Nutrition Flashcards
(168 cards)
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