All right, good afternoon, everyone. And I appreciate you staying for some of the later sessions. So my name is Shelby Osusko. I'm a nutrition support clinician. I specialize in our surgical ICU population, as well as work in the ambulatory setting, managing both enteral and parenteral nutrition support. And I have no conflicts of interest to declare. So for the objectives for this talk today, I want to review metabolism in patients with obesity who are critically ill. We'll talk about the 2021 Adult Critically Ill Nutrition Support Guidelines. And lastly, I want to discuss some recent literature and gaps of literature as it relates to obesity in our ICU population. So I want to start by asking you all a question. Should nutrition be provided to an ICU patient, or is nutrition important to provide to a critically ill patient with obesity? Why or why not? We often think of malnutrition as it relates to an individual who is thin or underweight. But the reality is malnutrition comes in many different forms. Unfortunately, this is not a problem in just the United States, but countries across the globe are working to treat malnutrition and obesity as it has become a global health issue. Patients with obesity are complex, as you've heard with a variety of speakers today, and present in the critical care setting with a high degree of variability and baseline risk for poor outcomes. Patient size does not necessarily predict individual risk. I hope you can be encouraged to see the need for specialized and individualized nutrition therapy with ongoing educational efforts among your clinical staff involved in the management of these complex patients. Malnutrition-related diseases, in particular patients with obesity or those with severe obesity, are major causes of diseases across the world, and more than half of the leading illnesses are attributed to nutrition-related diseases. Malnutrition is truly a neglected disease and manifests itself just as often in patients with obesity and severe obesity versus an individual considered to be at a healthy body weight or normal body weight. So by the end of this lecture, in the next 15 to 20 minutes, I hope you can appreciate the importance of providing adequate nutrition to your critically ill patients with severe obesity. It's not appropriate to put these patients on a diet or withhold nutrition from them in your units. I want to provide an overview of malnutrition in the hospitalized patient because I do find these numbers to be quite powerful when you review them. This graphic is from the American Society of Enteral and Parenteral Nutrition, otherwise known as ASPEN, and it highlights the impact of malnutrition in our hospitalized patients. We know there's a significant gap from malnutrition diagnosed and coded versus the actual prevalence in practice. But fortunately, we are slowly doing a better job at recognizing malnutrition. As evidence, you'll see an uptrend of 8.9% back in 2018 where we're found to have a malnutrition diagnosis upon discharge from the hospital setting. Overall, malnutrition leads to poor outcomes, including a 3.4 times higher risk of in-hospital death, two times higher discharge rate to an LTAC or rehab facility, 1.9 times longer length of stay, and 1.4 times higher need for home health services. What is just as concerning with these numbers is that our statistics show we are not using nutrition support as often as we should be in helping to treat and intervene with those whom have or are at risk of having malnutrition. In fact, ASPEN reported only 2.9% of patients coded for malnutrition received parenteral nutrition and 2.7% received enteral nutrition during their hospitalization. So more specifically, let's dive into malnutrition as it relates to our critical care population setting. Inadequate nutrition in the intensive care unit is associated with increased mortality, ICU length of stay, and hospital length of stay. Additionally, critically ill malnourished patients have up to a 6.5 times higher average cost per patient compared to our general ward patients. This graphic, again, is from ASPEN and highlights the prevalence of malnutrition in the ICU patient by disease state. You'll see varying percentages here, but what you'll notice that among the listed types of patients, malnutrition is quite prevalent among all of them with up to an 80% range in patients with acute kidney injury. What is interesting is that we just talked about how the low reported use of nutrition support in these patients with malnutrition, despite knowing that there's many clinical benefits of using nutrition support, which we'll talk about today. ASPEN reports the use of nutrition support is cost saving. They did a project called the ASPEN Value Project, if you're interested, looking at a number of different five component areas. What I want to talk about today is that they did publish this back in 2021 in J-PEN, if you're interested, but it essentially highlights there's a projected $222 million in cost savings yearly for Medicare patients if nutrition support was utilized in these patients with sepsis. So let's review the newly published guidelines for the provision of nutrition support therapy in our critically ill patients. This was published in 2021 in J-PEN. These guidelines are an update from the 2016 report and focused among five different question areas related to protein and energy intake, nutrition support feeding modality, the use of supplemental parenteral nutrition, and the type of lipid emulsion that is used in our critically ill patients. The authors for these guidelines reported that they used a higher standard of inclusion as they only included RCTs for this particular report from 2001 to 2020. While not as robust, Aspen reports they use a much higher standard of inclusion criteria compared to the 2016 guidelines. So question number one, Aspen found no significant difference in clinical outcomes between patients with higher versus lower levels of energy intake. They