For a 20kg four-year-old girl in shock, what is the appropriate initial fluid bolus?

In pediatric patients, the initial fluid resuscitation for shock is typically calculated based on the child's weight. The recommended initial fluid bolus for children experiencing hypovolemic shock is generally 20 mL/kg of isotonic fluid, such as normal saline or Lactated Ringer's solution.

For a four-year-old girl weighing 20 kg, this calculation would be:

20 mL/kg × 20 kg = 400 mL

This amount is crucial in stabilizing hemodynamics and improving perfusion to vital organs. While it is standard practice to reassess the child after the initial bolus and provide additional fluid as necessary based on the clinical response, the first step in management is to give this calculated volume of fluid to address the shock state adequately. Therefore, the correct choice reflecting the appropriate initial fluid bolus is 400 mL.

In clinical practice, providers will reassess the situation after administering the bolus to ensure the child is responding adequately, and further fluid administration can be adjusted based on the patient's ongoing needs and response to treatment.