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Intubation & Hypotension
16 Plays3 years ago
In this episode of the podcast, we will discuss tracheal intubation-associated hypotension. Endotracheal intubation is a common procedure in the clinical care of critically ill patients. Tracheal intubation in the ICU is often associated with cardiovascular complications that can include hypotension, cardiac arrest, or death. A recently published clinical trial evaluating the impact of a 500ml- bolus of crystalloid solution intravenously on cardiovascular complications post-intubation is the catalyst for our discussion.
Additional Resources
Effect of Fluid Bolus Administration on Cardiovascular Collapse Among Critically Ill Patients Undergoing Tracheal Intubation. A Randomized Clinical Trial. The PREPARE II Investigators.
https://jamanetwork.com/journals/jama/fullarticle/2793545
Effect of a fluid bolus on cardiovascular collapse among critically ill adults undergoing tracheal intubation (PREPARE) a randomized controlled trial. The PREPARE Investigators. https://pubmed.ncbi.nlm.nih.gov/31585796/
Previous episodes of Critical Matters discussing other Intravenous Fluid topics.
Critical Matters_Fluid Responsiveness: https://bit.ly/3bBTOg7
Critical Matters_Fluid BaSICS: https://bit.ly/3y99S0j
Link to REBELEM post on Post Intubation Hypotension: The AH SHITE mnemonic.
https://rebelem.com/post-intubation-hypotension-the-ah-shite-mnemonic/
Link to PulmCrit Blog on PREPARE clinical trial.
https://emcrit.org/pulmcrit/prepare/
Books mentioned in this episode:
Leonardo Da Vinci. By Walter Isaacson.
https://amzn.to/3Nw0PfG
Benjamin Franklin. By Walter Isaacson.
https://amzn.to/3OM3N0C
Recommended
Transcript
Introduction to Podcast and Topic
00:00:06
Speaker
Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine.
00:00:14
Speaker
Sound provides comprehensive critical care programs to hospitals across the country.
00:00:19
Speaker
To learn more about our programs and career opportunities, visit www.soundphysicians.com.
00:00:26
Speaker
And now your host, Dr. Sergio Zanotti.
00:00:33
Speaker
Tracheal intubation is common in the clinical care of critically ill patients.
00:00:37
Speaker
We have all experienced complications after intubation that include hypotension, cardiac arrest, and death.
00:00:44
Speaker
In today's episode of Critical Matters, we will discuss intubation-associated hypotension.
00:00:50
Speaker
In previous episodes of the podcast, we have discussed different aspects of intravascular fluid administration in critically ill patients.
00:00:58
Speaker
Links to those episodes in the show notes.
Insights into the PREPARE-2 Clinical Trial
00:01:00
Speaker
Today, within the context of our discussion, we will be digging into a recently published study titled Effect of Fluid Bolus Administration on Cardiovascular Collapse Among Critically Ill Patients Undergoing Tracheal Intubation, the PREPARE-2 clinical trial published this month in JAMA.
00:01:21
Speaker
Reading this excellent study prompted me to choose this topic for the podcast.
00:01:25
Speaker
And for today's episode, we will try a slightly different format.
00:01:29
Speaker
We will have no guest, instead I will provide a short overview of the topic, followed by a discussion of the evidence, some personal thoughts of how the evidence impacts our practice, and I will close with our customary questions on topics not related to the clinical topic.
00:01:45
Speaker
I also anticipate this episode will be shorter in duration than our typical critical matters discussion.
00:01:51
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We will be back with our usual format next month, just wanting to try something different
00:01:59
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at this time.
00:02:00
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Okay, well with that let's go ahead and really talk about the topic of intubation and associated hypotension.
00:02:11
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There is
00:02:14
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a platitude of small studies that have tried to identify the actual incidents, and I've seen a wide range of percents being quoted, but it seems that on average, what is reported in the literature is that 20 to 25% of critically ill adults have cardiovascular complications during their peri-intubation period.
00:02:40
Speaker
So this is obviously a common problem, and as I'm sure all our listeners will identify, something that they have experienced at the bedside.
00:02:50
Speaker
In terms of its importance, peri-intubation, hypotension, or cardiovascular complications has been associated with increased mortality and increased length of stay.
00:03:00
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So clearly, it is something that we would like to avoid if possible, and it is an event that is associated with worse patient outcomes.
Cardiovascular Complications and Risk Factors
00:03:12
Speaker
Studies have reported different risk factors, but once again, I believe that the literature is very clear on two risk factors as being usually present in patients who have cardiovascular collapse after surgery.
00:03:28
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intubation, and that is patients who are hemodynamically unstable during this period, who start with instability, who might be in shock, and also patients who are on vasopressors at the time of intubation.
