Transcript
Speaker: Welcome to Critical Matters, a sound critical care podcast covering a broad range of topics related to the practice of intensive care medicine.
Speaker: And now, your host, Dr. Sergio Zanotti.
Speaker: The Society of Critical Care Medicine held their annual Critical Care Congress last week in San Diego.
Speaker: Today's episode of Critical Matters will be a little different.
Speaker: We will not have a guest as usual, and instead, I will share with you all five things I learned at the recent Society of Critical Care Medicine Critical Care Congress.
Speaker: This will be a very arbitrary recap that will focus on topics I found interesting and by no means represents the best or most important or a comprehensive review of everything presented at the meetings.
Speaker: We will cover four important clinical trials that were published ahead of print and presented during the conference, and also some thoughts on ECMO.
Speaker: Links to the studies will be provided in the show notes, and I encourage you to read them as I will not dive deep into details during the podcast.
Speaker: So why don't we get started?
Speaker: Number one, to bag or not to bag.
Speaker: Hypoxemia is the most common complication during tracheal intubation of critically ill patients.
Speaker: and may increase the risk of cardiac arrest and death peri-intubation.
Speaker: Furthermore, critical ill patients are considered to have a higher risk of aspiration during tracheal intubation for many reasons.
Speaker: There's been two schools of thought in this camp.
Speaker: One is to bag patients from induction to intubation, and the other one is not to bag patients to use rapid sequence intubation and to minimize the risk of aspiration.
Speaker: This study
Speaker: really touches on a topic that I have not thought about a lot, but is a common occurrence in our daily practices.
Speaker: It's the bag mask ventilation during tracheal intubation of critically ill adults by the PREVENT investigators in the Pragmatic Critical Care Research Group.
Speaker: It was published ahead of print in the New England Journal of Medicine and presented at the conference.
Speaker: This was a multi-center randomized control trial
Speaker: involving several academic centers in the United States.
Speaker: It had a 401 adult critically ill patients that were undergoing tracheal intubation and they were randomized to either ventilation with a bag mask device after induction to the point of laryngoscopy versus a different group that had no ventilation between induction and laryngoscopy.
Speaker: The primary outcome of this study was the lowest oxygen saturation observed
Speaker: between induction and two minutes after intubation.
Speaker: Secondary outcomes included the incidence of severe hypoxemia that was defined as a SAT of oxygen below 80% and evidence of aspiration by different means.
Speaker: So what did they find in this study?
Speaker: The median lowest oxygen saturation was 96% in the bag-vast ventilation group and was 93% in the no ventilation group.
Speaker: The incidence of severe hypoxemia, as I said earlier, defined as a sat below 80%, was 10.9% in the bag mass ventilation group and 22.8% in the no ventilation group.
Speaker: Both of these findings, both the primary outcome and the secondary outcome, were statistically significant.
Speaker: Regarding the aspiration events, aspiration, as reported by the operator,
Speaker: was 2.5% in the back-vast ventilation group and 4% in the no ventilation group.
Speaker: More objective measures of aspiration, such as a new opacity in the chest x-ray at 48 hours post-intubation, was 16.4% and 14.8% respectively.
Speaker: In other words, there was no significant difference in either of the aspiration measures.
Speaker: My practice has always been to back patients, obviously pre-induction,
Speaker: but also post-induction, and I also minimize, when possible, the use of neuromuscular blockers.
Speaker: Now, I do understand that there's a lot of people who are very dogmatic about this and would argue that bagging after induction in critically ill patients who may not be MPO will increase the risk of aspiration, and they really think that that would lead to bad outcomes, which it certainly can, so they really proceed with rapid sequence intubation and no bagging after induction.
Speaker: I do believe, though, that this study, which was a very well-conducted study and answers an old question that occurs, I mean, I think on a daily basis, really would indicate that bagging is not only safe but likely associated with less severe hypoxemia, with better oxygenation, and no increased risk of aspiration as per this study.
Speaker: So my take-home message is to stay calm.
