Gary F. Purdue

American Burn Association consensus conference to define sepsis and infection in burns.

Because of their extensive wounds, burn patients are chronically exposed to inflammatory mediators. Thus, burn patients, by definition, already have “systemic inflammatory response syndrome.” Current definitions for sepsis and infection have many criteria (fever, tachycardia, tachypnea, leukocytosis) that are routinely found in patients with extensive burns, making these current definitions less applicable to the burn population. Experts in burn care and research, all members of the American Burn Association, were asked to review the literature and prepare a potential definition on one topic related to sepsis or infection in burn patients. On January 20, 2007, the participants met in Tucson, Arizona to develop consensus for these definitions. After review of the definitions, a summary of the proceedings was prepared. The goal of the consensus conference was to develop and publish standardized definitions for sepsis and infection-related diagnoses in the burn population. Standardized definitions will improve the capability of performing more meaningful multicenter trials among burn centers.

An evaluation of risk factors for mortality after burn trauma and the identification of gender-dependent differences in outcomes.

BACKGROUND The primary objective of this study was to determine an objective method for estimating the risk of mortality after burn trauma, and secondarily, to evaluate the relationship between gender and mortality, in the setting of a quantifiable inflammatory stimulus. Previously reported estimates of mortality risk after burn trauma may no longer be applicable, given the overall reduction in case-fatality rates after burn trauma. We expect that future advances in burn trauma research will require careful and ongoing quantification of mortality risk factors to measure the importance of newly identified factors and to determine the impact of new therapies. Conflicting clinical reports regarding the impact of gender on survival after sepsis and critical illness may in part, be from different study designs, patient samples, or failure to adequately control for additional factors contributing to the development ofsepsis and mortality. STUDY DESIGN Data from the prospectively maintained burn registry for patients admitted to the Parkland Memorial Hospital burn unit between January 1, 1989 and December 31, 1998 were analyzed. Logistic regression was used to generate estimates of the probability of death in half of the study sample, and this model was validated on the second half of the sample. Risk factors evaluated for their relationship with mortality were: age, inhalation injury, burn size, body mass (weight), preexisting medical conditions, nonburn injuries, and gender. RESULTS Of 4,927 patients, 5.3% died. The best model for estimating mortality included the percent of total body surface area burned; the percent of full-thickness burn size; the presence of an inhalation injury; age categories of: < 30 years, 30 to 59 years, > or = 60 years; and gender. The risk of death was approximately two-fold higher in women aged 30 to 59 years compared with men of the same age. CONCLUSIONS We have provided a detailed method for estimating the risk of mortality after burn trauma, based on a large, contemporary cohort of patients. These estimates were validated on a second sample and proved to predict mortality accurately. We have identified an increased mortality risk in women of 30 to 59 years of age.

The risk factors and time course of sepsis and organ dysfunction after burn trauma

BACKGROUND Sepsis and organ dysfunction are common and likely contribute to death after burn trauma. We sought to define relationships between sepsis, severe multiple organ dysfunction (MOD), and death after burn trauma. METHODS Adults with > or = 20% total body surface area burns were prospectively enrolled. Information regarding infection, severity of sepsis, and organ failure was collected daily. Risk factors (e.g., age, burn size, shock) were analyzed for their association with severe MOD, complicated sepsis, and death. We characterized the temporal relationship between organ failure and sepsis. RESULTS Of 175 patients, 27% developed severe MOD, 17% developed complicated sepsis, and 22% died. Full-thickness burn size, age, and inhalation injury were associated with MOD, sepsis, and death. Infection preceded MOD in 83% of patients with both. A base deficit of > or = 6 mEq/L at 24 hours after injury was associated with death. CONCLUSION When it occurs, severe MOD is usually preceded by infection. In addition, an elevated base deficit at 24 hours and septic shock are the most important factors associated with and possibly contributing to death after burn trauma.

