Fluid Stop Points! More POCUS goodness from Korbin Haycock. #FOAMed, #FOAMcc

I am really enjoying this exchange, and I think it is in the true spirit of #FOAMed to foster these discussions, as we have the opportunity to combine and fine tune our understanding of a topic from several really bright people’s view and experience. 

Korbin:

Jon-Emile, excellent points and insight. I should clarify a couple of my comments. To be specific, by “renal vein flow” I am referring to intra-renal venous flow. Apologies for my imprecision! Thanks for pointing that out.

Yes, a lot of these renal and portal Doppler patterns are surrogates of CVP. But I don’t think any of us would use CVP in isolation these days to make any decision what-so-ever on whether fluids were indicated in our patient.

Also, to clarify, I am not using intra-renal venous flow or renal resistive index as measures of non-fluid responsiveness. Rather, I use these measures as a stop point for attempting to solve the patient’s hemodynamic dysfunction with crystalloid regardless of whether or not my straight leg test tells me the patient is still fluid responsive.

And that is a key re-iteration to me. It is important to set these stop points and not only look at whether the cardiac output can be maximized. This has been tried. And failed. Let’s remember that sepsis is not inherently a disease of low flow. It isn’t cardiogenic or hypovolemic shock at the core.

My rationale for the strategy of using intra-renal Doppler, E/e’, and Lung US (now, I can include portal vein pulsatility) as a stop point for IVF administration is that I think the patient is best served to avoid iatrogenic edema of the upstream organs, primarily the lungs and the kidneys. These are the two organs (maybe you could put the endothelium in this category as well–glycocalyx being a whole other can of worms!) most easily damaged by the chase for optimizing every bit of fluid responsiveness. We have good evidence that getting wet lungs and swollen, congested kidneys is a bad thing, and we have these tools to hopefully warn us when we are pushing things too far.

Absolutely. And the whole glycocalyx is something to keep in mind, even if only to me mindful to disrupt it as little as possible.

Of course renal resistive index, intra-renal venous flow, portal vein pulsativity, and whatever else you like will have limitations and confounders. As long as you understand what can cause abnormalities with these tools, you can make an educated guess as to what’s going on. If our creatinine is off and our RRI is high, but intra-renal venous flow and portal vein flow is normal, perhaps the RRI is caused by something other than renal congestion, like ATN. If the portal vein is pulsatile, but the Doppler patterns of the hepatic vein, kidney and the heart look ok, maybe something else is wrong with the liver. But, if all our modalities are in agreement and pointing to congestion, we should perhaps believe that it’s congestion and stop the fluids. 

That is an awesome approach to integrating RRI. I’ve been toying with it for the last couple of days, and much thanks to Korbin, I think that the limitations of RRI can be overcome by using the rest of our clinical and POCUS data.

It isn’t a hard technique, though in some patients getting a good signal can be tricky.

I think that the kidney, being an encapsulated organ, and the fact that much of our crystalloid ends up as interstitial edema, the kidney will develop sub-optimal flow patterns before CVP would cause congestion. The same is true regarding the lung, except that it’s just related to increased pulmonary permeability due to inflammation. Regardless, the idea is to save organs, and the earlier you can detect the problem, the sonner you can stop battering the more delicate organs with fluid.

As I think we have all mentioned, you really have to look at the whole picture, and put it together to tell the story of what is wrong, so we can logically and thoughtfully treat our patients.

I really appreciate this discussion. Thanks!

 

 

Thanks to Andre, Jon and Korbin for making this very educative for all!

Cheers

 

Philippe

Portal Vein POCUS: A Reader’s Case and a Follow-Up to the Denault Discussion

So I’ve been meaning to post a follow up and discussion about portal vein POCUS and how I am integrating it so far, and a few days ago I got a really interesting comment from Dr. Korbin Haycock, and I think it’s got some awesome elements to discuss.

Before we get into it, I would invite anyone reading this to go listen to the original Denault Track here, without which this discussion would be missing some elements.

What we are looking at here is the physiological assessment of venous congestion, and how doppler interrogation of the portal vein may help us. So here is Korbin’s case, and I will interject (in bold) where I think a point can be made, or at least my thoughts on it.

“Awesome post. Awesome website. I had never heard about portal vein pulsatility until reading your blog. I have previously been looking at the renal resistive index and renal vein Doppler pattern in my hypotensive/shock patients (along with doing a bedside ECHO and POCUS pulmonary exam) to guide when to stop fluid resuscitiation.

