To POCUS or not to POCUS… No, that is NOT the question! #FOAMed, #FOAMus, #FOAMer

So a few weeks ago I got into some twitter debates after I – not uncharacteristically – stated that, in my opinion, practicing acute care today without using/learning POCUS  is unethical. Now I was hasty, and, in my wording did not exclude those docs who simply do not have access to the technology, and I apologize for that. For the rest, however, I totally stand by my words.

So there was a bunch of smart people who exhibited the monosynaptic reflex of asking for the evidence, the studies, or else brandishing some that showed that some aspect or other of POCUS is flawed, or some anecdote about misdiagnoses, bla, bla, bla…

Now this time, I’m going to start the discussion with the bottom line, in a sense, and leave the nitty gritty for later (which is actually the most important part, tho). But here it is:

Unless you think that the addition of ultrasonography cannot perform more accurate and rapid diagnoses than you can with your inspection/palpation/percussion/auscultation, you cannot rule against POCUS. 

Now if you actually believe that, the corollary would be to never ask for an echocardiogram, abdo-pelvic ultrasound, etc… Not too many takers. Thats what I thought.

What you can challenge, however, is the process of POCUS, meaning how do you get Dr. John Doe competent enough to make a call of pathology X (for the diagnostic aspect) and how do we clinically integrate and act on the POCUS findings, many of them being “new” from increased sensitivity, what do they mean, what does their evolution mean? Many good questions there.

That’s why I lament the entire debate around POCUS. These smart people should focus their neurons on helping us fine-tune POCUS instead.  POCUS is a huge, exploding field. I’m pretty POCUS-comfortable, but don’t ask me to start looking at bones and tendons and ligaments and a myriad of other applications. There’s not much in the body we can’t get some ultrasound into, so all those represent areas of additional information to be assessed.

The education process is also clearly in need. I’m on a panel of the Quebec College of Physicians whose mission is to put some parameters around POCUS. There’s no holding it back, it’s just about getting it going in the right direction.

It’s like anything else in medicine. We have no perfect tools, because we are working with a hypercomplex system with many variables.

And speed. Anyone interested can scan thru the POCUS cases on my blog, and what you see every time is the speed and accuracy that POCUS brings. Studies are hard, and complex. POCUS is not a single intervention, so measuring impact is difficult. Let’s say we have a septic patient with an obstructed kidney. POCUS will assess the hemodynamics, guide fluid resuscitation and inotrope use, but also find the probable source quickly, then perhaps make sure there is no gastric distension prior to intubation, confirm ETT and CVC placement, and more as the evolution goes. How do you make an RCT around that?  It is, however, a good idea to validate every aspect (which has essentially been done already, but certainly there is more to do).

Sadly, most of the naysayers, in my experience, are not echo-competent and likely don’t want to feel like med students all over again, learning a complex skill from scratch, and instead are crossing their fingers hoping that somehow, ultrasonography will be discredited… Yup, it’s not just a river in Egypt.

POCUS is a work in progress. It won’t go away. Hop on and give us a hand. Your patients will benefit.

 

cheers!

Philippe

Bedside Ultrasound Quiz Part 2: A 50 yr old man with dyspnea, acidosis, hepatitis and leg edema. #FOAMed, #FOAMer, #FOAMus

So I was glad to see some great answers on twitter about this case, so let me fill you guys in on the management and the details.

So my diagnosis was of a (likely viral) myocarditis as a subacute process over the last weeks, with a superimposed pneumonia causing the acute deterioration and presentation to ED.  I didn’t think that his elevated lactate represented shock, but rather a reflection of adrenergic activation and reduced hepatic clearance due to congestive hepatitis.  He also had congestive renal failure. Of course, the LV had a 4 x 2 cm apical thrombus, which is likely secondary to the dilated cardiomyopathy.