TLR4 and TNF-α polymorphisms are associated with an increased risk for severe sepsis following burn injury

Context: Sepsis, organ failure, and shock remain common among patients with moderate to severe burn injuries. The inability of clinical factors to identify at-risk patients suggests that genetic variation may influence the risk for serious infection and the outcome from severe injury. Objective: Resolution of genetic variants associated with severe sepsis following burn injury. Patients: A total of 159 patients with burns ⩾20% of their total body surface area or any smoke inhalation injury without significant non-burn related trauma (injury severity score (ISS)⩾16), traumatic or anoxic brain injury, or spinal cord injury and who survived more than 48 h post-admission. Methods: Candidate single nucleotide polymorphisms (SNPs) within bacterial recognition (TLR4 +896, CD14 −159) and inflammatory response (TNF-α −308, IL-1β −31, IL-6 −174) loci were evaluated for association with increased risk for severe sepsis (sepsis plus organ dysfunction or septic shock) and mortality. Results: After adjustment for age, full-thickness burn size, ethnicity, and gender, carriage of the TLR4 +896 G-allele imparted at least a 1.8-fold increased risk of developing severe sepsis following a burn injury, relative to AA homozygotes (adjusted odds ratio (aOR) 6.4; 95% confidence interval (CI) 1.8 to 23.2). Carriage of the TNF-α −308 A-allele imparted a similarly increased risk, relative to GG homozygotes (aOR = 4.5; 95% CI 1.7 to 12.0). None of the SNPs examined were significantly associated with mortality. Conclusions: The TLR4 +896 and TNF-α −308 polymorphisms were significantly associated with an increased risk for severe sepsis following burn trauma.

A multicenter clinical trial of a biosynthetic skin replacement, dermagraft-TC, compared with cryopreserved human cadaver skin for temporary coverage of excised burn wounds

This multicenter study compared the use of a biosynthetic human skin substitute with frozen human cadaver allograft for the temporary closure of excised burn wounds. Dermagraft-TC (Advanced Tissue Sciences, Inc.) (DG-TC) consists of a synthetic material onto which human neonatal fibroblasts are cultured. Burn wounds in 66 patients with a mean age of 36 years and a mean burn size of 44% total body surface area (28% total body surface area full-thickness) were surgically excised. Two comparable sites, each approximately 1% total body surface area in size, were randomized to receive either DG-TC or allograft. Both sites were then treated in the same manner. When clinically indicated (> 5 days after application) both skin replacements were removed, and the wound beds were evaluated and prepared for grafting. DG-TC was equivalent or superior to allograft with regard to autograft take at postautograft day 14. DG-TC was also easier to remove, had no epidermal slough, and resulted in less bleeding than did allograft while maintaining an adequate wound bed. Overall satisfaction was better with DG-TC.

Effects of oxandrolone on outcome measures in the severely burned: a multicenter prospective randomized double-blind trial.

Severe burns induce pathophysiologic problems, among them catabolism of lean mass, leading to protracted hospitalization and prolonged recovery. Oxandrolone is an anabolic agent shown to decrease lean mass catabolism and improve wound healing in the severely burned patients. We enrolled 81 adult subjects with burns 20% to 60% TBSA in a multicenter trial testing the effects of oxandrolone on length of hospital stay. Subjects were randomized between oxandrolone 10 mg every 12 hours or placebo. The study was stopped halfway through projected enrollment because of a significant difference between groups found on planned interim analysis. We found that length of stay was shorter in the oxandrolone group (31.6 ± 3.1 days) than placebo (43.3 ± 5.3 days; P < .05). This difference strengthened when deaths were excluded and hospital stay was indexed to burn size (1.24 ± 0.15 days/% TBSA burned vs 0.87 ± 0.05 days/% TBSA burned, P < .05). We conclude that treatment using oxandrolone should be considered for use in the severely burned while hepatic transaminases are monitored.

National Burn Repository 2005: a ten-year review.

