Transcript
Speaker: Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine.
Speaker: Sound provides comprehensive critical care programs to hospitals across the country.
Speaker: To learn more about our programs and career opportunities, visit www.soundphysicians.com.
Speaker: And now your host, Dr. Sergio Zanotti.
Speaker: Administering intravenous fluids is one of the most common interventions in critically ill patients.
Speaker: Despite its frequency in our practice, there are significant gaps in our knowledge concerning best practices based on solid evidence.
Speaker: In today's podcast episode, we will discuss rational fluid therapy.
Speaker: Our guest is Dr. Adrian Wong, a practicing intensive care medicine and anesthesia physician.
Speaker: He's a consultant and clinical lead at King's College Hospital in London.
Speaker: Dr. Wong is a member of the Intensive Care Unit, Intensive Care Society, FUSA Committee, as an examiner of the European Diploma of Intensive Care Medicine.
Speaker: He was the ex-chair of the Social Media and Digital Content Committee of the European Society of Intensive Care Medicine and the course director of the Genius Ultrasound course.
Speaker: He's on the executive committee of the International Fluid Academy.
Speaker: A true pleasure to have him here today to discuss this important topic.
Speaker: Adrian, welcome to Critical Matters.
Speaker: Thank you very much for having me.
Speaker: I'm very excited.
Speaker: I would like to start with a big question.
Speaker: Why should intensivists care about this topic?
Speaker: Well, I think it is a fluid management, fluid prescription is ubiquitous across healthcare, be it intensive care, anesthesia, emergency medicine, all branches of medicine, intravenous fluid is involved.
Speaker: And especially for being on the intensive care unit, it's core practice, it's core business, it's what we do.
Speaker: We give fluids, we manage hemodynamics, that's what we do on the intensive care unit.
Speaker: And yet, as you alluded to in your introduction, I think there is a lot of variability.
Speaker: in terms of what actually happens on the shop floor.
Speaker: Now, straight bias declaration, I think that fluid therapy is given almost too easily.
Speaker: The patient's heart rate is up, we give fluid.
Speaker: The patient's urine output is down, we give fluid.
Speaker: The blood pressure is down, we give fluid.
Speaker: So I hope we can discuss some of these issues and hopefully provoke thought, reflection amongst all of us in the use of intravenous fluids.
Speaker: Perfect.
Speaker: You mentioned how easy it is to give fluids, almost like we say, a knee-jerk reflex many, many times during the day in our clinical practice.
Speaker: And maybe one way to start framing this conversation is to start thinking about fluids as true therapeutic agents, true medications.
Speaker: And I know that you've worked with some of your colleagues and others on this 4Ds.
Speaker: Could you give us a little bit of a more background on that?
Speaker: Absolutely.
Speaker: So I think if I said to you intravenous fluids are drugs, I don't think any of yourself or your colleagues would disagree with that.
Speaker: And like all drugs, they've got the correct indications and contraindications.
Speaker: So we started off with the four Ds, which is a term coined by Professor Malumal Brand, who's done a lot of work in all this.
Speaker: And the four Ds were initially, the first D is the drug.
Speaker: So what type of intravenous fluid you are going to prescribe?
Speaker: The second D was for dosing.
Speaker: So how much of the intravenous fluids you're going to give, over what period of time, and that's the duration.
Speaker: And finally, the fourth D, which is an element that's often seen as an afterthought and probably neglected, is de-escalation.
Speaker: Now, since the four Ds have been published, Professor Malbrainer has added a few more Ds.
Speaker: So rather than just drug dosing duration and de-escalation,
Speaker: He's added diagnosis.
Speaker: So what's the problem with the patient, the drug, the dosing, the duration, the de-escalation is still there, but now he's added documentation, diligence, and discussion education.
Speaker: And this all feeds into the whole concept of fluid stewardship, which I'm sure we'll come to.
Speaker: Absolutely.
Speaker: Could you give us maybe a quick example of how this would be applied at the clinical practice, at the bedside?
Speaker: So I think if you start with the first of the new these, the diagnosis, so what is wrong with the patient?
Speaker: So it's not just about the elevated heart rate.
Speaker: Is there a problem?
Speaker: What is the diagnosis?
Speaker: So it could be a community acquired pneumonia leading to septic shock.
Speaker: There is evidence of malperfusion for which I am going to administer fluids.
Speaker: So that's the diagnosis.
Speaker: The drug, in a sense, is this whole argument around what type of fluid you're going to give.
Speaker: So broadly speaking, again, is the whole discussion around crystalloids versus colloids.
Speaker: Certainly in the intensive care world and in my own practice, the only colloids we use these days are human albumin.
Speaker: So we don't have the gelatins, we don't have the starches, we don't have the dextranes.
Speaker: We only use crystalloids.
Speaker: And with regard to crystalloids, our practice has now swung towards more balanced solutions such as Hartman's or PlasmaLite as opposed to 0.9% saline or abnormal saline.
Speaker: With regard to the doses, I think we no longer give fluid because.
Speaker: 10-hour bags, 12-hour bags, all these other things.
Speaker: Certainly in my practice, I try to reduce that.
Speaker: I think of fluids with regard to, is this fluid for resuscitation or is this fluid for maintenance?
Speaker: And that will decide the dose.
Speaker: So if it's more for resuscitated purposes, I would tend to go with fluid boluses or fluid challenges.
Speaker: And that will tie in nicely with the duration side of things.
Speaker: I think in my own clinical and research practice, the emphasis now, as continuously trying to evolve, is the concept of de-escalation.
Speaker: When is it time to start taking away fluid from the patients, diureasing them, or using renal replacement therapy to bring their fluid balance back down to neutral?
Speaker: So that's a brief overview of the Ds.
Speaker: You talked about giving fluids for resuscitation, giving fluids for maintenance.
Speaker: We also sometimes give them for replacement.
