shock

December 30, 2019

The Resus Tracks: Trans-Pulmonary Dilution Catheters in the ED…myth or reality? #FOAMed, #FOAMer

So anyone who knows Korbin (@khaycock2) realizes he is a true trailblazer in the ED, essentially doing cutting edge critical care from the get go in his shock patients. In my mind this should be the goal for any critically ill patients, that they get the highest level care right at entry and for however long they may be staying in the ED until they get to the ICU.

So today, I was really happy to corner Korbin lounging somewhere in sunny California (as 6 inches of snow come down hard in Montreal) to tell me how he is using this technology in his resus patients.

 

 

So this has got me interested in using this technology. I see it as an early warning signal that your patient may be less fluid tolerant than you may think, and that the signs of pulmonary fluid intolerance I use (oxygen requirement, appearance of B lines (FALLS Protocol-style), etc…) have yet to manifest.

So I’m looking forward to hearing Korbin explain this further (during H&R2020!) and in actual cases where the change in management is clear.

 

cheers

 

Philippe

 

 

 

 

December 8, 2019

#FOAMresus Case from Amand Thind (@Thind888)

So #MedTwitter is truly an incredible forum for case discussion, where you get to exchange with literally some of the best medical minds on the planet who often also happen to be front-line clinicians in the nitty-gritty therapeutic decision-making. Here’s a discussion which I think was great. Recently, Dr. Thind has been generating some great cases and hemodynamic discussions. I thought this one was worth highlighting!
Dr Thind is an internist and currently Critical Care Hospitalist (and upcoming ICU fellow) at the Cleveland Clinic, and tweets out some great #FOAM from @Thind888 on twitter.
Case:
OK, let’s give this a shot. Here’s a ‘hemodynamics special’. Saw this case a couple weeks ago. A lot of decision making was based on educated guesses so it should be a good one for discussion. – 51 yo woman being worked up on the floor for chronic diarrhea, moved to ICU for hypoxia.
Dyspnea progressed over few hours. Vitals significant for tachycardia (140s) and hypotension (MAP in low 60s). On arrival, SBP 60s – improved with fluid bolus. CXR attached. Patient has H/O of pericardial effusion for several months that has been managed conservatively. 
The patient has an official ECHO performed on arrival in ICU (images attached). IVC difficult to assess but about 2cm without collapse. Lung US – diffuse B lines. 
OK so right there a flag goes up for me. A plethoric IVC means something is wrong. Sounds too vague maybe, but you need to find the reason for this, as it likely has therapeutic implications. Let’s see what comes up.
Modifed A5C.
LVOT doppler

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CXR

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Pressing questions –
(i) Is it hydrostatic or increased permeability pulmonary edema?
(ii) Fluids, diuresis, or none?
(iii) Would CPAP help?
(iv) Drain the pericardial effusion?
(v) What about that LVOT doppler? 
Mitral inflow velocities and TDI attached. M-mode through PLAX almost uninterpretable. Lung infiltrates are new so less likely lymphangitic carninomatosis. Note: ScVo2 = 40s. Another Q to ponder on –
(vi) Is tamponade typically associated with hydrostatic pulmonary edema?

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Perhaps this slowed up (0.5x) A3C loop will help with that LVOT doppler!

Great discussion as expected. Lets discuss:
Q4. Is it tamponade? – This is not a slam dunk. Chamber collapse can sometimes be controversial. In these situations I try my best to get MV E-wave variation. I think our tech got a decent signal. But note these are fused E/A waves.
The first thing I look at to screen for tamponade is the IVC. Tamponade is an obstructive form of shock, dependant on the intrapericardial pressure exceeding the right atrial pressure. If it does, unless respiratory efforts are extreme, the IVC should become plethoric. Hence, the absence of such would make the effusion – given the current RA pressure – NOT tamponade. Yet again, another point scored by the IVC for usefulness.
Although I don’t see why we can’t use fused waves for this purpose (couldn’t find anything on it in the literature). Note that in spite of the cardiac motion, the mitral inflow variation is <25% (~23%). It’s close though, and certainly seems to have increased from 3 days ago.

