Ten Year Experience of Burn, Trauma, and Combined Burn/Trauma Injuries Comparing Outcomes

The role of nasal carriage in Staphylococcus aureus burn wound colonization

Thermal injury destroys the physical skin barrier that normally prevents invasion of microorganisms. This and concomitant depression of local and systemic host cellular and humoral immune responses are important factors that contribute to colonization and infection of the burn wound. One of the most common burn wound pathogens is Staphylococcus aureus. Staphylococcus aureus is both a human commensal and a frequent cause of infections leading to mild to life-threatening diseases. Despite a variety of infection control measures, for example patient cohorting and contact precaution at burn centres, S. aureus is still frequently encountered in burn wounds. Colonization with S. aureus has been associated with delayed wound healing, increased need for surgical interventions, and prolonged length of stay at burn centres. In this minireview, we focus on S. aureus nasal carriage in relation to S. aureus burn wound colonization and subsequent infection, and its impact on strategies for infection control.

Aging and animal models of systemic insult: trauma, burn, and sepsis

In the acute-care setting, it is widely accepted that elderly patients have increased morbidity and mortality compared with young healthy patients. The reasons for this, however, are largely unknown. Although animal modeling has helped improve treatment strategies for young patients, there are a scarce number of studies attempting to understand the mechanisms of systemic insults such as trauma, burn, and sepsis in aged individuals. This review aims to highlight the relevance of using animals to study the pathogenesis of these insults in the aged and, despite the deficiency of information, to summarize what is currently known in this field.

A population-based study of the epidemiology of acute adult burn injuries in the Calgary Health Region and factors associated with mortality and hospital length of stay from 1995 to 2004

INTRODUCTION

Trauma resulting from acute burns is relatively common and we wished to study the incidence, outcomes and factors related to mortality and hospital length of stay to identify potential areas of prevention and improve the care of burn-injured patients. To do so, we studied a population of adult burn injury patients from a large area of Canada (the Calgary Health Region (CHR) over a 10-year period. Burn data from this population-based sample has never been published and is not currently included in the American Burn Association Repository report.

METHODS

We extracted data on all adult (>or=18 years) residents of the CHR who suffered a burn injury requiring hospital admission between January 1995 and December 2004. Of particular interest were patient demographics, incidence and mortality rates of the victims as well as any factors that were associated with mortality or increased length of hospital stay.

RESULTS

A total of 928 burn-injured patients were identified. The highest incidence of burn injury admissions in the CHR occurred in 1996 (12.2 burn injury admissions per 100,000 population) and 2004 (12.3 admissions per 100,000 population). The largest number of burn injury admissions occurred during the months of July and August (23.3%), while the fewest occurred during the winter months of February and December (11.9%). Mean patient age was 45.2 years (range 18-97) and 658 (70.9%) were male. The majority of our patients were admitted with second-degree burns (48.7%) and burns of the head and neck were the most prevalent (22.2%). The mean length of hospital stay for burn patients was 20.4 days (range 1-312). Over the course of the 10 years of the study, 9 (1.0%) burn patients died during their hospital stay. In univariate analyses, burn survivors differed significantly from non-survivors with respect to mean age, burn degree, body part burned and year of admission. In adjusted analyses, survivors and non-survivors differed significantly with respect to year and month of admission, degree of burn, patient age and length of stay. Factors significantly associated with increase length of hospital stay included degree of burn, older patient age and hospital site.

CONCLUSIONS

In this Canadian health region, patients who die from burns tend to be older, present to the hospital during the winter months, and suffer more acute burns to the torso or multiple body regions. Additionally, patient length of stay is influenced by older patient age and greater burn thickness.

Development and validation of a model for prediction of mortality in patients with acute burn injury

BACKGROUND

The objective was to develop a user-friendly model to predict the probability of death from acute burns soon after injury, based on burned surface area, age and presence of inhalation injury.

METHODS

This population-based cohort study included all burned patients admitted to one of the six Belgian burn centres. Data from 1999 to 2003 (5246 patients) were used to develop a mortality prediction model, and data from 2004 (981 patients) were used for validation.

RESULTS

Mortality in the derivation cohort was 4.6 per cent. A mortality score (0-10 points) was devised: 0-4 points according to the percentage of burned surface area (less than 20, 20-39, 40-59, 60-79 or at least 80 per cent), 0-3 points according to age (under 50, 50-64, 65-79 or at least 80 years) and 3 points for the presence of an inhalation injury. Mortality in the validation cohort was 4.3 per cent. The model predicted 40 deaths, and 42 deaths were observed (P = 0.950). Receiver-operator characteristic curve analysis of the model for prediction of mortality demonstrated an area under the curve of 0.94 (95 per cent confidence interval 0.90 to 0.97).