00:03:42
Speaker
So these obviously are two risk factors that we would all identify as increasing the risk of a patient having hypotension, cardiac arrest, or even death associated with intubation.
00:03:55
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In terms of the mechanisms that are associated with hypotension after intubation, clearly the underlying disease is an important driver.
00:04:05
Speaker
Many of the patients that we see present with hemodynamic instability from sepsis or other causes, so that is obviously always something that can be an underlying mechanism.
00:04:18
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Inadequate resuscitation, patients who come either hypovolemic from hemorrhage or hypovolemic related to fluid losses associated with sepsis or other critical illnesses early on in their course might be inadequately resuscitated.
00:04:34
Speaker
That is probably a bigger problem in the emergency departments as they usually see these patients in the initial phases of their care.
00:04:43
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As patients come to the ICU and a lot of the intubations that we do in the ICU, it is more likely that this has been treated to some extent.
00:04:54
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Another mechanism that's very important and perhaps one of the most important ones in terms of frequency is the cardiodepressant effects of the induction agents that we might use for intubation.
00:05:06
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And we won't dive deeply into
00:05:09
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into the pros and cons of different medication options.
00:05:14
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We will touch a little bit about that at the end.
00:05:17
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But what I would say on this respect is that it's not only the medication that matters, but also perhaps the dosing of these medications in these unstable patients.
00:05:28
Speaker
Another very important mechanism to consider is decreased venous return due to increased intrathoracic pressure resulting from positive pressure ventilation, including the effects of positive and expiratory pressure, such as PEEP and sometimes breath stacking and out of PEEP, which are commonly seen in patients in the peri-intubation period and might be more common even in some subtypes of patients, such as COPD patients.
00:05:58
Speaker
And finally, another mechanism that should be considered is the hemodynamic effects of worsening acidosis during apnea.
00:06:07
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A lot of these patients have severe metabolic acidosis with very high minute ventilations to compensate.
00:06:14
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And if we stop their breathing drive and make them apneic by anesthetic induction, they very quickly can have worsening acidosis
00:06:27
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that may exacerbate their underlying hemodynamic instability.
00:06:32
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So all these are important mechanisms that play a role when we're intubating patients that are critically on the ICU in terms of potential hypotension and other cardiovascular complications post-intubation.
00:06:48
Speaker
We have all been called by the bedside nurse post-intubation due to low blood pressure.
00:06:53
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It's a common occurrence.
00:06:55
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It happens a lot of times.
00:06:56
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You think everything went well.
00:06:57
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You walk out of the room.
00:06:59
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And next thing you know, you're getting called or paged by the nurse because the patient's now hypotensive.
00:07:04
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And I do believe that a lot of clinicians have a reflex to give fluids or treat the blood pressure, but I think it's worthwhile to take a little bit of time to think about the differential diagnosis of a post-intubation hypotension.
00:07:22
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As we alluded in the mechanisms, most often it might be either the effects of positive pressure ventilation in somebody who might be intravascular volume depleted.
00:07:33
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It might be related to the cardioporacent effects of our drugs.
00:07:38
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But there are other causes in the post-intubation period that can also be associated with
00:07:43
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with hypotension and it is important for us to evaluate our patients in these cases and not just react reflexively with fluids or more vasopressors.
Diagnostic Mnemonic for Intubation Hypotension
00:07:54
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So I found a very nice blog post by Rebel EM a couple years ago with a mnemonic that they crowdsourced that is A-H space S-H-I-T-E or A-Shitty.
00:08:11
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And it really stands for the A stands for acidosis and anaphylaxis.
00:08:17
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The H star stands for heart and that includes tamponade and pulmonary hypertension.
00:08:23
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Then for the shitty part, S stands for stacked breaths, which is something that we mentioned as a mechanism, especially causing auto-peep.
00:08:33
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H stands for hypovolemia.
00:08:35
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I stands for induction agent.
00:08:38
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T stands for tension pneumothorax and E for electrolytes.
00:08:43
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So let's talk a little bit about each one of these as part of your quick differential.
00:08:49
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So we did mention acidosis, especially when we blunt the imminent ventilation or the high respiratory drive, we might exacerbate acidosis.
00:08:59
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That often can be associated with a worsening in hemodynamics.
00:09:03
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So the best probably prevention of this is to recognize patients who...
00:09:08
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pre-intubation or pre-induction of anesthesia, have a very high respiratory rate or very high minute ventilation.
00:09:16
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We can even look at the end tidal CO2.
00:09:19
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And as we back ventilate these patients or as we put them on the ventilator initially, make sure that we are targeting that end tidal CO2 and keeping that respiratory drive or minute ventilation at a high level in order to prevent a worsening of
00:09:34
Speaker
of the acidosis by producing on top of their metabolic acidosis a respiratory component.