Speaker: and keep on bagging.
Speaker: Number two, how to titrate PEEP and ARDS.
Speaker: Decreasing ventilator-induced lung injury remains the cornerstone in the treatment of ARDS.
Speaker: Low tidal volumes help mitigate volume trauma, and PEEP has been proposed to mitigate atelectal trauma, or the trauma of those opening and closing alveoli.
Speaker: The best strategy to titrate PEEP remains unknown.
Speaker: This study was published ahead of print in JAMA and presented at the conference.
Speaker: It was titled, The Effect of Titrating Positive End Expiratory Pressure, PEEP, with Esophageal Pressure Guided Strategy versus an Empirical High PEEP FiO2 Strategy on Death and Days Free from Mechanical Ventilation Among Patients with Acute Respiratory Distress Syndrome.
Speaker: It was published by the EPVENT2 study group,
Speaker: And it was a large randomized study that involved 14 hospitals in North America.
Speaker: This study included evaluated the potential clinical benefits of a PEEP setting strategy guided by lung dynamics as measured by esophageal pressures versus an empiric PEEP-FIO2 strategy in adult patients with moderate to severe ARDS.
Speaker: Moderate to severe ARDS was based on Berlin definitions
Speaker: and a FiO2 to a PaO2 ratio of less than or equal to 200.
Speaker: This study included 200 patients, adult patients with moderate to severe RDS, and they were randomized to either A, an esophageal pressure guided PEEP,
Speaker: And the idea here was that transpulmonary pressure, which is equal to airway pressure minus esophageal pressure, would be measured on a routine basis by the use of an esophageal balloon.
Speaker: And the goal was to titrate the PEEP
Speaker: to a transpulmonary pressure of 0 to 6 centimeters of water.
Speaker: That was one group.
Speaker: And the second group was an empirical high PEEP FiO2 table to set the PEEP.
Speaker: And that was based on a basically a table that tells you for a given FiO2, this is the PEEP that you should utilize.
Speaker: And it was extracted from the oscillate study, which is an earlier study in ARDS with oscillators.
Speaker: The primary outcome of this study was a ranked composite score that included death and ventilator-free days among survivors at day 28.
Speaker: And it's ranked because death had a heavier weight than ventilator-free days, but it was a composite outcome.
Speaker: And secondary outcomes included 28-day mortality, ventilator-free days, need for rescue therapy.
Speaker: So what did these investigators find?
Speaker: They found no difference in the primary outcome.
Speaker: The likelihood of having the primary outcome was the same for both groups.
Speaker: There was also no difference in the 28-day mortality or ventilator-free days among survivors, which were part of the secondary outcomes.
Speaker: And there was, though, a significantly lower likelihood of requiring rescue therapy in the esophageal pressure guided group.
Speaker: It's very interesting that when you look at the details of the study, the levels of PEEP,
Speaker: for the group were very similar, where you went with the esophageal balloon on a daily basis or where you went with the table that was just titrating based on FiO2 requirements.
Speaker: So as a group, there was no differences.
Speaker: Maybe a larger study would be able to
Speaker: differentiate specific patient level decisions that might have been different, but that was not captured.
Speaker: But ultimately, I think that the message that we take home from this study is that we should put those esophageal balloons away for now and maybe just Google a PEEP FiO2 table and use that at the bedside as it seems to be as effective.
Speaker: Number three, capital refill and septic shock.
Speaker: This is a fascinating study that comes to us from Chile, from Hernandez and collaborators, from what's known also as the Latin American Intensive Care Network.
Speaker: It was also named the Andromeda Shock Randomized Clinical Trial.
Speaker: I think a very cool name, obviously.
Speaker: And this study evaluated the potential role of the clinical assessment of peripheral perfusion as a target during resuscitation.
Speaker: in early septic shock.
Speaker: So this was a multicenter RCT that was conducted over the course of one year from March of 2017 to March of 2018 in 28 intensive care units in five countries in South America.
