Hi, good afternoon everyone It's quite an honor to be speaking in front of you. I'm without further ado. I'm going to get into this We're going to talk. I'm going to talk about the airway challenges and management in the obese patient I'm Sanjay Panda. I'm a third-year pulmonary critical care fellow and chief fellow at SUNY Upstate Medical University. I have no disclosures The lesson objectives for today are to identify airway challenges in the obese patient and how to manage the airway in an obese patient So the introduction of general introduction to obesity as defined by WHO It's defined as an excess or abnormal fat accumulation that presents risk to health The prevalence of obesity is about 20% in ICU patients I wanted to break down this topic into anatomic and physiologic challenges So to look at it first, there's this crudely drawn diagram, you know, my creation at the right side. I wanted to just point out How gravity affects our patients so to look at the first point, you know, these patients have limited mouth opening They have decreased mobility short and thick neck and it's difficult to achieve the traditional sniffing position to intubate these patients There's a lot of redundant soft tissue again that limits neck motion and also makes air intubation challenging there's an increased likelihood of pharyngeal wall collapse even with or without in you know association with obstructive sleep apnea and The identification of anatomic landmarks if in your initial airway assessment or for evaluation for a cricothyroid to me It's difficult because of the you know, the amount of fat present There's an abnormally elevated diaphragm and especially in the supine position. This presses up on the lungs reduces your functional residual capacity The physiologic challenges encountered in obesity Patients have increased oxygen consumption and increased carbon dioxide production There's an increase in the airway resistance and in decreased chest wall elasticity as we all know their functional residual capacity is reduced Which gives them less reserve of oxygen before we start to intubate these patients Other factors which kind of add on to the challenge are they have an increased risk of aspiration pneumonitis? There's increased risk of complications secondary to the other comorbidities present in an obese patient The pharmacokinetics of most medications are altered especially with the lipophilic drugs and drugs that are excreted by the kidney They increase in GFR results in an LR decrease half-life of these drugs now supine positioning as I showed you in the image before Worsens your anatomic and physiologic challenges and as we all know critical illness worsens your physiologic challenges with increased oxygen requirement and increased carbon dioxide production So with knowing these challenges in the hand what happens when we actually try to place an airway in these patients There's difficulty in bag and mass ventilation again because of how our anatomic challenges present This is a great study from 1997 that was published in one of the anesthesia journals I don't think they'll be able to repeat this study But what they did essentially at this time was they observed how long it takes patients to desaturate And if you notice the blue line shows what happens to a normal 70 kg patient without any illness It takes about eight minutes for this oxygen saturation to drop under 90 percent for a moderate 70 kg patient It's about five minutes for a non ill morbidly obese patient that time is reduced to 2.5 minutes So that's the challenge you are dealing with when you try to intubate these patients along with that There's a poor view of the glottis and like I mentioned before since the anatomic landmarks are difficult to identify It's difficult to perform an emergent cricothyroidotomy Assessing an airway I use the mnemonic lemon to you know, evaluate and I think most people use this as well You know look evaluate your 3 3 2 evaluate for malamparty score See if there's any concern for obstruction obesity and assess for neck mobility It has been observed in obese patients that patients with high malamparty score and large neck circumference has been directly linked to difficult intubation Airway management techniques the first thing I would like to talk about is the positioning If you come back to the same diagram I showed you now if you keep your patient in an upright or reverse Trendelenburg position before you start intubating them this eases the load on the from the diaphragm on the lungs and it also helps Increase some room in the pharyngeal passages, which helps, you know Pre-oxygenating them before and now during intubation you can move them to a head elevated position or a ramped position Ramp position has been noted to provide a better glottic view and reduces airway position complications. Usually I try to get this ramped Positioning done by placing a wedge under the shoulder for your patient There's specific pillows you can use too But if you're in a pinch, you can't find anything just any pillow or a folded towel can be placed under their shoulders Which can help you achieve this view Pre-oxygenation, I usually use bilateral nasal trumpets and I