Very impressive. I have only ever heard of a handful of resuscitationists looking at this (including Andre, and consequently myself) so I’m gonna have to have a chat with this fellow soon! For those who have not tried or are not familiar, some basic info can be found here. I’ll have to review this, but I think one issue with RI is that there is an associated ddx, so that without knowledge of baseline, I would not be certain how to use it. Renal vein doppler seems very interesting to me, as that venous path is the one of the cardiorenal syndrome (forget about all that “low flow” nonsense in CHF – not in shock – patients), and there is clearly bad prognosis associated with abnormal (discontinuous) flow patterns. Here is a really good study (Iida et al)  and its editorial (Tang).

Iida Doppler_CHF Heart Failure JACCHF 2016

Tang Editorial JACCHF 2016

I had a case last night that I think illustrates that fluid administration can be the wrong thing to do in some septic shock patients. Plus, I got to try something new and look at the portal vein for pulsatility.

My case was a gentleman in his late 60’s with a history of HTN, atrial fibrillation and HFrEF who presented with three days for a productive cough and fever. POC lactate was 2.7. His HR was 130-140’s, in atrial fibrillation, febrile, MAP was 50, and he looked a bit shocky and was diaphoretic. The resident had started antibiotics and a fluid bolus of LR, of which not much had gone in (maybe 200cc) when I came to start a night shift and evaluated the patient. I asked that the fluids be stopped until we could have a look at him.

His IVC was about 1.5-2 cm with >50% collapsibility.

So I’m gonna hit the pause button right there for a couple of comments. That’s not a hypovolemic IVC. The RAP may be raised by some of the  It may very well be volume responsive, but I think the first thing to go for is correcting that tachycardia. The antibiotics are definitely the right call, but the fluids should, in my opinion, be held until assessment for volume tolerance is done.

His LV looked to have some mildly decreased EF and was going very fast. RV looked normal. His average SV was 45, CO was 6.1, E/e’ ratio indicated a slightly elevated left atrial pressure. His estimated/calculated SVR by the ECHO numbers was about 550. Lungs were dry anteriorly, without B-lines, but PLAPS view was c/w bilateral lower lobe PNA. Renal vein Doppler was biphasic and the resistive index was very high. I looked at his portal vein and it was pulsatile.

Excellent. So there is pulmonary pathology, which makes fluid tolerance already of concern. The CO is certainly adequate and SVR is low, suggesting a vasodilatory shock etiology. 

In the past, based on the IVC and the way the RV looked, I would have done a straight leg raise or given a given some crystalloid to see if his SV and BP improved, and if it did, give some IVF. Instead, I told the staff to given no more fluids and I gave him 20 mg of diltiazem.

His heart rate decreased from 130-140’s to 90. His averaged SV increased to 65 (probably due to increased LV filling time and better diastolic perfusion time), CO was 5.9, estimated SVR was 570. The renal and portal vein Doppler were unchanged. The MAP didn’t bulge and stayed low at 50-55. At this point I ordered furosemide and but him on a norepinephrine infusion to increase the SVR, first at 5 mcg/min, then 7 mcg/min.

Totally awesome to see. It isn’t unusual for me to diurese patients in vasopressor-dependant shock, as more and more data is emerging on how venous congestion has deleterious effects on the gut and may even contribute to the SIRS-type state. And once a patient is in a euvolemic to hypervolemic state, the only fluid they get from me is the one containing norepinephrine. Maintenance fluid is not for critically ill patients IMO.

The NE gtt increased his MAP to 75 mmHg. His SV was 80, CO 7.1 (I was a little surprised it didn’t go down a bit), estimated SVR was 700. I had his labs back at this point and his creatinine was 1.8 and the last creatinine we had was 1.1 a few months ago. His renal vein pattern was still biphasic and his renal resistive index was also still quite high at 0.89, which would probably predict a significant kidney injury in 2-3 days.

Even though his MAP and hemodynamics looked great, I was worried about the renal resistive index. I ordered a little more furosemide and started him on a little bit of a vasopressin infusion. After things settled down, MAP was 75-80, his average SV was 80, CO 7.3, estimated SVR was about 800, and his renal resistive index (RRI) was 0.75. He looked much better too. The second lactate was 1.3.

Very interesting to see the drop in RRI.  Great case to show how you don’t need to chase lactate with fluids. That is an antiquated knee-jerk reflex hinging on the concept that hyperlactatemia is primarily due to tissue hypoperfusion, which we have learned is not the main cause. 

This morning his creatinine had improved to 1.3 and he is doing well.