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The cardiologist (understandably) was non-committal and read it as “possible early tamponade”.
Q5. What about LVOT doppler? A good M-mode could not be obtained but the A3C in 6/ shows SAM. The report mentioned “chordal SAM” but I think you can clearly see “valvular SAM” too.
Chordal SAM is SAM of the chordal apparatus (you could see it bumping against the septum in 6/). It is (typically) NOT hemodynamically significant (PMID: 27241937). – When we see mitral SAM, it is important to quantify its hemodynamic effects – with LVOT peak gradient via CW.
In HOCM, DLVOTO is defined by an LVOT gradient of >30; >50 is considered severe. Our patient had a gradient of ~70. Although classically a/w HCM, SAM can be seen in anyone with thick, hypercontractile, underfilled LV. Tachycardia further hampers LV filling (PMID: 27726435).
Mitral SAM is often a/w MR – this acute MR can cause flash pulmonary edema. These patients may actually need fluids (to help with SAM) to fix there hydrostatic pulmonary edema!! (PMID: 20661209). However, our patient only had trace MR (you could see it in 1-2 CD frames).
Working theory (similar to Lars) – Chronic stable pericardial effusion –> diarrhea (pt had 15 BMs the day before the admission) –> reduced venous return –> brought the patient at the verge of low-pressure tamponade (PMID: 16923755) –> further reduction in LV filling  —> reduced stroke volume –> adrenergic drive causing tachycardia and increased inotropy –> all factors culminating in mitral SAM and DLVOTO.
This also explains the low ScVO2. Note – CPAP would further reduce venous return (Q3) so wouldn’t help, may hurt.
Now the most important Qs: why pulmonary edema and what to do about it (Q1 and 2). As tamponade causes impedance to venous return, it is not typically associated with high LAP and hydrostatic pulmonary edema (Q6).
But first, let’s check out another CW tracing. Any thoughts?

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This is a CW beam through LV apex and mitral valve – typically performed to assess mitral inflow and MR velocities and is part of the standard ECHO exam. However, the tracing is not typical for MR (late peaking, dagger shape). Remember, CW does not have depth resolution.

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This is likely mid-cavitay/intra-ventricular obstruction. This is caused by complete mid-systolic obliteration of LV cavity (see PSAX) causing obstruction to the apical systolic flow. Again, seen in hypercontractile, underfilled, thick LV – e.g. sepsis (PMID: 26082197).
Finally – what does the ECHO tell us about LV filling pressures? – E/A ratio: As Lars pointed out, an E/A < 0.8 usually means normal LAP. However, the exception to this is sinus tach. This was shown in a study by none other than Dr. Nagueh (PMID: 9778330). (Also, see image)

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The idea is that when early filling (E) is incomplete due to short diastolic time, the LA remains “full” at the time of the atrial kick – causing higher A velocities. NB: In that paper, E/E’ > 10 had a specificity of 95% for elevated LAP in ST. In our case: E/E’ = 75/5 = 15!

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Potential contributors of high LAP – (i) SAM-associated MR – ‘trace’ in this ECHO but maybe we didn’t catch it. (ii) Tachycardia – E’ is 5 suggestive of delayed relaxation. Tachycardia causes “incomplete relaxation”. (iii) High afterload – high-grade dynamic obstructions.

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So at this point, it’s still contentious but I have my money on hydrostatic pulmonary edema. Will detail our interventions and the remaining course in a bit. …Sorry to make this long but I think it’s worth it!
Now for the home stretch, the remaining course: We realized pericardiocentesis may be required soon but wanted to see if volume helps with (i) Peri-tamponade (ii) Dynamic obstructions. It helped a little – O2 requirements went from 60% HF to 6L NC. BP okay but still tachy.
Day 2: We pushed 2.5 mg metop x2 with concurrent ECHO. LVOT gradient improved from 70s to ~10! (I did not compare mid-cavitary gradient, apologies). Started on 25 bid of PO metop later that night. HR now 90s Day 3: Official ECHO shows improved but persistent gradients.

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Evaluation of tamponade was similar to previous ECHO but E-wave velocity variation now 38% –> elective pericardiocentesis: 550 cc removed. Fluid was transudate We also tapped a small pleural effusion pocket: transudate, cx negative (again goes with hydrostatic pulmonary edema).

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Day 3 (contd): inc metop to 50 Q12H to blunt the gradients.
Day 4 – HR in 80s. ECHO shows no DLVOTO and non-significant mid-cavitary gradient. Oxygenation improved but still not normal. Why?! Check the E-velocity post-pericardiocentesis: it has jumped to 120 with E/A > 1.