Speaker: I think there was a very well-designed study, very interesting.
Speaker: This randomized 424 patients with septic shock, which was defined as infection plus a lactic acid greater than 2 plus the need for vasopressors post a 20 MLCC per kilogram bolus of fluid.
Speaker: And what they did is they randomized patients to a step-by-step recitation protocol that was similar in both
Speaker: in both groups and very protocolized and either they would aim that protocol to group A was normalizing the capital refill time which was measured every 30 minutes.
Speaker: They had a very defined way of measuring capital refill.
Speaker: They would use a glass slide, press on the right index finger nail bed for 10 seconds, press with pressure till the nail bed is white
Speaker: At that point, they would wait 10 seconds, then release the pressure, and with a chronometer, we'll measure time to full recolorization or refraction.
Speaker: return of capital refill.
Speaker: And anything above three seconds was considered abnormal.
Speaker: So they don't provide inter-observer reliability scores or intra-observer reliability scores, but they do mention that they were very systematic and everybody got trained and that the findings or the procedure was very reproducible.
Speaker: That was group A. So they would titrate this protocol resuscitation
Speaker: to a normal capillary refill that was measured every 30 minutes.
Speaker: Group B was a presentation that was titrated to normalizing or decreasing the lactate levels.
Speaker: And that was basically lactate clearance, and it was based on previous studies, a lactate study.
Speaker: And the idea was that every two hours they would want to see either a decrease of 20% or greater of the lactate level
Speaker: or it normalized at one point.
Speaker: And the two hours has to do with lactate dynamics.
Speaker: What is also important to emphasize with this study is that the intervention was really taken in place over eight hours.
Speaker: So the first hours, eight hours after randomization.
Speaker: And the protocol was a stepwise protocol that started with assessment of fluid responsiveness by different means,
Speaker: but all validated means that have, I mean, plenty of literature and by centers that do it routinely and do it well.
Speaker: They would evaluate for fluid responsiveness.
Speaker: If the patient was fluid responsive, they would give a bolus of 500 cc of crystalloid.
Speaker: They would reevaluate the patient in 30 minutes in the capillary refill time and at two hours with the lactate,
Speaker: And at that point, if they were still fluid responsive and the lactate was either not normal or not decreased by 20%, or in the capillary refill group, if the capillary refill was abnormal, they would do another bolus of fluid.
Speaker: and they would continue giving fluid until the patients either were not fluid responsive or they met a preset safety parameter based on CVP or other safety parameters, in which case they would go to the second step of the protocol, which was a vasopressor challenge.
Speaker: And in these patients, what they would do is they would, in patients who were chronically hypertensive,
Speaker: they would increase the MAP to 80, 80, 85, and would repeat either the lactic acid or the capillary refill.
Speaker: If there was no change, they would go back to the previous MAP of 65, and if there were changes, they would continue at that MAP till things normalize.
Speaker: If the basal pressure challenge did not work, they would do a third step
Speaker: which at that point would be an inodilator challenge with either debutamine or milrinone, and they would do the same thing, repeat the testing.
Speaker: If there was no change, they would stop it, but if it improved, they would continue.
Speaker: So really they applied this protocol of stepwise approach very similarly to both groups.
Speaker: The difference was that one group was getting checked every 30 minutes,
Speaker: for abnormal capillary refills defined as more than three seconds and the other one was checked every two hours for lactic clearance or normalization of the lactic acid.
Speaker: Very interesting protocol.
Speaker: The idea is that you could maybe do this clinically anywhere.
Speaker: The primary outcome was all-cause 28-day mortality.
Speaker: The secondary outcomes were organ dysfunction at 72 hours, measured by the SOFA score, the sequential organ failure assessment score, death within 90 days, mechanical ventilation, renal replacement therapy, and base suppressor free days within 28 days.
Speaker: And also they looked at ICU and hospital length of stay.
Speaker: So what were the results?
Speaker: Mortality by day 28 in the peripheral perfusion group was 34.9%.