So the management was diuretics, antibiotics, and anticoagulation, which resulted in a gradual improvement of the respiratory status and renal/hepatic dysfunction. He had a coronary angiogram the day following admission which showed two 50% stenoses deemed to be innocent bystanders.

Bottom Line:

I think the learning point in this case is that, without POCUS, this could easily have been treated as severe sepsis with multiple organ failure (potentially rationalizing away the BP of 140 as a “relatively low” BP due to untreated hypertension), and as such, may have received fluids… Especially south of the border where they are mandated to give 30 cc/kg to anything deemed “septic.”  This would have been the polar opposite of the necessary treatment.

The scarier thought is that he may have then progressed to “ARDS,” been intubated and then the debate between keeping him dry and giving fluids for the kidneys may have ensued.  Though a formal echo likely would have been done, it may not have happened in the first 24-48 hours… If MSOF progressed and he succumbed, the rational may have been that he was “so sick,” and died despite “best care…”

The reality is that he is not yet out of the woods today, with an EF of 15% and afib, but he is off O2 and sitting up in a chair. Fingers crossed he falls in the group of those with myocarditis who improve…

Love to hear anyone’s thoughts!

 

Cheers

Philippe

Bedside Ultrasound Clip Quiz! A 72 year old man with fever, weight loss and tachycardia. #FOAMed, #FOAMcc, #FOAMer

So a 72 year old man is brought to the ER after collapsing at home. His family had noted weight loss in the last months, and recently some fever and general weakness.  His HR is 108, T 38.8, BP 80/40, GCS 14 – somnolent – he is in lactic acidosis (4.5) and renal failure (cr 180 – baseline 120), with some vague abdominal pain, a clear chest and warm extremities.

POCUS shows a normal IVC, normal RV/LV, A profile lungs, no ascites, and this on the left flank:

 

What is the main diagnosis?

Scroll below for the answer:

 

 

 

 

 

 

 

 

 

So the clip shows fairly severe hydronephrosis, the “bear paw” with very dilated calyces.  The patient was suffering from obstructed pyelonephritis due to massive retroperitoneal adenopathy later found to be lymphoma.  A couple of hours later he got a nephrostomy tube to take care of the septic source (double J could not pass) and his sepsis resolved within a few days, and he headed off to chemo for the NHL.

The advantage of POCUS here is. once again, the speed of diagnosis. He went straight from CT to the readied urologists and source control happened within a couple of hours. His relatively benign abdomen may not have prompted a rapid CT otherwise.

See here for more POCUS!

cheers!

 

 

Philippe

Hepatic Portal Venous Gas (HPVG): a Less Ominous Sign than We Thought? A Case of HPVG associated with massive PE… #FOAMed, #FOAMcc

So a few years ago I had a patient in the ICU, post op for some abdominal surgery, and, using POCUS, I detected a hyper echoic area in the liver, in a wedge shape.  I scanned the patient and, lo and behold, there was a matching area of air-filled hepatic venous sinuses on CT scan. Well, my surgical colleague and I were very concerned and proceeded to inform the patient he would be needing exploratory surgery for what was likely ischémie bowel. He essentially – though in more polite words – told us we were idiots and that his belly felt fine and he didn’t think surgery would be needed at all.

His belly did feel fine. So were his labs. So we worried, but, given this whole thing about free will and consent, etc, couldn’t very well force him into what we felt was necessary surgery.

The next day he was fine. On POCUS, the area of air had shrunk. The next day, it was gone altogether.

We thanked him for his keen clinical acumen and for teaching us a good lesson.