Speaker: But one aspect that I think we often forget at the bedside is what's called fluid creep.
Speaker: Could you talk a little bit about that and how it contributes to the overall fluid balance?
Speaker: Yep.
Speaker: And so this concept of fluid creep is the type, the fluids that we give that we don't necessarily clock.
Speaker: So, for example, if I prescribe a fluid bolus or a bag of maintenance fluid, be it heartmins, dextro saline, so on and so forth, we are generally speaking aware of it.
Speaker: Our nurses chart it on the fluid chart, on the intravenous therapy chart, so on and so forth.
Speaker: Fluid creep includes those drugs or fluid amounts that we give that we don't necessarily clock immediately.
Speaker: And the example I normally give is, for example, intravenous fluids.
Speaker: For example, in the intensive care unit, the sedative medications that we give, vasopressors that we give, all these drugs are given in a particular volume.
Speaker: And that volume...
Speaker: contributes to the total amount of fluids being administered.
Speaker: And so there was very nice study from Professor Van Riegel-Moltens based in Belgium, who accounted that actually fluid creep accounted for about 30-40% of all fluids administered to the critically ill patient on an IITU.
Speaker: So we need to be aware of it.
Speaker: We just don't think about it because it's not often the forefront of our clinical minds.
Speaker: So it's almost one of those givens in the ICU.
Speaker: I used to say, I think people are changing now, but I used to say that inevitably, yeah, drips for sedation would go up at night.
Speaker: And inevitably over time, people's fluid balance goes up no matter what we do, right?
Speaker: I completely agree with that.
Speaker: I think it's just too easy at times to put a bag up, a slow bag up because the patient is, you know, he's not drinking very much, not eating very much.
Speaker: We'll just hang a bag up for the overnight.
Speaker: Yeah, agreed.
Speaker: And I think this is going to be also an important aspect as we talk about fluid stewardship and de-escalation a little bit later.
Speaker: Now, you did mention, Adrian, the drug portion, right, and the types of fluids that we have available.
Speaker: And this has been an ongoing debate, but I do believe that in the last several years,
Speaker: We've had some important studies that maybe have inclined us to use one type of fluid over others more commonly.
Speaker: Could you just give us a brief overview of the best type of fluid in general?
Speaker: So I'm interested in first balanced versus unbalanced crystalloids, and then crystalloids versus colloids, just kind of like your appreciation of where we stand today based on the available evidence.
Speaker: OK, I think let's start off with your second question, which is around the crystalloid and colloid question first.
Speaker: I think we all remember going to medical school, nursing school, and remember being told, you know, colloids are great.
Speaker: They expand the intravascular volume by three times.
Speaker: They stay in the circulation for longer, so on and so forth.
Speaker: However, you know, numerous trials which looked at the different types of colloids being used when compared to crystalloid solutions, they aren't as good as we thought they were.
Speaker: Certainly they don't expand the intravascular volume by three times.
Speaker: They do stay a bit longer in the circulation, but not that much longer.
Speaker: And like everything else in life, there are the benefits, but also the risks.
Speaker: And we started learning about the coagulopathic effects, the effects of some of these colloids on kidney perfusion and increased rates of kidney injury.
Speaker: So for a variety of different reasons, certainly in the UK,
Speaker: I remember when I started my anaesthetic intensive care training, we would use gelatin quite liberally, and that fell away quite rapidly with all these trials.
Speaker: And to this day, I think I struggle to think of the last time I prescribed a bag of gelatin in
Speaker: the dextrins have been removed from the European market completely.
Speaker: So I think that the discussion, arguments, debates around crystalloid and colloids have swung heavily in favour towards the crystalloid side such that I don't think many of us in the UK use colloids routinely now as a resuscitative fluid stroke drug.
Speaker: so on to the balanced crystalloids versus normal saline argument um that's more interesting there are lots of trials which examine them so the most recent of which i certainly clocked you've had the plus trial the basics trial the split trial the salt ed trial the smart trial and all of them seem to be much of a muchness but with a
Speaker: slight slant towards balanced solutions.
Speaker: Now, normal saline, I'm sure you all know, does not reflect the composition of plasma.
Speaker: There's too much sodium in it and definitely too much chloride in it.
Speaker: And this hypochloremic acidosis has been associated with worse kidney outcomes.
Speaker: So therefore, the logic of
Speaker: or the rationale for swinging towards more balanced crystalloid solution.
Speaker: If you take, for example, the PLUS trial, which was led by Simon Finfer and the ANZICS group.
Speaker: So it was comparison of balanced crystalloid versus normal saline, and there was no difference in 90-day mortality between the two groups.
Speaker: When you combined all the different trials together into a meta-analysis, it seems again to favor the balanced crystalloid group as opposed to the
Speaker: normal saline or any old joke amongst the fluid resuscitationist abnormal saline group.
Speaker: And it's interesting, right?
Speaker: Because how names impact behavior is also interesting in terms that when people say normal saline, of course, it sounds like that's the right thing to give whenever I need to give something, right?
Speaker: And like you said, it has nothing normal in it.
Speaker: And I wonder how that name came up.
Speaker: It does make you think.
Speaker: Yeah, you're right.
Speaker: I don't know how normal saline became normal saline.
Speaker: Yeah, and I think it's important what we label things because I think it conditions our behavior.
Speaker: But like you said, I grew up training in medicine and in critical care background, and we were big on normal saline for everything, right?
Speaker: And slowly, I think...
Speaker: And we would almost like confirm our bias and decay.
Speaker: You would have hypercloremic, metabolic acidosis.
Speaker: You'd say, well, it's just a side effect.
Speaker: Or you would justify a lot of the things that you would see at the best side as collateral damage, right?
Speaker: And I think one of the things that we have learned is that there is a lot of damage that's not only collateral, but that probably impacts outcomes and that we should be paying attention to that.
