Fluid balance assessment and fluid resuscitation is a major aspect in the management of burn patients. It has been show that patients with burns less than 20% TBSA may not require IV fluid resuscitation since these patients do not experience the severe systemic inflammation and edema of non-injured tissue.46 Patients with less than 20% TBSA burned can be managed with oral hydration therapy.47, 48 However, increased capillary permeability and the release of vasoactive mediators leads to intravascular depletion in burn patients with greater than 20% TBSA burned. This intravascular depletion requires optimal fluid resuscitation to avoid shock, acute renal failure, multi-system organ failure, and/or death. Maximum edema occurs in these patients at 8 to 12 hours post injury.13 Therefore, adequate fluid resuscitation should be instituted early to improve outcomes. It has been suggested that fluid resuscitation within the first 2 hours after injury decreases the mortality and morbidity of severely burned children.29, 49 The optimal composition of burn resuscitation fluid and the rate of infusion are debated heavily in medical literature.
Many trauma centers use normal saline and lactated Ringer ís solutions interchangeably in trauma patients. However, most burn centers use lactated Ringerís solution for burn victims, although there is no strong evidence to support any one crystalloid solution over another. Popular fluid resuscitation models are historically based on lactated Ringer ís solution. Lactated Ringerís solution is slightly hypotonic with 130 mEq/L of sodium, but it adequately corrects hypovolemia and extracellular sodium deficits caused by thermal injury.47
Resuscitation formulas are a topic of debate among burn management experts. All formulas are similar and estimate fluid needs based on the patientís weight and TBSA injured. The Parkland formula is the most popular formula in use at burn centers in the U.S. Baxter retrospectively reviewed fluid requirements of 954 patients in 1968. He discovered that the total fluid requirements were between 3.7 and 4.3 mL of lactated Ringerís solution per kilogram body weight per percent TBSA burned. Therefore the Parkland formula was set at 4 mL of lactated Ringerís solution per kilogram body weight per percent TBSA burned.50 Only partial-thickness and full-thickness burns should be included in the calculation for fluid resuscitation. Young children require slightly more fluid than adults and require maintenance fluid rates to be added to the Parkland formula.51, 52 Also, many experts argue that glucose should be added to the maintenance fluids used in children since their decreased glycogen stores place them at risk for hypoglycemia.53 The volume calculated by the Parkland formula should be divided over 24 hours, with the first half given in the first 8 hours after the burn occurred and the second half over the remaining 16 hours. Therefore, if there is a delay in treatment, the first half should be given more rapidly than over 8 hours. Another popular resuscitation formula is the Galveston formula (5000 mL of lactated Ringerís solution per patientís body surface area (m2) per percent TBSA burned plus 2000 mL lactated Ringerís solution per patientís BSA (m2) per day for maintenance). This volume is divided in the same manner within 24 hours as the Parkland formula.
Numerous studies have attempted to prove or disprove the accuracy of the predicted fluid needs and the actual fluid needs of burn victims. However, it has repeatedly been shown that resuscitation formulas are meant to give the emergency practitioner and burn care specialist a starting point for fluid administration. It should not be used as an absolute therapy goal. It is important that emergency practitioners realize that the most accurate method of determining fluid needs and response to therapy is to monitor the patientís urine output. A bladder catheter should be placed in any burn patient requiring intravenous fluid resuscitation. The goal of therapy set forth by the experts is 0.5 to1 mL/kg/hour in adults and 1 to 2 mL/kg/hour in children.47,53,54
Adjunct monitoring modalities are sometimes used to aid resuscitation management. There is some evidence that serum lactate levels and base deficits from arterial blood gases may predict injury extent and prognosis.43,55-57 However, there are no prospective research trials to suggest lactate or base deficits are adequate parameters to manage fluid resuscitation in burn patients. Goal-directed resuscitation based on invasive hemodynamic monitoring with central venous catheters and pulmonary artery catheters was initially thought to increase preload and cardiac index.47,58 However, a prospective randomized trial by Holm et al including 50 patients did not show any improvement in preload or cardiac output parameters. Patients within the invasive monitoring arm of this study received 68% more fluid volume than those in the Parkland formula arm.58
The fact that the monitored patients in Holm et alís randomized study received fluid volumes in excess of the calculated resuscitation needs is not unusual. It has been observed in burn centers that patients are beginning to be resuscitated with larger volumes than in the past. The reason for this increase, which has been termed the ďfluid creep,Ē has not been determined but may not be insignificant. 47,59-62 Under-resuscitation can lead to acute renal failure, multi-system organ failure, or death, but over-resuscitation can also have deleterious effects. There is concern that excessive fluid resuscitation in thermally injured patients could lead to increased edema, acute respiratory distress syndrome (ARDS), and compartment syndromes involving the abdomen, extremities, or the eyes.58,63-65
