William B. Norbury

Urinary Cortisol and Catecholamine Excretion after Burn Injury in Children

INTRODUCTIONnA severe burn causes increased levels of urine cortisol and catecholamines. However, little is known about the magnitude of this increase or how and when the levels return to normal. The purpose of this study was to determine in a large clinical prospective trial the acute and long-term pattern of urine cortisol and catecholamine expression in severely burned children.nnnMETHODSnPediatric patients with burns greater than 40% total body surface area (TBSA), admitted to our unit over a 6-yr period, were included into the study. Clinical data including length of stay, number of operations, and duration and number of infections were determined. Patients had regular 24-h urine collections during their acute admission and reconstructive periods. Urine collections were analyzed for cortisol, epinephrine, and norepinephrine. Each urine cortisol was compared with age-adjusted reference ranges. Ninety-five percent confidence intervals and ANOVA analysis were used where appropriate.nnnRESULTSnTwo hundred twelve patients were included in the study (75 females and 137 males), with a mean +/- sem TBSA of 58 +/- 1% (third-degree 45 +/- 2%) and mean age of 9 +/- 0.4 yr. Urinary cortisol levels were significantly increased (3- to 5-fold) up to 100 d after the burn and then approached normal levels (P < 0.05). The rise in urine cortisol was significantly higher in male than female patients (P < 0.05). Early hypercortisolemia was associated with increased duration of severe infection (P < 0.05). Persistent hypercortisolemia was associated with increases in both infection rates and duration of severe infection (P < 0.05). Urinary catecholamines showed a significant increase at 11-20 d after the burn (P < 0.05). Urinary norepinephrine levels were significantly increased up to 20 d and then returned to normal (P < 0.05).nnnCONCLUSIONSnUrinary levels of cortisol, epinephrine, and norepinephrine are significantly increased after a major burn. Early hypercortisolemia is associated with increased duration of severe infection. Persistent hypercortisolemia is associated with increases in both infection rates and duration of severe infection.

Special considerations of age: The pediatric burned patient

Abstract Children are disproportionately affected by burn injuries. Differences between adult and pediatric burns range from epidemiological characteristics to pathophysiological considerations, which vary between different age subgroups. All these factors must be taken into account in each phase of burn care. This chapter reviews the most important aspects of the management of the pediatric burned patient.

Treatment of Infection in Burn Patients

Abstract Burn wounds are conduits for infections. From the inciting thermal trauma to finalization of therapy, burn patients are exposed to multiple drug-resistant organisms. This chapter presents the definitions and types of infections afflicting burn patients, from cellulitis and wound infections to pneumonias and bloodstream infections. Topical and systemic antimicrobials are covered, as well as specific etiologic bacteria, fungi, and viruses. A care algorithm is elaborated, centered on source control with early surgical excision and skin grafting augmented by culture-directed antimicrobial therapy. Regardless of the etiologic organism, the best intervention for both prophylaxis and treatment of infections in the burn patient is the prompt closure of burn wounds with skin.

BURN SIZE DETERMINES THE INFLAMMATORY AND HYPERMETABOLIC RESPONSE

BACKGROUNDnIncreased burn size leads to increased mortality of burned patients. Whether mortality is due to inflammation, hypermetabolism or other pathophysiologic contributing factors is not entirely determined. The purpose of the present study was to determine in a large prospective clinical trial whether different burn sizes are associated with differences in inflammation, body composition, protein synthesis, or organ function.nnnMETHODSnPediatric burned patients were divided into four burn size groups: <40% total body surface area (TBSA) burn, 40-59% TBSA burn, 60-79% TBSA burn, and >80% TBSA burn. Demographic and clinical data, hypermetabolism, the inflammatory response, body composition, the muscle protein net balance, serum and urine hormones and proteins, and cardiac function and changes in liver size were determined.nnnRESULTSnOne hundred and eighty-nine pediatric patients of similar age and gender distribution were included in the study (<40% TBSA burn, n = 43; 40-59% TBSA burn, n = 79; 60-79% TBSA burn, n = 46; >80% TBSA burn, n = 21). Patients with larger burns had more operations, a greater incidence of infections and sepsis, and higher mortality rates compared with the other groups (P < 0.05). The percentage predicted resting energy expenditure was highest in the >80% TBSA group, followed by the 60-79% TBSA burn group (P < 0.05). Children with >80% burns lost the most body weight, lean body mass, muscle protein and bone mineral content (P < 0.05). The urine cortisol concentration was highest in the 80-99% and 60-79% TBSA burn groups, associated with significant myocardial depression and increased change in liver size (P < 0.05). The cytokine profile showed distinct differences in expression of IL-8, TNF, IL-6, IL-12p70, monocyte chemoattractant protein-1 and granulocyte-macrophage colony-stimulating factor (P < 0.05).nnnCONCLUSIONnMorbidity and mortality in burned patients is burn size dependent, starts at a 60% TBSA burn and is due to an increased hypermetabolic and inflammatory reaction, along with impaired cardiac function.

Laser for Burn Scar Treatment

Abstract Restoration of form and function after burn injury remains challenging. Emerging laser and pulsed light technologies have been beneficial in the treatment of patients with hypertrophic scars, which may be associated with persistent hyperemia, chronic folliculitis, intense pruritus, and neuropathic pain. The following lasers have been used with varying levels of success in burn scar reconstruction: 1) vascular-specific pulsed dye laser (PDL) to reduce hyperemia, (2) ablative fractional CO 2 laser to improve texture and pliability of the burn scar, (3) ablative Erbium:YAG laser (4) lasers to target pigment including the ruby, NgYAG and Alexandrite lasers and (5) intense pulsed light (IPL) to correct burn scar pruritus, dyschromia, and alleviate chronic folliculitis. This chapter will briefly review the history of lasers, the physics of laser, and provide an overview of the different lasers utilized in burn reconstruction thus far. Additionally, at the end of this chapter, laser safety will be reviewed along with future directions for laser surgery in burn reconstruction.

Nutritional Needs and Support for the Burned Patient

Abstract Burns involving more than 20% of the total body surface area represent a massive metabolic injury. This metabolic response to massive burns creates an immediate, intense, and persistent strain on the patients nutritional status. The systemic response to burn injury alters essentially all aspects of energy-substrate metabolism. Given the immense metabolic challenges created by burn injury, optimizing nutritional support is essential to improving outcomes in this patient population. Total calories provided should be based on ongoing assessment of energy expenditure, ideally using indirect calorimetry. Providing calories in excess of the patients needs (i.e., overfeeding) is counterproductive. Enteral nutrition is the first line of nutritional support in the burn patient, and enteral feeding should be administered as soon as possible. Accurate serial assessment of nutritional status and body composition is central to identifying patient needs, trajectory, and efficacy of care. Changes in lean body mass and body composition represent the ultimate reflection of cumulative nutritional status, and evolving applications of imaging technology have made routine serial evaluation of lean body mass feasible. The physiologic response to massive thermal injury represents an enormous nutritional insult. The consequences of this intense acute malnutrition include compromises in immune function, wound healing, and mobility—all major drivers of morbidity and mortality in thermal trauma. As such, thoughtful and comprehensive nutritional support based on continuous assessment is essential.