GI clinical: Malnutrition, Vitamin Deficiencies and Nutritional Support Flashcards
What nutrients do we need?
• 9 essential AA: histidine, isoleucine, leucine, lysine, methionine/cystine, phenylalanine/tyrosine, threonine, tryptophan and valine
• Essential FA: linoleic acid (w -6), alinolenic acid (w -3)
• Fat soluble vitamins: A, D, E and K
• Water soluble vitamins: C, _____ (B1), _______ (B2), niacin(B3), _______ (B6), b12, folate, pantothenic acid (B5), biotin, choline
• Minerals: Ca, PO4, Mg, Fe
• Trace elements: Zn, Cu, Mn, Se, chromium, molybdenum, fluoride, iodine
thiamine; riboflavin; pyridoxine
- ________________ is the amount of nutrient estimated to be adequate for half of the healthy individuals of a specific age /sex. Hence it is actually the Median nutritional requirement for a group and therefore, not an effective estimate of nutritional adequacy in an individual as this requirement may not sufficient to maintain good health for 50% of individuals.
- ____________, defined as 2 standard deviations above the estimated average requirement, is the average daily dietary intake that will meet the nutritional requirements of nearly all healthy persons of a specific age/sex. When there’s no established EAR, the RDA cannot be calculated. In these cases, adequate intake is used. This is the observed or experimentally determined approximations of nutrient intake in healthy people.
- ____________ is the highest level of chronic nutrient intake that is unlikely to have an adverse effect on health for most of the population. While nutrient levels in commonly eaten food rarely exceed UL, heavily fortified foods/dietary supplements provide more concentrated amounts of nutrients per serving and pose a potential risk of toxicity.
Estimated average requirement; Recommended dietary allowances;
Tolerable Upper Levels (UL)
Energy is provided by the macronutrients that we consume.
Fat provides ____ per g of fat ingested Both carbohydrate and proteins provide ___ of energy per gram ingested. It is recommended that 45-65% of our caloric intake should come from carbohydrates, 20-35% from fat and 10-35% from proteins.
It is important to understand that energy and nutrient requirement is not the same for everyone. It is affected by age, sex, growth rate, level of physical activity pregnancy, lactation and when a patient has concomitant illness.
In children, it is important to supply sufficient energy to ensure adequate growth and maturation. In adults, the aim is to supply adequate energy to maintain weight and bodily functions.
During pregnancy and lactation, with increase demands of the fetus and lactation, energy supply must be increased to match demands Similarly during disease states, there is also an increase demand in energy from inflammation, cancer, trauma and post surgery, and without supplementation, supply will not be able to match energy demands, which can be exacerbated by ongoing losses, specific nutrient requirements, weight loss ensues and health and recovery of the patient will be affected.
9kcal; 4kcal
The total energy expenditure or TEE is the Approximate total caloric need for a person of certain age, sex, wt., ht., and physical activity over 24hr period
The main components of TEE is contributed by
a. The basal metabolic rate BMR/or resting metabolic rate RMR
b. ____________________
With minor contribution from the energy cost for metabolizing food and thermogenesis, also known as TEF, i.e. thermic effect of food.
The BMR and RMR can be measured using indirect calorimetry.
There are minor differences in BMR and RMR. BMR or basal metabolic rate or also known as basal energy expenditure is the minimal rate of energy expenditure to maintain the body’s basic physiological function/ compatible with life. It is measured in the ______ just after waking up from 8hrs of sleep, 12hrs fasting, immobility, thermoneutrality and mental relaxation. Resting metabolic rate or RMR and also known as = Resting Energy Expenditure (REE): Is BMR + energy expenditure for eating/light activities It is measured under less restrictive conditions and only requires 4hrs fast and can be measured at anytime of the day
Level of physical activity level or PAL; supine position
[Malnutrition- Effects on Metabolism and Body Composition]
- As the body attempt to conserve energy, there is a downregulation of energy dependent metabolism in the body, including glucose & amino acid transport, protein synthesis and na/k pumps. There is also a decrease in hormone secretion, such as insulin, glucagon, catecholamines, growth factors and thyroxine.
- But over a prolonged period of malnutrition, the body begins to draw on functional reserves in tissues such as _________________ leading to changes in the body composition.
- Weight loss due to depletion of fat and muscle mass, including organ mass is the most obvious sign of malnutrition.
- There is a loss of subcutaneous fat, decrease in skin mass, decrease in skeletal, cardiac and respiratory muscle mass and even intestinal mass. Bone density is also decreased. There is a relative protection of brain and visceral function initially but as malnutrition worsens, brain function becomes affected as well.
muscles, adipose tissue and bone
[Malnutrition- Effects on Biological Function & Clinical Outcome]
As the body’s metabolism and composition becomes affected, this eventually lead to loss of biological function and a poorer clinical outcome.