00:09:41
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Anaphylaxis, just to mention that some of the induction agents such as ketamine and etomidate have been associated with case reports of anaphylaxis.
00:09:53
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More commonly, although still rare, some of the neuromuscular blockers that are utilized like suctionalcholine and rocoronium can also be associated with anaphylaxis.
00:10:02
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So even though this is not a common finding, it should be on your differential.
00:10:08
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And obviously, by examining the patient, if you recognize that this might be the case, should be treated appropriately.
00:10:16
Speaker
In terms of the heart, we talked about tamponade and that it's well described that patients who have tamponade physiology are at increased risk of cardiovascular collapse during intubation or induction of anesthesia.
00:10:29
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So we should be very careful about
00:10:31
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Some authors have proposed having a little bit of a higher threshold for intubating patients with tamponade.
00:10:39
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On the other hand, I think that we might be ready to act when needed if that's the case.
00:10:44
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And this might be something that is very important, not only in trauma patients who are at a higher risk of having hemorrhagic tamponade, but also in other medical patients.
00:10:53
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Patients with pulmonary hypertension also can have a very important decrease in their venous return and in their filling pressures with induction of anesthesia.
00:11:09
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So just remember that in patients who have a documented history of pulmonary hypertension.
00:11:14
Speaker
Hypovolemia, I think, is self-evident.
00:11:17
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What I would say is that when we have patients who we suspect are hypovolemic on arrival, we should adequately resuscitate them as we initiate treatment and do the best we can as we approach the intubation time.
00:11:31
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The induction agent, we talked about the cardiorespiratory or cardiodepressant effects of some of these induction agents.
00:11:41
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There is...
00:11:43
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Obviously, literature that supports that perhaps ketamine has a lower cardiodepressant effect.
00:11:49
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Etomidate has also been reported as having lower impact on blood pressure.
00:11:56
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There's been other issues associated with etomidate related to adrenal dysfunction.
00:12:01
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We're not going to dive deeply into those.
00:12:04
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But what I would say with the induction agent that more and more people are recognizing ketamine
00:12:08
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is that perhaps, I mean, in patients in whom we're concerned about hemodynamic instability, we should be using lower doses, and that might be as important as selecting the right agent.
00:12:19
Speaker
Tension pneumothorax is clearly something that can be exacerbated when we put patients on positive pressure ventilation,
00:12:27
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So something to keep in the back of our mind, obviously very, very, very high on the list in trauma patients, but also in patients post CPR or patients who have other reasons for their critical illness, attention pneumothorax should be part of our differential.
00:12:46
Speaker
And finally, electrolytes, and specifically here, could be cardiac changes associated with hyperkalemia in patients who receive succinylcholine, for example.
00:12:56
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And we don't always have the electrolytes at hand when we intubate somebody emergently.
00:13:02
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And they're obviously well-described.
00:13:05
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But there might be patients that for other reasons have an unrecognized elevation in their potassium that can be exacerbated by the use of neuromuscular blockers such as saxonyl choline.
00:13:15
Speaker
So again, this is a differential that I find very, very useful.
00:13:21
Speaker
I think it's important for us to always ask ourselves questions.
00:13:25
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Post-intubation, when there's hypotension, could I be missing something?
00:13:29
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Or is this just something that is related to volume or the induction agent?
00:13:34
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So think about these other causes in your differential and make sure that you evaluate the patient.
00:13:41
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We have also ordered, I'm sure, STAT IV fluids in patients we are intubating, either due to concern for potential cardiovascular collapse pre-intubation or in response to low blood pressure post-induction of anesthesia or intubation.
00:13:56
Speaker
And it's very common that we will...
00:13:58
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order for stat fluid bolus and what I want to go next to is to review the evidence on this practice.
Analysis of PREPARE-1 and PREPARE-2 Trials
00:14:07
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Obviously this is a very important clinical topic, something that we see frequently at the bedside but it's not something that has been studied extensively.
00:14:16
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Furthermore, I believe it's something that is probably very difficult to study.
00:14:20
Speaker
So there are two studies by the same group, PREPARE and PREPARE 2, that really are the most important studies in this area.
00:14:32
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We're going to talk in more detail about PREPARE 2 that, as I mentioned in the intro, was recently published in JAMA.
00:14:39
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But I just want to give you a little bit of background on PREPARE 1.
00:14:43
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which was published in 2019.
00:14:46
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It was a pragmatic, multicenter, unblinded, randomized trial that took place in nine sites in the USA.
00:14:52
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Of those, eight were ICUs and one was in ED.
00:14:56
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And this study looked at critically ill adults undergoing tracheal intubation.
00:15:01
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And these were randomly assigned to either an intravenous infusion of 500 mLs of crystalloid solution or no fluid bolus.
00:15:09
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The primary outcome was cardiovascular collapse, defined as a new systolic blood pressure below 65 millimeters of mercury.
