Good afternoon, everybody. My only disclosure is that I'm a speaker and consultant for Boston Scientific. Not a very good one. I've never actually been paid, although I've done a lot of work. My talk today is on the safe insertion, use, and maintenance of devices in ICU patients with severe obesity. This is a really hard topic. Being someone who actually this is very fitting for as I'm both an intensivist, but I'm also a bariatric surgeon, I thought this would be a little bit easier, but going through the literature, not so much. Being a bariatric surgeon, I had to take the opportunity to talk about obesity a little bit, first starting on why language counts when we talk about patients with severe obesity, remembering not to use the words morbid obesity. There's a lot of stigma around the terminology of morbid obesity. Really obesity is an identity. It's a disease. We don't have obese people. We have persons with obesity, and kind of remembering that terminology is really important what we talk about in the care of our patients as it really does impact them, and there's a stigma which goes to the ICU as well. I know everybody has seen this, but I can't help but put it up there, again, as a bariatric surgeon. Again, really this is to point out that really no state or territory has a prevalence rate of less than 20%. So this we all see, and we all take care of patients with obesity no matter what type of ICU you're in, and really the estimation is that by 2030, 78% of our population is predicted to have an elevated BMI. So and the cost is great, both direct and indirect costs. The direct costs are estimated to be about $152 billion, and this was in 2009, and obviously a lot's changed since then. So there's a lot of effects of obesity that's relevant in critical illness that really impacts every single kind of physiologic parameter that we see in the ICU, and about 20% of our patients will be patients with obesity, and so kind of what do we know so far? About a fifth of our patients in your ICU will have obesity, that it's a disease that does impact critical illness, and that patients with obesity have increased morbidity and resource utilization. And so therefore the care that we provide, really we have to have some unique considerations. And so our goal today is to learn the necessary considerations for safe initiation, use, and maintenance of devices in patients with obesity in the ICU, and these are the areas that I've chose to focus on. Obviously I'm sure there are things that I've missed, but monitoring, vascular access, imaging, and ICU procedures. First to start with monitoring. It's really simple, but I couldn't not talk about non-invasive blood pressure monitoring. And I actually had to look this stuff up and learned quite a bit in putting this talk together. The blood pressure cuff standards, if you don't know, is that the length of the bladder of the cuff should be 80% of the circumference of the patient's arm, and the bladder width should be 40% of the length. Obviously we all know when cuffs are too big, it falsely lowers the blood pressure. If cuffs are too small, it falsely elevates the blood pressure. And blood pressure measurements taken with a standard cuff in patients with obesity is often significantly higher. So then we say, okay, we'll just use a bigger cuff, right? Well, is that the right answer? No, because as this picture shows, a bigger cuff is a poor fit. And practically the things that we need to think about is just because a patient's arm is bigger doesn't mean that it's longer. And so the bigger cuff doesn't fit them appropriately. And that the arms of patients with obesity are shaped in an inverted cone. So you get this kind of poor fit that you see in this picture. So it's really hard and difficult to find the right size cuff. And I didn't put it here, but the largest size is a thigh cuff. And we also have to remember the stigma around telling our patients, okay, I'm going to put a thigh cuff on your arm. So for us to just think about those words and what we use. And also I think it's actually listed on the cuff itself. So often the correct diameter but the wrong length leads to inaccurate measurements. And so in patients with obesity that can't fit an appropriately sized cuff on the upper arm, we try to use an appropriately fitting cuff on the forearm. It's not ideal, but that is what a lot of the literature suggests is going to give us the best non-invasive measurement. Hold the forearm at the level of the patient's heart. The hose should exit over the radial artery, which is smaller and more distant than the brachial artery. And really to remember that the measurements, the blood pressure measurements will vary by a mean of 7 to 15 millimeters of mercury at accuracy. Kind of similarly, some monitoring, but very different, is intra-abdominal pressure monitoring. This is not really about how you do it, but more what do the numbers mean and what we need to think about. And this is near and true to my heart as a surgeon. So we all know that BMI has an effect on intra-abdominal pressures. But really I think it's that importance to recognize that the pressure changes are relatively small in patients with severe obesity, that you're not going to have these very high intra-abdominal pressures. Again, intra-abdominal hypertension is defined as an intra-abdominal pressure greater than 12 millimeters of mercury. The studies have been done to see exactly what those differences are in that incremental increase in intra-abdominal pressure, and it's listed here per unit of BMI. But really this is to remind everybody that it's still within kind of normal limits. So patients that have high intra-abdominal pressures should be really taken seriously. And it shouldn't be thought, oh, well, because their BMI is 50, it's normal. They should have an intra-abdominal pressure of 20. That is not normal, and that should really be investigated and typically is an acute change and warrants that acute attention and not dismissive of the fact that this is because of their high BMI. To switch a little bit, and I'll focus a lot on vascular access and different types of vascular access, obesity has been shown to be an independent risk factor for difficult IV access due to increased adipose tissue, increased tissue edema, and just in general smaller vein calibers. The IV cannulation failures occurred due to the increase of subcutaneous tissue, making