suggest providing between 12 and 25 kcals per kilogram of body weight in the first seven to 10 days of ICU. And we'll talk about body weight and what use that may be in this particular patient population with a severe obesity later on. The quality of this evidence was rated as moderate with a strength of recommendation weak, meaning there's essentially a lack of certainty regarding the harms and benefits. These updated guidelines are different from our 2016 publication, whereas the recommendations used to be provided on nutrient risk level, disease state, and used to include BMI class. Really this means there's a bigger role for us as clinicians to have clinical judgment and really personalize our nutrition prescriptions for these patients. We really need to consider the use of indirect calorimetry, which I'll talk about in a moment, especially those of greater BMI classes where it is quite unclear what an individual's estimated energy needs are. Recommendation number two explores clinical outcomes associated with higher versus lower protein intake due to the limited availability of high-quality evidence. Aspen continued prior recommendations from 2016, essentially recommending that protein needs should be calculated between 1.2 and 2.0 grams per kilogram of body weight. The quality of evidence rated low with a weak strength of recommendation. Recent guidelines for obesity are not specified in this 2021 update, as there is not any specific trials which met the inclusion criteria for this report. The third question seeks to identify what feeding modality is most beneficial in our first week of ICU admission and critical care. Aspen found no significant difference in clinical outcomes between early exclusive parenteral versus enteral nutrition during the first week of our ICU stay. Neither modality is considered acceptable in this report, as it does not appear that there are any harms or benefits concerning the choice between modalities. The quality of evidence was rated as high with a strong level of recommendation. More contemporary practices and nutrition support is likely what was led to these updated guidelines from the 2016, since we have adopted safer practices around the use of parenteral nutrition, including improved catheter care, glycemic control, and the avoidance of overfeeding and the use of indirect calorimetry in a lot of our ICU settings, which thus has likely led to reduced risks of bacteremia and hyperglycemia. However, we cannot forget the well-documented benefits of using the gut and using enteral nutrition in this patient population and setting that are non-nutritive. Caloric low-dense, otherwise known as trickle or trophic feeds, as you may have heard, is the practice of feeding these minimal amounts, generally speaking, between 10 and 30 mLs per hour in our adult patient population of enteral nutrition with the primary goal to maintain gut function and integrity, despite not necessarily meeting our caloric needs. We know that enteral nutrition stimulates organs of digestion to function in normal capacity and also assist in the digestion and absorption of nutrients. It also presents passage of bacteria among the GI tract into the systemic circulation, reducing infection rates, enhancing immune function, and preserving GI mucosal structure and function. Trophic feeding may also reduce the development of a postoperative ILEUS. Therefore, despite the new recommendations, EIN is still the preferred source and form of nutrition support when it is appropriate and accessible to provide. The fourth question explores whether it's beneficial or harmful to provide supplemental parenteral nutrition to a critically ill patient who cannot meet their estimated nutrition needs by enteral nutrition alone. Aspen recommends against the initiation of supplemental PN prior to day seven of ICU stay with a quality of evidence reported as high and a strong level of recommendation. Lastly, our fifth question is really two parts, looking at two types of intravenous lipid emulsions, our mixed oil and fish oil, and if there's an advantage over the predominant soybean oil lipid that dominates the United States market. This is definitely a hot topic and absolutely could be its own talk. At this time, Aspen reports there's not statistically or clinically significant differences in patient outcomes and included RCTs of these guidelines to provide an advantage over using a soybean oil lipid emulsion. However, the quality of evidence was reported as low with a weak strength of recommendation. There's a lot of literature coming out in this area, so I do believe that this recommendation may be updated or changed in the near future based on some of the publications coming out looking at some of the different types of lipids and their impact on inflammatory status. So patients admitted to the ICU increasingly present with overweight and obesity and severe obesity that require individualized nutrition considerations due to a number of different factors, immunological factors like inflammation and changes in energy expenditure and other aspects of metabolism. These patients may present with altered nutrient processing and pharmacokinetics, as mentioned earlier, which potentially complicates both our medication management as well as our nutritional management of these patients. So how do we really predict energy or caloric needs in this patient population? Well, there's more than 200 predictive equations that are out there in existence, many of which were developed up to 80 years ago and really does not always reflect current contemporary body composition, nutritional risks, age, or ethnicity of the populations that they're applied to, unfortunately. So there's really no consensus on whether actual, ideal, or an adjusted body weight should be used to calculate energy needs in this patient population, especially for our critically ill patients with severe obesity. There's really just not the literature there and available at this point. Our