use a high-flow nasal candela which is something I can use during the apneic phase of Intubation as well But if your patients not you're not able to bring up their saturations before you are intubating consider using a trial of nib V This improves the oxygenation and decreases your VQ mismatch as you can see in the picture This is not in obese patients But it shows the amount of room that you can get now in a non-critically ill patient You can significantly improve your po2 with pre-oxygenation in a critically ill patient that difference might not seem that large But in a difficult situation that difference can mean a lot So always try to pre-oxygenate your patients as well as you can now during apnea like I mentioned before I continue with the high-flow nasal oxygenation and Back in mass ventilation if available use a two-person technique now This has been studied before that Athena grip technique as you see in the second slide and be Tina technique provides better chest wall rise and improves pa o2 compared to the traditional two-hand technique So if you're skilled with this, this is something good to use Other tools to have at hand This is something you should take into your room when you're intubating a patient is having the nasopharyngeal airway This can be used in patients with an intact gag reflex and OPA is useful if they do not have a gag reflex PEEP valve is something that I take in with every patient I'm intubating that's obese because it improves the oxygenation and improves recruitment while you're trying to rescue your airway Now a Bougie is something you should have available in your room It's a semi rigid stylet and it can help intubating those difficult patients now medications Neuromuscular blocking agents have shown to have a high fast first pass success rate. It's important to look at what? Way to use for dosing your medications. I'll not get into too much into detail of this, but you can look these up just Something to keep in mind and and benzodiazepines are lipophilic so can have a prolonged effect now mode of intubation the preferred mode of intubation would be video laryngoscopy provides a better glottic view over direct laryngoscopy and faster tracheal intubation a Supraglottic airway can be placed blindly in a difficult situation it can also be used as a rescue airway a wake intubation with a bronchoscope can be done to just inspect the airway or even to get a definitive airway and Something to keep in mind as a cricothyroidotomy if you have a failed airway if you want to secure a rescue airway And if there's difficulty Intubating a patient this is something you need to keep in mind a bedside ultrasound is very useful to identify a cricothyroid membrane Now airway plan keep in mind first attempt should be with the technique that the operator is most familiar with If intubation is difficult change something to improve your chance of success anticipate a difficult airway Don't be scared to call for help and call for help early And if you're in a pinch try to secure a rescue airway in the interim and do not delay cricothyroidotomy So take home points if you have a difficulty in obtaining a glottic view try ramp positioning due to decrease time to desaturation pre oxygenation napnic oxidation are very important and To improve your bag and mask ventilation use airway adjuncts and peep valve and always plan for a failed airway Be prepared to do a cricothyroidotomy Thank you. That's my session a Lot of what I have to say is gonna be a little bit of an overlap, but Always good teaching technique to let repetition is good teaching technique I'm gonna talk a little bit on the challenges on mechanical ventilation for the patients who have obesity I am Alice Gallo I am an intensivist at Mayo Clinic in Rochester, Minnesota, and I'm an APD for the internal medicine residency program there and I'm very thankful that all of you are still here at 1 p.m. On the last day of chest for the critical care Topics I appreciate all of you being here I'm obsessed with social media Gallo demoralized MD is how you find me. So at me. I'm on Twitter. I'm on threads and I'm on Instagram So let's continue the conversation there if we don't have time today So my objectives for my objectives for you today are to identify the changes that happen in the respiratory system of patients with obesity so like I said a little bit of Overlap, but some extra things that we need to think about lung physiology itself Demonstrate what are the parameters for safe mechanical ventilations in patients with obesity and recall how unique winning and extubating patients with obesity can be I Am a firm believer that all of us went into health care to take a care of people So I would like to bring this to a case. This is a 55 year old patient with past medical history of OSA Hypertension hyperlipidemia who was admitted to your ICU With acute hypoxemic respiratory failure in the setting of community-acquired pneumonia. Very simple Thanks to radiopedia. I just took their pictures as an example but this is what your patient's lungs look like so you can see just by the picture that if this patient goes into Restory failure and needs an airway that we just review a safe way of