Speaker: But definitely, it sounds like currently, not only we should be using more crystalloids, obviously, than colloids, like you said, but also when we're using crystalloids, the current evidence and our physiologic understanding would push us probably to preferentially use balanced crystalloids, which I think makes a lot of sense.
Speaker: I think so.
Speaker: I think so.
Speaker: So let's talk about some new concepts, and maybe we can start by just an overall explanation of what's understood by fluid stewardship, and then dive a little bit deeper into some other terms that I think are common when we're talking about fluids.
Speaker: Okay, so fluid stewardship is a variant, draws a lot of parallels with the concept of antimicrobial stewardship.
Speaker: Put simply, it's the right fluid in the right patient for the right indication for the right duration.
Speaker: So I don't think any of us would disagree with that.
Speaker: But I think the extra layer of fluid stewardship, similar to antimicrobial stewardship, is that it is not just one step.
Speaker: It involves multiple steps.
Speaker: It involves multiple colleagues.
Speaker: So this is a multidisciplinary approach to ensuring that the right fluids get into the right patient for the right duration.
Speaker: And with that, there is an element of the clinical side.
Speaker: So what we talked about, the indications, the type of fluid, so on and so forth.
Speaker: But also other non-clinical aspects, such as is there an educational program involved
Speaker: for your team, not just the clinicians, but also the nurses, the pharmacists, so on and so forth.
Speaker: Is there an active governance audit data collection program to ensure that what's really happening is actually what's happening as opposed to what you think is happening?
Speaker: So right amount of fluid, right type of fluid to the right patient for the right time and all the various steps to ensure that happens.
Speaker: And it's interesting also, Adrian, that I'm sure you're aware that this year in the U.S., a series of big storms impacted what apparently we did not even know were some of the critical and few facilities that were manufacturing IV fluids.
Speaker: So all of a sudden, something that nobody bats an eye to give and that's considered to be abundant was scarves.
Speaker: And some hospitals got into a lot of trouble to the point of canceling elective surgery, which has real impacts for patients, right?
Speaker: And it just shows you also that we live under the impression, especially in many hospitals like the ones we practice in some parts of the world that are resource rich, that the resources are basically abundant and unlimited.
Speaker: But that is not true.
Speaker: Some of these resources can very easily under stress disappear and become very, very scarce.
Speaker: But I think what we've also learned during these months that we were tight on intravenous fluids is that maybe if you think about it, you don't have to use as much of it.
Speaker: No, agreed, agreed.
Speaker: I think sometimes we're both very lucky.
Speaker: We work in relatively resource-rich settings that I think we take things for granted until we no longer have it.
Speaker: I wouldn't wish the storm upon anyone, but it is emerging from it is that challenge to look at and review what we do
Speaker: how we practice with regard to intravenous fluids.
Speaker: Why do we prescribe intravenous fluids?
Speaker: Is it because?
Speaker: Why do we do things a certain way?
Speaker: Is it because it's always been that way?
Speaker: It's the way we've always done things?
Speaker: So when faced with such a dramatic challenge, it's an opportunity as well to re-evaluate what we actually do by the bedside.
Speaker: So the other terms that I wanted to hear a little bit more about are there's two terms that everybody uses at the bedside, fluid responsiveness and fluid tolerance.
Speaker: I'm sorry, and fluid overload.
Speaker: And in between is this emerging term of fluid tolerance.
Speaker: Could you kind of tell us what is fluid responsiveness?
Speaker: How do we use it?
Speaker: How do we misuse it?
Speaker: How would you think about fluid overload?
Speaker: And then go into fluid tolerance in more detail.
Speaker: Let's start off with fluid responsiveness first.
Speaker: So fluid responsiveness is put simply, and there are various different definitions out there, is a state where after the administration of fluids, your stroke volume goes up.
Speaker: And depending on which cut of use, so 10, 15%, generally speaking, is the cut of use in response to a fluid challenge.
Speaker: So after the administration of
Speaker: 250 mils or 4 mils per kilogram of intravenous fluids, your cardiac output or stroke volume goes up by 10-15%.
Speaker: And we generally speaking, translates fluid responsiveness to improve tissue perfusion.
Speaker: Now, that is clearly not going to be the case anymore.
Speaker: under all circumstances.
Speaker: We tend to use fluid responsiveness, at least from a macro circulatory perspective, because it's something that we can measure, be it from the stroke volume calculator on an echocardiography, or if you've got some cardiac output monitors, such as the swan GANS, or less invasive devices.
Speaker: That's what we think fluid responsiveness is.
Speaker: And therefore we think if I make the, if I
Speaker: give fluids to this fluid-responsive patient, tissue perfusion will be better.
Speaker: It's obviously very difficult to measure tissue perfusion per se, and so we rely on surrogates, lactate, central venous saturations, capillary refill time, if you have time, we can discuss that later on.
Speaker: But just because you are fluid-responsive doesn't mean you need fluids.
Speaker: So you and I sitting here having our chat, we may not have had a drink of water, a cup of tea in the last hour or so, and if we did any fluid responsiveness tests on either of us, I'm sure we're going to be fluid responsive.
Speaker: However, if we then look at markers of tissue perfusion, our markers of kidney injury, our lactates, so on and so forth, I'm pretty sure we are okay, Sergio.
Speaker: We're going to be okay.
Speaker: So just because you're fluid responsive doesn't mean you need fluids.
Speaker: I've mentioned cardiac output as sort of the benchmark in terms of assessing fluid responsiveness.
Speaker: But there are other parameters that we could use.
Speaker: Some people have used this diameter of the inferior vena cava.
Speaker: I think it's probably incorrect to use mean arterial pressure, urine output, although that's easily done by the bedside, because strictly speaking, we're looking at how the heart responds, how the circulation responds to that fluid challenge.
Speaker: Does that make sense?
