Renal Imaging and Blood Clotting for COVID-19 Patients: A Follow-Up Talk with Dr. Justin Kirk-Bayley

May 14, 2020

Dr. Justin Kirk-Bayley is the Clinical Director of Therapeutics at the Royal Surrey County Hospital in Guildford, England. Dr. Kirk-Bayley is an expert in the use of ultrasound in the ICU and anesthesiology.

On April 30, Fujifilm Sonosite Chief Medical Officer Diku Mandavia, M.D. interviewed Dr. Kirk-Bayley for insights on using ultrasound to treat and manage COVID-19 patients. That interview can be found on Sonosite’s COVID-19 resource page, or you can read the full transcript. In addition to this interview, we asked Dr. Kirk-Bayley several follow-up questions regarding renal imaging, blood clotting, his personal experience with COVID-19, and the general mood of the UK during the pandemic.

Sonosite:

Tell us more about renal imaging and fluid resuscitation for COVID-19 patients.  

Dr. Kirk-Bayley:

Dr. Philippe Rola in Canada has been talking about this for a while in his publications about venous extraction ultrasound (VEXUS). And realizing that with fluid dynamics, essentially there's a sweet spot for fluid resuscitation. We know that you need to get oxygen delivery right, with cardiac output right, but the worry and the issue is that you need to really think about resuscitation, optimization, stabilization, and extraction, or evacuation. And it's that last bit there—that evacuation bit that people don't really pay enough attention to.

And so people get patients who are going into renal failure and they think, “Oh gosh, it's renal failure, we need to give them some more fluids.” And of course, what they fail to appreciate is over the preceding 14 days or so, they may have put 20 plus liters of fluids into these patients with the incumbent salt load in there, and water goes where the salt goes. And actually what you've got is tissue edema, and now you've got tissue edema within the abdominal compartment that's causing a reduction in venous flow within the kidney complex. That's actually reducing your glomerular filtration. And so fluids is not the answer.

What you have to be doing is doing anything that's available to you to try and get the fluid out. Now that might be put it in one for filtration or dialysis, or it might be just using what little renal output you have to use diuretic or something like that. But that's something that we've been working with for about the last 12 months or so. Just saying, “Okay, is this renal failure or actually fluid overload? And how can we look at this? Can we look at the flow within the kidney or we can take it all the way back to the IVC or with their hepatic system and stuff like that?”

And there are a whole lot of published waveforms as to what you should be looking at. But of course, COVID-19 is mimicking that because if you look at the venous flow reduction, and they haven’t been fluid overloaded, we have to assume then that it's micro-thrombosed stuff in the kidney. These waveforms that are showing with the reduction in renal flow are just as apparent in the kidney, and we know that the major write-up for COVID-19, right at the beginning, has been to keep them dry, super dry. But now, as our experience has progressed, we've realized that's the wrong thing to be doing because by the time they come to you, they're already really dry because they've been having fevers of 40 degrees Celsius, way above 100 Fahrenheit. They've not been eating, they've not been drinking. And to dry these patients out is absolutely the wrong thing to do. So you need to try and correct for that free water deficit.

And all the traditional tools, for those B lines on the lungs that you might think about usually and the circulation changes. They're just not quite there, you have to try and work it out, and then try and work out if you've gone too far and a bit of clinical work there. But the VEXUS stuff from the kidney things, I have to say that's been really useful. I work in a unit that's got tertiary hepatobiliary patients coming in, so we pick up patients who come in from lots of other hospitals. And they come in looking like Bibendum, the Michelin Man, like somebody who's just taken an air hose and been inflated up to three times their size. And that's just free water. And they've got edema, and they have renal failure. And a lot of their renal failure, it has become really apparent over the months with this skillset, is that it's simply renal failure because they are very, very wet.

Sonosite:

So when you're doing the renal imaging, what exactly are you doing? What is the procedure?

Dr. Kirk-Bayley:

We’re looking for the color Doppler flow. So if you go from the IVC to lack of distensibility, collapsibility, then you go to hepatic vein. There's a particular waveform that you should see both in the hepatic waveform and the portal venous system. So they should behave with a standardized waveform. What happens is that that changes or you get flow reversal. And as the total circulation gets more engorged, and the flow through the intestinal system from the portal venous system changes as well, those patterns change. Eventually the very worst fluid overload is when you start to get renal parenchymal distention because it's almost a fixed system within the renal capsule there. You start to see a reduction in the venous flow within the renal parenchyma that you can pick up. And you can see that drop right down when you're using color Doppler on that. And that then is your clue that you may be underperfusing the kidney, because pressure from edema within that system is greater than the renal venous flow, then actually that the glomerular filtration is just not happening.

