Establish intravenous (IV) access, and begin fluid resuscitation. Place 1 or 2 large-bore peripheral lines, and administer crystalloids. With the loss of the vapor barrier provided by intact skin, burn victims have large insensible fluid losses. Burn victims will need copious amounts of fluid because only 20-30% of it will remain in the intravascular space.

Patients with burn wounds smaller than 20% of total body surface area (TBSA) can be treated with a combination of oral and IV fluids. For larger burns, the Parkland formula (see below) and its variations have become the standard method for resuscitating the burned patient.

Moderate burn victims should have at least 1 large-bore IV line placed through unburned skin, and severe burn victims should have at least 2 lines in place. If necessary, venous catheters may be placed through burned skin or via venous cutdown using the saphenous vein at the groin or ankle.

When a burn patient requires considerable fluid resuscitation or has evidence of cardiopulmonary disease, a central venous line is indicated. Patients with massive burns or respiratory injury and elderly patients with severe burns or cardiac disease should be monitored with a pulmonary artery (Swan-Ganz) catheter to avoid fluid overload or inadequate replacement of volume.

Microvascular injury caused by a burn leads to increased vascular permeability with edema formation that results in ongoing plasma volume loss. Maximal edema formation occurs at 8-12 hours after burn injury for small burns and at 24-48 hours for large burns. The purpose of fluid resuscitation is to restore effective plasma volume, avoid microvascular ischemia, and maintain vital organ function. The amount of fluid required varies with the patient’s age, body weight, and percentage of TBSA burned.

Ideally, weigh the patient on a scale. In the absence of this measurement, obtain an estimate of the patient’s weight from the patient, a relative, or the patient’s driver’s license. Carefully map the burned areas over the entire body, including the back, to estimate fluid requirements during the first 48 hours after injury. Typically, burns larger than 20% of TBSA require IV fluid resuscitation because the accompanying gastrointestinal (GI) ileus precludes sufficient oral intake.

Calculation of fluid needs

All patients with a major burn injury must receive fluid resuscitation that is influenced by the percentage of the total body surface area (TBSA) covered by the burn (see the images below), [1] as well as by the presence of inhalation injury.

Rule of nines for calculating burn area. View Media Gallery

Lund and Browder chart illustrating method for calculating percentage of body surface area affected by burns in children. View Media Gallery

Size of burn is best estimated by using chart that corrects for changes in body proportions with aging. View Media Gallery

Several different formulas for fluid resuscitation have been recommended, although all emphasize that adequate resuscitation is evidenced by a normal urinary output (1 mL/lb/h in children younger than 2 years, 0.5 mL/lb/h in older children, and at least 30-40 mL/h in adults), a normal sensorium, and stable vital signs.

A survey of burn units in the United States and Canada found that 78% of the centers used the Parkland formula to estimate resuscitation volume and that lactated Ringer solution was the most popular type of fluid. [14] In marked contrast, a United Kingdom survey revealed that most burn units used human albumin solution and the Muir and Barclay formula to estimate resuscitation volumes. [2]

Since the publication of the findings of the Cochrane Injuries Group Albumin Reviewers, much discussion has ensued regarding the use of human albumin solution in patients who are critically ill. [15] In 2007, Baker et al reported that resuscitation of patients with thermal injuries in burn units in the United Kingdom and Ireland is fairly consistent with a shift toward crystalloid resuscitation and away from the use of human albumin solution. [16]

The Parkland formula for calculating fluid needs for burn victims in the first 24 hours is as follows:

Fluid requirement (mL) = (4 mL of crystalloid) × (% TBSA burned) × body weight (kg)

Thus, a man who weighs 70 kg and has a 30% TBSA burn would require 4 × 30 × 70 = 8400 mL in the first 24 hours.

One half of the calculated fluid requirement is administered in the first 8 hours, and the balance is given over the remaining 16 hours. Thus, fluids would be given at 525 mL/h for the first 8 hours, then at 262.5 mL/h for the remaining 16 hours. It is important to calculate fluid loss from the time of injury, as well as to take into account the fluid administered by prehospital personnel for fluid replacement.

Monitor typical markers of fluid status (eg, urine output) and adjust fluids accordingly. Placement of a Foley catheter (see below) simplifies monitoring of hourly urine output. Urine output should be maintained at 0.5 mL/kg/h.

Strict adherence to a formula for fluid resuscitation does not guarantee successful fluid therapy. For example, the Parkland formula does not predict fluid resuscitation needs in electrical injuries accurately, and the presence of coexisting trauma may increase fluid volumes needed for resuscitation.

If the need is expected to exceed 6 mL/kg times the percentage of TBSA burned per 24 hours, if the patient appears unresponsive to resuscitation, or if signs of impending cardiac failure are present, insertion of a pulmonary artery (Swan-Ganz) catheter for measurement of pulmonary artery pressure and cardiac output is advisable. If the volume is found to be adequate but urine output remains diminished, then dopamine (5 µg/kg/min) may be used to increase renal perfusion.

