Impact of perioperative hyponatremia in children: A narrative review

Table 1 The 4-2-1 formula for maintenance fluids in children[10,11]

Weight	Daily fluid requirements	Hourly fluid requirements
3-10 kg	100 mL/kg	4 mL/kg per hour
11-20 kg	1000 mL + 50 mL for every kilogram > 10	40 mL/h + 2 mL/h for every kilogram > 10
> 20 kg	1500 mL + 20 mL for every kilogram > 20	60 mL/h + 1 mL/h for every kilogram > 20