Due to the possibility of increased edema and morbidity with excessive crystalloid fluid resuscitation, some effort has been made to decrease resuscitation needs in burn patients by using colloid fluid or hypertonic saline. Colloid fluid replacement does appear to decrease overall fluid requirements in burn patients.66,67 However, controversy remains about whether colloids should be used in the first 24 hours after injury. Two large prospective clinical trials have shown colloid resuscitation in the first 24 hours to provide little or no benefit to burn patients. Bocanegra prospectively studied 308 patients in 1966 looking at the differences in burn outcome with respect to isotonic saline, plasma, and dextrose resuscitations. He concluded the addition of plasma offered no advantage over isotonic saline.68 In 1983, Goodwin randomized 79 adults to receive lactated Ringerís versus lactated Ringerís and albumin. In this study, the patients receiving both crystalloid and colloid required less fluid resuscitation but appeared to have higher rates of pulmonary edema.67 Experts have begun attempting a compromise in fluid resuscitation. Practitioners are attempting to extort the positive aspects from both crystalloid and colloid resuscitation by combining the two approaches. This is being attempted by either giving both classes of fluids together or giving crystalloids first and colloid fluid approximately 17 to 24 hours after the initial injury.66,69,70 Hypertonic saline may be a promising modality for burn resuscitation. Several studies have demonstrated decreased volume administration with hypertonic resuscitation.71-75 The hyperosmolar effect of hypertonic saline increases plasma volume by favoring a water shift into the intravascular space. The American Burn Association recommends hypertonic saline resuscitation be reserved for use by providers experienced with this approach.47 Experience using hypertonic saline in burn resuscitation is limited and controversial. Huang and colleagues found an association with hypertonic saline and renal failure in a prospective trial of adult burn patients in 1995.76 Several studies have contradicted the idea that hypertonic saline decreases volume administration in thermally injured patients, and significant hypernatremia is always a risk with its administration.77-79 Therefore, future research is needed to determine if hypertonic saline has a role in burn resuscitation.
Pain management is a topic of interest in pediatric burn management. The emergency practitionerís main priority in pain management is to recognize the need for analgesic medication in the burn trauma patient, give appropriate doses, and be aware of possible consequences. Children with burn injuries, regardless of the depth of the burn, are often anxious in addition to being in physical pain, and each of these situations can exacerbate the other. Opioid agonist medications, specifically morphine sulfate, remain the treatment of choice in significant burn injuries. Traditionally, 0.1 to 0.15 mL/kg body weight is used as a starting dose and titrated to effect. There are no prospective randomized trials to support morphine over other analgesic medications in burn victims. Fentanyl is another narcotic analgesic that may be utilized in this population. It has been suggested that intravenous medication is superior to intramuscular or oral in major burns due to potential hypoperfusion and edema to the gastrointestinal system and extremities after a major burn.
Oligoanalgesia is well documented in burn patients, especially children.80-82 Singer and Thode suggested in 2002 that half of all burn patients seen in U.S. emergency departments did not have their pain assessed and/or did not receive an analgesic medication while in the emergency department.82 However, Sullivan et al reported in 2004 that burn center physicians have increased their use of opioid agonist in burn victims. They made an association between the increased use of opioid agonists with increased fluid administration, hypothesizing that the opioid agonist contributed to hypotension that resulted in a need for greater fluid resuscitation.80 Currently, this hypothesis has not been adequately studied to alter the acute care of pain management in the emergency department, and the emergency practitioner should strive for adequate pain control in their pediatric burn patients.
Alternative medications with improved hemodynamic effects are often evaluated. Ketamine has gained favor as an analgesic/sedative medication for painful procedures associated with burn care, such as burn dressing changes and debridement. Ketamine stimulates the cardiovascular system and results in vasoconstriction (as opposed to vasodilatation seen in narcotic medications), which may be advantageous in the presence of burn shock.83 Animal modal research has been conducted to evaluate ketamineís anti-inflammatory properties. In at least one animal study, ketamine was found to decrease mortality in severely burned rats due to increased heat-shock response after ketamine use.84 Further experimental and clinical trials are needed to evaluate the role of ketamine in burn analgesia.
