Thomas Kuhn, physicist and philosopher, in his groundbreaking and science changing text, The Structure of Scientific Revolutions, states that:
“Successive transition from one paradigm to another via revolution is the usual developmental pattern of a mature science.”
In other words, a science has growing pains and is bound to have a fair bit of debate and controversy, until a new paradigm becomes dominant. I think that there is a current – in part prompted by the power of socio-professional media which has allowed minds to connect and knowledge to spread – that will see many of the things that are now “Standard of Care” out the door.
So first of all, the following are must-listens, the first a lecture by Paul Marik, whom I have had the chance to collaborate with in the last years and respect greatly, on knowledge, experience, and even more on his refusal to take anything for granted and being in a seemingly-constant quest for the improvement of medicine.
The second link is Scott Weingart’s take on it, which I think is equally awesome.
I think Paul is pushing the envelope in an essential way, and Scott does a fantastic job of seeing or putting it in perspective. Enjoy:
My (very) humble opinion on this is a rather simple, almost philosophical one: why are we seemingly obsessed with treating a predominantly vasodilatory pathology with large amounts of volume? I’ve said this in previous posts and podcasts, but this, in my opinion, is largely cultural and dogmatic. “Levophed – Leave’em dead” is something I heard as a student and resident, and came to take for granted that I should give lots of fluid in hopes of avoiding pressors… But there’s no evidence at all to support this. The common behavior of waiting until someone has clearly failed volume resuscitation before starting pressors befuddles me (think how long it takes to get two liters of fluid in most ERs…). If I was in that bed, I’d much rather spend an hour a bit “hypertensive” (eg with a MAP above 70) than a bit hypotensive while awaiting final confirmation that I do, in fact, need pressors.
I strongly suspect that it’s just a matter of improving vascular tone, giving some volume (which may be that 3 liter mark), and ensuring that the microcirculation/glycocalyx is as undisturbed as possible. Now when I say it may be the 3 liters, I firmly believe this will not apply to everyone, and that it will be 1 liter in some, and 4 in others, and that a recipe approach will be better than nothing, but likely harm some.
I think that blind (eg no echo assessment) of shock is absurd, and for anyone to propose an algorithm that does not include point-of-care ultrasound is only acceptable if they are in the process of acquiring the skill with the intention of modifying their approach in the very near future.
The whole microcirculation/glycocalyx is absolutely fascinating stuff, and undoubtedly will come under scrutiny in the next few years, and it is definitely something I will focus on in upcoming posts & podcasts. Our resuscitation has been macro-focused, and certainly it is time to take a look at the little guys, who might turn out to have most of the answers. For instance, there is some remarkable data on HDAC inhibitors (common valproic acid) and their salutatory effects in a number of acute conditions such as hemorrhagic shock (Dr. Alam) which have nothing to do with macro-resuscitation, and everything to do with cell signaling and apoptosis. Hmmm…
please share your thoughts!
So right. Its the revised Starling equation and glycocalyx model you need to get to grips with the new paradigm. See also Curry & Adamson 2013.
Thanks Tom, will check that out!
I read your blog post on Paul Marik MD and fluid resuscitation with interest – particularly where you noted that ‘blind resuscitation (resuscitation without echo) is absurd’. We at ImaCor agree and for that reason developed a system and procedure for hemodynamic assessment and management with TEE. This hTEE system includes a miniaturized TEE probe cleared by the FDA to remain indwelling for 72 hours, and a three-view hTEE exam for assessing cardiac filling and function and appropriately guiding fluid and pressor therapies.
As you rightly pointed out, TEE can guide resuscitation; it can also identify fundamental problems such as LV and RV dysfunction which in Dr. Marik’s language affect cardiac performance and thus resuscitation strategies, and are also common in sepsis patients (c.f. a recent review by Dr. Antoine Vieillard-Baron (Septic cardiomyopathy, Ann Intensive Care 2011;1:6).
hTEE is also easy to learn (c.f. Cioccari L, et al., Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe, Critical Care 2013;17.3:R121) and thus provides a readily accessible approach for on-demand, bedside TEE-guided hemodynamic management, c.f. Maltais S et al., Episodic monoplane transesophageal echocardiography impacts postoperative management of the cardiac surgery patient, J Cardiothorac Vasc Anesth 2013;27:665-669.
We too have seen a fundamental paradigm shift in the way ICU patients are treated. I have had several interesting and enjoyable conversations with Dr. Marik and would welcome a conversation with you in this regard.
Harold M Hastings, PhD
Co-Founder and CTO
I’m familiar with Imacor and your probe. I do TEE so obviously agree. Email me at firstname.lastname@example.org.
Metabolic Theory of Septic Shock
Please do a search for the above