As the patients lose skeletal muscle mass, there is a loss of muscle strength.
Poor diaphragmatic and respiratory muscle function reduces _________ and expectoration of secretions, delaying recovery from respiratory tract infection.
Reduction in cardiac muscle mass results in decrease in cardiac output and has a corresponding impact on renal function by reducing renal perfusion and __________.
Chronic malnutrition also results in changes in pancreatic exocrine function, intestinal blood flow, villous architecture and intestinal permeability. The colon loses its ability to reabsorb water and electrolytes, and secretion of ions and fluid occurs in the small and large bowel, resulting in diarrhoea.
Immune function is also affected, increasing the risk of infection due to impaired cell mediated immunity, cytokine, complement and phagocyte function.
Delayed wound healing is also well described in malnourished surgical patients and patients are at risk of pressure sores as well. With loss of bone mass, patients are at risk of fractures too.
cough pressure;
glomerular filtration;
Causes of malnutrition usually falls into 4 main categories: Reduce dietary intake, reduce absorption of macro and micro nutrients, increase loss or altered requirements, and increase energy requirement.
- Reduce dietary intake can occur from a Depressed conscious level (for example from a cerebral vascular accident), from swallowing disorders in patients with Psychological issues such as depression, anorexia nervosa in special patient groups such as the poor, elderly, alcoholic and in those with disabilities.
- Reduce absorption of macro- and/ or micronutrients can occur in patients with GI obstruction, ileus, short bowel, malabsorption and maldigestion from various causes, including pancreatic insufficiency and bacterial overgrowth. Increase losses can occur in enterocutaneous fistulas and burns patients.
- And increase energy expenditure can occur in patients with major illness, trauma, which not only increases metabolic demands, it is often associated with reduced intake as well, further contributing to malnutrition.
- Pts with chronic liver disease/liver failure, often suffers from malnutrition through reduced intake for a variety of reasons, malabsorption and maldigestion due to reduction in ______, and _________ that can affect small bowel absorption of nutrients, as well as increased energy expenditure as many pt.’s have a raised resting energy expenditure and lastly, increased losses through diarrhoea, bleeding and __________.
bile salt pool; portal venous congestion; abdominal paracentesis
One example of a screening tool is the malnutrition universal screening tools or MUST.
And in 4 simple steps, the patient’s risk of malnutrition can be determined with this tool.
- In Step 1, determine that patients ___,
- In Step 2, determine the ________________
- And in step 3, determine whether the patient is acutely ill and if it’s likely that there will be _____________.
- Appropriate scores are then assigned for each step and added up and a pt.. is classified as low risk if the overall score is 0, medium risk if the overall score is 1 and high risk if the score is 2 or more.
Once the risk has been determined, in step 5 recommendations of management are
provided.
- Low risk patients should continue to receive routine clinical care, and nutritional screening can be repeated, for e.g. weekly if the patient is still in hospital.
- Medium risk patients should have their dietary intake documented, and observed for any improvement and whether intake is adequate. Actions should be taken if intake is inadequate. Nutritional screening can be repeated, for example again weekly if pt. remains in hospital.
- For high risk patients, they should be referred to the dietician or nutritional support team. And measures taken to improve and increase nutritional intake, while continuing to monitor and review the patient’s progress and care plan.
BMI; percentage of unplanned wt. loss in the past 3-6mths; no nutritional intake for >5 days
[Assessment of nutritional status]
- For at risk pts, an in depth assessment of the their nutritional status should be performed. This will include: A detailed dietary history, Clinical examination including functional assessment as well as their wt., BMI, ____________, skin fold thickness.
Functional testing such as hand dynamometry and respiratory function can be considered, although these are rarely performed.
Blood tests should be obtained to look for nutrient deficiencies including Full blood counts, urea, electrolytes, liver function test, glucose, calcium, phosphate, mg, zinc, copper, iron, thyroid function test, folate, vitamin B12, A, D, E and K. Specific tests can be performed depending on suspected clinical problems. For example, ________________. Lastly, assessment of intake should be performed, using food recall, and food diary.
mid arm circumference (MAC); swallowing assessment
[Nutritional Assessment- Physical Examination]
Physical examination of a malnourished patient may reveal
- Muscle wasting especially of the neck and ________, they are thin, with BMI < ____
o Loss of ___________ as reflected by a decrease in skin fold thickness
o Weak hand grip and leg extensor strength
o Peripheral oedema and even ascites may be seen due to _________
temporal muscles; 18.5; subcutaneous fat; hypoalbuminemia
[Types of nutritional support- oral]
If the patient is able to take orally and not at risk of aspiration as assessed by a bedside swallowing test or if necessary, a speech therapist, nutritional supplements can be taken orally. Appropriate dietary advice such as the type and consistency of food, _____________ help patient swallow better and minimizing the risk of aspiration. Patient can be advised to take fortified food to make up for deficiency in nutrients.