00:15:16
Speaker
So just to emphasize, that's a systolic blood pressure below 65 millimeters of mercury.
00:15:22
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So really severe hypotension, not something transient.
00:15:27
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It also included new or increased vasopressure administration two minutes after tracheal intubation or cardiac arrest or death within one hour of tracheal intubation.
00:15:37
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So this was the composite endpoint of cardiovascular collapse.
00:15:44
Speaker
And what they were trying to see is if giving somebody in the peri-intubation period, pre-induction 500 ml bolus of crystalloid would prevent the incidence or decrease the incidence of any of these complications.
00:15:56
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So cardiovascular collapse occurred in 20% of the patients receiving fluid bolus and then 18% of the patients that did not receive a fluid bolus.
00:16:05
Speaker
This study was terminated early for futility after approximately 337 patients.
00:16:12
Speaker
There's an excellent blog post attached to link in the show notes that talked about the study when it came out back in 2019 and
00:16:23
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But what they did find in this study, which was interesting, was in the subgroup analysis, they seemed to see a signal towards potential benefit in patients who were pre-ventilated before induction and after induction with positive pressure ventilation.
00:16:41
Speaker
So based on that and the fact that this study stopped up to 300 plus patients, the same investigators prepared a follow-up study.
00:16:55
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There was no pun intended there.
00:16:56
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The study was called PREPARE2.
00:16:59
Speaker
And here the research question was related to...
00:17:05
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In critically ill patients undergoing tracheal intubation, does intravenous infusion of a 500 ml crystalloid solution bolus decrease the incidence of severely low blood pressure, cardiac arrest, or death, the three of them referred together as a cause cardiovascular collapse, during or shortly after the procedure.
00:17:24
Speaker
So they were trying to see if in the special population,
00:17:28
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would this bolus prevent or decrease the incidence of the complications grouped within cardiovascular collapse.
00:17:38
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The objective of PREPARE-2 was to determine the effect of fluid bolus administration on the incidence of severe hypertension, cardiac arrest, and death associated with tracheointubation.
00:17:50
Speaker
This was a multicenter, pragmatic, randomized clinical trial that took place in 11 ICUs across the United States.
00:17:57
Speaker
It enrolled adult patients undergoing tracheal intubation with the planned use of medications to induce anesthesia and positive pressure ventilation with either a back mass device or a non-invasive ventilator between induction of anesthesia and laryngoscopy.
00:18:14
Speaker
So...
00:18:15
Speaker
In this study in particular, all patients enrolled were receiving positive pressure ventilation via bag, ambu bag, or non-invasive ventilation during induction and intubation.
00:18:29
Speaker
And they all received drugs, which really summarizes the most common situation when I intubate at the bedside.
00:18:36
Speaker
And I'm sure this is true for most of our patients, for most of our listeners.
00:18:40
Speaker
So I think that the adult patients that were captured in this study very well fit what we encounter on a daily basis at the bedside.
00:18:50
Speaker
Patients were excluded.
00:18:51
Speaker
They were pregnant, were incarcerated, had an immediate need for tracheo intubation, precluding randomization, or the clinician performing the intubation thought the patient had an indication, which means required fluid, or
00:19:04
Speaker
had a clear contraindication for fluid bolus during intubation.
00:19:07
Speaker
So again, I mean, these were some of the exclusion criteria, but in general, I think that the patients they were enrolling are really reflective of what we see at the bedside in our practice.
00:19:21
Speaker
In terms of the trial intervention, there were two groups, the fluid bolus group and the no fluid bolus group.
00:19:27
Speaker
The fluid bolus group received an infusion of 500 mL of isotonic crystalloid solution.
00:19:33
Speaker
The specific fluid was an operator's choice, so the clinicians could use whatever they use in the normal course of their clinical care.
00:19:41
Speaker
Operators were instructed to infuse fluid from above the level of the IV or IO axis by gravity, manual pressure, or pressure bag.
00:19:51
Speaker
So really try to do it as a bolus.
00:19:54
Speaker
Infuse as much of the 500 ml bolus prior to induction of anesthesia as possible without delaying the procedure.
00:20:01
Speaker
And three, infuse any of the 500 ml solution that remained after induction of anesthesia during the tracheal intubation procedure.
00:20:10
Speaker
So those were the indications for the fluid bolus and the fluid bolus group.
00:20:14
Speaker
The no fluid bolus group, intravenous fluid bolus was not permitted except as treatment for hypotension where the operator determined that an intravenous fluid bolus was necessary for treatment.
00:20:27
Speaker
All other aspects of the tracheal intubation were deferred to the operators, the clinicians taking care of the patient.
00:20:32
Speaker
And as this was a pragmatic trial, delivery of the assigned trial intervention occurred within the routine clinical care of the patient.
