Nutrition Flashcards
Sources of energy in the diet:
Main macronutrients: Carbohydrates, fats and protein. Oxidation of fats will provide energy.
Carbohydrate yields 4.2k/cal/g.
Fats yield: 9.5Kcal/g –> more energy dense therefore preferential storage most efficient way to store a larger number of calories.
Proteins yield 4.3 kcal/g.
Recommend 55-70% intake from cabrs, and 10-15% from protein.
Micronutrients
Compounds which cannot be synthesized adequately in the body and are needed in miligram or microgram quantities.
There are 2 types of micronutrients (organic vitamins), water soluble (energy releasing (thiamine, riboflavin, niacin, puridoxine, pantothenic acid, biotin).
Haematopoietic (B12, folate).
Vitamin C.
Fat soluble: A,D,E,K.
Micronutrients
Compounds which cannot be synthesized adequately in the body and are needed in miligram or microgram quantities.
There are 2 types of micronutrients:
1. ORGANIC: vitamins: water soluble (energy releasing (thiamine, riboflavin, niacin, puridoxine, pantothenic acid, biotin).
Haematopoietic (B12, folate).
Vitamin C.
Fat soluble: A,D,E,K.
2. Inorganic: trace elements: iron, copper, cobalt, zinc, manganese, iodine, molybdenum, selenium, fluorine, chromium.
BMR
Energy used in involuntary muscle contraction (heart pumping, breathing, gut) and cellular action (e.g maintaining ionic gradients, biosynthesis of DNA, RNA, proteins, fatty acids etc.).
-accounts for 60-70% of total energy expenditure.
Enteral nutrition:
first line nutritional support. Nutrition given into the GI tract. Early post-op enteral nutrition has been shown to benefit patients (eg. after gi surgery and may reduce complications).
Definition: administration of nutrients directly into the stomach, duodenum, or jejunum with the help of feeding tubes
Contraindications
Mechanical ileus, bowel obstruction
Acute abdomen (e.g., severe pancreatitis, peritonitis)
Upper GI bleeding
Mucositis
Severe substrate malabsorption
Congenital GI anomalies
High-output fistulas
Nonfunctional GI tract (e.g., gastroschisis, short bowel syndromes)
Routes
Short-term: nasogastric tube
Long-term (> 2–3 weeks):
Gastrostomy tube: gastric feeding tube inserted endoscopically through a small incision through the abdomen into the stomach or
Jejunostomy tube: feeding tube inserted through a small incision through the abdomen into the jejunum to bypass the distal small bowel and/or colon
Complications
Feeding-tube-related:
Blockage of the feeding tube
Nasogastric tube:
Accidental placement of the tube inside the trachea
Injury to, or perforation of the stomach wall
Gastrostomy or jejunostomy:
Peristomal infection
High-output fistulas
Diarrhea
Gastroesophageal reflux
Metabolic complications of specialized nutrition support
Why are so many hospital patients malnourished
Increased nutritional requirements Increased nutritional losses Decreased intake Effect of treatment Enforced starvation Missing meals Difficulty with feeding Unappetising food.
Parenteral nutrition:
Only do if patient is likely to become malnourished without it. It means that the GI tract is not functioning and is unlikely to function for at least 7 days. Parenteral feeding may supplement other forms of nutrition (short bowel syndrome, crohn’s disease), when nutrition cannot be sufficiently reabsorbed in the gut.
Definition: intravenous administration of nutrients that bypasses the gastrointestinal tract
Total parenteral nutrition: provision of all nutritional requirements intravenously without using the gastrointestinal tract
Contraindications
Enteral nutrition is feasible
Serum hyperosmolality
Severe hyperglycemia
Severe electrolyte abnormalities
Volume overload
Routes
Parenteral nutrition is required for < 2 weeks: peripheral venous line, or peripherally inserted central catheter
Parenteral nutrition is required for > 2 weeks: tunneled central venous catheter or a port
Complications
Venous catheter-related:
Catheter displacement
Thrombosis and/or embolism
Catheter-related blood stream infection
Fluid overload
Metabolic complications of specialized nutrition support
Reduced nutritional intake
Anorexia Side effects treatment Pain Dysphagia Physical disability Nil by mouth.
Increased nutritional losses
Malabsorption
Diarrhoea and/or vomiting
Wound exudate.
Metabolism response to starvation
No injury or stress
- overall energy needs decrease
- metabolic rate decreases
- energy from fat storage
- energy from protein
- protein store protected.
Catabolic insult
Induced protein-energy malnutrition -> burning a lot more energy, breakdown muscle including cardiac respiratory, increase hr.
- No adaptive responses activated
- Increased metabolic rate 35-40cal/kg/d.
- Increase glucose production in excess of need, become insulin resistant.
- increase use of protein for fuel (glucose)
- inefficient use of fat for energy
- wound losses.
Consequences of under nutrition
- Decreased muscle mass
- Decreaased visceral proteins
- Impaired immune response
- Impaired wound healing and response to trauma.
- Multiple organ failure
- Impaired adaptation
- Nitrogen death
Fatigue, general weakness, lack of intiative, bed ridden, apathy, depression, changes of behaviour and personality, total apathy, complete exhaustion.
Parenteral nutrition: NICE guidelines summary
Patients identified as being malnourished-
BMI < 18.5 kg/m2
unintentional weight loss of > 10% over 3-6/12
BMI < 20 kg/m2 and unintentional weight loss of > 5% over 3-6/12
AT RISK of malnutrition- eaten nothing or little > 5 days, who are likely to eat little for a further 5 days poor absorptive capacity high nutrient losses high metabolism
Identify unsafe/inadequate oral intake OR a non functional GI tract/perforation/inaccessible
Consider parenteral nutrition:
for feeding < 14 days consider feeding via a peripheral venous catheter
for feeding > 30 days use a tunneled subclavian line
continuous administration in severely unwell patients
if feed needed > 2 weeks consider changing from continuous to cyclical feeding
don’t give > 50% of daily regime to unwell patients in first 24-48 hours
Surgical patients: if malnourished with unsafe swallow OR a non functional GI tract/perforation/inaccessible then consider peri operative parenteral feeding.
Assessment of nutritional status
Malnutrition Universal screening tool
Malnutrition Universal screening tool.
1. BMI, Ask about unplanned weight loss, 3. Acute disease effect score.
2. Risk/no. of reasons of malnutrition.
Score added:
0-everything is fine, check weekly.
1= you may be monitored by nursing staff.
2= dietician gets involved and makes an assessment.
Assessment of nutritional status -subjective global assessment
Weight change, dietary intake, gastrointestinal symptoms, functional impairment, muscle wasting, subcutaneous fat loss, oedema.
