Acute renal failure: Symptoms, Causes, Dietary Management

Acute renal failure

There is sudden shutdown of renal function following injury to the normal kidney. This is a condition in which the kidneys are no longer able to maintain the normal composition of the blood.

Causes

1.     Loss of blood due to accidents and internal hemorrhage. Ulcers can cause acute renal failure as the blood flow to the kidneys decreases.

2.     Loss of plasma as in burns.

3.     Inhalation or ingestion of poisons such as carbon tetrachloride or mercury

4.     Shock from surgery

5.     Nephritis and Nephrosis can result in acute renal failure.

Symptoms

6.     Uremia - There is retention of urea and others urinary constituents in the kidney.

7.     Azotemia - accumulation of nitrogenous constituents in the blood.

8.     Oliguria - a scanty output of urine (less than 500 ml)

9.     Anuria - minimal production or absence of urine (less than 100 ml per day).

10.                        Serum potassium levels are high when tissue proteins are broken down to provide calories.

11.                        There is increased phosphate and sulphate with decreased sodium, calcium and base bicarbonate.

12.                        Patients are lethargic, anorexic, have nausea and vomiting.

Dietary Management

Energy

A minimum of 600-1000 kcal is necessary. In the initial period when oral intake is less due to vomiting and diarrhoea, 100 g per 24 hours intravenous glucose is given to reduce protein catabolism.

Proteins

Initially a protein free diet is used in the non-dialysed patients. In the diuretic phase 20-40 g protein is given. The protein content of the diet varies depending on the urea content of the blood.

Carbohydrates

A minimum of 100g per day is essential to minimize tissue protein breakdown.

Fluid

Fluid allowance is regulated in accordance with urinary output. The total fluid permitted is 500 ml + losses through urine and gastro intestinal tract. With visible perspiration an additional 500 ml may be given.

Sodium

Sodium restriction is judged based on the sodium loss in the urine. For the non-dialysed patient 500 to 1000 mg per day is given. Patients on dialysis are permitted 1500 to 2000 mg per day.

Potassium

Potassium allowance is based on serum levels. Hyperkalemia (potassium intoxication) has deleterious effects on the heart. Potassium sources like tomato juice, coffee, tea, cocoa are avoided.