00:20:41
Speaker
And that perhaps is a strength of the trial that it really occurred in real clinical environment.
00:20:49
Speaker
Obviously, this precluded it from being blinded because the treating physicians knew if the patient got Ebola or not.
00:20:56
Speaker
But clearly, I believe that we are seeing an increased number of pragmatic studies, and they obviously have advantages such as the one of reflecting clinical practice and making these trials feasible.
00:21:10
Speaker
The primary outcome of this trial was cardiovascular collapse, which as I said earlier is a composite defined by one or more of the following being present in the study period.
00:21:23
Speaker
New or increased receipt of vasopressors within two minutes of induction of anesthesia, a systolic blood pressure of less than 65 millimeters of mercury between induction of anesthesia and one hour after tracheal intubation, cardiac arrest,
00:21:39
Speaker
between induction of anesthesia and one hour after tracheal intubation, or death between induction of anesthesia and one hour after tracheal intubation.
00:21:49
Speaker
The single pre-specified secondary outcome was the incidence of death prior to day 28, which was censored at hospital discharge.
00:21:57
Speaker
They had some other safety exploratory outcomes, and we'll talk on some of those maybe a little bit ahead.
00:22:03
Speaker
But ultimately, I think that the most important outcomes were the primary outcome in terms of cardiovascular collapse.
00:22:11
Speaker
So in terms of the results, there were 1,576 patients screened.
00:22:19
Speaker
A number of patients, a little bit over 400 patients, were excluded.
00:22:23
Speaker
And the details of these exclusions are in the manuscript, which a link will be in the show notes.
00:22:29
Speaker
I'll defer that to our listeners to read in more detail if they're interested.
00:22:34
Speaker
But at the end, this left 1,067 patients enrolled and randomized in the trial.
00:22:40
Speaker
which, again, I mean, is a significant number.
00:22:42
Speaker
It's three times larger than PREPARE-1.
00:22:45
Speaker
And clearly, at a more selected population that I think better reflects what we see in the ICU, perhaps a more robust patient population and a more robust clinical study for sure.
00:23:00
Speaker
In terms of the baseline characteristics of the patients enrolled in the study, I think that important to mention that both groups were pretty similar in most characteristics.
00:23:12
Speaker
The average or the median age was around 61.
00:23:16
Speaker
62% of females and males was very similar and the ethnicity was very similar.
00:23:25
Speaker
The majority of the patients in this study in both groups were non-Hispanic whites.
00:23:32
Speaker
The median weight was the same.
00:23:35
Speaker
The median body mass index was very similar.
00:23:39
Speaker
27.6 in the fluid bolus group and 27.7 in the non-fluid bolus group.
00:23:45
Speaker
Comorbidities, active conditions were all very similar.
00:23:50
Speaker
Of note, this study had a low percent of patients with COVID-19, only 6% in each group had COVID-19.
00:23:59
Speaker
Indications for tracheo intubation, Apache 2 score, use of vasopressors.
00:24:05
Speaker
In summary,
00:24:06
Speaker
The two groups were very, very similar and very comparable, which I think is always important.
00:24:13
Speaker
I mean, it's a large randomized study, so no surprise there.
00:24:16
Speaker
In terms of the characteristics of the tracheal intubation per se, that is always...
00:24:22
Speaker
interesting and worth reviewing.
00:24:24
Speaker
I think that what I would say here is that first of all, adherence for the protocol in terms of intravenous fluid was phenomenal.
00:24:34
Speaker
In the fluid bolus group, 99.4% of patients got the fluid bolus as indicated by the protocol.
00:24:42
Speaker
And in the no fluid bolus group, only 1.1% of the patients got a fluid bolus.
00:24:49
Speaker
That would be probably because somebody indicated that the patient needed it.
00:24:53
Speaker
So there was a clear difference in intervention between the fluid bolus group and the no fluid bolus group.
00:25:00
Speaker
The volume infused between enrollment and two minutes after tracheo intubation, the median was 500 for the fluid bolus group as per protocol, and it was zero for the non-fluid bolus group as per protocol.
00:25:14
Speaker
So again, very clear differentiation between both groups.
00:25:20
Speaker
In terms of the management of the tracheal intubation, the pre-oxygenation methods were very similar between both groups.
00:25:27
Speaker
I would say that a third got bi-level positive airway pressure, a third got a bag mask device, and a third got a non-rebreather mask, roughly, and then there were other things that were added.
00:25:41
Speaker
A few patients, only bi-level,
00:25:44
Speaker
0.7 in the bolus group and 0.4 in the non-bolus group did not receive any pre-oxygenation.
00:25:51
Speaker
The vasopressor bolus or infusion administered between enrollment and induction of anesthesia to prevent hypotension, so before anesthetics, was very similar.