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So why is the LAP still high despite no significant dynamic obstruction? – Patients with chronic pericardial effusion may have chronically impaired diastolic filling –> low output –> volume retention (basic CHF physiology). When pericardial restraint suddenly released ––> increased LV preload –> high LAP.
Originally discussed elegantly here: PMID 6877287.
This is especially true if the LV has some baseline dysfunction. Day 5 – We started diuresis! The obvious risk was to precipitate the dynamic obstructions –> metop increased to 50 Q8H.
Day 7: Excellent diuresis (~2-3L negative per day). Hemodynamics stable (SvCO2 normal). Resting HR 60s – 70s. Follow-up ECHO confirmed no dynamic obstructions (see image). Day 8: Finally on room air. Pulmonary infiltrates improved (image). All cx remained negative.

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Some dogmalysis offered by this case – – Fluids (probably) helped the pulmonary edema; CPAP/diuresis may have worsened. – IV metop contraindicated in hypotension? Not in this case – Sometimes you may have to diurese someone who recently had DLVOTO, as discussed above.
This case highlights the cognitive flexibility required to deal with hemodynamic puzzles. One thing I would’ve done different is be more aggressive with metop early on as it made a huge difference with DLVOTO. This was quite a ride. Hope you had fun. Feel free to share! 
Much kudos to the treating team, I think this was excellently managed. As Amand says, cognitive flexibility ias absolutely key in assessing hemodynamics, particularly in the grey zones when multiple processes occur and co-exist. Managing this type of case using a recipe-based approach and without POCUS could have let to a poor outcome. 
Now the POCUS used in this case is on another level. Very impressive and allowing incredible insight and certainly many potentially clinically useful Doppler analysis tips for LVOTO and LAP assessment. 
In the end, I think that there were three pathologies, (a) tamponade physiology, (b) dynamic LVOTO, exacerbated by (c) hypovolemia (diarrhea)  I might have approached this differently, had I seen a truly plethoric IVC. In such a case, one can easily see how tamponade physiology would contribute to LVOTO in two ways by creating intracardiac hypovolemia, hence worsening LVOTO both by decreasing LV preload and by the compensatory tachycardia. My first approach would probably have been to drain the pericardial effusion, and reassessing the hemodynamics afterwards, but correcting the intravascular deficit was necessary.
The other important thing this case re-emphasize is that tamponade is not a static diagnosis but a physiological spectrum. For the same given effusion (read intrapericardial pressure – IPP), it is the RA pressure that will determine whether overt tamponade develops. In this patient, it is very likely that a day earlier, there was no frank tamponade, but that after some diarrheal volume loss, the RAP dropped, and now IPP > RAP.  It is important to know this because if you have an effusion and a fairly full IVC, one needs to be very careful with anything that can drop the RAP, meaning diuretics and vasodilators, because these can easily turn pre-tamponade into overt shock.  And, as this case illustrates so well, you might even end up with LVOTO and pulmonary edema!  Which is one of the myriad reasons one should have a basic POCUS exam in every acutely ill patient. These are things a resucitationist needs to know and prepare for.
cheers and thanks again to Dr. Thind!
Philippe
February 20, 2019

The Andromeda-SHOCK trial with Korbin Haycock and the Nuclear Bomb Approach to Sepsis. #FOAMed, #FOAMer, #FOAMcc

So managed to pin another really bright guy down today and get his thoughts. Of course we digress some, but I think in all the topics that are truly important to sepsis resuscitation.

 

 

So I think all the resuscitationists I have spoken to tend to hover around the same common points:

  1. lactate is a marker of severity of insult/injury/inflammation but NOT something to specifically treat with an automatic fluid “chaser.”
  2. getting a global assessment of the patient’s perfusion – including things such as CRT is important.
  3. a strategy that seeks to exterminate fluid responsiveness is non-sensical and pathological.

The nice thing for our southern neighbours is that this study may give you a solid excuse to shake off that lactate mandate.

And I think that Korbin’s ending remarks are important, and it is something I try to teach residents, that there is little value in rapidly normalizing hemodynamic values – which treats the medical team very well – if there is an aftermath that is not beneficial for the patient. Kathryn Maitland’s FEAST study is the real groundbreaker for that concept. So probably a coordinated and careful ground assault is better than dropping the nuke.

 For more discussion on this trial check out Rory Spiegel’s breakdown at https://emcrit.org/emnerd/em-nerd-the-case-of-the-deceitful-lantern/ and our discussion at https://thinkingcriticalcare.com/2019/02/19/the-andromeda-shock-study-a-physiological-breakdown-with-rory-spiegel-emnerd-foamed-foamcc-foamer/

cheers!

 

a couple points:

First, much thanks to Scott Weingart whose technical pointers are improving my audio quality! Still a ways to go but on the path!

