small intro:
And for those following, here is the discussion:
Do expect more from us about this. Watch this space. It is practice changing.
Lawrence’s work on sepsis analysis is truly groundbreaking. To put this in perspective, one has to recognize that sepsis is an exceedingly heterogeneous disease that, once upon a time, and for good reasons, an arbitrary definition was formulated. This, however, does not reflect sepsis adequately, and needs to change with observational data, as this has tremendous implications in therapeutics research.
Lawrence’s efforts have resulted in data systems revealing a number of different patterns of sepsis, with clear differences in physiologic effects or responses. This may explain why so many failed therapies for sepsis have occurred. It is entirely plausible that some of these therapies may have effects in some of these phenotypes of sepsis but get lost in the statistical mix.
Love to answer any questions anyone may have, and Lawrence will certainly chime in on the discussion!