Speaker: It does, and I think that the point you made, which is an important one, is to reemphasize is that just because you're fluid responsive doesn't mean that you require or that we should be giving you fluid, right?
Speaker: I think that has been, I think the two things that I have noticed in practice is that first, a lot of times people are not measuring for fluid responsiveness, which is
Speaker: It's another story.
Speaker: But when they use a dynamic hemodynamic measurement to look for it, they immediately equate that with more fluid.
Speaker: And we spend a lot of time thinking of a kind of upstream, right?
Speaker: Upstream impact or effects.
Speaker: But we don't really think about what's happening downstream, which is where the harm's being done.
Speaker: And we need to be more balanced in our approach.
Speaker: So with regard to fluid overload, now all of us probably, it's been drilled into us since day one medical school.
Speaker: If you give too much fluids, you're facing a patient who acutely becomes short of breath in full-blown primary edema.
Speaker: That's obviously one, the extreme end of what might happen.
Speaker: We know there are numerous studies out there that if you are in positive fluid balance after 48 hours on the intensive care unit, your outcomes are poorer.
Speaker: and outcomes include mortality, but also morbidity.
Speaker: So you spend more time on a ventilator, you spend more time on the intensive care unit, you have a higher incidence of complications, so on and so forth.
Speaker: But we know too much fluids is a bad thing.
Speaker: It's not just the lungs, it's all the other organ systems as well.
Speaker: So it's the liver, the gut, the brain, so on and so forth.
Speaker: So it is not just a cardiovascular system that sees the impact of too much fluid.
Speaker: The term fluid tolerance is a relatively new one.
Speaker: And essentially, it is the degree at which the body can handle the fluid without having
Speaker: organ dysfunction becoming evident.
Speaker: So in the same way as palmar edema is a measure of how the lungs are not coping, fluid tolerance just expands that concept to the other organ systems, the kidneys, the gut.
Speaker: Again, declaration of interest.
Speaker: I have a clinical research interest in the kidney, so that's the focus of
Speaker: my clinical practice at this moment in time and my research practice time.
Speaker: But simplistically, fluid tolerance is the degree at which the system, the body, copes with fluids without any evidence of organ dysfunction.
Speaker: And it is interesting how we've evolved over the last decades, right?
Speaker: I mean, I still remember practice long enough where you would almost think that peripheral lower extremity edema was just basically collateral damage.
Speaker: That's what you see in these patients in the ICU.
Speaker: If they got into pulmonary edema, a lot of times if they're still sick, you would just say, okay, that's an indication for intubation to keep giving fluids, right?
Speaker: And that we really did not see what was going on underneath the skin.
Speaker: You talk about the kidney, but obviously we've learned a lot about it.
Speaker: intra-abdominal hypertension and compartment syndrome and how that can also impact the kidney and impact other structures, even to the point where I think we've all recognized that we've had patients in the ICU for a long time who were quite encephalopathic and not waking up.
Speaker: And once you start diuresing them, all of a sudden, I mean, they...
Speaker: start waking up, right?
Speaker: So even at the CNS level, I think we've seen these effects.
Speaker: And I think that's really what we're trying to prevent, right?
Speaker: To use the concept of fluid tolerance to try to manage patients in a way that we don't get to those kind of very advanced organ failures that were precipitated by the overuse of this drug of intravenous fluids.
Speaker: So as we dive a little bit deeper into fluid tolerance, Adrian, can you tell me a little bit about how you think of the determinants of fluid tolerance?
Speaker: So I think the way I use it on a daily basis in my clinical practice is to think about fluid tolerance both from the palmary perspective and then the systemic perspective.
Speaker: The palmary perspective, because that's more or less drilled into us, you know, too much fluid, palm reedema.
Speaker: Okay.
Speaker: Okay.
Speaker: With regard to the other organ systems, the systemic side of things, I think my practice has evolved tremendously with the evolution of point of care ultrasound.
Speaker: So in my practice, I scan patients a lot, not just the heart.
Speaker: as can the lungs and more recently the abdomen and the venous circulation.
Speaker: So if we start with the lung first, we know that lung ultrasonography is superior to clinical examination and chest radiograph when it comes to detecting palm edema, consolidation, plurifusion.
Speaker: It's a relatively quick, non-invasive examination.
Speaker: So I use that to give me an idea of how wet the lungs are in the correct clinical context.
Speaker: With regard to the other organ systems, those of us who practice ultrasound would have undoubtedly heard of the VEXA score that was published two, three years ago now by colleagues in Canada.
Speaker: And the principle of the VEXA score is to quantify or examine the venous side of the circulation.
Speaker: For too long now, we generally speaking have just been focusing on the arterial side of circulation.
Speaker: What's the mean arterial pressure?
Speaker: What's the systolic blood pressure?
Speaker: And really with the venous side, we tend to be restricted by the fact that we've just got the CVP.
Speaker: But William and colleagues basically use ultrasound.
Speaker: And by performing Doppler analysis of the hepatic portal infrarrenal vein, in combination with the inferior vena cava, they tried to quantify and score the degree of venous congestion.
Speaker: And that led to the development of something called the Vexus score.
Speaker: An increasing VEXIS score is associated with poorer kidney outcomes in that original patient population, which was the post-cardiac surgery population.
Speaker: But the evidence base for the use of VEXIS is rapidly expanding.
Speaker: It's a tool that's out there.
Speaker: I don't think we know when the best time to use this tool, how to use this tool quite yet, but it's a rapidly evolving field, so keep an eye on it.
Speaker: And in terms of a, of a tolerance, I think that one, one of the, the, the issues, right.
Speaker: Is that we don't think about a lot of the duration and deescalation timing.
Speaker: Right.
Speaker: And this hopefully helps you, helps you limit that, that, that, that timeframe and initiate that, that phase a little bit quicker.
