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Difficulty: Very hardTrauma and Burns

Helicopter emergency medical services arrive at a regional burn center with a 50-year-old male who was extricated from a residential fire. The injury occurred exactly 3 hours prior to arrival. Upon presentation, he is intubated and mechanically ventilated. His estimated body weight is 80 kg. Vital signs show a blood pressure of 115/75 mm Hg and a heart rate of 112/min. Physical examination of the skin reveals blistering, weeping, and exquisitely tender lesions over the entire anterior trunk. The entire right lower extremity is covered in white, leathery, and insensate eschar. The entire left upper extremity exhibits diffuse erythema with intact epidermis, blanching on pressure, and no blistering. A large-bore peripheral intravenous catheter is successfully placed. Based on the most current Advanced Trauma Life Support (ATLS) guidelines for adult thermal burns, what should the initial intravenous crystalloid infusion rate be set to in mL/hr?

Answer: 576 mL/hr

Answer

The correct initial intravenous fluid infusion rate is 576 mL/hr.
Burn shock pathophysiology necessitates large-volume crystalloid resuscitation, guided by the most recent Advanced Trauma Life Support (ATLS) protocols. The current guideline for adult thermal burns is 2 mL of Lactated Ringer's per kg of body weight per percent of total body surface area (TBSA) burned. First, accurately estimate the TBSA using the Rule of Nines, strictly excluding first-degree burns (which present as simple erythema without blistering). The patient's 2nd- and 3rd-degree burns cover the anterior trunk (18%) and right leg (18%), totaling 36% TBSA. The 24-hour fluid requirement is 2 mL x 80 kg x 36 = 5,760 mL. Half of this volume (2,880 mL) must be delivered within the first 8 hours from the time of injury. Since the injury occurred 3 hours prior to presentation, the remaining time in this initial window is 5 hours. Therefore, the target infusion rate is 2,880 mL / 5 hours = 576 mL/hr.

Step-by-Step Solution

1
Identify burns to include in calculation
Anterior trunk (18%) + right lower extremity (18%) = 36% TBSA
First-degree burns (left upper extremity) are excluded from fluid resuscitation formulas.
2
Calculate total 24-hour fluid volume
2 mL * 80 kg * 36 = 5,760 mL
Current ATLS guidelines recommend 2 mL/kg/%TBSA for adult thermal burns (changed from the traditional 4 mL/kg Parkland formula).
3
Calculate the volume required for the first 8 hours
5,760 mL / 2 = 2,880 mL
Half of the total calculated 24-hour fluid requirement must be given in the first 8 hours after the burn injury.
4
Calculate the hourly infusion rate for the remaining time in the first 8-hour window
2,880 mL / 5 hours = 576 mL/hr
The injury occurred 3 hours prior to arrival, so the first 8-hour volume must be infused over the remaining 5 hours.

Key Concept

Fluid resuscitation in thermal burns using the updated ATLS guidelines (2 mL/kg/%TBSA), appropriate Rule of Nines application excluding first-degree burns, and adjusting rates for pre-hospital time.
Estimated Time:2m 30s
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Topics

Trauma and Burns

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