Sonosite:

Wow, that’s a phenomenal application for point-of-care ultrasound.

Dr. Kirk-Bayley:

Yeah, it's fantastic. The more I learn about point-of-care ultrasound, the more people publish, and every couple of years something else comes out. These things are just game changers really. I remember the excitement of using optic nerve sheath diameter as a marker for intracranial pressure. I now find myself going around and teaching neurologists and acute physicians this in the UK and for them it's fantastic. Should I be doing a CT before I do my lumbar puncture? Oh well, actually they've got raised intracranial pressure and I can see that from just a quick option scan. I'm not going to be doing that lumbar puncture, but I'm definitely going to be getting that CT scan and things like that. And it's just these really quick, easy wins that you can get with point-of-care ultrasound just make my life so much easier.

But there's still this thing in the UK that it's not nearly as widespread as myself and my other point-of-care ultrasound friends around the country would like. And there seems to be significant inertia to it. And it's really strange, I don't know why that is. It could be because it's so easy to get a CAT scan these days. And actually why do something yourself when you can have somebody do it for you? It’s that mentality.

Sonosite:

We see that in the U.S. and other places. I do wonder if the training of medical students will make a difference here.

Dr. Kirk-Bayley:

Yeah, I hope so. There isn't a medical school in the UK yet that I'm aware of that has got it in their undergraduate curriculum. We came tantalizingly close to having it in a medical school around the corner from us at the University of Surrey. One of our pitches was we would help deal with undergraduate education because we know from stuff that I've seen at the University of California Irvine and stuff like that that's been published there, it really enhances their understanding. Real cadaveric anatomy to sono-anatomy and actually being able to track the path of nerves with your own eyes and stuff in a living, breathing human being, not one that's being preserved is fantastic. So I think if you can catch people early and you can get that epiphanal moment of wonder, then that's when you sow the seeds for their future career. So to be a medical student now in the U.S. where that's starting to be embedded as an undergraduate would be really exciting.

Sonosite:

We’ve been getting reports that blood clotting is becoming a complication in COVID-19 patients. Have you been encountering that?

Dr. Kirk-Bayley:

Very much so, that is absolutely a thing. So not only is it a problem, and we're seeing lots of blood clotting, but we're finding that because of the impact of the virus, high levels of clotting factors that you would standardly measure. And seeing huge variation in some of these things. That means that when we go back to using the standard things that we would use to thin the blood, like Heparin and stuff like that, it's just not working properly. And so we're starting to use other things. We're having to use anti-thrombin drugs like Argatroban, and we're having to get hold of point-of-care coagulation testing machines. So I'm waiting for my thromboelastograph to arrive. So that I can actually find out what an in vivo coagulation profile looks like so I can adjust it quickly—because the last thing I want to do is turn a clot then into a bleed by getting it wrong.

The government in the UK have been really good. They've just literally opened their checkbook and said whatever you need. I'm lucky, I've got some great equipment. When I wanted a point-of-care coagulation profile testing machine, I've got one coming pretty quickly. Because clotting is killing people.

Sonosite:

As we track the deaths from COVID-19, there are still many other deaths from people not going to the hospital. What are your thoughts on this issue?

Dr. Kirk-Bayley:

Collateral damage is definitely going to be a thing. The difficulty with this disease is the public paranoia. People don't want to come into the hospital because of course the press said stay at home, stay at home. Because if you come into the hospital you're going to die. And so we're seeing people now who almost undoubtedly are having coronary ischemia and myocardial infarctions, but they're not coming into our EDs. So in 12 months' time, we're going to have a whole cohort of patients with heart failure. And we know that clearly people are dying out in the community and if they're not dying directly with the traditional respiratory factors of COVID-19, I strongly suspect that the clots and the thrombotic diseases are definitely a cause of demise. Because if they're sitting in the house, they're not getting out and about, they're not moving around. That exposes them again to another risk factor. And there's lots of stuff going out in the popular press saying if you get it and you're at home, just lie down, take it easy, not do too much. Actually, I'm not sure that's great advice. It should be drink lots of water and get up and move around.

Sonosite:

Could you go into more detail with your personal experience with COVID-19?