Second, if you’re not registered for H&R2019, there’s only about 20 spots left. And only a handful for the much-anticipated Resuscitative TEE course. Don’t miss out. If you enjoy these discussions, there will be plenty of that, especially in the protected meet-the-faculty times.

And finally, though he doesn’t yet have a blog, you can now follow Korbin on twitter @khaycock2!

 

Philippe

 

February 12, 2019

Is POCUS the new PAC??? A Chat with Jon-Emile Kenny (@heart_lung) #FOAMed, #FOAMcc

So here is what Jon tweeted a couple weeks ago:

Yikes! Does that spell doom for POCUS???

So clearly we had to get to the bottom of this statement…So a google hangout was in order.

 

Part 1 my intro:

and Part 2 our discussion:

 

So the bottom line is that we agree that there is a risk that POCUS may partly head the way of the PAC, or at least be challenged in a similar fashion. Hopefully the wiser physicians will see the inherently flawed logic that would push the field in that direction. Alternately, we could all get our minds and efforts together and try to do a triangulation of data to really pinpoint hemodynamics.

Love to hear comments!

For more of Jon’s physiology awesomeness, visit http://www.heart-lung.org.

Cheers

 

Philippe

 

 

PS for cutting-edge and bleeding edge discussions, including Jon-Emile and a lot more, don’t miss H&R2019 this may in Montreal…

November 23, 2018

The First Steps Towards Physiological Resuscitation: A Team Effort. #FOAMed, #FOAMcc

(original figure from this old post)

So Rory (@EMnerd) hit us last week with an interesting question that was brought up by David Gordon, a resus fellow working with him, and thought some of us may be willing to belabour his point. A lengthy and really fascinating exchange ensued, which I felt was worth sharing with the #FOAMed community:

 

Rory (Spiegel @EMnerd) find him on emcrit.org

Korbin Haycock (please leave comments to encourage him to get on Twitter)

Segun (Olusanya @iceman_ex) find him on LITFL.com and The Bottom Line

Me (@ThinkingCC) also thinkingcriticalcare.com

David Gordon

My editorial comments!

 

Rory: 

David brought up an interesting question today. Why not do a straight leg raise and use TAPSE to assess the likelihood the pt will be “volume responsive”?