South of your border, CMS considers me a bad doctor for not giving 30 cc/kg crystalloid as a knee jerk reaction and instead giving a diuretic and early vasopressors as we did in this patient. Just looking at his IVC would indicate that IVF would be a reasonable strategy. If I had done a SLR or fluid challenge and found him fluid responsive, in the past, I would be temped to chase every bit of fluid response with pushing more fluids, but the renal and portal vein Doppler made me stop fluids in this patient this time. I think this example illustrates the importance of looking at each of your patients on a case by case basis and looking at the whole picture (heart, lungs, kidneys, now portal system too for me!), rather than following protocols.

Kudos. 

 

So then, Andre decides to chime in as well:

Very interesting but be careful about the interpretation of portal pulsatility because it can be falsely positive particularly in hyperdynamic young patient, which was may be not the case. We published an algorithm in order to identify the true portal pulsatility associated with right heart failure and fluid overload and a normal portal vein with pulsatility:

Tremblay Portal pulsatility Flolan Mil AACR 2017

(Tremblay 2017 A&A care report) A & A Case Reports. 9(8):219–223, OCT 2017 DOI: 10.1213/XAA.0000000000000572 , PMID: 28604468)

The latter will be associated with normal RV even hyperdynamic, normal hepatic venous and renal flow, normal IVC. We still need to explore the significance of portal hypertension outside the area of cardiac surgery where we are finalizing our studies.

Always tell my residents and fellow, treat the patient and not the number or the image. That being said, the patient got better so cannot argue with success.

So I think this is a really important point, that it can become dangerous in POCUS to look for a simple, single-factor “recipe” with which to manage the patient, when in fact you can have many factors which, integrated, can give you a much better understanding about your patient’s pathophysiology.

My take on portal vein POCUS so far is that it is a marker of critical venous congestion, beyond simply a plethoric IVC. I think it is wise to stop fluids before the plethoric IVC, but a plethoric IVC with a pulsatile PV should bring fluids to a screeching halt and some decongestive therapy started. The data for this?  Andre is cooking it up, but in the meantime, there is plenty of evidence that congestion is plenty bad, and NO evidence that maximizing CO works at all, so I am very comfortable in witholding fluids and diuresing these patients. 

For fun, here is a little figure from Tang et al about the doppler patterns discussed.

Love to hear everyone’s thoughts!

and for those interested, there will be a workshop on this at H&R 2018:

more to come on this soon…

cheers

 

Philippe

The Resuscitation Tracks 1: Portal Vein POCUS with Dr. Andre Denault. #FOAMed, #FOAMcc, #FOAMus

So this is one of the key discussions I wanted to have in my process of synthesizing my resuscitation algorithm. Dr. Denault is the one guy I’d call a mentor, and I think one of the rare and true clinician-scholar, who is just as comfortable being the anaesthetist/intensivist at the bedside of the crashing patient as he is being the keynote speaker in major conferences, or writing the textbooks that lead the field in acute care/perioperative TEE and critical care POCUS.

So to put some perspective to this discussion, back in 2014 I organized a resuscitation afternoon for internists with Andre and another awesome guy you probably all know, Haney Mallemat (@criticalcarenow). In a quick 15 minute discussion between talks, he shared with me the most recent of his discoveries, portal vein POCUS as a marker of right-sided failure/volume overload in his post-op cardiac patients, and how aggressively managing these resulted in much improved post-operative courses in terms of weaning, vasopressors and even delirium.

Interesting stuff.

So here you are:

So I’ll let you all ponder that and I would really like to hear comments and ideas. Sometime in the next few weeks I’ll be finalizing my resus algorithm – which will not be a recipe approach, as you might suspect if you have been following this blog, and will rely heavily on POCUS and the clinical exam.

cheers and thanks for reading and listening!

Philippe

 

Twittercase: Fouled urine and #POCUS discussion. #FOAMed, #FOAMcc, #FOAMer

So I admitted a patient to the ICU yesterday from the ED.  He’s an 80-something gentleman from a nursing home with an indwelling catheter, and presented with stupor, hypotension, fever, leukocytosis and clearly infected urine.  His labwork showed a lactate of 5.3, a double-normal creatinine and, after 3 liters or so of crystalloid, he was started on norpeinephrine and hence came to the ICU. His extremities were fairly warm, and his cerebral saturation was 62%.

Before seeing the POCUS info, however, consider a clearly septic patient with AKI and elevated lactate. He did get 3 liters of fluids, but i’ve seen these patients get more fluids, whether for hemodynamics, lactate, AKI or any combination of the aforementioned.