addressing it It's going to be very hard to ventilate It's going to be very hard to set ideal PEEP and it's going to be probably very challenging to keep the ventilation Safe in the setting of all of these redundant chest tissue So let's just recall a little bit the respiratory respiratory self changes in patients with Obesity again, I'm not going to Focus too much on airway because we just talked about it. But again, usually very difficult mask ventilation We all know that using neuromuscular blockade to intubate Increased degree of first pet increases rate of first pass successful first pass we got to be ready to intubate this patients once they are paralyzed because there's going to be a lot of Resistance a lot of difficult mask ventilation a lot of redundant tissue Just Lung volumes like we saw in the pictures this patient's walk around with a decreased functional residual capacity And it's going to be hard to recruit that also when they need intubation And again, this patient's will have a telekinesis independent areas of the lung That will be areas that are going to be not easily recruitable for both oxygenation and ventilation Ventilation This patient's also have an altered ventilatory response to hypercapnia and hypoxia both because they produce more co2 like we were just reminded of and With that they also require more oxygen and they have a higher work of breathing baseline Just again because of redundant tissue and harder time keeping their minute ventilation that they need and best baseline higher oxygen consumption also Decreases the time that we have to keep them oxygenated prior to intubation and it's going to be Harder for us at the first minutes of mechanical ventilation to get them oxygenated Little little bit on non-invasive mechanical ventilation again non-invasive mechanical ventilation is an excellent first choice for acute hypercapnic respiratory failure and but We need to be mindful that this patient's again we have a much lower reserve both in oxygenation and ability to lead to deal with Hypercapnia before they go into full respiratory arrest and need to be intubated in an emergent situation Don't forget that for patients who are on Non-invasive at home like this patient of ours who has obstructive sleep apnea If they need an ICU or if you are staffing the the chest service in your in your institution They will need they are non-invasive mechanical ventilation at baseline To prevent them from going into respiratory failure and we see a lot of ICU transfers in patients who need Non-invasive baseline and don't get it for naps or at night in the hospital. So just a good good reminder And they are excellent for pre-oxygenation like we just talked about Obese patients I put old in quotations because again, yes, they're harder to oxygenate Yes, they are harder to recruit but safe parameters are the same regardless of a patient's Body habitus so still low tidal volumes tidal volumes are target for ideal body weight Because our lungs were made to grow with our height Not with our weight so low tidal volumes based on ideal body weight safe parameters ideal peep setting is still unknown in the sense that there are several ways of targeting an ideal peep for your patient But what I would like you guys to take home is that it should be individualized and whatever you use Whatever you're comfortable with using to target your peep that that's okay So if you use the ARDSnet tables use the ARDSnet tables if you are someone who? Uses it as a Fageot balloon, and I'm going to talk a little bit more about it. Please use it as a Fageot balloon so use individualized peep for your patients Driving pressure should still be ideally less than 13 to 15 and plateau pressure should still be less than 30 So what you're aiming for same old? ARDSnet parameters We already talked a little bit about this, but sitting position might be Necessary for you to be able to recruit a telek tatic areas of the lung and try to get to the FRC As best as you can oh, I should have said all my references have QR codes So you you can get your phones up and this will go straight to your to your to the page of the references Sorry, I should have said that before So again the sitting position in patients who are obese and need mechanical ventilation will Relieve the expiratory flow limitation from from the weight of their chest and will also help with with Recruitment and decrease alveolar pressures Just have a few words in as a Fageot balloon and again I am personally a fan of as a Fageot balloons and Extremes of height and weight and I'll tell you why in a second, but again. I'm not gonna I'm not gonna spend too much time on this, but again what? Since we are targeting safe parameters low driving pressure Low plateau pressure and those of a geoballoon in extreme of weights might be help in extremes of weight might be helpful So as a Fageot balloons are likely not better than the arts net peep table in patients Who are average size and height? Okay, so our 70 kilos 170 centimeters patient Your arts net peep table Might help you in my help your patient and might be okay, but In patients with the extremes of height and weight we have it has been shown that is helpful to