Speaker: Is that how you use it at the bedside when you think about this?
Speaker: I've reached a stage in my career where I constantly think about the fact if there's a bag of fluid hanging up there, I ask myself and the team, why is it up there?
Speaker: Because if you buy into the principle that intravenous fluids are drugs, and all drugs have got their side effects, first do no harm.
Speaker: So I constantly find myself asking, why is that bag of fluid out there?
Speaker: Is there too much fluid on board?
Speaker: So asking myself that question, and only by asking myself that question do I start thinking about possible solutions.
Speaker: Is it time now to take fluid away, be it from using diuretics, so LASIK furuzumide?
Speaker: Or if this patient is on renal replacement therapy, should I be setting fluid balance targets towards the negative side now?
Speaker: One of the frameworks that has been popularized in this context of people who obviously are doing the research and talking about this is the ROSE framework.
Speaker: I think there's others similar, but I think the concept is
Speaker: is the same.
Speaker: And the idea of really incorporating these four Ds into an algorithm for practice that's easy to remember.
Speaker: So could you talk about that in detail and kind of walk us through each phase?
Speaker: What does ROES signify?
Speaker: But then also talk to us in terms of not only how do we do it, what the best practice says, but how do you do it and how do you implement this at the bedside?
Speaker: Okay.
Speaker: So ROES stands for R for resuscitation.
Speaker: O for optimization, S for stabilization, and E for evacuation or de-escalation.
Speaker: The way I use it is that whenever I see a patient at the bedside on the ward in the emergency department, I ask myself, okay, where is this patient with regard to these different phases?
Speaker: Is it in the resuscitation optimization phase?
Speaker: Or if this patient has been on the intensive care unit for a number of days, is this patient towards the evacuation end of that spectrum?
Speaker: So if I start off with resuscitation
Speaker: So resuscitation is the life-saving phase.
Speaker: You're trying to rescue the patient.
Speaker: So early, adequate fluid management needs to be given.
Speaker: So, for example, if you have the surviving sepsis guidelines, they recommend 30 meals per kilo in the first hour or multiple fluid boluses.
Speaker: Four meals per kilo tends to be the standard fluid bolus given in across five to ten minutes or so.
Speaker: to use fluid boluses more so small aliquots of fluids given give reassess give more reassess so your triggers to starting this phase sort of this is a patient in shock essentially so you've got a mean arterial pressure that's barely recordable you get a patient who's drowsy and if you've got any test of
Speaker: fluid responsiveness, there will be fluid responsiveness.
Speaker: You've got evidence of malperfusion, so the lactate is up, the central venous saturations are down, your cardiac index and cardiac output is down, so on and so forth.
Speaker: So that's a resuscitation phase, so this is a patient really sick, you need to rescue them.
Speaker: Once you've administered some fluids and you've
Speaker: bought yourself a bit of time, then it becomes optimization.
Speaker: And this is about trying to rescue the organs and avoiding fluid overload.
Speaker: So this is a time where your advanced cardiac output monitoring goes in, your
Speaker: echocardiography comes in, your various different tests of perfusion, be it biochemical or physiological, so your lactate, your cardiac index, your pulse pressure variation, you've hopefully cited arterial lining.
Speaker: So that's the optimization phase.
Speaker: Now, the stabilization phase is this is when the patient is getting better.
Speaker: You know, you've got them to a state where their blood pressure and their organ perfusion are all reasonable.
Speaker: This is the phase that I think that most people are saying to themselves, well done team, we've managed to save this one.
Speaker: They're slowly on the mend.
Speaker: So the antibodies are kicking in, they're recovering post-operatively or whatever it may be.
Speaker: But this is, I think, is the phase where if you are complacent, you take your eyes off the ball, you start letting the fluid creep happen.
Speaker: The positive fluid balance that was, you know, 500 mils here and there suddenly becomes three, four liters over the couple of days before you realize it.
Speaker: So this is the phase, I think.
Speaker: certainly for me, is the one I lose sight of and I try to remind myself, okay, are we approaching the E phase, the evacuation phase, where now you think actually we're reaching the stage where the positive fluid balance is starting to have a detrimental effect on the patient.
Speaker: And I should be thinking about resolving the fluid overload in order to improve the
Speaker: organ perfusion, and that is by achieving negative fluid balance in whatever form that you want to think of, whatever means you're thinking of and available to you.
Speaker: So diuretics or renal replacement therapy.
Speaker: So let's dive a little bit deeper in some of these.
Speaker: I'll ask you some questions, but that was a great, great overview, Adrian.
Speaker: And when we're thinking of the resuscitation phase, right, I think you mentioned that a lot of times clinically, it's very easy or very likely that we can predict if someone's going to be fluid responsive, right?
Speaker: When you meet a patient,
Speaker: who is hypotensive, tachycardic, presents to the ED or to the ICU briefly with a raging infection, septic shock, we know that if you give them fluid, they're going to be fluid responsive.
Speaker: Now, if we were to measure fluid responsiveness, like you said, it doesn't mean that being fluid responsive means that you need fluid, but at that stage,
Speaker: which might be creeping into the optimization stage.
Speaker: If we were to measure at one point flu responsiveness and they're not flu responsiveness, that should be a sign to pause, right?
Speaker: And think a little bit what we're doing because I think that people sometimes still get fluid.
Speaker: So I think you're absolutely right.
Speaker: I think the first thing I would say is that all the fancy tests that we do or have up our sleeves, it doesn't replace your clinical examination and your clinical acumen.
Speaker: So as a practitioner of ultrasound, I say to myself more often than not, don't treat the image, treat the patient.
Speaker: That's the first thing I would say.
