Nutrition Flashcards
What are the functions of the kidneys?
EPO, calcitriol, renin
What happens in CKD?
- Reduced activation of 25-OH vitamin D3 by OHase to calcitriol which regulates calcium intestinal absorption so low Ca levels
- Potassium is normally excreted in the urine = amount ingested to keep a balance so hyperkalaemia
- The kidney contributes to maintenance of the blood pH by excreting H+ and reabsorbing HCO3- in the PCT to keep blood pH at 7.4, leading to acidosis
- EPO production is a glycoprotein hormone produced in the kidney which regulates the red blood cell production
- anaemia
- The production of urine controls fluid balance and salt balance is maintained both contributing to blood pressure maintenance. The amount of salt excreted roughly equals salt ingested.
- HTN/ Fluid restricton
- Renin secretion: enzyme released in response to low blood volume or decreased sodium chloride concentration.
It activates the renin-angiotensin system by cleaving angiotensinogen to yield angiotensin 1 which is converted to angiotensin 2 by angiotensin converting enzyme. This constricts blood vessels and activates the thirst reflex leading to increased blood pressure.
What are the causes of CKD?
Diabetes, glomerulonephritis, polycystic kidney disease, polynephrittis, HTN, renovascular, uncertain aetiology/other
What are the stages of CKD?
x
What are the stages of disease and nutritional issues?
x
Which nutritional interventions are used in CKD?
Delay progression of CKD, minimise sx of uraemia, minimise effect of renal disease on blood biochem and fluid status, Id and treat malnutrition
What are the different routes of feeding?
Oral, NGT, jejunostomy tube (if aspirating or vomiting a lot), gastrostomy tube
What is an NGT?
Risk of aspiration in ICU _> ensure upright 30-45 degress; don’t place at night; high aspirates and inadequate calories common in ICU (RIG/PEG/ gestrostomy feeding for long term); can give higher rates/volumes into stomach
How do you delay the progression of renal disease?
Diabetic control which reduces nephropathy (HbA1c of 48mmol/mol); HTN (aim for 120-139/90mmHg; 120-129/80mmHg in diabetes/albumin:creatinine ratio of 70mg/mmol or more; strong evidence that CV risk reduced, as HTN can be contributory or causative); obesity aim for adequate glycaemic control and BP, morbid obesity linked to 2.3 RR developing CKD
How do you minimise uraemic Sx?
Sx before starting dialysis: tiring easily, weakness, anorexia/nausea, muscle cramps, bad taste in mouth -> protein restriction diet: 0.75g/kg ideal body weight/day for pts with stage 4-5 not on dialysis
How do you manage a low protein diet?
Start with high bio value proteins to reduce overall protein intake (Meat, fish, dairy, eggs), then consider low bio values of protein (Rice/paste/bread/cereals).
Complex and restrictive -> to meet kcal req may need to add in low protein high kcal snacks often high in fat/sugar; reducing protein also reduces K and PO4 intake
How do you minimise the effect of renal disease on blood biochem and fluid status?
Oedema (peripheral and pulmonary) = salt (recommendation <6g/d) and fluid restriction (CKD 5), controlling this improves BP, and salt reduces kidney injury as ^ salt intake = worsening albuminuria and kidney tissue injury; hyperphosphataemia: PO4 intake and PO4 binding medication - elevated sPO4 increases mortality risk; hyperkalaemia: reducing K intake and considering non dietary factors
What are the 2 types of renal bone disease due to CKD?
Bones become thin and weak;
deformities in joints in fingers and in rib cage;
sPO4 main factor determining the Ca/PO4 product and prevalence of metastatic calcifaction including vascular calcification and heart valve calcification
What is calciphylaxis?
Syndrome of vascular calcification and thrombosis and skin necrosis -> chronic non-healing wounds; rare but serious
Which foods are good for phosphate?
x
Which foods are bad for salt restricted diets?
x
What are the different types of phosphate binders?
x
What is the effect of hyperkalaemia?
Can be present in CKD, HD, PD pts; can lead to sudden death by arrhythmia; difficult to Dx -> K = 3.5-6 mmol/l HD, 3.5-5.5 in PD, 3.5-5.3 CKD
What are the non-dietary causes of hyperkalaemia?