keep safe parameters of mechanical ventilation and Just if people don't remember These are the peep tables again just as a reminder And a quick reminder where and as a Fageot balloon should be which is right behind the heart because What you're looking for? What you're looking for is for cardiac oscillations on your as a Fageot balloon And I just want to illustrate that this patient is on an FIO to a 50% we use an as a Fageot balloon to set the peep at 20 Because our trans pulmonary pressure was 1 and we won between minus 1 and 1 so we were happy about that and then for testing We put the peep down To 15 and you can see that the weight of the chest ended up weaning on this one and our true transpiratory pressure became negative and Which would increase a telectasis in this patient and decrease even more our FRC and Putting it up. We probably over distended and was also not helpful Now just a few words on weaning Our goal for weaning in general is a respiratory drive that is there But we not without excessive effort So you don't want their pressure and their flow waveforms on the vent to be too negative But you want them to breathe so you can be able to remove their their tube The five of pressure support and five of peep rule might not apply to someone who has Those tiny squished lungs like I showed you on the on the picture that our imaginary patient would have So again, if your patient part of a Fageot balloon, or they're non-invasive at home. They need a CPAP of 15 I'm making this up They might be someone that you might need to be okay extubating them with the peep of 15 straight to non-invasive So again, the five fresh support five of peep rule might not apply to someone who is on the extremes of of weight I just said that and So again extubated patients are non-invasive Does prevent reintubation in overweight and obese patients and this is this This is the data, this is the data to show so normal and underweight Extubated to high flow nasal cannula non-invasive Versus non-invasive. So the overweight and the obese patients did better If they were extubated to non-invasive So my take-home points is just like remember the the changes to lung mechanics and gas exchange To guide your initial approach to mechanical ventilation the safety parameters are the same But again, it might be then your patients with with obesity. You need to sit them up you need to use other strategies to set the ideal peep and Five and five of fresh support and peep might not be ideal for patients who are morbidly obese Thank you, and don't forget to evaluate our session Hi everyone, I'm Parijat Sen, I go by PJ I'm a pulmonary and critical care doctor at the University of Kentucky in Lexington We'll talk to you about the challenges of both hemodynamic monitoring and management in morbidly obese patients And these are some of the objectives of today's talk So like Alice, I would love to start with a patient from our ICU 46 year old female with diabetes and a BMI of 65 Body weight of 220 kilograms is admitted to the MICU for urosepsis The patient's drowsy but protecting their airway respiratory. It's not bad saturating pretty well on room air blood pressures Soft 94 over 61 map of 72 already gotten 4 liter of fluids in the ED Sorry for dunking on my ED colleagues over there Has already been started on broad-spectrum antibiotics Comes up to the ICU and you assess the patient further and you find that the patient has an increased capillary refill time and slightly elevated lactate But once again, the blood pressure doesn't look that bad and then you look harder and you see one of these two situations Either an undersized cuff on a large arm or someone's taking a forearm blood pressure Unfortunately, I could not find an image for the third scenario where the blood pressure cuffs on their shin So these are some of the challenges of non-invasive blood pressure monitoring in morbidly obese patients The first thing is of course standard cuffs do not work There's actually a lot of data in non-critical ill patients mostly mostly in outpatient settings which says that For arm circumference is over 35 centimeter for each centimeter increase in arm circumference Using a standard blood pressure cuff overestimates the blood pressure by around 5 millimeters of mercury However is the answer or solution to that just getting larger sized cuffs for larger sized arms Once again, this is a really interesting study that was done in an outpatient setting where they looked at something called the slant angle of the arm If you've carefully looked at large arms, particularly in morbidly obese patients These are not uniformly large. We are not talking about cylindrical arms which have the same diameter across the length of the arm. Typically they're conical and they taper down. So these investigators actually looked at what's called the slant angle, which is the angle between the horizontal cross section at the mid arm to the vertical, sort of longitudinal incline of the arm instead. What they found was that with each centimeter increase in the arm circumference, the mid arm circumference, the slant angle became more and more acute, which tells me the larger the arm is, probably more conical it