CONCLUSION

An accurate model was developed to predict the probability of death from acute burn injury based on simple and objective clinical criteria.

A model for predicting mortality among critically ill burn victims

OBJECTIVE

To develop a model for predicting mortality among burn victims.

METHODS

All casualties admitted to our intensive care burn unit (ICBU) with a diagnosis of thermal or inhalation injury were studied. Age, total and full-thickness body surface area (BSA) burned, presence of inhalation injury, gender, mechanism of injury, delay to ICBU admission and mechanical ventilation during the first 72 h were recorded. The 851 participants were randomly divided into derivation (671) and validation (180) sets. From univariate and multivariate logistic regression analyses a mortality predictive equation was derived.

RESULTS

Mortality was 17.6%. In univariate analysis, all variables were significantly associated with mortality except mechanism of injury and delay to ICBU admission. In multivariate analysis, age, total and full-thickness BSA burned, female gender and early mechanical ventilation were independently associated with mortality.

CONCLUSIONS

We propose a mortality predictive equation for burned victims. In this model, MV and not inhalation injury is a mortality risk factor.

Microalbuminuria in acute burn injury

Microalbuminuria is a known finding in inflammatory states. We hypothesized that urinary albumin/creatinine ratio (ACR) would correlate with injury severity and resuscitation demands after acute burns. This pilot study evaluated 30 adults admitted within 12 hours of injury with burns > or =10% total body surface area burn injury (TBSA). The urinary ACR was calculated for each patient at 7 to 12 hours, 19 to 24 hours, and 43 to 48 hours following burn injury. Microalbuminuria was defined as a urinary ACR > or =20 mg/g. Study patients (23 males, 7 females) had a mean age of 42.9 + 14.0 years and a median TBSA burn injury of 18.8%. Inhalation injury was present in 10 of the study patients, and all patients with inhalation injury had microalbuminuria at the time of admission. One study patient died. Median time from burn injury to resuscitation was 30 hours, and the median fluid requirement was 4.2 ml/kg/%TBSA. Microalbuminuria was not uniformly present in burn-injured patients during the first 48 hours after injury. ACR values early in the hospital course correlated with higher lactate concentrations early after burn injury. However, ACR correlated with neither injury severity nor resuscitation demands after burn injury during any studied time range. Microalbuminuria does not have apparent clinical utility in burn-injured patients, and other markers of injury severity and resuscitation demands should be sought.

Endovascular Repair of a Thoracic Aortic Injury in a Burn Patient

Mortality in burn patients who sustain concomitant mechanical traumatic injuries at the time of thermal injury is greater than in patients who sustain isolated injuries. Invasive interventions to treat these mechanical traumatic injuries may be a source of added mortality and contribute to an injury-induced state of immunosuppression. Less-invasive interventions may minimize morbidity and mortality and allow for improved recovery from thermal injury. A case is presented of a patient who sustained 20% TBSA electrical burns and an acute thoracic aortic injury near the diaphragmatic hiatus. Abdominal aortic stent-graft components were used to successfully exclude the patient's thoracic aortic injury. The patient made a successful recovery from his burns and sustained no infectious complications. This case report highlights the potential advantages of endovascular therapy for the treatment of aortic trauma in patients who sustain concomitant burn injuries.

Effects of differences in percent total body surface area estimation on fluid resuscitation of transferred burn patients

We sought to analyze the effect that differences in estimation of burn size and burn resuscitation had on complications and death among our transferred burn patients, in comparison with outcomes for burn patients directly admitted to our rural Level 1 trauma center. A retrospective chart review was performed for all patients suffering thermal injuries who were treated at a rural Level I trauma center and regional burn center. Percent TBSA burn estimates at referring hospitals were compared to burn center estimates. The Parkland formula was used to calculate the difference between the theoretical and actual resuscitation volumes given prior to admission. Of 127 burn patients, 82 (65%) were transferred from outside hospitals. For small burns (<20% TBSA), the mean estimate difference between outside hospitals and the burn center was 4.3 +/- 6.9%. For large burns (> or =20% TBSA), the mean estimate difference was -4.9 +/- 9.1% (P < .0002). The mean difference in intravenous fluid administered prior to admission to the burn center and the Parkland formula guideline was an excess of 554 +/- 1099 ml for small burns and a deficit of -414 +/- 2081 ml for larger burns (P = .03, Wilcoxon's rank-sum test). Differences in burn estimation and deviation from the Parkland formula were not statistically significant for complication and death. In the rural, transferred burn patient, smaller burns tended to be overestimated and overresuscitated and larger burns tended to be underestimated and underresuscitated.