My answer was the following:
“I don’t think the RV increases TAPSE in response to fluid and so the only way TAPSE would be able to assess fluid responsiveness would be if it decreased in response to a a SLR. My contention is this would be a late marker of fluid intolerance and others signs of venous congestion (portal/renal vein doppler) would be seen far earlier. “
In addition I brought up that “volume responsiveness” is a flawed surrogate and we should rather be focusing on volume tolerance.
And that is, in my opinion, the critical concept. 
Anyway David seemed less than satisfied with my answers so I figured I would open the discussion to you physiology nerds…
Korbin: 
That’s an interesting thought, you have brought up.  To clarify, are you asserting that an increase in TAPSE from a volume challenge or SLR could be a indicator of volume responsiveness?  If I missed your meaning, please correct me.
I think Rory is right in his assessment that TAPSE would likely be a more valuable indicator of fluid tolerance (or more importantly , intolerance), rather than fluid responsiveness.  TAPSE, however,  may be (I don’t know) a more sensitive indicator of fluid tolerance than things like IVC collapsibility index, etc.  This might make sense as a decreasing TAPSE (or TAPSV, too for that matter) in response to a fluid challenge might be an earlier indicator that the RV won’t do much with more fluids before it would manifest in things like a non-collapsing, plethoric IVC, decreasing S’/D’ wave ratio on HVD, portal vein pulsitivity, or pulsatile intrarenal venous Doppler.
One problem I’ve had for a long time with fluid responsiveness from the standpoint of the circulation up to the pulmonary valve (IVC collapsibility index being the most common example), is that it doesn’t measure what you really want to know, and that is LV fluid responsiveness.  There is a whole lot going on hemodynamically from when blood leaves the RV to where it finally contributes to LV preload.  I think if you want to know if the patient is fluid responsive, there are quite a few ways to assess this directly, rather than looking at the RV, IVC, etc.
I stopped chasing every bit of volume responsiveness a long time ago, however it does have its place in managing the sick patient, I think.  Usually, my first question is about volume tolerance/intolerance, before I start to think about volume responsiveness.
To investigate the fluid tolerance/intolerance status, I’ll look into a lot of things, usually using a lot of ECHO/US information.  My sonographic considerations are: LV contractility, diastolic function and ventricular compliance, LVEDP, valve pathology, SVR, B-lines (and if B-lines are present, put that into the context of what the LVEDP is because if the pressures are low, but the lungs are wet, pulmonary vascular permeability is high and I’ll think very hard before giving fluids), pulmonary artery pressures, PVR, interventricular septal shifts, RV contractility, IVC, HVD, portal vein, and renal Doppler.
(has anyone ever seen an ED doc do this anywhere??? Wow!!!)
Also, I’m lucky to have some other tools at my place like transpulmonary thermodilution catheters and pulse wave analysis devices to assess things as well.  Sometimes these things make serial assessments more convenient than dragging the US machine over multiple times, and can also give additional information, like EVLW, PVPI, etc.
(I think in the case of Korbin’s hospital, it may be important to bring downstairs care upstairs!)
Secondarily, if I think the patient is volume tolerant and then I have determined that they are volume responsive, and would benefit from volume administration, the next question I ask myself is what’s the best way to do this.
Clinical assessment combined with ECHO comes into play, as if the patient is genuinely volume depleted, volume repletion makes sense.  However, a lot of volume responsiveness is driven by syndromes of high CO and low SVR.  In these cases, I usually give very little volume and opt for a vasopressor to drive venous return instead.  This strategy tends to correct the CO/SVR derangement as well as take care of the volume responsiveness at the same time.  I feel much better if I know that my MAP is being generated by a balanced CO, SVR, and volume status rather than having a “normal” MAP.
I think that is a really, really important cognitive model. The common and traditional approach is to try to maximize CO with fluids and avoid the terrible vasopressors. In a disease where the primary derangement is vasodilatory, it doesn’t seem logical… However finding the right balance is difficult. And with the near-extinction of the PA catheter, we no longer have a low SVR value staring us in the face begging for some pressors.
Sorry to be so long winded, guys.  Hope I didn’t bore you with stuff I’m sure you already know.  These topics are really interesting to me though!  I’d be interested in all of your thoughts on the TAPSE question.
Segun:
I think the RV is more likely to dilate in response to Fluid than change TAPSE, as suggested by a paper or two on RVEDA changes as a predictor of Fluid responsiveness https://ccforum.biomedcentral.com/articles/10.1186/cc3503
(RV dilatation May result in a reduction in TAPSE too?) 
Potentially, yes. SV may not decrease but TAPSE may.
The end result should be a change in stroke volume, so one could argue that rather than TAPSE you could just measure RVOT VTI in response to a passive leg raise. (I don’t really see the difference between M mode and PW doppler, and RVOT VTI is simple enough to measure from a PSAX or RV outflow view)
TAPSE is an Uber-simplified method of looking at RV contractilty rather than volume (overloaded RVs can have excellent TAPSE, for instance). I think it would answer a very different question.
Me:
Interesting question indeed. I can’t agree more with Rory and Korbin. Korbin’s clinical run-through is, as far as I’m concerned, completely on point and, if i weren’t so lazy, and had all the hardware he is fortunate to have, would consider as gold a standard as possible, until  mitochondrial monitoring and trans-capillary flow monitor technology is made.
I think it requires a bit of a paradigm shift away from volume responsiveness, that has been all the rage in the last decade or since the end of the swan age, and instead towards focusing on tolerance. There is significant and building evidence that congestion is end-organ damaging, and evidence that chasing maximal CO is mortality-causing (80’s and 90’s literature supranormal o2 delivery and all that), hence on both fronts focusing on congestion makes more sense.
I think we have to follow the fluid path (venous congestion y/n, rv ok y/n, lungs ok y/n and finally lv ok y/n) and then do a global almost holistic ‘is fluid the best option’ reflection including brain, gut, kidneys, peripheral tissues, etc, with Korbin’s nice little twist on balance of CO, SVR for the BP/perfusion. I don’t think there’s any point of care monitoring tool to unequivocally ascertain the best level of each today.
Rory:
So here is my question, should we be asking “Is this pt likely to benefit from fluids?” rather than “Is this pt likely to augment their CO with fluids?” 
Stop for a moment and think of most of your septic patients (not all, yes, some have cardiomyopathy, some are profoundly hypovolemic), are they actually in a low CO state?  The near-obsession with CO is probably rooted in the common belief that the elevated lactate stems from hypoperfusion, a myth which has been debunked.