is. So now even if we have a large blood pressure cuff, we're trying to fit a cylinder on a cone and it is not going to give us accurate blood pressure measurements as well. Unfortunately there's not a lot of studies or trials that's really compared non-invasive blood pressure measurement with invasive in the specific subgroup of obese critical yield patients. There was a small retrospective study that kind of looked at patients who had both non-invasive measurements and invasive measurements and found that with both auscultatory and oscillometric measurements there was a significant underestimation of what the true intra-arterial pressures were when there was invasive monitoring available. So what do our guidelines say? This is surviving sepsis guidelines, point number 48, which mentions that for adults with septic shock we suggest invasive monitoring of arterial blood pressure over non-invasive monitoring as soon as practical and if resources are available. And the reason for that is that the quality of evidence available is really low and it's weak evidence. However, this is for all comers with septic shock and it is time for us to think if this holds true for specific body habitus, particularly extremes of body habitus, focusing on the morbidly obese patient group. So moving on, your MICU resident promptly places a radial arterial line and you note that the blood pressure on that is actually 48 over 29 and you immediately start pressors. About an hour later the patient looks more awake, capillary refill time has improved to two seconds, lactates come down to 1.6. But the blood pressure is still low and the pressors are escalating and a second pressor gets added. Now this is an image, I'll admit, I stole from Dr. Ogigaite's Twitter page. But this is what the radial arterial pressure tracing looks like. So you think about it and ask your resident to place a femoral arterial line and once that is placed this is the same patient having a femoral arterial line tracing. So is it better than in these patients to actually get a measure of central arterial blood pressure than peripheral arterial blood pressure? A lot of physicians would probably say yes only because it's really the central arterial blood pressure that determines what the organ perfusing pressures are. However, even in critically ill patients when peripheral arterial pressures have been compared with central arterial pressures they have found to be discordant and this discordance or bias increases further when the patients are in shock and needing norepinephrine. There was actually a small study of 14 patients who prospectively had both initially radial arterial line placed and started on pressors and then subsequently a femoral arterial line placed. And in 11 of those 14 patients placing a femoral arterial line actually led to a significant decrease in norepinephrine dosage. Well place a femoral arterial line on everyone. Better said than done. This is once again an image from a publication but probably something a lot of you are familiar with while trying to place a femoral arterial line or a central line in a lot of the morbidly obese patient groups. The anatomic landmarks that we use often do not work. We have to take care of the abdomen, often tape it, or in some worse situations have other operators or nurses just hold it for 45 minutes while you're placing your lines. And even then you may end up with what's called a high stick much above the ligament. I often joke with my trainees that we're lucky that we're not interventional cardiologists because they'll be killed for doing a high stick on someone with a large sheath that our cardiologists end up placing. And that's where really a lot of the data comes for about the safety of these procedures. So retrospective study once again looking at almost 5,000 patients who underwent cardiac catheterization through femoral approaches and found that with either extremes of body weight, either very, very low BMI or obese or overweight patients, the incidence of vascular complications was significantly higher with a femoral sheath approach. And what they found was that the commonest complication was what's actually called a low stick, which is not above the inguinal ligament but cannulating the superficial femoral artery rather than the central femoral artery as well. The other challenge that we face is that if we have exsanguination, you do not, you probably have to go through a lot of soft tissue to actually achieve significant hemostatic compression against the femur bone itself. So as well as it sounds in theory, practically this may not be the most feasible solution for our morbidly obese patients. Because as we see, there are pros and cons to each. In a radial, you don't have to come across any soft tissue challenge. It's much easier to compress. But we know that it becomes lesser and lesser reliable in shock. And you're trying to cannulate a much smaller caliber vessel. With femoral arterial lines, you get a larger caliber vessel, easier to cannulate. You get a central arterial blood pressure. But then becomes technically more challenging and higher vascular complications. So what's a good middle ground? My favorite arterial