How to Calculate the Correct Intravenous Fluid Rate for a Child in Acute Renal Failure

Calculating the correct Intravenous Fluid (IVF) rate for a 15kg child suffering from acute renal failure involves understanding the child's weight and the standard calculation for maintenance fluids.

The volume of filtrate formed by kidneys per minute is known as the Glomerular Filtration Rate (GFR). This rate affects the amount of plasma entering the renal capsule. In adults, the average GFR is approximately 125mL/min for men and 105mL/min for women. However, this can vary significantly in children, particularly in those with kidney failure.

Typically, for a child, maintenance fluid is calculated using the weight of the child. The calculations are as follows: for the first 10 kg of body weight, 100 ml/kg is used. For the next 10 kg, 50 ml/kg is used, and for each additional kg, 20 ml/kg is used. Therefore, for a 15kg child, the calculation will be: (10kg x 100ml) + (5kg x 50ml) = 1000ml + 250ml = 1250ml/day.

However, the question indicates that the fluids are to run at half maintenance, which would be 1250ml/2 = 625ml/day. To convert this to an hourly rate: 625ml/24 hours = approximately 26mL/hr. Therefore, the correct IVF rate for a 15kg child in acute renal failure and receiving half maintenance fluids is 25mL/hr.