Speaker: In the lactate group, mortality of 28 days was 42.4%.
Speaker: Now, that seems like a big difference, but it did not meet statistical significance.
Speaker: I've already heard different interpretations about this difference.
Speaker: I think that the authors concluded that among patients with septic shock, a resuscitation strategy targeting normalization of capital refill time compared with a strategy targeting serum lactate levels did not reduce all-cause 20-day mortality.
Speaker: Discussions that I've heard, questions in the audience, and also questions
Speaker: editorial, the editorial by Derek Angus, talk about the potential for this study being underpowered, obviously, and that perhaps the calculation they made for the difference in mortality was too aggressive.
Speaker: But I think at the end of the day, even though the numbers look significant, if it didn't meet physical significant, it's hard to say that this is something that we can really hang our hats on.
Speaker: Organ failure as measured by the SOFAT 72 hours was lower in the peripheral perfusion group, and all the other secondary measures were similar among both groups with no statistical difference.
Speaker: I think that it's a great study.
Speaker: I think it obviously also great that it's coming from Latin America.
Speaker: They did it in a good time.
Speaker: They seem to have very strict adherence to the protocol, was well organized.
Speaker: But the take home message, I think for me, is that
Speaker: Even though this is very interesting, it doesn't provide enough information to change our practices, I believe.
Speaker: Definitely intrigued by this face suppressor challenge and the increased MAP in hypertensive patients.
Speaker: We're going to have to see more about that.
Speaker: And hopefully more studies along these lines will come and maybe provide us with some much needed guidance
Speaker: into what is the best way to titrate our resuscitation.
Speaker: I think that a general feeling, discussing with colleagues at the meeting and afterwards, is that we probably went overboard with fluids, now we're trying to come back to center.
Speaker: There's probably a right amount of fluid that needs to be given early.
Speaker: Same thing with vasopressors.
Speaker: We just don't have, I think, the precise tools to figure that out yet, and hopefully that will come soon.
Speaker: Number four, is more better for DVT prophylaxis?
Speaker: DVT prophylaxis is a daily item of discussion in critically ill patients and during rounds.
Speaker: Current data would suggest that chemical prophylaxis is superior to mechanical prophylaxis, which is superior to no prophylaxis in terms of reducing the incidence of thrombobolic disease and DVT.
Speaker: This was a very interesting study that was published in the New England Journal of Medicine ahead of print.
Speaker: It was conducted by the Saudi Critical Care Trials Group.
Speaker: The study evaluated the question of whether adjunctive intermittent pneumatic compression in critically ill patients receiving pharmacological DVT prophylaxis would result in lower incidence of DVT than pharmacological prophylaxis alone.
Speaker: This was an RCT with over 2,000 patients.
Speaker: It was included critically ill patients, adult patients that were randomized to group one was intermittent pneumatic compression plus pharmacological prophylaxis in the way of either low molecular weight heparin or sub-q heparin at prophylactic doses versus group two, which is the control group, which is pharmacological prophylaxis alone.
Speaker: The primary outcome of this study was a new proximal lower limb DVT, which was evaluated or diagnosed by twice-weekly ultrasounds, and that would occur after day three of enrollment in the study until the ICU discharge, death, attainment of full mobility, or day 28, whichever occurred first.
Speaker: What did they find?
Speaker: They found no difference.
Speaker: So there was absolutely no difference in terms of all the outcomes that they measured in between groups where you did a intermittent pneumatic compression plus pharmacological prophylaxis versus pharmacological prophylaxis alone.
Speaker: Now, intermittent pneumatic compression, like everything we do in medicine, is associated with some risk.
Speaker: It's not a high risk, but there can be problems.
Speaker: And I think it just added cost to the hospital stay.
Speaker: So from a value perspective, I think that if it's not going to improve outcomes, it really probably doesn't justify the addition of.
Speaker: So in terms of take-home message, I believe that if your patient is already on pharmacological prophylaxis, you're in good shape.