Speaker: I think the next thing I would say with regard to giving fluids in those situations is that
Speaker: fluid responsive you give fluids and nothing happens don't keep giving fluids I see it quite a lot in my years of training that okay I've given 250 500 mils of a fluid challenge nothing happens so I'm going to get more and I keep going I keep going I keep going I think it's if something hasn't gone according to plan or what isn't what you expect it to happen then I think it's a reminder to just stop think and
Speaker: Have you got the right diagnosis?
Speaker: Have you got the right treatment?
Speaker: Am I causing harm?
Speaker: So those are the things that crossed my head if I was faced in that scenario.
Speaker: And there's also this concept, obviously, of ebb and flow, right?
Speaker: And it's not like you are an R and all of a sudden you're an O and you remain an O because patients have ongoing inflammation with many of these diseases, right?
Speaker: So you might get to a point where you don't need additional fluids, but 24 hours later, 12 hours later, for many reasons, that patient might need an additional fluid and just recognizing-
Speaker: recognizing that that that it's kind of like it's not like a clear cut right we kind of are can you talk a little bit more about that concept i think i think one of the thing great things i enjoy about intensive care medicine is that it's such a dynamic place patients change hour by hour day to day and i think that when you see the patient just because the strategy worked
Speaker: an hour, two hours ago or a day ago.
Speaker: It doesn't mean that it's still going to work.
Speaker: So this constant
Speaker: going to the bedside, examining a patient, evaluating the patient, making a plan, and after you've done what you think was the right thing to do, vasopressors or fluid or whatnot, go back and reassess.
Speaker: I think sometimes when we prescribe, coming back to the core topic around fluid, we give fluids and when we walk away, well, and by the time you come back, it may be a couple of hours,
Speaker: You know, that fluid bolus that you gave, that fluid you've administered, you've lost sight of what it actually did.
Speaker: So you're completely right in the sense that things change with the patient day by day, hour by hour.
Speaker: And the take-home message is go back and reassess, go back and reassess.
Speaker: Do something, make a decision, go back and reassess.
Speaker: Has it worked?
Speaker: Has it not worked?
Speaker: Is it beneficial or has it caused harm?
Speaker: The other aspect that I was thinking and wanted to ask you about, Adrian, is there is a point where giving fluid will still help raise the blood pressure, but you're probably at an inflection point where it also will start causing harm.
Speaker: How do you think about that?
Speaker: I mean, the fact that even it gives you the physiologic effect that you are looking, I think raising the blood pressure would just be maybe a surrogate for...
Speaker: for fluid responsiveness, but there's a point maybe where you're seeing signs of harm or considering the fluid tolerance concept that probably, even though it might help your hemodynamics, the right answer at that point is not giving more fluid.
Speaker: Can you talk a little bit about that?
Speaker: Yeah, and I think this is where the concept of fluid tolerance that's emerged over the last couple of years has really made me sit up and think a lot more because we tend to think of...
Speaker: fluid tolerance and fluid responsiveness as one as a start point all the way to the other end of fluid unresponsiveness and fluid intolerance almost like it's almost like a straight line but um more so
Speaker: So we think about fluid tolerance and fluid responsiveness on one side, and then all the way to the other side, fluid intolerant and fluid unresponsive, almost like a straight line joining up between these two dots, if you will.
Speaker: But there is reasonably good evidence emerging, certainly from colleagues such as Glenn Hernandez of the Andromeda trial, and then other South American colleagues, for example, Munez, who's talked about the fact that you can be...
Speaker: fluid intolerant and yet be fluid responsive and you can also be fluid tolerant and also fluid unresponsive.
Speaker: So now you've got four phenotypes, if you will.
Speaker: The tolerant-responsive and the intolerant-unresponsive are obviously the ones that seem obvious to everyone.
Speaker: And then what's emerging now is that the other two states.
Speaker: So
Speaker: fluid-responsive and yet fluid-intolerant, and fluid-unresponsive and fluid-tolerant.
Speaker: And I think that just reflects the complexity of the circulation hemodynamics and what we thought we understood about it.
Speaker: So it's the field that's gradually emerging.
Speaker: The evidence and studies are only starting to emerge, but you are right.
Speaker: The way I tend to work it is, okay,
Speaker: This patient may be fluid responsive using whatever test I choose to use, but yet on my assessment of fluid tolerance, the risk benefit now swings towards the side of the degree of harm is a much more real possibility.
Speaker: So perhaps in this patient, I am not going to give any more fluids.
Speaker: I'm going to stick with vasopressors or a wait and see or whatnot.
Speaker: I hope that makes sense.
Speaker: Yeah.
Speaker: And I think it's a great illustration of the complexities of this topic, but of any topic related to critical care in medicine.
Speaker: And I think it...
Speaker: it really invites us to be a lot more humble, right?
Speaker: And to really appreciate that we really understand very little of what we do and how these complex systems such as a biological system interact.
Speaker: are are things that we're just basically understanding i think the very very surface of it but but but i like this i love this discussion adrian because i think that a lot of clinicians would assume that ivy fluids is just a it's an easy topic it's just something we just do right but when you start really peeling the layers of this onion it starts getting really really interesting
Speaker: You know, I am old enough to remember when I graduated from medical school that in terms of fluid balance and fluid strategies, you gave two litres of normal saline and one litre of dextrose.
Speaker: You know, it's a balance of sweet and salty and you change it up in between.
Speaker: And the more I progressed in my career, the more I realised how little I knew then and how little I know now about something as...
Speaker: core, as fundamental as fluids.
Speaker: So since we graduated from medical school, you could prescribe fluids.
Speaker: You couldn't do the same for chemotherapy agents or anything like that.
Speaker: But fluids, go knock yourself out.
Speaker: Everyone, knock yourself out.
Speaker: So we used to say, I mean, when you finish medical school, you're 007, right?
Speaker: License to kill.
Speaker: And maybe the most accessible tool was fluids at that time.
Speaker: Yeah, but it just, I think when you reach the stage where you realize that you don't know everything and you may have caused harm with what your practice is, it's truly a time to reflect on what you know.