ICU nutrition guidelines, looking at both the American as well as our European guidelines, recommend that we should use indirect calorimetry is the gold standard for measuring energy expenditure in our critically ill patients, particularly those with severe obesity. Many of the limitations we've previously thought and we previously may have had with using some of the older devices have been overcome by some of our newer indirect calorimetry models, such as the use of a metabolic cart with our CVVH patients or FiO2 limitations. We just reviewed the data for specific energy targets in obese patients, which is lacking. But what about hypocaloric feeding? We've all heard the term used, let's hypocalorically feed these patients. Well, the reality is most of these patients are already being underfed in the ICU setting, especially our patients with obesity or those whom have severe obesity. We know from Darren Hyland's international ICU survey that ICUs surveyed around the world, we feed our patients about half of their estimated calorie needs for the first two weeks. And this number is often worse in patients with more elevated BMIs. In the absence of consistent guidelines to estimate energy needs for patients with obesity, clinicians should and must continue to use an individualized and personalized approach when considering the current guidelines, the amount of metabolically active tissue the patient may have, which then influences the degree of hypermetabolism, and the need to respond to changing nutritional requirements and altered metabolism throughout the stay. Nutrition should be monitored and nutrition regimens should be adjusted accordingly for outcomes such as hyperglycemia, hypercapnia, and other metabolic disturbances that come up. Ultimately, the nutritional management of critically ill patients with obesity should aim to reflect a net protein catabolism without concurrent feeding complication and worsening of physical functions or limitations. Personalized nutrition approach is key to delivering our adequate protein intake while reducing the risk of excessive feeding in patients who are critically ill with severe obesity to reduce both mortality and morbidity complications and risks. A practical approach to apply this essentially is the use of a high protein, lower caloric energy enteral formula in addition to things like protein modulars or supplements. For parenteral nutrition, perhaps a lower dextrose, higher amino acid content formula should be prescribed to your patient population. So looking at protein and how we apply some of this precision nutrition in this patient population, factors such as advanced age, immobility, inflammation, insulin resistance, and medications all may increase the protein requirements of this patient population. These factors, along with many of them coming in with chronic low protein provision at baseline upon their admission to your ICU setting, may contribute further to the loss of lean body mass as well as the development of sarcopenic obesity. Sarcopenic obesity could be a talk in and of itself as we know that this leads to things like ICU acquired weakness. Sarcopenia and cachexia are both more common than we've previously recognized, which is being more and more documented in our literature in patients with patients whom are critically ill with obesity and severe obesity. Meanwhile, there's no consensus on protein requirements in patients with obesity, leaving us clinicians really to depend on clinical judgment in many cases. Most of the data is from small-scale studies, populations, as well as the current guidelines that are available. Ultimately, muscle mass may and often will continue to occur despite the delivery of what we think is adequate protein provision in this patient population. Research supports that the extent of obesity appears to influence the amount of protein required for this patient population or those with whom have severe obesity compared to those who may have a lesser BMI class. Therefore, it's essential to provide adequate protein in patients to help maintain nitrogen balance as well as lean body mass while encouraging the use of adipose tissue for fuel. Patients with severe obesity receiving high protein through permissive underfeeding have reduced insulin resistance, lower insulin requirements, better glycemic control, decreased ICU stay, and reduced duration of mechanical ventilation, as noted in the current literature. So I want to ask you all again, let's bring this question back one more time. Do we think it's important, or do we think patients with obesity or severe obesity should be provided nutrition support in their ICU or intensive care unit stay? Absolutely. Patients with obesity and critical illness present with several clinical challenge due to the possibility of underlying comorbidities, systemic inflammation, and a lack of evidence to routinely guide us as clinicians through their nutritional management interventions. We must consider individual factors that considers the whole person, including the potential for chronic stigma associated with obesity that could then impact the delivery of effective and evidence-based practice care. Inappropriate nutrition prescription in a critical care setting is a necessity for all patients despite BMI class, or if a patient has an elevated BMI, including those with severe obesity based on up-to-date guidelines, as high-quality evidence continues to be lacking. Other studies really do need to focus on nutrition priorities in this population with efficient and adequately powered studies. If anyone's interested, happy to collaborate. And I want to remind all of us that it takes a village. So continue consulting with your multidisciplinary team and recognize the importance of all these different factors that we discussed today among our patients with severe obesity and how to best manage them within practice guidelines. Thank you.

nutrition support

critically ill patients

obesity

malnutrition

ICU