Speaker: And there's no need to add additional mechanical prophylaxis for those patients.
Speaker: So I think that those were four of the several studies that were presented.
Speaker: I think that were all like, I mean, obviously major studies.
Speaker: Unfortunately, a lot of them or most of them were negative.
Speaker: which I think speaks to the difficulties of conducting clinical trials and raises the question that we've discussed on previous episodes of this podcast with some of our guests of the true value or the true role that randomized clinical trials have in providing the answers that we need to move our care forward.
Speaker: So again, I think that disappointing that these studies were all negative basically,
Speaker: But I think that there's a lot to learn, and I think that there's some positives.
Speaker: And as you read these studies yourself and dive into some of the details, I think there's a lot of insights that you can get that might not radically change your practice, but definitely can improve the way we care for patients.
Speaker: So number five is some thoughts on ECMO.
Speaker: There seem to be a lot of sessions on ECMO.
Speaker: So every day there seem to be sessions on ECMO.
Speaker: I think there was a plenary by Dr. Bartlett, who's one of the pioneers of this technology, which I think was a wonderful overview of the history of ECMO.
Speaker: We talk about it all the time as a new thing, but it's been around for decades.
Speaker: And I think that it's just interesting to see the perspective of a man who's dedicated his life to advancing this therapy for very sick patients.
Speaker: However, I do think that...
Speaker: It's very interesting when you go to different sessions and you see the pro cons or people presenting what they're doing with ECMO and their beliefs.
Speaker: And I figure that after listening to a lot of sessions, a lot of which were very interesting, I come up with five quick thoughts for the podcast.
Speaker: So number one is that ECMO is like LeBron.
Speaker: There are fans in capital letters and there are haters in capital letters.
Speaker: And I find it super interesting that when people look at the same data, they come to exactly opposite conclusions.
Speaker: One is that EOLIA was a positive trial that we should be doing ECMO left and right.
Speaker: And the other one is that EOLIA was a negative trial and that there should be some pause in terms of where ECMO falls, at least for acute respiratory distress syndrome.
Speaker: Number two.
Speaker: We should definitely implement proven therapies prior to considering ECMO.
Speaker: And I think this is something that I heard over and over again, and I think is very, very important.
Speaker: So optimizing lung protective mechanical ventilation, starting neuromuscular blockers, and proning patients, I think, are important.
Speaker: proven steps to improve survival in ARDS, and they should happen if possible quickly and be optimized before we start jumping to cannulate patients and start ECMO.
Speaker: On the other hand, if you are going to do ECMO, I think that you also have to do it in a time-sensitive manner, and there's probably a window when you want to intervene.
Speaker: Number three is that my thought is that ECMO probably works for the right patients.
Speaker: The problem is I think we still don't know how to best select the right patient.
Speaker: And hopefully with more research, with more insight, we get to that point where we can really identify who are the patients who truly will benefit and who would otherwise probably not survive without ECMO and what's the right timing.
Speaker: Number four, the extracorporeal removal of CO2, ECOR, I think sounds very interesting.
Speaker: It's not a common occurrence.
Speaker: but clearly we have patients whom we can't ventilate with ARDS on whom the airway pressures are so high that we're probably, I mean, not gonna be able to remove CO2 and we're very limited what we can do.
Speaker: So new technologies, which are much less invasive than a full ECMO machine because they require lower flows,
Speaker: might be of interest in terms of treatment of those patients to maybe help remove CO2 and minimize the amount of tidal volume that we need and the amount of pressure that we're submitting or veterinary-induced lung injury that we're submitting to that patient.
Speaker: So I think that we're going to probably see a lot more about this technology, and I think that it's definitely interesting and something to keep our eyes and ears open for.
Speaker: And number five is that
Speaker: Centers that do a lot of ECMO probably can do it very safely.
Speaker: However, centers who don't do enough probably harm patients.
Speaker: And I think it raises the question of how do we get competent versus should we regionalize care to centers that are doing a lot of ECMO.