00:26:00
Speaker
12.3% in the fluid bolus group and 11.8% in the no-fluid bolus group.
00:26:07
Speaker
So both groups very low, I mean close to 10%.
00:26:12
Speaker
And then there is no difference in terms of the oxygen saturation and induction of anesthesia.
00:26:19
Speaker
The median was 99% in both groups.
00:26:21
Speaker
And in terms of the induction agent, which I always find interesting to see what a large multi-trials and pragmatic study reveals about practice,
00:26:33
Speaker
The number one induction agent was etomidate.
00:26:38
Speaker
76.8% of the patients in the fluid bolus group got etomidate versus 78.9% in the no fluid bolus group.
00:26:46
Speaker
Second was ketamine, 12.3%.
00:26:49
Speaker
in the fluid bolus group and 10% in the no fluid bolus group.
00:26:53
Speaker
And third was propofol, with it being a little bit under 10% in the fluid bolus group and 10% in the no fluid bolus group.
00:27:02
Speaker
So clearly, in this large pragmatic trial, the use of etomidate was overwhelmingly the most common induction agent.
00:27:11
Speaker
94.6% of the patients in the bolus group got neuromuscular blocking agents, and 93.4% in the no-fluid bolus group got a neuromuscular blocker.
00:27:22
Speaker
And of these, the most common 74% and 71% respectively was rocoronium.
00:27:29
Speaker
So again, very interesting just information on this study, and it seemed that the vast majority of these patients were treated with etomidate and with brocoronium as their induction and neuromuscular blocker agents.
00:27:44
Speaker
And again, the vast majority of patients did receive a neuromuscular blocker.
00:27:49
Speaker
So from the perspective of baseline characteristics and the perspective of management of the tracheal intubation, clearly groups were similar except for the intended differences which were per protocol.
00:28:03
Speaker
And there's been tremendous adherence in this study to the protocol and clear differentiation in the bolus for these two groups.
00:28:15
Speaker
So finally, let's just go to the outcomes of tracheo intubation.
00:28:19
Speaker
As we mentioned earlier, the primary outcome was cardiovascular collapse.
00:28:23
Speaker
And in the fluid bolus group, that occurred in 21% of the patients.
00:28:28
Speaker
In the no fluid bolus group, that occurred in 18.2% of the patients.
00:28:32
Speaker
And the absolute difference and 95% confidence interval did not reach significance.
00:28:39
Speaker
So there was no difference.
00:28:40
Speaker
When you look at individual components of the cardiovascular collapse aggregate, which are newer increased receipt of vasopressors, systolic blood pressure below 65, and cardiac arrest and death, again, no significant difference.
00:28:56
Speaker
Very similar numbers between both groups.
00:28:59
Speaker
The secondary outcome was in-hospital death prior to day 28.
00:29:05
Speaker
40.5% of the patients in the fluid bolus group died before day 28, and 42.3% in the no-fluid bolus group.
00:29:13
Speaker
Again, the difference and the 95% confidence interval did not achieve statistical significance.
00:29:20
Speaker
Other exploratory outcomes included the lowest level of the systolic level, the change in blood pressure, lowest arterial oxygen saturation, oxygen saturation below 80, need for invasive mechanical ventilation, I'm sorry, invasive mechanical ventilation free days through day 28, intensive care unit free days through day 28,
00:29:42
Speaker
And in none of these exploratory outcomes did they find a difference between both groups.
00:29:49
Speaker
And furthermore, when they looked at subgroup analyses, there also were no identifiable differences.
00:29:57
Speaker
So the authors concluded that
00:30:00
Speaker
Among critically ill adults undergoing tracheal intubation, administration of an intravenous fluid bolus compared with no fluid bolus did not significantly decrease the incidence of cardiovascular collapse.
00:30:13
Speaker
I think this was a very well-conducted trial, obviously a difficult topic to study.
00:30:20
Speaker
It doesn't cover all situations that are associated with
00:30:23
Speaker
with hypotension and intubation.
00:30:26
Speaker
This was prophylactically giving a wide group of patients a fluid bolus prior to intubation.
00:30:33
Speaker
I don't think that's warranted based on this and the previous PREPARE study.
00:30:39
Speaker
Obviously, if you think somebody needs fluids for other reasons or because you think they're being resuscitated, we should proceed with giving fluids.
00:30:47
Speaker
But if you don't think that there's a clinical indication at that time, just giving them a 500%
00:30:53
Speaker
ML bolus of crystalloid is probably not going to make a big difference and might delay your intubation.
00:31:01
Speaker
So I think that there's a lot to comment on the study.
00:31:06
Speaker
People always like to find faults with studies.
00:31:10
Speaker
I, as a
00:31:12
Speaker
practicing bedside clinician just tip my hat to researchers that are able to pull studies like this together that inform our practice and help us advance our understanding of what we need to do at the bedside.