During resuscitation, the most common error is overhydration, which increases the risk of acute respiratory distress syndrome (ARDS) developing 3-5 days after the burn. In patients with concomitant large TBSA burns and inhalation injury, the Parkland formula may result in unnecessarily large fluid loads. To avoid overhydration, resuscitate patients who have inhalation injuries with amounts substantially lower than specified by the formula, accepting a urinary output in the range of 0.3-0.5 mL/kg/h.

Replacement of lost protein

After a burn injury, a substantial amount of intravascular protein is lost through endothelial leaks in the burned vessels. When endothelial integrity is restored 24 hours after the injury, some clinicians favor the administration of 5% albumin at 0.5 mL/kg/% TBSA to maintain dynamic forces between the extracellular spaces and the intravascular system. In addition, a low-dose dopamine infusion (3-5 µg/kg/min) is beneficial in restoring renal and splanchnic blood flow in patients with major burn injury.

Catheterization and intubation

Place a Foley catheter into the bladder to monitor the effectiveness of IV fluid replacement. Burns of the perineum also are best cared for with an indwelling Foley catheter to decrease urinary soiling of the wound.

In patients with major burn injuries who require IV fluid resuscitation, pass a nasogastric (NG) tube for initial evacuation of fluid and air from the stomach and feeding access. Removal of the gastric contents prevents vomiting and aspiration, sequelae of the ileus that commonly occur soon after burn injuries involving more than 20% of TBSA. Early feeding through the NG tube within 6-8 hours of the burn injury diminishes the hypermetabolic response and maintains intestinal integrity.

Hypertonic saline solutions

Resuscitation with hypertonic saline solutions reduces the fluid volume required. The volume of fluid administered using hypertonic fluid solutions is notably less, yet fluid requirements and percent weight gain have not been shown to be lower with hypertonic saline than with Ringer solution. The anticipated benefits of fewer escharotomies and limited ileus have not been uniformly encountered either.

On the contrary, hypertonic saline resuscitation has been associated with an increased incidence of acute tubular necrosis and hyperchloremic metabolic acidosis, which can exacerbate the metabolic acidosis of hypovolemic shock. Therefore, hypertonic saline is not currently recommended for resuscitation of burn patients.

Decision not to resuscitate

When a patient with a major burn injury is extremely unlikely to survive (eg, an elderly patient in whom more than 80% of the TBSA is burned), the clinician must be encouraged not to begin fluid resuscitation. This decision must be made only after thoughtful discussion with family members. When resuscitation is not undertaken, the clinician must ensure that patients are not in pain, keep them warm, and allow them to remain in a room with family members.

Special considerations in children

In most respects, burn care in children is similar to that in adults; however, there are some relevant physiologic differences that must be considered in the care of burned children.

Differences in TBSA-weight ratio

The Parkland formula is effective in estimating fluid loss in adults, but it underestimates the evaporative fluid loss and maintenance needs in children. Compared with adults, children have a larger TBSA relative to weight and generally have somewhat greater fluid needs during resuscitation.

An alternative formula that is preferred by many for calculating fluid needs in children is the Galveston formula, which is based on TBSA rather than body weight. Although many pediatric burn centers believe that this formula is more accurate than the Parkland formula, it is more time-consuming to calculate.

By the Galveston formula, the amount of lactated Ringer solution administered over the first 24 hours is determined as follows:

Fluid requirement = 5000 mL/m2 × % TBSA burned + 2000 mL/m2

One half of the total fluid is given in the first 8 hours, with the balance given over the next 16 hours. The maintenance fluid should then be lactated Ringer solution with 5% dextrose; the dextrose is added to the resuscitation fluid to prevent hypoglycemia because children have smaller glycogen stores than adults do.

In children, keep the urine output at 1 mL/kg/h, the pulse in the range of 80-180 beats/min (depending on age), and the base deficit lower than 2.

Differences in thermoregulation

In infants younger than 6 months, temperature is regulated by nonshivering thermogenesis, a metabolic process by which stores of brown fat are catabolized under the influence of norepinephrine, which requires large amounts of oxygen. Consequently, prolonged hypothermia in burned infants may result in excessive lactate production and acidosis.

After 6 months, infants and children are able to shiver. Because they have greater evaporative water loss relative to weight than adults do, infants and children are especially prone to hypothermia; therefore, keep the ambient temperature high to decrease radiant and evaporative heat loss from burned infants and children to the environment.

Differences in renal function

Differences in renal function between infants and adults may have important therapeutic implications for the treatment of burned children. The glomerular filtration rate in infants does not reach adult levels until the age of 9-12 months, because of an imbalance in maturation of tubular and glomerular functions. During this early period, infants have approximately half the osmolar concentrating capacity of adults, and a water load is handled inefficiently.

The rate of water excretion is time dependent and decreases as water loading continues. During the first several weeks of life, infants are likely to retain a larger portion of a water load administered as part of burn resuscitation. The hyposmolarity of lactated Ringer solution, when used in accordance with the Parkland formula, already accounts for the free water needs of infants during the first 24 hours after the burn. Additional water often results in fluid overloading.