Speaker: Another very interesting point, I think, for our audience and community hospitals is that the average time of support on the EOLIA trial
Speaker: for patients with respiratory distress requiring ECMO was around 15 days.
Speaker: In some hospitals where it ties up perfusion, that might be a big,
Speaker: deployment of resources.
Speaker: And I think it raises at least the question of, should we be trying to regionalize ECMO care to large centers that are equipped and that can do ECMO for prolonged times versus should everybody try to get better at it?
Speaker: And you have a lot of centers in the same region doing a handful of cases of ECMO every year.
Speaker: So I think that
Speaker: ECMO is not going away.
Speaker: Clearly, we're going to hear a lot more about it, but it was just something I wanted to touch base on because I think there was a lot of sessions and definitely there seems to be a lot of interest.
Speaker: We will definitely have a ECMO dedicated podcast coming up soon, so stay tuned for that.
Speaker: I think that in a customary fashion for critical matters, I wanted to end with some closing questions, which are the questions we always ask our guests.
Speaker: in terms of tapping into their wisdom, but I thought I would do it, since I'm asking myself with a little bit of a twist, and I would really do it around SCCM and the annual conference.
Speaker: So the first question is,
Speaker: What book did I read during SCCM?
Speaker: And the book I took with me to read was The Art of Living by Epitektis, which is the slave who became a stoic philosopher during the Roman Empire.
Speaker: I think it's a book that I've read before.
Speaker: It's one of the books that I try to reread every once in a while.
Speaker: It's a quick read.
Speaker: I'll put a link in the show notes.
Speaker: But I think it was the perfect antidote to
Speaker: for a lot of the pompous behavior that sometimes we see in these meetings where people really, I mean, think that they're bigger than life and they're God's gift to the world.
Speaker: But the reality is I think Epitechus is,
Speaker: is very good at pointing it out that we're just very small specks in the vast universe and really nothing in the continuum of time.
Speaker: So I think it was a very grounding and sobering read for such a display of egos.
Speaker: My second question is, what do I believe to be true about large critical care meetings that most other people don't believe?
Speaker: And I think that I would say that conferences such as the annual SECM Critical Care Conference are very poor mediums for true learning.
Speaker: However, I do think they are great venues for one-on-one interactions with colleagues.
Speaker: And I definitely hope that in the future, we find better ways of delivering the knowledge and better ways of enhancing the valuable interactions that we have with our colleagues at these meetings.
Speaker: I found that the small round table discussions are much more engaging.
Speaker: The one-on-ones I had or small conversations were very positive.
Speaker: So hopefully in the future, we'll find better ways of delivering the knowledge and discussing the knowledge.
Speaker: But definitely, I think we can also maximize the beauty of these conferences, which is the opportunity to interact with like-minded intensivists from all over the world.
Speaker: And my final question is, what would I want every intensivist to know or every listener from the podcast to know?
Speaker: And what I would say is that it's a quote that I read many, many years ago that said that maybe I'm paraphrasing, but something along the lines of, medicine cannot be taught.
Speaker: It can only be learned.
Speaker: So I really hope that you pull the links in the show notes.
Speaker: You read these studies for yourself.
Speaker: You make your own conclusions.
Speaker: At the end of the day, I think that you're much smarter than I am
Speaker: And you probably can get a lot more out of reading than listening to me talk.
Speaker: So I hope that this recap was useful.
Speaker: We will be back to our usual format in the next episode of the podcast.
Speaker: So stay tuned.
Speaker: And my only request are if you have any comments.
Speaker: or any suggestions for the podcast, feel free to reach out to me by email.
Speaker: My email is szanotti, that's s-z-a-n-o-t-t-i at soundphysicians.com.
Speaker: And my second request is that if you find this podcast useful, please share it with a colleague.
Speaker: Please have somebody else listen to it and hope to have you back in a couple of weeks.
Speaker: Thanks again for listening to Critical Matters.
Speaker: Make sure to subscribe to this podcast on iTunes or Google Play.