However, we were a bit perplexed, because traditional teaching equated portal venous air with a severe bowel disorder, usually ischemic or inflammatory, with exceedingly high mortality. At least that is what we had been fed. We are both grads of 1999. Hmmm…

So over the next few years we saw a few of these cases, sometimes bad, sometimes not, and a review of the literature (see below)  showed an interesting evolution of the disease. Described in the 1950’s on plain films, hepatic air was a bad omen indeed, with mortality in the 75-90% range. In the CT era, the mortality started to “drop” to the 35-60% range. Now you can find quite a few reports of “surprisingly” good outcomes with conservative management. So this evolution doesn’t represent a change in severity so much as the technological capability to detect smaller and smaller amounts of air in the venous system – just increased sensitivity. And now, with POCUS – ultrasound is the most sensitive detector of air in a vascular tree – the associated mortality is likely to take another drop, not only because of our ability to detect very small amounts of air, but also because we are actually looking at the area, and also in a wider range of patient’ pathologies that those commonly associated with HPVG.

 

Clinical Case: HPVG and PE!

So a couple weeks ago I saw a patient in the ED who’d recently broken an ankle, had her foot put in a boot and managed conservatively and came back dyspneic and tachycardic. Here are a couple of clips:

As always, I start with the IVC:

Big & fixed.

Hepatic veins:

Biphasic flow.

Femoral veins:

So here the source of the problem is pretty clear, a large common femoral DVT.

She wasn’t very echogenic so I don’t have great clips of the heart but she had a dilated and hypocontractile RV with a McConnell’s sign (preserved apical contraction), small and hyper dynamic LV with septal flattening.

Now here is where it gets interesting, the portal vein:

You can clearly see bubbles traveling up the portal vein. Ominous, or not?

So clinically, her abdomen was normal, she had no abdominal symptomatology at all…

 

Pathophysiological musings:

So the severe RV obstruction resulted in significant venous congestion. Additionally, the decreased cardiac output – as manifested by a lactate of 4 and mild tachycardia/hypotension (110 HR, BP sys 90’s) was clear.

The etiology of HPVG in the literature isn’t clear – mucosal disruption, bacterial gas are all mentioned but as far as I could find, no definitive answer.

Is it possible that there is a “normal” inward leak of mucosal gas that is normally fully dissolved in the venous bloodstream, but that, in cases of low flow and/or venous congestion, the dissolution capacity (per unit time) decreases, and that gas comes out of solution?  Alternately, those who have increased intraluminal pressure (gastric distension, etc), the increased transmembrane gas driving pressure may overload an adequate blood flow…

This would explain the benign course of many patients, particularily those with gastric dilation.

 

Clinical course:

Based on hemodynamics, tachypnea and, to some degree, venous congestion, I decided to thrombolyse her using 1/2 dose lytics. Within a couple of hours her HR decreased to the 90’s and BP rose to 110 systolic.  Echographically, however, the IVC/RV findings remained similar, but the HPVG decreased. By the next day, HPVG was altogether gone, lactate had resolved and dyspnea was significantly better.

 

Take Home Message:

HPVG, although not quite as poor a prognostic sign as once thought, nonetheless warrants concern and investigation, even if the abdominal exam is entirely normal and without symptomatology, as correction of an underlying cause of “benign” HPVG (whether low-flow or bowel distension) would still need to be addressed.

In the meantime, I suspect that, reported or not, this has been noted by other POCUS enthusiasts, since we are now looking more frequently at this area, and are dealing with patients with low-flow states, congestion, bowel obstruction/ileus or more than one of these.

Hopefully some investigators will take a look at this phenomenon and delineate the pathophysiological mechanism!

Love to hear of your experience with this.

cheers!

 

Philippe

For those interested in POCUS, see here for a quick read primer on clinical applications of POCUS.

 

HPVG Review article 2009:

wjg-15-3585

 

Bedside ultrasound case: Fibroids, Syncope and Dyspnea. #FOAMed, #FOAMus, #FOAMcc

So today, a 33F presented following syncope. She was mildly tachypneic wiyh a HR of 135 and BP of 130/80. I’m inserting the clip of my bedside ultrasound evaluation, as this takes place essentially simultaneously with my history-taking:

So this clip runs thru a few views, starting with an IVC long axis, showing a relatively plethoric IVC with minimal variation. This is not normal. Tells me to expect something abnormal downstream, unless someone has flooded the patient with IV fluids. The next view is the parasternal long, then short axis, showing an increased RV to LV ratio, and a small, hypercontractile LV, with septal flattening consistent with RV pressure overload, the “D” sign.  The apical 4 chamber follows with little else to add (difficult to measure TAPSE well in that segment).