Or the patient can take specially formulated oral macronutrient and micronutrient supplements. Such as ensure plus, boost. Special formulations are available for different patient groups, e.g. ______ for diabetes, ______ for renal patients, module for ___ patients.
thickened fluids
Glucerna; nephro; IBD
[Enteral feeding]
Enteral tube feeding can be done via 3 routes:
1) Through the nose is __________
2) through the abdominal wall directly into the stomach, that is, ______________
3) directly into the jejunum, that is __________.
Tubes can also be placed deeper via gastrostomy into the jejunum, that is, gastrojejunostomy tube feeding.
The most common form of enteral feeding is the nasogastric tube feeding. As you can see, nasogastric tubes are inserted through the nose, past the ______ and esophagus, into the stomach.
A nasojejunal tube, which is longer and can be inserted deeper past the stomach, into the jejunum may be necessary in some patients for example, a pt. with gastroparesis with high nasogastric aspirates.
As some patients do not like the discomfort of having a tube in their nose, an alternative to nasoenteric tubes is delivering nutrients directly into the stomach, using a gastrostomy tube inserted endoscopically, known as _____________ or PEG tube as its commonly known. Some patients with high gastric aspirate, may benefit from using a gastrojejunostomy tube, as you can see from the diagram, where a thinner jejunal feeding tube is passed through the PEG, into the small intestines.
naseoenteric tube feeding; gastrostomy tube feeding; jejunostomy tube feeding
pharynx ; percutaneous endoscopic gastrostomy tube
[Enteral tube feeding- complications and contraindications]
Contraindications include patients with complete bowel obstruction, ileus, malabsorption, and pts with high output intestinal fistulas.
Complications of enteral tube feeding may be related to the feeding tube itself, such as mispositioning in the trachea and esophagus, resulting in _____________.
Nasoenteric tubes causing ___________ pain, erosions, sinusitis, and __________ at gastrostomy/jejunostomy sites.
Gastrointestinal complications include bloating,distention with enteral feeds, reflux, regurgitation, constipation and even diarrhoea.
And lastly metabolic complications include hyperglycemia, and electrolytes disturbances
for e.g. hypophosphatemia in refeeding syndrome. Its placement, misplacement and displacement. For example, a nasogastric tube may be misplacement into the lung, instead of the stomach, or displaced into the esophagus after initial correct placement, resulting in aspiration.
aspiration pneumonia;
nasopharyngeal; stoma infection
[Refeeding syndrome]
In starvation, the basal metabolic rate decreases. The liver decreases ___________ and the body switches from cho to fat and protein as the main energy source. Muscle and other tissues decrease the use of ketone bodies and increase the use of ________, increasing the amount of circulating ketone bodies. The brain switches from using glucose to using ketone bodies as the source of energy. Intracellular minerals gradually become depleted, through serum concentrations may remain normal.
In refeeding malnourished patients, the basal metabolic increases and _______- again becomes the predominant source of energy. This anabolic response to refeeding causes _______ movements of electrolytes resulting from hormonal and metabolic changes. And a rapid fall in serum levels of electrolytes may lead to cardiac and respiratory failure, lethargy, confusion, coma, convulsions and even death.
These symptoms of refeeding syndrome is thought to be predominantly due to __________. But is also contributed by changes in sodium and fluid balance, glucose, thiamine deficiency, hypokalaemia and hypomagnesemia.
gluconeogenesis; fatty acids;
glucose; intracellular;
hypophosphatemia
[Refeeding syndrome: metabolic and hormonal changes]
Glycemia results in an increase in insulin and decrease in glucagon secretions. Insulin then stimulates glycogen, fat and protein synthesis, requiring minerals including phosphate, magnesium and cofactors such as _________. Insulin also stimulates the absorption of potassium into the cells through the _____________. Mg and phosphate are also taken up into the cells, and water follows via osmosis
This results in decrease circulating levels of ________________. The clinical features of refeeding syndrome occur as a result of the functional deficits of these electrolytes, and the rapid change in basal metabolic rate. Hence, close monitoring is required in the first stages of refeeding, and replacement of these electrolytes is essential.
thiamine; sodium-potassium ATPase pump;
phosphate, potassium, magnesium and thiamine