Acidosis, low HCO3 level, constipation, medicines (K sparing diuretics), blood transfusions, poor blood sugar control, dietary high K foods
What are the foods with high potassium?
To cook low K, need to boil NOT fry, steam
What do you do to reduce K?
Reduce spinach and other high K foods and drinks; suggest alternative veg; boil instead of steaming/frying
What are the causes of malnutrition in renal disease?
Uraemia, anorexia, acidosis, infections, dietary restrictions, tiredness due to Tx, nutrient losses, hypercatabolism, depression, family support
What are the calorie requirements for CKD HD, PD?
CKD/HD = 35kcal/kg/d, 30 >60y; PD = 35 kcal/kg/d or 30 kcal/kg/d >60y including kcals from dialysate
How do you treat malnutrition?
Enteral nutrition support: oral nutrition supplements/tube feeding; parenteral nutrition support: intra dialytic parenteral nutrition/total parenteral nutrition
What are the renal considerations when supporting nutrition?
Fluid restriction necessary?, electrolytes (PO4/K necessary); protein
What is the overall nutritional support for renal patients?
x
Which tumours have high, medium and low risk of weight loss?
High: head/neck, oesophago-gastric and pancreatic cancers; medium risk: prostate, colorectal, lung; low risk: breast, sarcomas and NHL; unintentional weight loss is associated with low QOL, poor treatment tolerance and poorer prognosis
What makes up weight?
Fat (subcut and visceral), muscle (skeletal and appendicular), bone, organs, fluid
What weight assessment do we do in clinical practice?
Weight, BMI, BSA, nutrition screening, visible signs of fat loss (orbital/triceps), visible signs of muscle loss (clavicle/temporal); fluid (oedema/ascites)
Why does weight loss matter?
Treatment toxicity, fatigue, sarcopenia, wound healing, skin integrity, dose reduction, reduced QOL, radiotherapy replanning, increased mortality
Why are lung cancer pts malnourished?
Iatrogenic causes of decreased intake; inadequate symptom control (no appetite, early satiety, pain, taste changes); tumour site (functional and physiological causes of malnutrition = GI function/motility, obstruction, malabsorption); increased metabolic rate; cancer cachexia
What are the iatrogenic causes of malnutrition?
Decreased intake, increased energy expenditure/losses; surgery: pain, SOB, fatigue; radiotherapy: odynophagia, mucositis, SOB, fatigue, dysgeusia, xerostomia, pain; chemotherapy: fatigue, N/V, mucositis, anorexia, infection, malabsorption, bowel changes, dysgeusia
What is cancer cachexia?
Multifactorial syndrome, which leads to on-going loss of skeletal mass with or without the loss of fat mass, that cannot be fully reversed by conventional nutrition support and leads to progressive functional impairment -> -ve protein/energy balance, anorexia, reduced oral intake, abnormal metabolism
What are the differences in metabolism in cancer cachexia?
x
How do you clinically assess cancer cachexia?
x
What are the stages of cancer cachexia?
At precachexia use nutrition and physical activity; refractory cachexia use pharmaceutical
What are the roles of nutritional interventions?
Early intervention: oral nutritional support; benefits vs risks of preop support, predicted Tx outcomes or side effects, psychosocial and psychological status
What are the goals of nutritional support?
x
Which artificial nutritional supports exist?
Mod-severely malnourished if given 7-14d pre-op, prophylactic tube placement for certain anti-cancer therapies; anticipated inability to ingest/absorb nutrients for 7-14d in a malnourished patient during Tx
Why do breast cancer pts increase weight?
Average of 2kg between CTx cycles: hormonal influence, dysguesia, increased appetite 2ry to steroids, reduced physical activity -> BMI >40 2x risk of death; excess adiposity associated with 30% increased risk of mortality -> THUS: increase physical activity decreases risk 20%, avoid weight gain, abdominal girth <80cm, body fat <36%; BMI<25
What advice for diet in breast Ca pts?
x
Compare lung vs breast cancer pts in terms of nutrition
x
How is immunity affected by weight loss?
x
Why is weight lost?
x
What is the difference between nutritional goal and guideline?
Goal: sets target = fat intake should be 35% of total intake; guideline: tells you how to get there = low fat dairy products, avoid fried food
Who sets goals and guidelines for nutrition?