line, which is an axillary arterial line. Now you have a comparatively larger vessel caliber that you can cannulate. You don't run into similar soft tissue challenges as you do with femoral. Positioning becomes much easier. We often use the soft restraints and position the arm against the bed. And in case you run into bleeding issues and you need to compress, it is much easier to achieve that hemostatic compression against the humerus bone itself. So now, your MCUE resident went ahead and placed an arterial line, and you're back for rounds on day two. And you're told that the patient is stable today on a whiff of pressors. It's probably a term most of you have heard on rounds. And you look at the patient, and truly the patient's only on what's considered a whiff of pressors, which is 0.08 mics per kick per minute of norepinephrine. You have a good arterial blood pressure maps of 66. Patient looks fairly well resuscitated, but is now in atrial fibrillation with a slightly rapid rate of 120 per minute. So what do we do going forward? We assume that the patient is truly stable. We do not need to make any changes and maintain status quo. Or do we go along and actually make some changes? So this patient has a body weight, if you remember, of 225 kilograms. 0.08 mics per kick per minute for this patient translates to an absolute norepinephrine dose of 18 micrograms per minute. The question is, does it still sound like a whiff of pressors? So if you really look at guidelines, surviving sepsis guidelines does not make any recommendation on absolute dosing. It says that if your weight-based dosing is around 0.25 to 0.5 mics per kick per minute, then you should probably consider adding a second pressor, which is preferably vasopressin. If you look at the big vasopressin trial, adding it to norepi, the vast, it was interestingly found that at fairly lower cumulative doses of norepi, 15 mics per minute, when vaso was added, there was actually reduced mortality. The overall effect was diluted when you looked at the entire population. But when vaso was started at a dose lower than 15 mics per minute of norepi, there was actually a mortality benefit. The second clinical decision making is, when do we add steroids? Once again, kind of going by a proxies trial by Dr. Nunn, steroids were started if your norepi dose was 0.25 mics per kick per minute or more than one milligram per hour. 18 mics a minute is around 1.1 milligrams an hour. So once again, a fairly higher dose. There's a really interesting study that came out in CHESS this year, which is how I do it, walking us through brilliantly, through how we approach septic shock from adding a pressor to a second pressor to steroids. And over there, it mentions also that, hey, consider adding a second pressor for doses that are 0.25 to 0.3 mics per kick per minute or more than 15 mics per minute. That is not true, necessarily for our patient. These are not equivalent numbers when you're looking at a BMI of 65 and a total weight of 220. Last but not the least, is it just about the clinical decision making of adding the second pressor and steroids, or does the actual dose of pressors matter? When looking at obese, critically ill patients, with strategies of weight-based and non-weight-based, by the way, anyone over here still uses non-weight-based norepi dosing in their institutions. We switched over in our institution around 2016, took some adjustment, and now every ICU uses a weight-based dosing. What they found retrospectively was that there was similar time to achieve your goal map, but when looking at cumulative doses, there was significantly higher cumulative dose of norepinephrine in the morbidly obese population when a weight-based approach was used. This is a really interesting paper that actually came out of Alice's division, looking at, retrospectively once again, cumulative norepinephrine doses in close to 5,000 patients with septic shock. And what they found was that in the morbidly obese patient group, the cumulative dose adjusted for severity of illness and other demographic factors was significantly higher in the morbidly obese patient group. Does that matter? Interestingly, they actually developed a score called the Mavic score, which utilized, after propensity matching, the logarithmic score for norepinephrine equivalent, which is the cumulative norepinephrine dose, as well as other pressures that were used. And found that this score was an excellent predictor of 28-day and one-year mortality, and actually performed better than Sofan Apache's score. That probably tells us that norepinephrine by itself is not necessarily just a benign drug that we can keep escalating to achieve our goal map without any consequence. And that makes us wonder that, once again, for our morbidly obese population, is it important to start focusing on absolute doses than what the weight-based dose is? And norepinephrine is not a lipophilic drug. It's probably the least lipophilic of pressors. Do we need to move to ideal body weight dosing instead of total body weight dosing for norepinephrine? So take-home messages, the right-sized cuff matters. But even then, with large arms, due to the conical nature of it, they may