00:31:26
Speaker
You could argue that perhaps 500 mls is not enough
00:31:29
Speaker
that we should be pre-selecting those who might or might not need fluid.
00:31:33
Speaker
And those are all very valid points, but not what they studied in this particular trial.
00:31:39
Speaker
So in terms of the take-home points, I do believe that as we're treating critically ill patients, we should always be evaluating their resuscitation and we should be resuscitating them.
00:31:51
Speaker
A lot of that is still to be defined what's the best way to resuscitate a patient.
00:31:56
Speaker
If you feel somebody is intravascular volume depleted,
00:31:59
Speaker
For all means, they need fluids.
00:32:01
Speaker
We should be giving them fluids as we are preparing to intubate them.
00:32:04
Speaker
I also think that we should plan as best we can to intubate in the best manner possible.
00:32:13
Speaker
A lot of people like to use rapid sequence intubation.
00:32:17
Speaker
Some people have called that resuscitated sequence intubation.
00:32:22
Speaker
People have preferences for different drugs.
00:32:25
Speaker
We talked about some of the cardio-depressant properties of these drugs.
00:32:29
Speaker
I mean, I do believe that in general, we all would agree that propofol probably would cause more hypertension or cardiac depression than etymidate or ketamine.
00:32:38
Speaker
Which one you choose to use, I think, depends a lot on your practice.
00:32:42
Speaker
I did mention that there are some concerns with Atomidate regarding adrenal insufficiency.
00:32:47
Speaker
The truth is that perhaps more than the drug that we select for induction, it's recognizing that patients who are hemodynamically unstable especially might require lower doses or might benefit from lower doses.
00:33:00
Speaker
So think about the appropriate dosing of patients.
00:33:03
Speaker
It's not one dose fits all.
00:33:05
Speaker
The use of neuromuscular blockers has been associated with post-intubation hypotension in some studies.
00:33:13
Speaker
And clearly in this study, they had a very high penetration of neuromuscular blockers, over 95% in both groups.
00:33:20
Speaker
So again, which neuromuscular blocker you choose to use and the dose that you utilize is also very important perhaps.
00:33:27
Speaker
Clearly, it seems that based on this study, the clinical practice of these 11 ICUs overwhelmingly prefer to use rocoronium.
00:33:38
Speaker
So again, what I would say in terms of as you plan your intubation, choose your drugs, think about the dosing.
00:33:45
Speaker
A lot of people would argue that a bolus
00:33:49
Speaker
A 500 is not as effective regardless to increase blood pressure.
00:33:52
Speaker
So perhaps, I mean, if you're concerned about that, should you have vasopressors ready or running?
00:33:59
Speaker
And we're also seeing a movement in our willingness to use vasopressors peripherally.
00:34:06
Speaker
So a lot of times you might not have a central line by the time you're treating a patient early on in their course.
00:34:12
Speaker
So I do believe that probably if you're concerned about blood pressure, having vasopressors ready or infusing vasopressors peripherally probably is going to be more effective on raising the blood pressure than giving a
Clinical Implications and Recommendations
00:34:24
Speaker
bolus.
00:34:24
Speaker
So these are all things that you should be planning and anticipating as you are getting ready to intubate these patients.
00:34:31
Speaker
So for sure, more to come, I hope, as more studies are done.
00:34:36
Speaker
But I do believe that we should always plan as best we can and anticipate potential problems and be ready.
00:34:46
Speaker
But based on this study and the previous study, just giving people a bowl of IV fluids as we are preparing to intubate does not seem to make a difference in the incidence of cardiovascular complications.
00:35:00
Speaker
There are some guidelines that recommend that.
00:35:03
Speaker
It seems that the evidence at this point would not support that.
00:35:07
Speaker
So clearly a fascinating topic, something that we see commonly.
00:35:12
Speaker
I hope that the discussion was useful.
00:35:15
Speaker
I encourage our listeners to pick up the articles and the links, to look at the links to other sources.
00:35:22
Speaker
This is something that for as much as we see at the bedside, there's probably not as much literature.
00:35:28
Speaker
But I do believe that there is some evidence that we should be incorporating into our practices.
00:35:34
Speaker
As I said at the beginning, today is a little bit of a different episode.
00:35:39
Speaker
I don't have my customary guest.
00:35:42
Speaker
So I will finish by answering some of the questions that I have asked my guest throughout previous episodes of Critical Matters.
Book Recommendations and ICU Practices
00:35:53
Speaker
The first question relates to books that have influenced me the most or books that I gifted often.
00:35:59
Speaker
I think I've talked about this previously.
00:36:03
Speaker
So what I'll do today is actually mention two books that I've read in the last month that I found really fascinating and with great lessons for all of us.