Dr. Kirk-Bayley:

I had come back a couple of days after a ski holiday in Europe, and I just did a bit of gardening. Nothing too strenuous, but I really ached. I had severe myalgia for about four days. I thought, “I didn't deserve that.” And then I started to develop this cough. A really, really bad cough. I'm unlucky, I've got a lobar bronchiectasis. So I have a bit of an issue with coughing anyway. And it was just terrible. And then my wife and my son were just a bit unwell at the same time. So, with the retrospective look at it, we had it pretty early. And I tell you what, if I didn't have it then either I've got a super, super immune system or I have been amazing with my PPE. Because I cannot imagine I have not had full exposure to it.

Because back at the beginning, there were patients who other colleagues were saying in other specialties, “Nope, no, no, this patient doesn't have COVID-19.” Sometimes they'd say the swab testing has come back as negative. And of course, the swab testing that we had available to us in the UK was only about 75, 80% sensitive. I got asked to put an ultrasound probe on a patient reasonably early on who was unwell and was asked, "Is this pus in the lungs? Is this a big empyema?" So I got my ultrasound probe on and I said, “Nope, it's COVID-19.” And this guy had been coughing on me for about 10 minutes. So I and plenty of my colleagues have had similar experiences where we've definitely been exposed to it and, of course, there's a proportion of people who will just simply be asymptomatic. But it's quite difficult to know if you've got it at work or you just got it out in the community, just standing in the queue for the chemist or whatever.

Sonosite:

You’ve touched on a topic we want to discuss. Not everyone presents with fever, and that seems to be the hallmark for everything. They're scanning people at airports, walking into hospitals. What do you see along those lines in the population?

Dr. Kirk-Bayley:

I'm slightly separated from it because of what I was mentioning, the ED guys and the acute physicians really picking up those less unwell patients. The only people who come across my path are the people who are really suffering. The people who've got severe hypoxic respiratory failure where their lungs are just giving up on them. But I know from having spoken to my ED colleagues, people are being sensible enough to think, “Hmm, could this be COVID? I don't feel like I can function normally. I can't look after myself. I haven't got a fever but I just don't feel right.” I think there's been a reasonable degree of introspection in the UK over the last few years that's been propagated by a great character called Ron Daniels, who was part of the UK Sepsis campaign. You see signs on the bus shelters and on the Underground, and big signs that say, “Could this be sepsis?” And I think there's a proportion now of people who are realizing, “I don't want to go near hospital because I'm worried about getting COVID-19. But actually I think I might have it, but I don't have a fever.” So we are still seeing people coming in.

But I get a bit of a distorted view because although I work in a major cancer center, and my local population is quite an affluent area. So my local population tend to have fewer comorbidities. But what that does mean though is that the people who are coming in tend to be older. Because when they come in, they may not have many comorbidities, but they've lived healthy lives. So my day-to-day practice is that when they get to the doors of intensive care, they are in their mid-70s and beyond. And of course once they get to me, it's not good news.

Sonosite:

How about the overall population of your area? How are they dealing with the pandemic and on their day-to-day basis?

Dr. Kirk-Bayley:

I suppose the worry is the unemployment. That's definitely a thing. The government has put this thing where if you're lucky enough to be employed, then your employer can do what's called furloughing, and the government will cover 80% of your salary. So certainly for the UK economy, the government's going to take a hit paying out all that money. But of course, there are plenty of people who are self-employed and their businesses are just going down and they don't know what to do. Or things are not so bad if you can work from home, for example a litigation attorney or someone like that who can do everything over the web. But if you've got a physical workplace job and you have to get out there, those people are suffering, there's no doubt.

People are missing social contact. I live in a little cul-de-sac of seven houses. And we all know each other, and we stand outside our houses, and so we sort of wave at each other. But those sort of degrees of human interaction are changing. But people are finding new ways as well. This whole internet thing with the camera thing and online stuff, it is really taking off. People are clearly sitting at home and not having something to occupy themselves, so they're clearly trawling social media. And I'm having contact from people I haven't seen for 20 or 30 years and they've clearly looked me up and realized what I do. And so people are just changing their lives.

I think when we come out of this, life is never going to be the same again. I think that I mentioned about my commute being better. I think about my commute into work, and I only live 18 miles away from my hospital. But some days it can take me an hour to get there. I reckon that actually when I come out of this is actually going to take me less than that in future because there are people who realized they just don't need to actually have a physical presence at their job. And I think companies are also going to realize that the money they've been spending on the rents and the leases for their buildings to have people within the workplace is wasted. They could actually just spend that money on other things, and people could just have reasonable productivity outside of the workplace and work from home. And if we're really lucky, that'll be translated either into better salaries for people or maybe better profits for companies and better dividends and the like.

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