still not be accurate, and one needs to consider invasive blood pressure monitoring. If you do elect invasive blood pressure monitoring, probably getting a central arterial blood pressure would be better than peripheral, and an axillary may be a better choice than femoral. And last but not the least, remember that in your morbidly obese patient, weight-based dosing of pressors may actually underestimate the severity of shock and influence clinical decision making, like adding second pressors and steroids. Thank you. I'm on Twitter or X if you have other questions after the session. Let's see. All right, unfortunately, my voice still hoarse. So I was unlucky that I think I had laryngitis or something. It's not COVID, so do we have any clinical pharmacists in here? Good, so now I feel safe to talk about pharmacokinetics. All right, so it was very like a learning. I learned a lot while I'm preparing for this session, because sometimes we forget about how lucky we are when we have the clinical pharmacist in the unit. So I'm Mohamed Megri, I'm the least expert in this panel, and I'm honored to be with you in here, guys, and thank you for staying that late. So when I was looking at obesity and BMI, so where I did my residency and I did my fellowship and the first two years of my practice, more than 50% of our patients are morbidly obese. And it was very difficult, but I was happy that I trained in this situation. At least it would be easy for me for practicing and stuff like that. And with time, you feel like it's normal for you. Most of your patients are obese patients, you think it's normal. And actually, when you see non-obese patients, you'll be like, okay, there's something wrong. So obesity, as it was the first 160 years ago, Adolfo, when he said obesity is BMI more than 30, and that's like obese patients. And we see a lot of these obese patients in our units. So most of our medications, and it's packaged from the factory according to the total body weight. So I try to look more and more to see any big study that studied our medications in the ICU for morbidly obese patients. Unfortunately, there is none. There's some retrospective studies, but there's nothing that can give us any exact answers for what we are looking for, how obesity can affect the pharmacodynamics. So we have body mass index, body surface area, total body weight, ideal body weight, adjusted body weight, lean body weight, and predicted normal weight. I know only body mass index and total body weight. So the thing is, when you look at the proportion in people, in any obese patient, the proportion of increase in adipose tissue and the lean body mass, it's not proportional with the obesity. So the adipose tissue, yes, it will be proportionally increased, but the ratio of your lean body mass will be decreased according to the kilogram. So that's why there's no one measurement that can fit all medication. You have to adjust everything according to the characteristic of your medication itself, not just for the patient weight. So when you do a total body weight, yes, you can, if the medication is lipophilic medication, then you'll be like, okay, there's a lot of adipose tissue that that medication will go, it will have high volume of distribution. And we'll talk more about volume distribution. If I have hydrophobic medication or hydrophilic medication, it will be the opposite. So you cannot just pick one measurement or one descriptor and you say this will work well for obese patient. So when we talk about pharmacokinetics, we have how the medication get absorbed, how medication get distributed, how the medication will metabolize and eliminate. And I picked in this talk, because of time, just like for distributed medication. And why is that? Most of our medication in the ICU in critically ill patients, IV medication. So we don't care a lot about absorption, because just like giving straight in the vein. When we talk about pharmacokinetics, the first thing is the blood flow. It depends on how is the blood flow, how is the cardiac output, and how is the vascular beds inside that tissue. If I have a lot of blood vessels inside that tissue, we'll have more distribution in that tissue. If I have less blood vessels, I will have less distribution. And we are talking about ICU, so most of our patients have sepsis, septic shock, they are in presses, they are hypoxic, hypoxemic. So there's a lot of other factors that will affect our blood flow, not just the obesity. And the other thing, the permeability of the medication through the blood wall. We give medication that it goes through, we need to fix across the blood brain barrier, across other barriers. So it depends a lot of the characteristic of the medication itself. Is it high molecular medication? Is that medication positively charged, or negative charged, or polar charged? So it depends a lot of the medication and the characteristic of the disease itself. Because as we mentioned, in sepsis, septic shock, we'll lose a lot of that permeability. It will be more permeable, and that will affect the distribution. That's without talking about obese patient, just generally. And the other thing, that protein binding. As we know, just a quick