So this is sure looking like pulmonary embolism, and I’m already toying with a half dose TPA, MOPETT-style, until the reveals that the cause of her starting oral contraceptives two months ago was to control heavy menses associated with large uterine fibroids… So I figure I’ll buy myself some decision time anyhow by ordering the CT angio – unless in pre-arrest, I don’t thrombolyse without formal confirmation – but I did start IV heparin on the echo findings. Here is the CT:

So this indeed confirms submissive embolism, particularly to the left PA.

Next?  I work in a community hospital, and although I’m totally comfortable thrombolysing PE, in this case, I was concerned about bleeding related to the fibroids, and I haven’t yet figured out a way to embolize bleeding vessels at the bedside, so I felt that the safest thing was to transfer her to a tertiary care center with a solid interventional radiology program. So off she went. I’ll update if anything funky was done like a catheter suction and I can get some clips.

So in terms of POCUS, I think this illustrates how speedily a diagnosis can be made, and although in this case the pre-test probability and index of suspicion was pretty high, it isn’t always!

cheers!

 

Philippe

 

For more POCUS tips, see here!

MOPOCUS: A great synopsis by Ha & Toh. #FOAMed, #FOAMcc, #FOAMus

Just came across this review and figured I should share. The authors make a great synopsis and review of POCUS in acute illness:

MOPOCUS Review by Ha &To

The only thing I would add to this is a more physiological way to assess the IVC, which I’ve blogged about here.  Sadly, I’ve heard a few people stating how they didn’t want to get into the dogma of IVC ultrasound, that it wasn’t reliable, etc.  The IVC doesn’t lie. It’s just not a recipe. The IVC findings have to be integrated into the rest of the echo graphic and clinical examination.  Trying to use it as a single value is akin to using serum Na+ as a diagnostic test for volume. It works only sometimes.

Please spread among the POCUS non-believers. We’ll convert them, slowly but surely. But the sooner, the better for the patients. Again, there’s no excuse to practice acute care without ultrasound. It’s not right. I’m not saying every probe-toting MD is better than one without, but everyone would up their game by adding POCUS, once past the learning curve!

cheers!

 

Philippe

The NYC Tracks with Jon-Emile: The Glycocalyx – The Next Frontier. #FOAMed, #FOAMcc

I was really psyched when Jon-Emile mentioned he would like to talk about the glycocalyx.  I first blogged about it here, basically when I stumbled on the extensive literature on this huge organ we have been completely ignoring in terms of physiology and therapeutics. It lines our entire endothelium, which is where most of our therapeutic interventions go, and we only heard of it in passing, possibly in histology class as med 1’s.   Hmmm.  Anyhow, here, Jon-Emile and I talk about it a little, discuss possible clinical implications, but more importantly Jon mentions the relatively new blog of Dr. Thomas Woodcock (@thomaswoodcock), http://www.fluidtherapy.org, who is one of the pioneer clinicians who have studied the glycocalyx, and who is now trying to bridge the bench to the bedside.

I’ve been fortunate enough to get in touch with him and we’re planning to record some discussions soon.

So, in my view, the glycocalyx is a formidable force we have been ignoring, and have been damaging often with our interventions. I’m hoping to see some developments allowing glycocalyx assessment outside of the labs in order to give us the tools to reassess every fluid in terms of the relative damage it does to what is essentially the gatekeeper between the blood and the tissues.

Love to hear some comments!

Here is the chat with Jon:

 

cheers

 

Philippe