A nurse is preparing to administer ephedrine 3 mg/kg/day IV bolus divided in equal doses every 6 hr to a school-age child who weighs 70 lb. Available is ephedrine injection 50 mg/mL. How many mL should the nurse administer per dose? (Round the answer to the nearest hundredth. Use a leading zero if it applies. Do not use a trailing zero.)

Convert the child's weight from pounds (lb) to kilograms (kg) using the conversion factor of 2.2 lb/kg. Patient's weight in kg = 70 lb / 2.2 lb/kg = 31.8181 kg. Calculate the total daily dose in milligrams (mg) for the child. Total daily dose = Ordered dose (mg/kg/day) × Patient's weight (kg) = 3 mg/kg/day × 31.8181 kg = 95.4543 mg/day. Calculate the dose per administration (every 6 hr, which is 4 doses per day). Dose per administration = Total daily dose (mg/day) / 4 doses/day = 95.4543 mg / 4 = 23.8635 mg/dose. Available concentration = 50 mg/mL. Calculate the volume in milliliters (mL) to administer per dose. Volume (mL) = Dose per administration (mg) / Available concentration (mg/mL) = 23.8635 mg / 50 mg/mL = 0.47727 mL. Round the answer to the nearest hundredth. = 0.48 mL.