100-50-20/4-2-1 Rule for Estimating Maintenance Fluids
First 10 kg body weight | 100 mL/kg/24h (4mL/kg/h) | |
Second 10 kg body weight | 50 mL/kg/24h (2 mL/kg/h) | |
Each additional kg body weight | 20 mL/kg/24h (1 mL/kg/h) | |
Example for a 70 kg pt: (10x100)+(10x50)+(50x20) = 2500 mL/24h; (10x4)+(10x2)+(50x1) = 110 mL/h | ||
Quick calculation of maintenance fluid rate in ml/h: Body weight (kg) + 40; Example: For 70 kg pt, rate is 70+40 = 110 mL/h; This order may be written as 1/2NS at 110 mL/h x 24 hours *The values shown assume normal renal function, no CHF, and no edema present. Care should be exercised in geriatric, thin, frail patients who may require a reduction from calculated value. |