Below is the clip, a quick POCUS sequence going from IVC (with hepatic vein flows), subxiphoid cardiac views, both lung views.

So here, we see a plethoric and fixed IVC (sorry I didn’t include the short axis but it was round and full, so in this case the LAX is reliable) with biphasic hepatic flow. Cardiac views show normal ratios and a poor LV function. Chest views show bilateral effusions and consolidations.

So what did I do?

  1. stopped fluids (I do not believe in routine maintenance fluids any more than in maintenance antibiotics or vasopressors).
  2. gave lasix (given that he is on the flat part of FS curve, I was unconcerned with some diuresis decreasing his preload, vasopressors and lactate notwithstanding, and with the goal to decongest his kidneys, likely suffering from congestive insult on top of the septic one).
  3. did not try to chase his lactate with increasing cardiac output (lactate being a great alarm bell and prognosticator, but little else, and because he was worm and with a decent cerebral saturation, I did not feel that there was a major cardiogenic component to his shock).

So what happened?

This morning, after a negative balance of 1,500 cc in 24 hours, his levophed dose has dropped by half, his lactate is normal and his creatinine is decreasing. A decade ago, I would have chased down the last ounce of volume responsiveness with fluids, aggressively trying to drive down the lactate and creatinine, and maybe, 24 hours later, he would have developed “ARDS” because he was “so sick.”  😉

cheers

 

Philippe

 

Fluids in Sepsis: An EmCrit Webinar! #FOAMed, #FOAMcc

Screen Shot 2016-04-27 at 2.00.28 PM

Screen Shot 2016-04-27 at 1.43.23 PM

So a few weeks ago Scott (@EmCrit) asked me to be part of a pretty cool webinar organized by the Greater New York Hospital Association about fluids in sepsis. The gang consisted of David Gaiesky, Emmanuel Rivers and moderated by Scott himself. And for some obscure reason, he asked me to be part of it – much to my honour (terror, also), naturally.  It was only afterwards that he told me it was to help stir the pot and be controversial, challenge the “old school” etc… He seemed to have overlooked that I am Canadian, and inherently and perhaps overly polite and considerate – at least live and in “person”!

We talk about a bunch of stuff around fluids, which, how much, how to assess, etc.

Anyhow, I hope I got a few ideas across, but it was really cool to hear that these gurus do use ultrasound – don’t necessarily strictly adhere to, for instance, EGDT, and also advocate that guidelines are guidelines and not necessarily gold standards.

Here is the link to the webinar for those interested:

 

https://t.co/dbL03Vuqlj

 

And here is the figure for the section where I refer to fluid responsiveness/tolerance:

Screen Shot 2016-02-21 at 9.25.50 AM

I further talk about this in a previous post here.

Scott and I also recorded a debrief which should be coming up in the next weeks on EmCrit – link to follow!

cheers!

 

Philippe

Musings with Jon-Emile & Philippe – Fluid Resuscitation: Physiology and Philosophy! #FOAMed, #FOAMcc, #FOAMer

So here, Jon-Emile and I explore a topic I’ve posted about before (http://wp.me/p1avUV-bd) so I can see if a master physiologist agrees with my rationale (…not just my rationale but supported by a ton of literature many choose to overlook!).

Please visit http://www.heart-lung.org for Jon’s awesome physiology tutorials!

Love to hear listeners’ thoughts!

cheers

 

Philippe

The Great Septic Debate (Part 2): Resolution? #FOAMed, #FOAMcc

So, echoing my thoughts form the end of the debate, Steven adds:

Well, I didn’t expect to see my name in a headline, but I suppose it’s a hazard one should expect when they go spreading their arguments across the interwebs!

In truth, I don’t think that Dr. Lynn and I really think that much differently on these issues. We both desire for the science of sepsis to continue developing and to be better than it is. I, personally, would love to be a part of the clinical trials that use genome-based data to determine which treatment arm a patient belongs in. We both deplore any “old guard” attempting to prevent the onward march of discoveries that make our knowledge and abilities more complete. I am actually sorry that some young scientists feel intimidated and that there is anything less than civility and scientific curiosity in our community. Period.

Likewise, I would be shocked if Dr. Lynn did not at least use the observation of infection, SIRS, and organ dysfunction as physical markers of sepsis and warning signs that intervention is necessary. It will be true for a very long time that it is going to be an interaction between two human beings that initiates the diagnosis and treatment of sepsis. A physician will recognize a patient in distress by some means and start the process. For now, these findings are the best we have, and they should prompt us to intervene before the completely diagnostic test results are available. Even when we have the tricorder, something is going to trigger the doc to pull it out of a pocket and use it.

