Metabolic Stress Part 2

Metabolic Stress Part 2


Welcome back. This video is the second
part of nutrition in metabolic stress As a quick review from last video, we
learned how three body systems respond to stressors. The first was a hormonal
response that increased metabolism, which means the calorie demand is much higher. The hormones also induced a breakdown of lean tissue, glycogen and fat to mobilize the energy nutrients. The inflammatory response changed blood flow, and increased both blood clotting and immune factors. The GI tract was affected with lowered motility. So, let’s just keep these factors in mind as we discuss our nutrition therapy. This is a really good graphic to explain the effect of nutrition with an acute stressor. At the beginning of this graphic, it depicts where the stressor begins. As he enters the acute phase, this is where we see the hormonal and
inflammatory responses take effect. Nutrients are mobilized into blood, especially with protein broken down from lean tissue. Metabolism increases causing the
body to break down body stores even further. In other words he is completing
running off of his body until we initiate nutrition therapy. The longer it takes to get nutrition started, the more the body is depleted, decreasing his chances of
fighting off infection and recovering. Remember every cell in your body, whether immune cells, blood cells, hormones, etc are made of protein and other nutrients. The
more the body is depleted, the harder it is to recover. By the time we get to
resistance is at the height of hyper metabolism and catabolism. If we do not
have adequate nutrition established by this point, his body will continue to
break down rather than healing and recovering, leading to exhaustion. We may or may not get him out of this…if we do, it will likely be a long process If we do introduce adequate nutrition during the acute phase, we are able to minimize the body losses allowing it to
fight off infection, heal, and recover. I think this graphic does such a great job of explaining the importance. Now this particular graphic demonstrates the
process of an acute stressor, which is usually a sudden onset with severe effects, but short-term about 7 to 10 days. That means the height of resistance usually occurs somewhere around 3-5 days. So, those of you going into nursing, when you have the dietitian coming around day 3-4 asking “where’s the nutrition?”, pay attention because it is with good reason. The dietitian understands the effects of stress on the body and what
will happen if we don’t get adequate nutrition initiated. So now let’s discuss the nutrition therapy we need for these stressors. Before we get into the details, we should establish our goals. Understanding the body’s responses to stress we know the
body’s catabolic and in high energy demand. So, our goal is to minimize the nutrient losses and then once the acute phase is over, we want to restore any deficiencies, promoting nitrogen balance. The immediate nutrition concern in any severe stress is to restore
adequate fluid. Without proper appropriate level of fluids and
electrolytes circulation and normal body processes can continue. Of course the
stressor effecting the body will also be a top priority for medical staff, but
nutritionally speaking hydration is most important. Depending upon the stressor and reaction
from the body, restoring adequate hydration may include IVs with fluid and electrolytes, medication, or draining excess fluid. The medical staff must be very careful to ensure enough fluid is in the body to restore
circulation allowing nutrients, oxygen and medications to reach cells as well as
allow filtration and removal of toxins in the body. Once the individual is
stabilized, the other nutrients may be addressed. As I mentioned earlier,
initiating nutrition during the acute phase is critical to the recovery process. Recall from the first video that severe stress causes hyper metabolism
hyperglycemia and protein breakdown with negative nitrogen balance. Inadequate calories may affect organ function, decrease wound healing, increased infection risk, and impair ability to recover from the stress. So, it is very important to establish adequate
nutrition as soon as the individual is stable. At the same time we do not want
to provide excessive calories as this will increase CO2 production. I briefly mentioned this in the metabolism videos. You remember, those videos detailing glycolysis, kreb’s cycle and electron transport right? Well if you
recall, as you are breaking down your as you are breaking down your carbs, fats, and proteins to obtain energy from them, several of the steps of the byproducts
CO2. This CO2 then has to be removed from the body )through respiration). So, the more calories or
energy nutrients you provide to the body, the more CO2 is produced causing more
demand on the heart and lungs. We do not want to cause more work on the organ systems than we already have during severe stressors. Avoidance of overfeeding is even more important when the patient is in respiratory failure. So, finding the right
amount of calories can feel like walking a tightrope. Too few calories can affect
healing organ function, immunity, and recovery while too many calories can