Lets say we use Korbin’s gold standard I think we still have to ask what is the benefits of giving this pt fluids? There are many patients I see who would meet all the criteria outlined by Korbin in whom I still don’t administer fluids because whatever increase in cardiac output I get will be transient at best. I am inclined to sit tight allow my antibiotics to take effect and let the pt correct their own vasoplegia. After an initial small aliquot of fluid in the ED I like to see obvious signs of hypovolemia before I give additional boluses. I do like the CLASSIC trials criteria:

(1) Lactate of at least 4 mmol/L
(2) MAP below 50 mmHg in spite of the infusion of norepinephrine
(3) Mottling beyond the edge of the kneecap (mottling score greater than 2)

(4) Oliguria 

All this from the perspective of a decongested venous system and a under-filled heart on US
Korbin:
To Rory’s point, I agree that just because there is a lack of fluid intolerance and the presence of fluid responsiveness, it doesn’t necessarily mean fluids are indicated.
If I have a clinical story that supports a likely lack of hydration plus I’m looking at a high SVR, low CO, and a low SV, I will usually give some fluids.  Mottling, especially if pressors are on board, to me is a clue that some sort of volume might be indicated.
That’s actually quite interesting.  The pathophysiology of mottling isn’t clear (click here for an interesting read), but definitely a space to earmark, when trying to find the optimal balance between vasopressors and CO augmentation.
As far as the lactate goes, as everyone here knows, there’s a whole lot of reasons to have a hyperlactatemia.  It’s drives me a little crazy when I see a lactate come back elevated and the first thing someone wants to do is give fluids, especially if they haven’t considered any of the stuff we’ve been talking about.
I think if you have a patient with a high lactate, the first thing to do is ask yourself why they have a high lactate, rather than trying to correct the number.
Rory:
Agreed, most of the time in a septic pt I view a rising lactate as a sign I don’t have source control rather than a signal to give additional fluids.
Philippe:
So in terms of fine tuning, here is one thing I like to do with tissue saturation – SctO2 (cerebral)  and peripheral:   if it drops with vasopressors I favor augmenting CO (fluids if not too congested, inotropes to consider) if it rises or stays flat with pressors i stay the course. This is definitely not evidence-based, but to me, if tissue saturation decreases while increasing vasopressor dose, it seems logical that the perfusion is dropping, and not a course worth pursuing. I like to think of it as an example of MBE (medicine-based evidence) in the patient in which it is occurring.
David:
It seems to me the feeling is that we shouldn’t be chasing any single indicator of fluid status/tolerance/response/optimization evaluation and the key is to ask the clinical questions and pair that with our sonographic assessment.   RV functional assessment may have a role in that discussion, but TAPSE may not be the best indicator as RVOT VTI may be a better answer to the initial question.
The study that Segun sent out seems to indicate that LVEDA may be a better predictor of SVI.  The septal interdependence plays a larger role than I initially thought and perhaps using M mode to look at changes in septal motion gives you more information about the ability of the heart as a whole to manage the fluids…
That’s an excellent point, because even if the RV can handle the fluid, if the LV cannot, it’s gonna end up in the lungs.
Philippe, what kind of time course do you allow for your lactate to change, other than just response to your initial resuscitation?
Lactate should improve over hours. As Rory says, if a day later it’s still hovering above 4, and you don’t have impaired hepatic clearance, you might be missing something…
Korbin:
That’s something that certainly something to consider, Rory.   I think a lactate that is suddenly rising is most likely driven by a catecholamine surge driven by something going the wrong way.  But not always.
The important thing is to stop and think about what’s going on.
Case in point:  Last week I had a patient that had cardiac arrest due to an asthma exacerbation.  I had put a TEE probe down during he resuscitation, and a little bit afterward based on what I was seeing on the TEE, I felt she needed a pressor.  I used epinephrine because the beta-2 agonism might help with bronchodilation.  Everything hemodynamically look pretty good, except the lactate came up.  The ICU resident saw the lactate and ordered a liter of LR.  I called them and explained that the epinephrine was likely the cause of the lactate and it probably wasn’t anything to worry about.
Rory:
Just the other day I was called to the floor to assess a pt because the treating team was concerned he was septic when his lactate came back at 6.5. I walked in the rm as they were hanging the 30cc/kg fluid bolus. A brief assessment revealed he was in florid CHF. Once I convinced them to stop giving fluids and instead use an aggressively dose of diuretics he did just fine and cleared his lactate without issue.

