Renal Disease

Kidney functionsThe nephrotic syndromeAcute Renal Disease Chronic Renal Failure Kidney Stones

Kidney Functions

Regulate extracellular fluid volume and osmolarity Regulate electrolyte concentrations Regulate acid-base balance Excrete metabolic waste products like urea and

creatinine and a number of drugs and toxins Help to regulate blood pressure Produce the hormone erythropoietin, which

stimulates the production of red blood cells in the bone marrow

Convert vitamin D to its active form – plays a primary role in calcium regulation and bone formation

The Nephrotic Syndrome: Treatment

Protein and energy– Helps minimize losses of muscle tissue– High-protein diets not advised – can exacerbate urinary protein losses– 0.8 – 1.0 grams of protein per kilogram of body

weight/day– 35 kcalories/kilogram body weight daily – sustains

weight and spares protein– Weight loss or infections–signal the need for additional kcalories

The Nephrotic Syndrome: Treatment

Fat– A diet low in saturated fat, cholesterol, and

refined sugars helps to control elevated blood

lipids

– May need lipid-lowering medications prescribed per physician

The Nephrotic Syndrome: Treatment

Sodium– Sodium restriction helps to control edema– Suggested to limit intake to < 2-3 grams

daily– If diuretics prescribed for edema –

potassium wasting may occur– Encouraged to select foods rich in

potassium

The Nephrotic Syndrome: Treatment

Vitamins and minerals– May require vitamin D and calcium

supplementation – prevent bone loss and rickets

– Multivitamin supplements – prevent additional

nutrient deficiencies

Acute Renal Disease: Consequences

Kidneys become unable to regulate the levels of electrolytes, acid, and nitrogenous wastes in in blood.Urine may be diminished in quantity or absent.Diagnosis – often a complex task.Fluid and electrolyte imbalances

Acute Renal Disease

Goals of nutritional therapy for ARF patients: debilitated:– Minimize uremia (accum. of bld nitrogenwaste

“urea”) and maintain the body’s regular chemical composition

– Preserve the body’s protein stores– Maintain fluid, electrolyte, and acid-base

homeostasis

Nutritional therapy for ARF patients

Protein – Due to catobolic condition associated with

hypermetabolism and muscle wasting – sufficient protein

and energy needed to preserve body’s protein content 0.6g/kg/day in non-dialyzed, non-hypercatabolic patient. With dialysis – protein restricted to 1.2 – 1.3

Calories – 35 kcal/kg of BW/day .

Nutritional therapy for ARF patients

Fluids.– Needed to monitor weight fluctuations, blood pressure,

pulse rates, appearance of skin and mucous membranes

– Daily fluid intake should equal urine output, plus approximately 500ml to replace insensible losses

( the water lost through skin, lungs and perspiration) – Individuals with fever, vomiting, or diarrhea requires

additional fluid– If on dialysis more liberal fluid intake allowed –1.5-2

liters/day

Nutritional therapy for ARF patients Vitamins/Minerals –

Electrolytes must be closely monitored. Potassium and phosphate levels may be elevated. There may also be salt and water imbalances.

With oliguria (abnl production of urine) – sodium intakes limited to 2-3 grams daily

If on dialysis-generally can consume electrolytes more freely Oliguric patients who experience diuresis may need electrolyte

replacement to compensate for urinary losses Some patients need enteral or parenteral nutrition support to

obtain adequate energy (high Kcal Low ptn and electrolytes)

Chronic Renal Failure: Consequences

Generally progresses over many years without causing symptoms

Typically diagnosed late in the course of illness, after most kidney function has been lost

Most common causes :• Diabetes mellitus (43%)

• Hypertension (26%)

Altered electrolytes and hormones Uremic syndrome

Chronic Renal Failure

Goals of nutritional therapy.– Prevent symptoms of uremia while restoring

biochemical balance. – Retard progression of the disease. – Provide adequate calories to maintain or achieve

ideal body weight.

Nutritional therapy for chronic renal failure

Protein – Protein should be restricted to 0.6g/kg/day, with

sufficient essential amino acids. Once dialysis begun – protein restrictions relaxed

• Dialysis removes nitrogenous wastes • Some amino acids –lost during the procedure.

Calories – Calorie intake should be about 35 kcal/kg to maintain

body weight. Foods and beverages of high nutrient density Malnourished patients may require oral formulas or

tube feedings to maintain weight

Nutritional therapy for chronic renal failure

Fat – Restrict saturated fat and cholesterol levels, some renal

patients at risk for coronary heart. Renal diets include high-fat foods to increase calories –

encourage patients to select foods providing mostly monounsaturated fats.

Nutritional therapy for chronic renal failure

Fluids and Sodium – Fluid intake should be based on the patient’s ability to eliminate

fluid Fluid intake should match the daily urine output,if urine output

decreases Fluids – should be restricted Excrete less urine as CRF progresses – can’t handle normal

sodium and fluid intake Monitor total urine output, changes in body weight and blood

pressure and serum sodium levels 2-3 gm/d.adeq., but 1gm/d if the renal failure is severe. Once on dialysis – sodium and fluid intakes controlled so that

water weight gain is 2 pounds between dialysis treatments

Nutritional therapy for chronic renal failure

Potassium – 2 to 3 gms/day should be initiated.

Calcium and Phosphate – supplement calcium and restrict phosphate to 8-12

mg/kg/day.

Vitamins and Mineral- Supplementing folic acid, B6, B-complex, Vitamin D, Vitamin

C necessary. Vitamin A and E not recommended because it may accumulate with renal failure.

Kidney Transplants

Immunosuppressive Drug Therapy

– Side effects of nausea, vomiting, diarrhea, glucose intolerance, altered blood lipids, fluid retention, hypertension and infection

– Increases risk of food borne infection – food safety guidelines discussed with patients and caregivers

– Dietary interventions

Kidney Transplants

Energy: 30-35kcal/kg/d. adjust to maintain reasonable weight. Protein: 1.3-1.5 g/kg/d ,reduced to 1g/kg/d after 6-8 weeks Carbohydrate: consistent CHO intake/d. increase fiber. Fat: Limited saturated fat and cholesterol to help control serum

lipids. Sodium: Restricted (to 2-4g/d ) if fluid retention and hypertension

are present. Potassium: adjust according to serum potassium levels. Calcium: 1000 to 1500 mg to minimize bone loss associated with

drug therapy. Phosphorus: 1200-1500 mg: supplement needed if serum

phosphorus is low. Fluid: No restriction

Kidney Stones

Kidney stone – crystalline mass that forms within the urinary tract . Stone passage can cause severe pain or block the urinary tract.

Formation of kidney stones- 75% of kidney stones – made up primarily of calcium oxalate

Factors that predispose to stone formation:• Dehydration or low urine volume• Renal disease• Urine acidity• Metabolic factors• Calcium oxalate stones• Uric acid stones • Cystine stones • Struvite stones (could be initiated by bacteria forming from

ph)

Kidney Stones: Consequences

Consequences of kidney stones– Renal colic– Urinary tract complications

Kidney Stones: Prevention and treatment of kidney stones

– Diet containing 800 – 1000 mg of calcium per day is recommended because calcium combines with oxalate in the intestines, reducing its absorption and helping to control hyperoxaluria

– Moderate protein and sodium restriction advised

High fluid intakes recommended

hemodialysis

peritoneal dialysis

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