Which of the following factors directly affects stroke volume?

Choice A: Administer intravenous pain medication
Administering intravenous pain medication is crucial for managing pain in burn patients. Pain management is essential to ensure the patient's comfort and to prevent complications such as shock. However, while important, it is not the immediate priority in this scenario. The primary concern should be assessing and securing the airway, especially given the location of the burns on the face and chest, which could indicate potential inhalation injuries.

Choice B: Draw blood for a complete blood cell (CBC) count
Drawing blood for a CBC count is important for assessing the patient's overall health and identifying any potential complications such as infection or anemia. However, this action is not the immediate priority. The nurse must first ensure that the patient's airway is clear and that there are no life-threatening conditions that need immediate attention.

Choice C: Inspect the mouth for signs of inhalation injuries
Inspecting the mouth for signs of inhalation injuries is the priority action. Burns to the face and chest can lead to inhalation injuries, which can cause airway obstruction and respiratory distress. Early identification and management of inhalation injuries are critical to prevent respiratory failure. Signs of inhalation injury may include soot around the mouth or nose, singed nasal hairs, and difficulty breathing. Ensuring the airway is clear and managing any inhalation injuries takes precedence over other actions.

Choice D: Insert an indwelling urinary catheter
Inserting an indwelling urinary catheter can be important for monitoring urine output, which is a key indicator of renal function and fluid balance in burn patients. However, this action is not the immediate priority. The nurse must first address any potential airway issues before proceeding with other interventions.

Choice A Reason:
0.9% sodium chloride is an isotonic crystalloid solution often used for fluid resuscitation. However, it is not the preferred choice for burn patients because it lacks the necessary electrolytes to replace those lost through burn injuries. While it can be used if Lactated Ringer's is unavailable, it does not provide the same balanced electrolyte composition.

Choice B Reason:
Lactated Ringer's is the preferred fluid for initial resuscitation in burn patients. It is an isotonic crystalloid solution that closely mimics the body's plasma, providing essential electrolytes such as sodium, potassium, calcium, and lactate. The lactate in the solution acts as a buffer, helping to correct metabolic acidosis, which is common in burn patients. The Parkland formula, widely used for calculating fluid needs in burn patients, specifically recommends Lactated Ringer's for the first 24 hours.

Choice C Reason:
Dextrose 5% in water is a hypotonic solution that provides free water and calories but lacks electrolytes. It is not suitable for initial fluid resuscitation in burn patients because it does not address the electrolyte imbalances and large fluid shifts that occur after a burn injury. Using this solution could lead to further complications such as hyponatremia.

Choice D Reason:
Dextrose 5% in 0.9% sodium chloride is a hypertonic solution that provides both glucose and electrolytes. However, it is not typically used for initial burn resuscitation because the high glucose content can lead to hyperglycemia, which is detrimental to burn patients. Additionally, the solution's osmolarity can exacerbate fluid shifts and worsen edema.