OK, so I have to admit that Dr. Lynn stung me a little with his characterization of TNF-alpha as a “biomarker”. I would rather say that TNF is one of the heavy hitters in the proteomics of sepsis, and I’ll bet that I can get him to concede that point! It stimulates receptors and causes other actions to take place, it’s synthesis and release are regulated and dysregulated; it’s more than just a marker! And I ABSOLUTELY agree that the failure of TNF-directed therapies stems from the fact that they were given both to patients who could benefit from them and patients who, with better characterization, we would have known had no chance of benefitting. The same goes for high dose corticosteroids, anti-endotoxin antibodies, IL-1 directed therapies, and coagulation based therapies. In fact, that’s what I’ve been teaching my trainees for years – if you can call bemoaning the fact that we can’t yet recognize and separate responders from non-responders teaching. We have a desperate need for understanding better, and the science MUST be encouraged. Again, period. Or full stop, for those of you who have that bent! That is, I think, Dr. Lynn’s argument in a nutshell.

I REALLY appreciate the interchange. It is healthy and necessary. The two of us are aiming at the same thing – fewer people dying from sepsis. I haven’t met Dr. Lynn (though I hope to), but I suspect that he spends more hours in his day formulating and doing the new science, while I spend more hours in my day pushing people who think that it isn’t sepsis until it’s shock and multiple organ failure to do something about it before it gets that far. Those are both important parts of the war, but in the end, it is the same war. And we are allies in it.

Steven Q Simpson

And, soon after, Lawrence reaches for that handshake:

I agree completely with Dr. Simpson. We all teach that a good history, physical, basic lab, and a high degree of vigilance for subtle signs of sepsis are pivotal. This includes the use of awareness campaigns which simplify sepsis to something easily understood and screening protocols to assure vigilance. These are great advances.

I also share Dr. Simpson’s concern about empowerment of naysayers who may use the promulgation of the imperfections of sepsis science as a reason not to move forward with early action based detection protocols.

Relevant TNF-alpga, I have to agree that it likely has a fundamental role in some phenotypes of sepsis including the sepsis-like syndrome generated in Ebola patients.

So Dr. Simpson and I probably agree on most sepsis related issues.

To explain a little further, many years ago our research team applied for an NIH grant to define the dynamic relational patterns of all the lab and vitals over time in infected patients. The reviewers did not seem to comprehend why we wanted to do that since a standard for a single unified phenotype of sepsis was already widely accepted. Yet had they realized the need for these types of complete data sets, the entire time time series matrix of vitals, lab, biomarkers, and treatment for each case would have been acquired in PROcess , ARISE, and Promise. This would have occurred if the entire field of scientists had not convinced themselves they already knew that “sepsis/septic shock ” comprised a unified phenotype, “an entity” “a single condition” “a thing or object” definable by a few static thresholds.

So this is why we say the young should call for reform ASAP of sepsis science (not sepsis awareness) and at the upcoming SCCM. Imagine a mult-center trial where these complete time matrices are generated and we define the phenotypes. We can define the phenotypic subtypes and then examine treatments in relation to these.

One might think of sepsis syndrome as analogous to the syndrome of CHF where there is systolic failure, diastolic failure, hypertensive failure, and valvular failure defined phenotypes of CHF.

Perhaps we might have sepsis with capillary membrane failure phenotype and/or, vascular muscle failure phenotype, coagulation control failure , neutrophilic control failure, TNF-alpha mediated immune control failure.

These are simply general gross simplistic considerations, Discussion points.

However the final conclusion of my original post is that, beginning at this SCCM, we must stop trying to explain away the anomalies caused by the past sepsis dogma and accept that these anomalies ARE counter instances. We must accept that we cannot rely on research which uses billing codes as data or by using retrospective controls at the same time the denominator balloons as a function of awareness.

Then we can finally assure that we do not fool ourselves because the world depends only on us. There is no back up. We must accept that we need a new surge of sepsis research ASAP, and…..in a new direction.

This, along with the effort and dedication of Dr. Simpson team, the Sepsis Alliance, and the SSC (now gathering the entire time series matrix of all the diagnostic and treatment data and not just thresholds) will produce an exciting future. If this happens, it would be great to be a young sepsis scientist in 2015.

So yes Dr. Simpson and I actually agree. We are simply fighting the war on sepsis from different fronts.

Most Respectfully
Lawrence Lynn

Thanks again Steven and Lawrence for what I think was both a really informative AND formative discussion.

Philippe