Estimate of fluid requirement in adults after burn injuries. In 2nd- and 3rd-degree burns, RingerÕs lactate 4 ml/kg/% body surface area is given in 1st 24 hours after burn is sustained (not when treatment is started). Half of total fluid is given in first 8 hours and balance is given in remaining 16 hours, assuming signs of resuscitation (urine output, blood pressure) are adequate.