overwork respiratory functions. It is a precarious position that the dietitian must get
right. The good news is the dietitian is the one to set the goals for calorie, protein and micronutrient needs. But, I want to give you a quick overview of how the dietitian determines these needs. If you recall from the weight management
chapter, the amount of calories a person needs to consume to maintain body mass
is equal to energy expenditure. Energy expenditure is made up of basal
metabolic rate, physical activity, and a very small amount from the thermic effect of food. A person with a stress is not much different… they have the same basal needs. So, the dietitian uses some very complex formulas to determine these basal calorie needs. You can see 2 different formulas on the screen. Note the formulas take into account not only height and weight, but age and gender as well. These formulas are used to determine the
resting metabolic rate of an individual whether healthy or undergoing a stressor.
If this were a healthy individual, the dietitian would then consider the
individual’s physical activity. But in the case of respiratory and metabolic stress, the individual is bedridden and has no physical activity to consider. While the
individual may have no physical activity to consider, he/she she does have
a higher calorie demand due to the stressor. So, instead of an activity factor,
the dietitian considers a stress factor. This slide demonstrates the process. First, the dietitian calculates the resting metabolic rate for the individual, using
the formula I described in the previous slide, then multiplies by the appropriate
stress factor to determine the amount of calories the person needs. Sometimes
adjustments must be made for higher demand if the person has additional stressors such as a ventilator or having a fever. If the patient is obese the dietitian may
also make adjustments for lower calories. Once the calorie needs are determined, the dietitian calculates the appropriate amount of carbohydrates and protein to
make up those necessary calories. The specifics of how much of each nutrient
is needed depends on the condition of the patient. The dietitian will use various factors from the assessment including blood sugars (which are often elevated during stress), blood proteins (which are usually low), hydration levels, organ function, immune factors, etc. But the main premise you need to take away is that carbohydrate and lipids will be supplied in adequate
amounts to spare the protein from being used as an energy source Remember these individuals are hyper
metabolic and in negative nitrogen balance. Our goal is to minimize losses
by 1) providing enough calories and 2) prevent protein catabolism. We do that by providing ample calories in carbs and fat as well as the right amount of
protein. Because we are trying to prevent protein from being used as a calorie
source we do not calculated in terms of percent of calories. Instead we calculate
the protein based on body weight. This was discussed briefly in the protein
chapter. The recommended amount of protein for a normal individual is 0.8 grams of protein per kilogram of body weight. Depending on the level and type of stress to the body, the protein factor increases to 1-3 grams per kilogram of body weight. Again, determining protein needs is the job of the dietitian, but it is important
for you to know the normal requirement of 0.8 grams per kilogram, and that higher protein factors are used with stress and most diseases. There are a few additional nutrients that are important to note. Two amino acids are often added to nutrition plan
incidentally stressed individuals. Both Glutamine and arginine have been found to improve immune function, preserve muscle mass, and promote
healing. You will often find these amino acids added to the tube feed formulas designed for metabolic and respiratory distress. The micronutrients we are most likely to
increase with stressors are vitamins A & C the mineral zinc. These 3 micronutrients have critical roles in immunity and healing. They may be supplemented in higher amounts during stressors. Ideally we always prefer to provide
nutrition through oral diet. However in the case of severe stressors we often
do not have this luxury. The next best choice is enteral nutrition or tube feeding. Providing nutrition enterally can be challenging, though. As I mentioned in part one of the stressors video, one of the
body’s responses to stress is decreased gastric motility. This means the stomach may not move contents into the small intestine very well. Generally the doctor
will try treating this with medication. We have meds that are often successful
at increasing motility. If we are unable to use the GI tract, the last resort
is parenteral nutrition. Due to the high-calorie demand, PPN or peripheral parenteral nutrition, would not be indicated so TPN would be used. But with TPN comes a high risk of infection which is even more dangerous in the metabolically stressed individual. Again, TPN is a last resort only one the gut cannot be used. I guess that wraps up our segment on
nutrition in metabolic stress. Thanks for joining me. joining me

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