review, the medication is highly protein bound, so we'll have less distribution because it will stay more inside the blood vessels. And less distributed outside to the tissue. And if it's low protein bound, so we'll have a lot of medication will be distributed. So how does obesity can affect this? So when we talk about obesity, we have the flow, the blood flow. First of all, because of the change of the compartments of our bodies, that will change the flow. Do we know exactly how that flow change? Unfortunately, we don't. We don't know if that, yes, we have more adipose tissue. Then we have more, because normally it's 5% of the cardiac output goes to the adipose tissue. If I have higher adipose tissue, it means that I have more flow goes to the adipose tissue. But we don't know that how exactly it will affect the medication, unfortunately. And there's no studies, there's no data. The other thing that the volume, when we, like obese patient, like we'll have higher volume. And that will dilute your medication in the blood vessels. And then that will give you less concentration of medication in your serum, and that will affect our decision of like how to dose this medication and how much is affecting this patient. The other thing that the blood, the different compartment, it will change the, maybe the blood flow will be the same. However, the blood flow to each compartment is not the same. And that's why we need to know, how does that affect our patient? And the last thing is that there is a lot of data talking about protein binding, so the high triglyceride, and lipoprotein, and cholesterol, and the fatty, free fatty acids that affect the medication protein binding, and that will increase the patient bound to the protein. And that will decrease the, I mean, the medication bound to the protein, and that will decrease the medication, the free serum. And the opposite with the acute phase protein, like an obese patient, we have more IL-8, IL-6 tissue necrotizing factors. All of these acute inflammatory markers is higher in obese patients, so that's what will like alter the protein bound to medication. So everything normal in pharmacokinetics will be affected by obese patient. But to be honest with you, I did not tell you how it will increase or decrease, it will be affected, but we don't know exactly how it will be affected. And the other thing that the consequence of being obese, like having altered hepatic flow, that will affect like a fatty liver, and like how the metabolism of the fat, of the medication in the liver, and the clearance and elimination through the renal system with the effect of the flow. All of that will lead to effect of our pharmacokinetic. So, and this is just like a summary slide of what I have mentioned about the effect of the medication. So, what I'm trying to say. So how can we adjust our, like if I adjust it to the total body weight, possible there is an overestimation of our dose. If I adjust it to ideal body weight, there's possible underestimation, sorry. Possible underestimation, and adjusted body weight, yeah, most of like if you open up to date, it'll say like, yeah, more than 30 BMI. Yeah, adjusted body weight is, but do we have data? No, we don't have any data, so we don't know. So, so most of expert opinion says like, adjust most of the medication, adjust the body weight. And that's because it will take the lean body mass, and the adipose tissue, and the total body water, which is, that's the, like, closest to the right answer. But we don't know, unfortunately we don't know. So loading dose, if you will like think about the medication itself. If it's medication distributed mainly in the lean mass, it's good to adjust it according to the lean body weight. If the medication is very high, like our medication, propofol, and like etimidate, or like opioids, all is like highly libo, libo, libophilic medication, that you can adjust it to the total body weight, or according to the adjusted body weight as well. So, take home point, we are lucky that we have clinical pharmacists, and like after preparing for this, I was like, okay, I'm, like, we are really lucky. Like, where, where I'm from, from Libya, like North Africa, we don't have clinical pharmacists. Like, we just like practice, you are the physician, does everything. So and, and this is, this is like, we are very lucky that in here, we have clinical pharmacists. The other thing that in the ICU, yes, maybe the loading dose, that it depends on adjusted according to the weight, but whatever it's running, as my colleagues mentioned, that the medication is according to the effect of the medication. So we don't, like, care a lot about what weight that we, we calculated the medication for. We, what, what we really, really care about is the effect of that medication. And that's how we look, like, at, we, we measure the RAS, or like CPOT, or MAP, or training for, like, according to all of these medications, that we can adjust it according to the effect of it. And thank you so much, and sorry again for my voice, guys. Thank you.

obese patients

critical care

airway challenges

mechanical ventilation

hemodynamic monitoring

pharmacokinetics

intubation

positioning techniques