In my mind lactate in and of itself uninterruptible. In a pt who is otherwise improving and the lactate is not clearing as fast as I would like I tend to just stop checking it. The one I find troublesome is in the post resus pt who doesn’t look great, I don’t have an obvious source, their pressor requirements are slowly rising and the lactate is hovering in the 4-5 range. That’s the pt that tends to do poorly if you don’t identify and establish source control

Korbin:
Agree with that Rory.
If I have those patient with a persistent lactate elevation, and they look like they could be malnourished, I’ll give them some thiamine, too.
Segun:
My two cents- there’s data soon to be released that compared echocardiographic dimensions (RV/LVEDA, IVC etc) to mean systemic pressure- showing no correlation with ANY echocardiographic parameters.
It would seem that going purely by dimensions, you cannot predict volume state on echo… so at the moment we can detect hypERvolaemia with lung, portal vein, and renal vein POCUS (and to a degree IVC), and profound hypOvolaemia by looking at doppler patterns (although the patient is more likely to tell you).
The other side of things, which has been clearly elucidated by everyone in this thread, is the concept of “permissive responsiveness”. Ruthlessly thrashing every heart to its maximum myocardial stretch doesn’t necessarily seem to be the best idea, to my mind.
I agree with everyone’s thoughts. Beyond the initial LLS/Shocked AF stage, you need a very good reason to give a fluid bolus!
And don’t get me started on lactate…
Korbin
I would only comment that the magic of Doppler probably is far more valuable than cardiac dimensions when dealing with hemodynamics.  Dimensions give anatomic values that can be extrapolated to hemodynamics, but PW and CW Doppler interrogation infers pressure differentials, which can directly be applied to things like flow and resistance.  Tissue Doppler has the added informative value of cardiac compliance, so that a comprehensive picture can be painted in light of filling pressures and the relationship to preloading.
When I look at all this together, I really feel that in most cases, a quite accurate picture of what’s going on is within grasp.
To emphasize again, something like B-lines with a compliant, low LVEDP LV, tells me valuable information about pulmonary vascular permeability.  Tread carefully about fluids here.
David:

How does the RV respond to a fluid bolus?

To answer this question first we must understand the role of the right heart in the circulatory system. Often the right ventricle (RV) is compared to the left ventricle, in reality it serves an entirely different function. The left ventricle generates the necessary pressures required to maintain systemic perfusion. The right ventricle’s job is to enable venous return, which is generated by the gradient between the mean systemic filling pressure and the right atrial pressure (RAP). The role of the RV is to maximize that gradient by keeping the RAP as low possible. 

With this in mind let us examine the RV’s response to a fluid bolus. As the RV becomes filled, conformational changes occur within the RV that allow it to increase its stroke volume without increasing the distending pressure.Under normal circumstances, the RV end diastolic distending pressure does not increase in response to fluid loading. Therefore, if the RV is functioning appropriately, RAP does not accurately reflect RV preload. But in pathological states, when the RV is hypertrophied, diseased, or overdistended there is an inverse relationship between RVEDV and RV stroke volume. Any fluid, or increased RV pressure beyond this point results in an increase in RAP, decreasing venous return.1

1. Pinsky MR. The right ventricle: interaction with the pulmonary circulation. Critical care (London, England). 2016;20:266.

So that was the discussion. I certainly thought it was very interesting. Following this, we decided we’d band together and try to hammer out what we think should be the optimal management of shock, trying to tie in physiology, the scant evidence that is out there about resuscitation, and the pitfalls of venous congestion. Finding the sweet spot in the balance between vasopressors, inotropes and fluids is a very real challenge that all resuscitationists face regularly, and it is very unlikely that, given the complexity of such a protocol, looking at tolerance, responsiveness and perfusion, that an RCT would be done anytime soon.

We’ll be sure to share when we come to a consensus, but certainly the broad strokes can be seen here, and I’d love to hear anyone’s take on this!

And of course, we’ll definitely be discussing this further with smarter people at H&R2019 – think Jon-Emile Kenny (@heart_lung), Andre Denault and Sheldon Magder!

Cheers

Philippe

November 4, 2018

H&R2019! Final Programme. Register Now! Montreal, May 22-24, 2019! #HR2019

This event is past. It was awesome. If you really wish you’d been there, you can catch most of it here!

And don’t miss H&R2020!

Click here to register!

Registration is open and we have said goodbye to the snail mail process. Fortunately, we are a lot more cutting edge in medicine than in non-medical technology.

We are really excited about this programme, and a lot of it comes from the energy and passion coming from the faculty, who are all really passionate about every topic we have come up with.

