Pediatric Burns By Bradley J. Phillips

Once acquired, lines should be secured by sutures, as exudative fluid will not permit adhesive tapes and edema will render wraps impractical.¹

Fluids

Though the skin’s gross appearance may be deceptively intact, burn injuries have 5 to 10 times the evaporative loss of normal skin. In smaller burns, patients are able to maintain hydration with oral fluids or with a combination of oral fluids supplemented with low volumes of intravenous fluids.³ Patients with burns involving greater than 15% TBSA have substantial exudative and evaporative fluid loss and require intravenous fluid resuscitation.⁸ Different factors, such as electrical or chemical injury, may lead to higher than expected fluid requirements. Inhalation injury is known to increase resuscitation requirements by up to 50%.⁸ Large burn injuries will cause systemic physiologic changes which exacerbate intravascular loss. Inflammatory mediators are released from the wound and lead to significant capillary leak. Fluid is able to escape the intravascular space and migrate into the interstitium. Capillary permeability peaks 18 hours following injury, and maximum edema is observed at 48 hours.⁹ The use of colloid as resuscitation fluid is controversial and generally not recommended in the first 24 hours. Extravasation of colloid during the initial resuscitation period is thought to prolong edema secondary to capillary leak. Instead, colloid use in resuscitation should be reserved for persistent hypotension or to possibly prevent overresuscitation in patients who manifest a less than ideal response to crystalloids.³ Beyond the first 24 hours, colloid may be given regularly in order to supplement the disproportionate protein loss observed in pediatric patients.

Initial resuscitation may be calculated based on a number of formulae, such as the Parkland formula and the Galveston formula (Figure 2).¹⁶

In addition to the resuscitation volume, maintenance fluids must be added and will constitute a greater proportion of the fluid delivered to patients relative to adults.¹ The goal of resuscitation is adequate end organ perfusion, which can be evaluated by a combination of clinical and laboratory findings. A Foley catheter, rather than diapers or urine bags, should be placed to more accurately monitor hourly urine output in order to evaluate fluid resuscitation. Appropriate goals are 1 cc to 1.5 cc urine/hour in children and 1.5 cc to 2.0 cc urine/hour in infants. In the event that urine output does not respond to resuscitation after substantial amounts of crystalloid fluids, such as lactated Ringers solution, a transesophageal echo or pulmonary artery catheter may be invaluable to determine intravascular fluid status. Resuscitation efforts can be evaluated based on vital signs, peripheral temperature, capillary refill, and level of mentation. Lab values such as hematocrit, base deficit, central venous pressure, and lactate levels may be helpful in evaluating tissue perfusion and should be monitored regularly throughout the emergent phase.

Although certain injuries will require more fluid than calculated by the resuscitation formula, health care providers must be cognizant of possible overresuscitation. Complications of excessive resuscitation include pulmonary edema, electrolyte imbalances, and prolific third spacing. Electrolyte imbalance is commonly seen in conjunction with the massive cellular damage of a significant burn injury. Specifically, hyponatremia can occur, while hypovolemia and the generous use of albumin may lead to hyperkalemia. Large fluctuations of sodium in the pediatric population can lead to seizures, cerebral edema, herniation, and central pontine myelinosis,^3,12,17 which are all associated with increased mortality. Such significant electrolyte fluctuations may be prevented by close monitoring. Continued third spacing of excess fluid from overresuscitation can result in abdominal compartment syndrome. This complication should be considered when bladder pressure, acting as a marker for abdominal pressure, exceeds 30 mmHg (thus overcoming capillary filling pressures).¹⁸ Abdominal compartment syndrome may be relieved by reducing intravenous fluids or by performing a paracentesis or decompressive laparotomy. Diuretics are inappropriate in the setting of acute burns.

Infants and small children younger than 2 years and with a weight less than 20 kg require the addition of glucose to their resuscitative fluids since they have sparse glycogen stores and are susceptible to hypoglycemia.^1,12,18 Their glucose should be monitored hourly during the initial resuscitation period and replaced as necessary.

Temperature

Temperature dysregulation is a hallmark of burn injury, with a tendency towards hypothermia. A subnormal body temperature should be minimized, as it leads to coagulation dysfunction and is associated with increased mortality. The use of warm intravenous fluids, particularly during resuscitation, when large volumes are used, can help maintain core body temperature.¹ The ambient temperature in the intensive care setting and operating room should be kept warm in order to decrease radiant heat loss through large, hyperemic burns.⁸

Secondary Assessment

Though the temptation is to immediately address a burn injury, a systemic head-to-toe evaluation should be performed. Any potentially life-threatening injury should be addressed before wound management is initiated.