Speaker: And I think more importantly, what you don't know.
Speaker: And there's a lot we don't know in medicine and intensive care.
Speaker: For sure.
Speaker: And one of the themes that keeps coming up over and over again on the podcast as I speak with colleagues and experts from around the world is that at the end of the day in medicine,
Speaker: there is probably more value in having the right questions than having the right answers, right?
Speaker: And really thinking at the bedside and asking the questions.
Speaker: And the question I want to dive in right now is, at what point do you say, okay, it's time to de-escalate and to de-resuscitate or to get into that evacuation phase?
Speaker: And how do you proceed then?
Speaker: Okay, so I think this is a fascinating one, and I've been trying to answer that question in my own practice for the last couple of years.
Speaker: There was a very fascinating study by colleagues in Belfast, Jonathan Silversides, who essentially surveyed clinicians, presented scenarios, the fluid overloaded, fluid access patients.
Speaker: What would they do?
Speaker: And the take-home message across all the various parameters and questions given was that there is huge amount of variability in terms of what clinicians would do, in terms of what indicators they would use, what parameters they would use to indicate, I'm going to start taking fluid off.
Speaker: And then subsequently, a lot of variability in terms of how you would achieve that negative fluid balance.
Speaker: So a bolus of LASIK, an intravenous infusion of LASIK.
Speaker: You put them on renal replacement therapy, so on and so forth.
Speaker: I wish I could say to you that if you did de-resuscitation, your patients will do better.
Speaker: The trials just aren't out there.
Speaker: A recent systematic review by colleagues based in Switzerland have basically shown that.
Speaker: However, in all the trials that looked at de-resuscitation versus conventional therapy,
Speaker: the intervention arm and the control arm, there was never really a significant separation between the groups in terms of the fluid balance.
Speaker: Hence, that might be why we didn't see the outcome that we would have liked to have seen.
Speaker: So putting it all together, what I do in my practice, I ask myself, okay, is this patient appropriately resuscitated?
Speaker: Is there any evidence of organ malperfusion?
Speaker: Is there any evidence of fluid access?
Speaker: Is there any signs of venous congestion?
Speaker: If the answer, I work through that in a sort of like a checklist fashion, and the answer is yes, the patient is appropriate resuscitation.
Speaker: There's no evidence of organ dysfunction at this moment in time.
Speaker: No, yes, there's starting to be evidence of fluid access, be it
Speaker: In the lungs, in the tissues, in the kidneys, yes, there is evidence of venous congestion on, say, ultrasound.
Speaker: And if the patient has no ongoing vasoactive drug requirement or significant vasoactive drug requirement, then I would think about de-resuscitating them.
Speaker: So that, generally speaking, is my approach to it.
Speaker: Some colleagues would advocate if they're no longer fluid responsive, you could start de-resuscitating them then.
Speaker: My personal opinion is that there are tools, easily available tools out there to give you that extra layer of security just beyond the question, is this patient fluid unresponsive responsive?
Speaker: But there's also probably a role for implementing dynamic measures as you resuscitate them, right?
Speaker: Could you use them in the reverse way to say, okay, I'm getting to a point where there's a good point?
Speaker: Can you talk about that a little bit?
Speaker: Yeah, so one of the strategies that they put forward is that generally speaking, well, the traditional speaking, as we talked about earlier, was that these patients who are fluid intolerant are going to be fluid unresponsive.
Speaker: So if you de-resuscitate them to the point, you know, they become fluid responsive,
Speaker: regardless of what your parameters you use.
Speaker: So that's one way of gauging how much you can de-resuscitate.
Speaker: The other way, which I think is a nicer way of doing it, is with using the VEXA score, which we briefly talked about.
Speaker: So we know there are several studies out there that show us that in patients who have a high VEXA score, so multiple sites of venous congenital
Speaker: a de-resuscitation strategy, these scores will track.
Speaker: In the same way as we know from colleagues in mostly from the nephrology, but also in critical care world, if you have a wet set of lungs on ultrasound and you start de-resuscitating, evacuating them, you can assess them again and track their lungs going from a wet state to a dry state.
Speaker: So yes, there are other tools available out there to help you fine tune how much fluid to remove or what period of time.
Speaker: Perfect.
Speaker: As we close the clinical discussion, Adrian, are there any major pitfalls and pearls that you could share with us?
Speaker: I've already said my number one take-home message was just because you're fluid responsive doesn't mean you need fluids.
Speaker: That's the first thing.
Speaker: Definitely is my one take-home message from this.
Speaker: I suppose the other pearl is to keep
Speaker: Your eyes, ears, peel for the evolving evidence base, certainly when it comes to fluid tolerance.
Speaker: I think the concept of fluid responsiveness is more or less established now across critical care and acute specialties, but I think the concept of fluid tolerance is less well established.
Speaker: And my sincere hope over the next couple of years, both in terms of the clinical side of things and the research side of things, is that that concept of fluid tolerance, the degree of harm, becomes more widespread and it becomes part and parcel of our daily discussions by the bedside.
Speaker: Excellent.
Speaker: And I think that as pitfalls, obviously, it would be the converse of your number one message, which is don't give fluid just because they're fluid tolerant and they're fluid and responsive, right?
Speaker: That would be kind of like the pitfall that we obviously see.
Speaker: Is there anything in particular that you're really, I mean, I think you mentioned some of the things that seems that you're quite excited about the evolving research and studies on the concept of fluid tolerance and how to apply this at the bedside.
Speaker: But are there other large clinical trials that we should be paying attention to coming up in the upcoming year?
Speaker: I think I'm aware of certainly looking at, there are a few trials looking at a more conservative fluid strategy when it comes to various different clinical conditions, but also more specifically when it comes to more conservative fluid strategies, the use of
Speaker: tools to assess the venous side of the circulation, ultrasound being the most obvious ones, is starting to be part of the newer clinical trials.