Wound Care And Infection Control
The emergency practitionerís role in burn wound management is largely focused on partial thickness wounds. Superficial burns do not require topical treatments and full-thickness wounds have improved outcomes with early surgical excision and closure by burn surgeons.85 In the emergency department, health care personnel should be focused on wound cleansing, debridement, and applying appropriate dressings.
Cleansing burn wounds should be done using a mild soap and water mixture. Skin disinfecting agents such as povidone-iodine and chlorhexidine liquid may inhibit proper wound healing and should be avoided.86,87 Iodine toxicity and renal failure have been associated with the use of topical povidoneiodine solution in large surface area burns.88
Blister management continues to be a controversial aspect of partial-thickness wound care. There is conflicting evidence in regard to actively rupturing blisters versus leaving them intact. Experts have begun to favor leaving blisters intact unless they are large, painful, or if rupture is imminent.89,90 Blister fluid has been studied in regard to its effects on wound healing with both positive and negative implications. Some researchers have stated that the fluid contained in blisters is comprised of factors that inhibit wound healing in part by vasoactive substances that can decrease circulation, increase inflammatory response, decrease reepithelialization, and increase the contractility of fibroblast.91-95 However, other research supports that blisters promote wound healing in part by the presence of various growth factors and cytokines that stimulate growth and the ability of the fluid to promote mitogenic activity and growth of fibroblast.96-101 In 1957, Gimble et al showed that intact blisters healed faster than ruptured blisters in 14 volunteers in which partialthickness injuries were created.102
Debridement of devitalized tissue decreases the incidence of infection and promotes healing by removing necrotic tissue, which carries a higher bacteria load than healthy tissue. The incidence of infection is further decreased by the application of antimicrobial preparations plus a nonadherent dressing or occlusive dressings. In the 1960ís, Winter and Hinman published research showing that a moist wound environment promotes wound healing.103,104 Since that time, many different occlusive dressing options and topical preparations have been developed for wound care.
Silver-containing products have been popular for over 200 years and are still used today.90,105 Silver sulfadiazine has broad antimicrobial properties and is a popular topical preparation for burn care. However, there is little evidence to support that it decreases wound infection or burn-related sepsis. Silver sulfadiazine has also been shown to have adverse effects such as local skin reactions, hypersensitivity reactions, and a delay in wound healing.106 Due to properties that can cause tissue hypopigmentation, its use on facial wounds should be limited. Also, silver sulfadiazineís antimicrobial properties can be inactivated by wound exudates therefore requiring more frequent dressing changes that cause pain and may delay healing of burn injuries.107 Mafenide acetate is a topical preparation that penetrates easier and deeper than silver sulfadiazine. Mafenide acetate is used on e chars and wounds overlying s cartilage. This preparation is a carbonic anhydrase inhibitor that can cause a metabolic acidosis and is painful on application. Bacitracin, mupirocin, and neomycin are also often utilized for burn wound application. There is little evidence to support one product over another.
There are several observational and randomized studies that support the use of synthetic and biological dressings. In 2007, Paddock showed that silver-impregnated antimicrobial dressings reduce hospital length of stay for pediatric patients with burns.108 A dressing made of rayon/polyester fibers that is impregnated with silver has been shown to be superior to silver sulfadiazine cream in preventing mortality from Pseudomonas aeruginosa, reducing pain, and improving wound healing.90,109-112 A silver-impregnated dressing composed of sodium carboxymethyl-cellulose has also been found beneficial in partial-thickness burn management.113-114 In 2002, Ulker suggested through animal research comparing dressings made of rayon/polyester fibers that are impregnated with silver, chlorhexidine acetate 0.5%, and 2% fusidic acid that fusidic acid was the most effective against Methicillin-resistant Staphylococcus aureus (MRSA). Ulker suggested that dressings made of rayon/polyester fibers that are impregnated with silver were also effective against MRSA and may be the most beneficial in relation to its less frequent dressing changes.
Although topical antimicrobials are still the mainstay of burn management, evidence does not support the use of systemic antibiotics in burn patients. However, tetanus prophylaxis should be evaluated. A tetanus toxoid booster should be given to any child with partial or full-thickness burns if they have not received a tetanus booster immunization in over 5 years. If the child has not completed their primary tetanus immunization series (3 doses), they should receive a tetanus toxoid immunization as well as human tetanus immune globulin at the time of evaluation.115