it harder to locate and puncture a target vessel, and really the failure to advance the needle and catheter into that vessel lumen. And the complications in terms of peripheral IV access is often local phlebitis infection, injury to the adjacent artery or hematoma. And studies have been shown that it is not just something that we think is harder. It actually is harder. The cannulation time was longer. The successful at first attempt was less, and patients ultimately needed more than one IV. I'm not going to go over all the tips of how to place an IV access in a patient with obesity. The one thing I do want to point out is that you do need to think about using a longer IV cannula. And it may need to be greater than one inch to get through the tissue and into that vessel. And that's to put it in the vessel, but also really to keep it in the vessel, which is a theme you're going to see through this presentation, to prevent dislodgement, infiltration, extravasation, of either fluids or medications that you're giving. And then lastly, really, that you may need to really adjust the angle at which you're cannulating the IV, less of the 10 to 15 degrees, more of the 30 to 45 degrees. And to remember that ultrasound guidance really is essential and very helpful in aiding in difficult IV access. It really leads to higher success rates than the blind approach, less time to successful cannulation, fewer needle sticks, and patients are obviously happier because they're stuck less. And it really allows, with ultrasound, for you to assess the vein characteristics, the depth, the diameter, and the veins pathway. And that really allows you to have all the equipment and tools and different types of IVs and lengths that you may need. And that the outcomes the studies have shown really are better. And these three studies, in particular, the success rate was much higher with use of ultrasound than without. And also, the last study really looked at the education and training required for someone to be proficient at this, and for non-physicians, including physicians. And really, it was about two hours, so not a significant amount of resources that it's going to take to get somebody comfortable with ultrasound guidance. And much better for patient outcomes and satisfaction. If perf-IV access is not an option, there is intraosseous access. But this is also not simple in patients with obesity. And the length of that intraosseous needle really needs to be considered, and may not be long enough. There are actually two needle sizes, which I learned, I didn't know before, 25 and 45. And you have to be careful, because if you put a 25-millimeter IO in a patient and it's too short, that extravasation of, again, the medication and the fluids can lead to compartment syndrome in that extremity. And so, one of this particular study that I included really looked at whether or not the tibial tuberosity is palpable. And if it's palpable, then the 25-millimeter IO is safe. And if it's not, then you should go to the 45-millimeter one. In terms of both, I think this slide is pertinent to both PICC lines and central venous access. Really, there's a lot of different operator techniques to consider. I'm not going to go through all of them. They're listed here. But most importantly, again, using longer introducer needles. But probe orientation, one versus two operator techniques, where your PICC line is placed, whether you do it at the bedside or whether it's done in interventional radiology. And then, really, to spend a little bit more time in terms of the measurement for the PICC line, that traditional methods and using measuring tape to determine the length may not be accurate in this patient population. For central venous catheter access, very similarly, the things to consider greatly is that your normal anatomic landmarks are not reliable in this patient population. You often have a shorter neck, deeper veins, and a lot of anatomic variations that can affect your access. There's increased tissue between the surface and the central vasculature. You may need to use longer needles to be able to access it. If you do use a standard needle to access it and you hit the vein, it still may be too short and the angle may be wrong. So even though you get that flash, subsequent passage of your wire, your dilator, and your catheter may be very difficult and challenging. And so going to that longer needle will aid in success. And that using ultrasound guidance is imperative. I know many of us already probably do it, but really in this patient population, so important to decrease the number of punctures, reduce skin and neck trauma, less hematomas, less thrombosis. And studies have shown that patients with obesity do have increased anatomic variations in the neck, much more likelihood of the internal jugular and the carotid to actually be overlapping. And so if you use ultrasound guidance, it will help you identify that and prevent that complication. Some of the complications that can be seen is that if you do use a longer needle, you're at greater risk of inadvertent injury to intrathoracic structures. So you have to really be aware and cognizant of that. There is an increased associated risk of CLABSI in this patient population. And then really, whether it's a PICC line or a central line, whether it's a dialysis line or a cortis or a triple lumen, really being cognizant of the fact that position changes can cause dislodgement of your line. And this is not my patient, but this is one of my colleagues' patients. The central line was placed, obviously, with a patient in Trendelenburg, but the breast was not properly positioned. And so when the patient was sat up in normal position, the weight of the breast actually pulled that central line out into the soft tissue, which is what you see here. This is extravasation of vasopressors and fluid. And so often, you have to take into account that tissue movement. And when you're positioning the patient to do the procedure, you need to make sure you account for that, but also need to periodically check the positioning of that catheter. So if it's done in the operating room or in the ICU and the patient gets rolled and moved and travels and comes back, that you may need to check the positioning of that catheter and not just to see whether it draws back, right? Really imaging is really important to ensure that that catheter is in the right place to