The hidden gem in this conference is the 4 x 40 minutes of meet the faculty time that is open to all. Personally I’ve always felt that I learn so much from the 5 minute discussions with these really awesome thinkers and innovators, so wanted to make it a priority that every participant should get to come up to someone and say ‘hey, I had this case, what would you have done?’   Don’t miss it!

CME Accreditation for 14 hours of Category 1.

This programme has benefitted from an unrestricted educational grant from the following sponsors (listed alphabetically):

Cook

Fisher-Paykel Healthcare

GE Healthcare

Maquet-Gettinge

Masimo

Medquest

MD Management

Medtronic

Novartis

Teleflex

 

The Accreditation is as follows:

 

Here is the Final Programme:

Final Programme

Wednesday May 22 – PreCongress course

  1. Full day Resuscitative TEE course

FOR DETAILS SEE HERE

 

    2. Full day Keynotable

    3. Half day Hospitalist POCUS (PM)

    4. Half day Critical Care Procedures (AM)

    5. Half day Brazilian Jiu-Jitsu for MDs (AM)

for more details on these pre-conference courses please see here.

 

Main Conference Programme: H&R2019 Full Pamphlet

Social Events:

Thursday May 23rd Meet the Faculty cocktail! 1900 – Location TBA – BOOKMARK THIS PAGE!

 

Register here!

FOR ANY QUESTIONS CONTACT HOSPRESUSCONFERENCE@GMAIL.COM.

 

December 14, 2017

The Hospitalist & The Resuscitationist. Montreal, April 18th & 19th, 2018. #Hres2018

NOTE: THIS WAS THE H&R2018 PAGE, SO IF YOU ARE LOOKING FOR H&R2019, CLICK HERE!

So for this winter, we’ve put together a little gem of a conference which will be a mix of hospitalist and critical care medicine, both with a dash of POCUS for good measure. Our focus here will be short, to the point, highly relevant and highly physiological talks on key topics, in short, 15 minute talks.

What are we going to talk about?

Day 1: The Hospitalist

 

Day 2: The Resuscitationist

 

 

You can figure there will also be late-breakers, “ask the crowd” talks and more.

Workshops? Sure:

Yup. You can ask for a workshop. Enough similar requests will probably make it happen. A few have already asked for Neuro-POCUS, so that is a likely addition.

 

So, who will be talking?  The lineup already includes Andre Denault, Josh Farkas (@Pulmcrit), Jon-Emile Kenny (@heart_lung), Rory Spiegel (@EMnerd), Hussein Fadlallah, Peter Barriga, Daniel Kaud, Davide Maggio, Michael Palumbo, William Beaubien-Souligny, and a few more to confirm. And who knows who might do an impromptu drop-in…

 

The short answer is yes. Of course, it does depend on what you do. If you are a hospitalist, involved in critical care or acute care of any kinds, you will find something here for you. Totally awesome for IM residents/FM residents planning on doing some hospital medicine or ICU coverage. Who will get the most bang for his or her buck here? Real docs training or working in the trenches. This isn’t a cutting edge research conference, but a cutting edge clinical application conference.

 

Oh yes, and the CME, of course:

 

This will be a small, fun conference. Space is purposely limited, for an intimate feel and to encourage discussion between peers. No need for these exclusive “meet-the-professor lunch” or anything like that: that’s what the whole event is like!

 

Registration is open! Print, fill, write a cheque and send the form below:

RegistrationV2

If you’re crazy busy, or have any questions, feel free to email hospresusconference@gmail.com or tweet (@ThinkingCC) to reserve a spot! 

Download the brochure here:

H&R2018 Brochure – Participants

 

cheers!

 

The H&R 2018 Scientific & Organizing Committee:

Dr. Philippe St-Arnaud – ER and Critical Care doc, POCUS instructor and constantly pushing the clinical envelope.

Dr. Carola Zambrana – our Hospitalist on the panel, constantly seeking excellence in care and working on bringing POCUS to the wards.

Dr. Mario Rizzi – our friendly neighborhood respirologist and educator.

Dr. Philippe Rola – Critical Care doc, long time POCUS aficionado and instructor, working at bringing POCUS into the everyday physical exam.

 

December 7, 2017

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

 

ps don’t miss the POCUS Workshops on venous assessment at  !!!

December 3, 2017

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 run by Andre and myself on this at :

more to come on this soon…

cheers

 

Philippe

November 19, 2017

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!

Don’t miss Andre running a POCUS workshop on PV/HV at  next april!

Philippe