00:36:13
Speaker
And both books are by the same author.
00:36:16
Speaker
There are two biographies by Walter Isaacson.
00:36:19
Speaker
I first read the biography of Leonardo da Vinci and was...
00:36:23
Speaker
fascinated by by the book which led me to pick up another book by Walter Isaacson on Benjamin Franklin and I would say was equally fascinating from these two polymaths geniuses of multiple domains I think we can definitely learn a lot that we can apply today at the bedside
00:36:45
Speaker
and elsewhere in our life so from the leonardo da vinci book for sure the the value of true curiosity of trying to learn every day is something that we should all do better and if leonardo was so curious i think that we can all try to to be as curious as he was
00:37:07
Speaker
He would every day write in his notebook things he needed to learn.
00:37:12
Speaker
And one of the entries that I find most fascinating was he needed to understand and describe the tongue of a woodpecker.
00:37:19
Speaker
If you read the book, I think you will find that that is quite fascinating and has a link to traumatic brain injury.
00:37:25
Speaker
So something very cool.
00:37:27
Speaker
The other lesson from Leonardo that I think we should all take
00:37:31
Speaker
a home is learning from other disciplines.
00:37:35
Speaker
And I believe that as we move post COVID in the ICU, there's a lot of innovation that will be required in our ICUs.
00:37:43
Speaker
And the best way to find new ideas is to look elsewhere outside of medicine.
00:37:48
Speaker
So I would encourage all our listeners to expand their horizons and to seek for inspiration outside of critical care, outside of medicine.
00:37:59
Speaker
And I think that Leonardo probably is the utmost example of how that really can be done very well.
00:38:06
Speaker
The second book on Benjamin Franklin, very similar in terms of being a polymath that really had an unquenchable desire to learn and explore.
00:38:16
Speaker
But the two things I would take home from this book are pragmatism and really the role that Benjamin Franklin had in our independence, but also in the Constitution itself.
00:38:29
Speaker
really, really comes through in this book in terms of trying to find pragmatic solutions and compromises, which I think is something that we should do better at the bedside and something that we all could do better outside of medicine.
00:38:44
Speaker
So that compromise towards pragmatic solutions, super, super valuable.
00:38:50
Speaker
And the second lesson that I would take from Benjamin Franklin is tolerance.
00:38:55
Speaker
and the ability really to tolerate other ideas, to tolerate other philosophies, to tolerate other views of the world.
00:39:04
Speaker
I think more than ever, it's super important in the ICU, but also outside of the ICU with everything that we're living in our country.
00:39:12
Speaker
So I would encourage you to pick up one of these books and enjoy the read, but also recognize that there's much we can learn from the life of great men.
00:39:22
Speaker
The second question relates to what do I believe to be true that most other people don't believe?
00:39:27
Speaker
And I would say less is more.
00:39:31
Speaker
We have a tendency in life, but for sure in the ICU of wanting to do more and more and more.
00:39:37
Speaker
And over and over again, as this study that we reviewed today has shown us, sometimes doing less is actually the most effective way of moving forward.
00:39:48
Speaker
So I would say that we should definitely do less things in the ICU for more impact as opposed to doing many, many things with a whole side of side effects.
00:40:00
Speaker
So think about that every day.
00:40:02
Speaker
Less is more.
00:40:03
Speaker
And there's opportunities at every corner to really implement this.
Final Thoughts on Communication
00:40:08
Speaker
And finally, in terms of what would I want every listener to know, I would just say that we need to listen more.
00:40:15
Speaker
Listen more and talk less.
00:40:17
Speaker
And when you listen to others, try to understand where they're coming from and try to learn something.
00:40:24
Speaker
Try to convince yourself of why their position might be better than yours as opposed to just waiting for your turn to tell them why they're wrong.
00:40:31
Speaker
I think we need to listen more.
00:40:34
Speaker
and talk less, be less assertive, and be more humble.
00:40:38
Speaker
So with that, I'll stop.
00:40:41
Speaker
And I really want to thank you for your ongoing support for the podcast.
00:40:45
Speaker
Would encourage you to share the podcast if you find it valuable, to reach out via email to myself if you have comments.
00:40:56
Speaker
And you can find my email, I'm sure, very easily.
00:41:00
Speaker
And also,
00:41:03
Speaker
to put comments if they're valuable for you.
00:41:07
Speaker
Once again, we're trying to just share content that ultimately makes our life a little bit easier at the bedside.
00:41:13
Speaker
Thank you very much.
00:41:15
Speaker
Thank you for listening to Critical Matters, a sound podcast.
00:41:19
Speaker
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00:41:25
Speaker
Sound's transforming the way critical care is provided in hospitals across the country.
00:41:29
Speaker
To learn more, visit www.soundphysicians.com.