Fluid management and wound care in Burn Patients

Sharat Kumar

Associate Consultant – Burns, Plastic and Reconstructive Surgery,

Kauvery Hospital, Alwarpet, Chennai

Background

Arguably, the greatest issue surrounding patients sustaining burn injuries is fluid loss. Therefore, volume replacement is crucial. Burns management can be divided into three phases:

Early resuscitative
Wound management
Rehabilitative/reconstructive.

This paper will primarily discuss the early resuscitative phase after initial stabilization has been performed.

Factors of severe Burns

Patients are classified as having severe/major burns if they have any of the following;

>10% TBSA (Total Body Surface Area) (<10 years old) or elderly (>60 years old)
>20% TBSA in adults
>5% full thickness
High-voltage electrical burns
Significant burns to the face, eyes, hands, joints, or genitalia

Other factors that should be considered and will increase the patient’s morbidity and mortality include associated inhalation injury, associated traumatic injury, and the patient’s baseline medical conditions like heart disease etc.

Pathophysiology

In the early resuscitative phase, the major concern is hypovolemia due to capillary permeability. Thermal injury prompts the release of inflammatory markers not only at the site of injury but also systemically.
These inflammatory markers increase the capillary permeability throughout the body and cause a massive fluid shift out of the intravascular compartment.
Among these inflammatory markers, histamine is likely responsible for the early phase of burn injury, creating capillary permeability. Cardiac output is decreased, and systemic vascular resistance is increased
Worsening the state of shock.

Burn shock is a combination of distributive, cardiogenic, and hypovolemic shock. Therefore, it is imperative to replace the fluid in the intravascular compartment to preserve tissue perfusion of vital organs.

Primary goal of the treatment

The goal of fluid resuscitation is to prevent rather than treat burn shock. This goal is achieved in the following ways;

Restore circulating volume
Preserve tissue perfusion
Avoid ischemic extension of the burn wound.

Goals for fluid resuscitation are generally accepted as follows;

Urine output >0.5mL/kg/hr in adults, 0.5 to 1.0 mL/kg/hr in children of less than 30 kg, and 1.0 to 2.0 mL/kg/hr in infants.
Base deficit less than 2,
Systolic blood pressure greater than 90 mm Hg, and
Clinically with peripheral pulses palpable and no altered mental status.

Management

A variety of formulas exist, like Brooke, Galveston, Rule of Ten, etc., but the most common formula is the Parkland Formula.

After the TBSA is calculated and the patient’s body weight is determined, the Parkland formula can be implemented to estimate the total fluid requirements for critically burned patients in the first 24 hr after the time of injury and not from the time of evaluation by a provider.

The formula recommends;

4 mL/kg/TBSA (adults)
3 mL/kg/TBSA (children) of crystalloid solution over the first 24 hr of care.

In treating burn injury patients, half of the total fluid volume must be administered within the first 8 hours after the burn, with the remaining volume given over the next 16 hr

Children should receive maintenance fluid on top of their calculated fluid requirements, as children are more susceptible to hypoglycemia due to limited glycogen stores.

Lactated Ringer solution is the preferred choice of resuscitative crystalloid solution as it effectively treats both hypovolemia and extracellular sodium deficits caused by burn injury.

It is isotonic, closer in plasma composition than normal saline solution, inexpensive, readily available, and easily stored. Normal saline is typically avoided in large quantities as a resuscitative fluid option in burn patients, as administration can lead to hyperchloremic acidosis.

Though adequate fluid resuscitation is essential during the initial 24 hr after injury, burn patients must remain adequately hydrated throughout their recovery.

After 24 hr, the fluid should be switched from Lactated Ringer solution to 5% dextrose in half normal saline (D5½NS) and administered at a maintenance rate using the 4-2-1 rule as a guide (4ml/kg/hr for the first 10kg, 2ml/kg/hr for the second 10kg, and 1ml/kg/hr after that, with a maximum of 100ml/hr maintenance).

Take Home Message

Fluid resuscitation is calculated from the time of incident and not from the time of presentation to the ER/hospital.

The amount of fluid received by the patient in the pre-hospital setting must be deducted from the amount estimated for infusion in the first 8 hr.

Resuscitation formulae provide only a rough estimate of fluid requirements.The actual amount of fluid administered should be individualized and titrated according to clinical parameters like UO etc.

Adequate resuscitation is the goal. Under/over resuscitation increases morbidity and mortality.

Wound Care

There is no consensus on which agent or dressing is optimal for burn wound coverage to prevent or control infection or to enhance wound healing. The selection and application of burn wound dressings and topical agents depends on the nature and extent of the burn wound, a particular wound quality or state (eg, contamination, infection), and the patient’s allergy history. The dressings and topical therapies that are used at a given facility depend upon regional and individual preference and experience, availability, and costs.

Local Burn Wound Care

Goals;

To protect the wound surface,
Maintain a moist environment & promote burn wound healing,
Provide splinting action to maintain desired position of function and ➢ limit burn wound progression while minimizing discomfort for the patient.

Burn wound surfaces are prone to rapid bacterial colonization with the potential for invasive infection. Measures to reduce the likelihood of infection include good infection control practices, topical antimicrobial therapy, and burn wound debridement/excision, when needed.

Management

First Degree Wounds

Minor with minimal loss of barrier function.
No dressing required.
Topical analgesics/moisturizers.

Second Degree Superficial

Requires daily dressing with silver based non adhesive mesh foams or topical silver based hydrogels.
Biological/synthetic grafts can be used on clean wounds, and they protect the wound from desiccation while promoting re-epithelialization. The graft separates from the wound once it has re-epithelialized.
These are especially useful in children as they are applied only once, decreasing the pain that typically accompanies wound dressing changes.

Second Degree Deep/Third Degree

These wounds require surgical excision and skin cover.
The choice of initial dressing should be aimed at holding bacterial proliferation in check and providing coverage till the time of surgery.

HBOT (Hyperbaric oxygen therapy) in Burns

HBOT is an adjunctive therapy that has been used to improve outcome in thermal burns especially in second-degree wounds.

It is the therapeutic administration of 100% oxygen at environmental pressures greater than 1 atmosphere absolute (ATA).

HBOT has been shown to reduce edema and preserve microcirculation leading to enhanced healing.

Dr. Sharat Kumar
Associate Consultant

Fluid management and wound care in Burn Patients

Fluid management and wound care in Burn Patients

Sharat Kumar

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