Speaker: So, for example, if I'm going to de-resuscitate someone, more often than not, it's just a urine output, weight-based outcome or guide.
Speaker: But now we're seeing trials being published or methodologies of trials being published where they are looking at more of
Speaker: dynamic parameters assessments of to guide the research station.
Speaker: So that's quite exciting.
Speaker: Excellent.
Speaker: So we'd like to close the podcast, Adrian, with a couple of questions that are unrelated to the clinical topic.
Speaker: Would that be okay?
Speaker: Yeah.
Speaker: The first question relates to books.
Speaker: Are there any, a book or books that have influenced you significantly or books that you have gifted often to other people?
Speaker: Okay, so there are two books.
Speaker: So the first book is, I expect most of your listeners will have heard about it, is Daniel Kahneman's Thinking Fast, Thinking Slow.
Speaker: And the reason why I love this book is because over the years, I've been fascinated by decisions.
Speaker: In other words, why healthcare professionals do the things that they do?
Speaker: For example, if you go back to the initial topic of fluid, why do you give fluid?
Speaker: What made you give the fluid?
Speaker: Is it more often than not, it's pattern recognition, it's the way we've done things, it's our bias.
Speaker: And I find Dan Economan's book, Thinking of Artings, so fascinating to help me answer that question.
Speaker: The second book I'm going to recommend is aligned with my interest with regard to fluid stewardship.
Speaker: And that is Simon Sinek's Start With The Why.
Speaker: How do you get a team working together with a common goal?
Speaker: And I find this book really, really insightful in terms of the slanty of the human mind.
Speaker: How do you get teams to work as a team?
Speaker: that unified sense of purpose, that unified goal.
Speaker: So, yep.
Speaker: So those two books are the ones I probably mentioned and influenced me the most in the last couple of years.
Speaker: Awesome.
Speaker: And we definitely will include those in the show notes, links to those books, and both are excellent reads.
Speaker: I think Thinking Fast and Thinking Slow, like you said, really an amazing book, giving us insights into cognition, right, and how we think and how we make decisions.
Speaker: Yeah.
Speaker: We do all the time in the ICU, but we're never metacognition.
Speaker: There's no metacognition thinking about how we think, right?
Speaker: So I think this is perfect.
Speaker: And definitely Simon Sinek, I think, is a very gifted communicator.
Speaker: And the golden circles and the start with white concept, I think, is a great framework to apply to patients.
Speaker: to everything, right?
Speaker: I mean, even to your own life, you could say, I mean, what is my why?
Speaker: And we'll definitely include those.
Speaker: And I encourage our listeners, if you have not read these books, absolutely, you should, because you're not going to regret it.
Speaker: The second question, it relates to, I think that the greatest sign of intelligence is when we can change our minds, right?
Speaker: When we can admit that we were wrong and move on and learn.
Speaker: So could you share something you changed your mind about over the last couple of years?
Speaker: So I have recently just come back from spending a week in Milan talking about patient safety in a fellowship organized by the European Society of Intensive Care Medicine.
Speaker: And over the years, aligned with my interest in healthcare decisions is the concept of clinical governance.
Speaker: So how do we get colleagues or how do we encourage colleagues to do the right thing?
Speaker: And when I started my training, my intensive care career, I remember thinking that clinical governance is just one of those tick box exercise.
Speaker: It's a bureaucratic paperwork.
Speaker: It's there to stop me being the clinician that I can be.
Speaker: And over the last few years, since I became a consultant, I think the importance of clinical governance has been underlined
Speaker: So many times through either a patient adverse safety event or clinical audits or service evaluation, how do we build a framework such that healthcare practitioners who go to turn up for work and want to do the right thing can do the right thing in order to achieve the best possible outcome for our patients?
Speaker: So from seeing this clinical governance as a negative bureaucratic thing,
Speaker: I'm not saying that it's definitely a positive thing.
Speaker: I've recognised now the importance of it and how we operationalise the term clinical governance and how important it is to delivering the best possible care for our patients.
Speaker: I think that's a very important point and definitely something that a lot of times, unfortunately, because of how it's structured, has a negative connotation for our colleagues.
Speaker: But you're right.
Speaker: It serves a very important why.
Speaker: And the question is, how do we make it work towards that why?
Speaker: And also as an enhancement of our practice.
Speaker: Agreed.
Speaker: 100% agree.
Speaker: The final question, Adrian, is what would you want every listener to know?
Speaker: It could be a parting thought, fact, a quote, anything you want to leave our audience with to think about.
Speaker: So when I first got into critical care practice, one of my wise professors said, sat us all of the new trainees fellows down, sat us all of us down and said, ladies and gentlemen, just because you can doesn't mean you should.
Speaker: And he followed up this
Speaker: immortal line with a quote from Professor Dunstan, who is a professor of theology and moral ethics from the University of London, and it reads, The success of intensive care is not, therefore, to be measured only by the statistics of survival, as though each death were a medical failure.
Speaker: It is to be measured by the quality of life preserved or restored, and by the quality of the dying of those in whose interest it is to die.
Speaker: and by the quality of human relations involved in each death.
Speaker: So I have this sort of pinned in multiple notebooks around the place just to remind myself of the why, if you will.
Speaker: Adrian, that's a good death can be a good outcome.
Speaker: Absolutely.
Speaker: And I think that is something that we should all think about and is a perfect place to stop.
Speaker: I really appreciate you taking the time to share your expertise with us.
Speaker: Learned a lot and look forward to having you back on the podcast soon.
Speaker: Thank you very much.
Speaker: It's been a real pleasure.
Speaker: Thank you for listening to Critical Matters, a sound podcast.
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Speaker: Sound's transforming the way critical care is provided in hospitals across the country.
Speaker: To learn more, visit www.soundphysicians.com.