In the early 1990s, the American Burn Association (ABA) started its first burn registry development initiatives. The impetus for the registry development software originated from several directions, including the following: (1) the recognition that national registries were widespread and of proven benefit; (2) growing demands from accrediting institutions, payers, and patient advocacy groups for objective and verifiable data regarding patient costs, treatments, and outcomes; and (3) the shift toward “evidence-based” medicine and the ongoing analysis of treatment effectiveness. The ABA has issued three calls for burn registry data for its National Burn Repository (NBR): 1994, 2002, and 2005. In 1994, 28 burn centers contributed data for more than 6,400 patients treated from 1991 to 1993. The ABA announced its second call for data in 2001 and distributed the published results of more than 54,000 acute burn admissions treated from 1974 to 2002 at the Association’s 2002 Annual Meeting. The third ABA call for data was issued in the Fall of 2005. The results are detailed in this report, which provides a summary of more than a quarter million acute burn admissions from 1995 to 2005, representing 70 hospitals from 30 states plus the District of Columbia. Statistics are presented in chart and table format to illustrate such key factors as patient age, burn size group, types of injuries, mortality rates, and average hospital charges by etiology and length of hospital stay. The data presented herein should help stimulate quality improvement programs in burn care, as burn centers compare their performance with the national data and as research is expanded using the NBR. The NBR will be published annually and, with continued refinements to the registry software, should become of increasing importance to clinicians, payers, researchers, and the public.

Electrical Injuries: A 20-Year Review

Electrical injuries continue to present problems with devastating complications and long-term socioeconomic impact. The purpose of this study is to review one institutions experience with electrical injuries. From 1982 to 2002, there were 700 electric injury admissions. A computerized burn registry was used for data collection and analysis. Of these injuries, 263 were high voltage (> or =1000 V), 143 were low voltage (<1000 V), 277 were electric arc flash burns, and 17 were lightning injuries. Mortality was highest in the lightning strikes (17.6%) compared with the high voltage (5.3%) and low voltage (2.8%) injuries, and mortality was least in electric arc injuries without passage of current through the patient (1.1%). Complications were most common in the high-voltage group. Mean length of stay was longest in this group (18.9 +/- 1.4 days), and the patients in this group also required the most operations (3 +/- 0.2). Work-related activity was responsible for the majority of these high-voltage injuries, with the most common occupations being linemen and electricians. These patients tended to be younger men in the prime of their working lives. Electrical injuries continue to make up an important subgroup of patients admitted to burn centers. High-voltage injuries in particular have far reaching social and economic impact largely because of the patient population at greatest risk, that is, younger men at the height of their earning potential. Injury prevention, although appropriate, remains difficult in this group because of occupation-related risk.

Child abuse by burning--an index of suspicion

Although general awareness of child abuse is increasing, abuse by burning is often unrecognized. Seventy-one consecutive children admitted with inflicted burns were studied. Mean age was 1.8 yrs and mean burn size was 13.5%. Mean length of stay was 18.9 days. Scalds (83% from tap water) were the most frequent cause of injury. An immersion pattern was present in 59%; six patients had a classic forced immersion injury. Fourteen children had nonburn trauma. Four patients died: all had tap water immersion burns. Inflicted burns are usually manifested by characteristic patterns of injury, which must be correlated with the given history. When compared with accidentally burned children, abused children were significantly younger, had longer hospital stays, and had a higher mortality. A team approach to child abuse with the addition of a specially trained group is important to insure prompt recognition, more objective appraisals, and further followup.

Objective estimates of the incidence and consequences of multiple organ dysfunction and sepsis after burn trauma.

BACKGROUND Organ dysfunction and sepsis are frequent after major burn trauma, represent quantifiable consequences of the systemic response to injury, and may be important end points by which to measure treatment effectiveness. However, standard and widely applied methods for their measurement have not been applied to burn trauma victims. Therefore, the purpose of this study was to quantify these complications after burn trauma. METHODS Patients with > or = 20% total body surface area burns admitted to a single center were prospectively enrolled. Standard sepsis criteria and multiple organ dysfunction (MOD) scores for the pulmonary, renal, cardiovascular, hepatic, and hematologic systems were determined. The incidence and risk factors for severe MOD (cumulative MOD score > or = 6) and severe sepsis were determined. The relationships between these complications and mortality and resource utilization were examined by univariate and multivariate analyses. RESULTS A total of 85 patients were enrolled over 1 year. Severe MOD developed in 24 (28%) and severe sepsis or septic shock developed in 12 (14%). Both were associated with increasing age and burn size and were more likely to occur in men. Most patients who developed severe MOD or severe sepsis survived (71% and 67%, respectively), and both were associated with longer intensive care unit stays and duration of mechanical ventilation. CONCLUSION According to simple and objective scoring systems, severe MOD and severe sepsis/septic shock are both related to burn size, age, and male sex. Both are related to intensive care unit length of stay and duration of mechanical ventilation.