avoid these really terrible complications. This study was just published in Intensive Care Medicine in 2021. It was an analysis of four large randomized control trials looking at the incidence of catheter-related bloodstream infections in patients with obesity. They defined obesity as a BMI greater than 30. And this is just a summary. There was a lot more in this article, but really showed was that in groups with a BMI greater than 40 compared to those less than 40, that your hazard ratio for essentially a CLABSI was a little more than 2. Also showed that actually the number of dressing change disruptions was much higher in this patient population, which probably again is associated with increased incidence of CLABSI. Shifting gears a little bit to arterial catheterization, I didn't spend too much time on this. I think a lot of the principles are the same no matter what vessel it is that you're cannulating. But to know that the radial artery is deeper and more difficult to palpate in this patient population. And again, the use of ultrasound guidance is really helpful and improves the success rate at first-time sticks and reduces post-procedure complications. This was a study that's just pre-published. It's April of 2020. Sorry, 2023. The study looks at, which I thought was very interesting, the single and double lines on ultrasound to help successful first-time attempt of radial artery cannulization. Basically, they did a study looking at ultrasound probes without a marker, one marker, or two markers, as you can kind of see in this picture. And the marks, particularly the double marks, really improved successful catheterization from 70% to 90%. And I think they just used the radio opaque wire and like a gauze or a ratex, sorry, I'm a surgeon, and they pulled that out and kind of taped it to the ultrasound probe and put a tegaderm on it. Pretty simple and not very complicated. I'm not going to talk too much about this other than to say this is a more newly published study really showing that once upon a time, we thought that patients with severe obesity was a contraindication to successful ECMO cannulation and outcomes. And really, this study, which looked at 153 patients with BMIs greater than 35, demonstrated that although cannulation was maybe a little bit tougher, it actually was successful as long as the team was thoughtful and well-planned out. And most of their cannulation attempts were in the neck, not surprisingly, rather than the groin, with reasonably good outcomes. Imaging in the ICU in this patient population is often limited, which affects our ability to do procedures. And often, what our radiologists will say is limited by body habitus in terms of when we look at the read. And that's really going to the quality of images. And these are just two x-rays side by side, one in a patient with obesity and one obviously without. And the challenges are that really, it requires more planning, maybe multiple images or cassettes to get the full image that you want, that the x-ray beams are really attenuated, and that might affect how you read, particularly if you've done a procedure, and that you have a lot of artifact kind of in the exposure. Very similarly with ultrasound and us in the ICU for POCUS, really, the ultrasound beams are attenuated by fat, which really affects our image quality. The thickness of the tissue has a direct impact on the quality and the distribution of where that adipose tissue is really critical and how good of pictures we get. So not surprisingly, every patient carries their adipose tissue very differently. Those who have it in the intraperitoneal space, our image quality is much higher than those that carry it in the subcutaneous space. And kind of paying attention to that can make a difference. And POCUS is very helpful. It helps us greatly in the ICU. It helps us with kind of diagnosis uncertainty and prognosis and management. But just as a caution, you know, image, getting those good images can be sometimes challenging and interpretation can be really limited, and not to maybe necessarily place too much on it because you don't want to over or under-diagnose somebody based on potentially poor image quality. And then really to avoid kind of excessive time in trying to obtain a good image, you know, and delay potentially assessing the patient or starting a treatment that might be life-saving. There's a lot of procedures that happen in the ICU. Surprisingly or not surprisingly, there's not a whole lot in the literature about doing common ICU procedures in patients with severe obesity. So this is my surmise after reading a lot and thinking about this. The things that are really important to consider. One, all BMIs are not created equal. I'm sure you've seen and I have definitely seen as a bariatric surgeon that a BMI-40 is not equal to a BMI-40. It's different based on gender. And so you can't treat everybody exactly the same in terms of planning. Really prior to starting any procedure, give, you know, a lot of attention to the equipment. You may need a longer needle, catheter, additional wires, and have everything prepared in advance. Request additional assistance in the room, positioning the patient, thinking about how the tissues move and how that's going to impact the procedure that you do. Consider also the ergonomics of the procedure for you as a person doing it to make sure that you're not leaning forward too much, that the bed height is appropriate and correct. Because your comfort level will also affect how well the procedure goes. And then really what I kind of surmised from everything I read is that image guidance is really critical. I know it's important for every patient and very helpful, but particularly in patients with obesity because those typical anatomic landmarks are really lost. And image guidance is really critical to help us through that. So in conclusion, we can make it safe, you know, to put obviously devices and patients in the ICU with obesity. We need to recognize that there is a need for kind of specialized care and plan ahead in terms of positioning personnel and the equipment. Always use image guidance if available. And then really to treat patients with dignity and respect as that's really important. Thank you so much. I'm happy to answer questions or you can reach out to me on email.

severe obesity

person-first language

critical illness

ICU procedures

ultrasound guidance

dignity