WHO, country specific agencies: Public health England, based on recommnedations: committee on medical aspects of food policy and scientific advisory committee on nutrition
Why are goals and guidelines needed for nutrition?
Amount of each nutrient needed = nutritional requirement which are different for each nutrient and between individuals and life stages
What is RDA?
Recommended daily amount; average amount of nutrient which should be provided per head in a group of people if the needs of practically all members of the groups are to be met, aim of preventing deficiency
What are UK dietary reference values?
UK COMA in 1991, take account distribution of requirements within a popn or group; uses: Lower reference nutrient intake, estimated average requirement, reference nutrient intake and safe intake -> statistical concepts relating to physiological requirements for health and well-being among popn groups; intended as a guide or reference for health professionals, food planners and the food industry, not unconditional recommendations
What are the objectives of UK DRVs?
Nutrient recommendations: amount judged appropriate to maintain health in most individuals in a given popn; obj: criteria of adequacy: prevention of deficiency, sufficient for storage, safe upper limits, optimal intakes (prevent chronic disease)
How do you determine nutritional requirement?
Metabolic demand + efficiency of utilisation = nutrient req.; methods: obs of intakes, balance studies, physiological est, clinical studies, functional tests
What is the reference nutrient intake?
Amount of nutrient that is enough to ensure that the needs of nearly all group being met, so many in the group will need less -> 97.5% of popn
What is the lower reference nutrient intake?
The minimum req; sufficient to meet req of 2.5% of popn
What is safe intake?
Level/range of intakes at which there is no risk of deficiency and below where there is risk of toxicity; there isn’t evidence of benefit above this level, BUT could have undesirable/toxic effects -> for some minerals and vitamins: pantothenic acid, biotin, vit E/K, manganese, molybdenum, chromium, luoride
What is the estimated average requirement?
Estimate of average requirement for energy or a nutrient ~50% of group of people will require less and 50% will require more; for group of people receiving adequate amounts, the range of intakes will vary around the EAR
What is the metabolic basis of energy needs?
Estimation of energy needs: energy stored (lipids) = energy intake (carbs, protein, fat and alcohol) - energy expenditure (BMR, physical activity, adaptive thermogenesis)
What is the best source of energy?
Carbs: 4 kcal/g; protein: 4; fat: 9; alcohol: 7; fibre ~0-2; water: 0
What is protein?
EAR = 0.6g/Kg BW/d, RNI = 0.75g/kg/d; extra for growth in infants and children and pregnant/breastfeeding women; allows for 70% of protein consumed is incorporated into body; 1g of protein = 17J/4kcal of energy; av. 16% dietary energy in UK
What are fats and carbs?
% of energy intake, fat = <35% EI (Sat =<11%); carbs = 50% EI (free sugars =<5% EI)
What is alcohol?
Guideline by Dep of health (UK); based on ethanol and health outcomes, but contributes to energy: 7kcal per g
What are the limitations of DRVs?
Don’t apply to individual specific popn not represented; DRV’s best evidence but not definitive; don’t apply to diseased; not everything is absorbed; variability in absorption; don’t change behaviour alone
Which substances have an intake below LRNI?
Iron: IDA and low iron stores in proportion of adult women and older girls; Vit D: low vit D status in adults and older children, implicating bone health, increasing risk of rickets and osteomalacia (23% of 19-64y)
Which groups of popn are at risk of low vit D so need supplements?
Pregnant/breast feeding; children <=5y; breast fed infants from 6m; formula fed infants (<500mls/d); individuals with high skin pigmentation; individuals who have little/no exposure during summer, or wear clothing which covers most of skin in summer; living in institutions; elderly
What are the 3 main categories that increase cardiovascular risk?
Those with CVD, those at high multifactorial risk; those with single raised risk factor (>= 6 elevated total chol:HDL ratio, stage 1 (>140/90-160/100)/2 (160/100) HTN and familial dyslipidaemia
What are the non-modifiable risk factors of CHD?
x
What are the modifiable risk factors of CHD?
Apple shape have a higher risk
What is the interheart study?
Nine potentially modifiable risk factors which account for over 90% of risk of an initial acute MI -> looked at relative contribution of the risk factors; diet has a big impact on lots of these factors, explaining 50% of CHD events