Burn patient characteristics and outcomes following resuscitation with albumin

BACKGROUND

Use of colloids in acute burn resuscitation may reduce fluid requirements, but effect on mortality is unknown. We hypothesized that patients who received albumin would have similar mortality to patients who did not receive albumin.

METHODS

We performed a case-controlled study of inpatients who sustained burns of > or =20% total body surface area (TBSA). Patients who received albumin during resuscitation because of increased fluid requirements (ALB) were compared to a cohort of patients matched for age and TBSA who did not receive albumin (CON).

RESULTS

Patients with inhalation injury were significantly more likely to receive albumin (OR 4.89, 95% CI 2.58-9.30). ALB patients had significantly higher mean initial lactate (3.64 versus 2.29, p=0.01), longer mean time to resuscitation (52.8 h versus 36.3 h; p=0.001), and higher resuscitation volume (9.4 mL/kg/%TBSA versus 6.4 mL/kg/%TBSA for CON). Mortality was not significantly different between the two groups (OR 1.90, 95% CI 0.85-4.22). Albumin was protective in a multivariate model of mortality (OR 0.27, 95% CI 0.07-0.97).

CONCLUSIONS

Despite more severe systemic dysfunction, burn patients who received albumin did not suffer increased mortality. A novel finding is the decreased likelihood of mortality associated with the administration of albumin during burn resuscitation.

Terror-Inflicted Thermal Injury: A Retrospective Analysis of Burns in the Israeli-Palestinian Conflict Between the Years 1997 and 2003

BACKGROUND

Terror attacks have changed in the past decade, with a growing tendency toward explosives and suicide bombings, which led to a rise in the incidence of thermal injuries among victims. The Israeli-Palestinian conflict of October 2000 marked a turning point when an organized terror campaign commenced. This article presents data of terror-associated burns from the Israeli National Trauma Registry (ITR) during the years 1997 to September 2000 and October 2000 to 2003.

METHODS

We analyzed demographic and clinical characteristics of 219 terror-related burn patients and 6,546 other burn patients admitted to hospitals in Israel between 1997 and 2003. Data were obtained from the ITR.

RESULTS

Burns contributed about 9% of all terror related trauma and about 5% of all other trauma (p < 0.0001). These percentages have not changed significantly before and after October 2000. Terror-related burns afflict Jewish males more than predicted by their percentage in the population, whereas other burns afflict non-Jewish males more than predicted. Adults and young adults (15-59 years) are the predominant group in terror-related burns (80%), whereas children younger than 15 years are the predominant group in other burns (50%). Large burns (20% to 89% total body surface area) are more common in terror casualties, with greater mortality (6.4% in terror-related versus 3.4% in others; p = 0.0258).

CONCLUSION

Although the incidence of burns has risen because of an organized campaign, this change was noticeable in other trauma forms as well in similar proportions. Terror-related burns afflict a targeted population, and generally take on a more severe course with greater mortality rates, thus requiring appropriate medical treatment.

Ventilator-Associated Pneumonia After Combined Burn and Trauma Is Caused by Associated Injuries and Not the Burn Wound

An increased risk of ventilator-associated pneumonia (VAP) has previously been demonstrated in trauma patients urgently intubated in the prehospital (ie, field) and emergency department (ED) settings. This study investigated the impact of urgent intubation on subsequent VAP in patients who sustained both a burn injury and a traumatic injury. We undertook a retrospective review of both trauma registry data and medical records for all patients with combined thermal and traumatic injuries admitted to a single verified burn center and level I trauma center. Patients undergoing field or ED intubation during the 5-year period ending December 2002 were identified and studied. Data abstracted included admission demographics and vital signs, presence of inhalation injury, location at the time of intubation, presence of associated injury, percentage TBSA burn, hospital and intensive care unit length of stay, and hospital day of VAP diagnosis. Seventy-eight of the 3388 patients (2.3%) admitted during the study period sustained a combination of burn wounds and trauma and underwent urgent field or ED intubation. The majority of patients were men (71%), with a mean age of 46 +/- 24 years. There was one failed oral intubation, which required cricothyroidotomy. The location of the patient at the time of intubation was ED, 66%; burn center ED, 17%; and field, 17%. Eighty percent of all patients were diagnosed with an inhalation injury. VAP was diagnosed in 39 patients (50%), with a mean time to diagnosis of 10 +/- 9 days. TBSA burn, smoke inhalation, and time (in days) to diagnosis of VAP were not independent risk factors for the occurrence of pneumonia in any of the 3 groups. However, those intubated at the initial ED were more likely to develop VAP (P = .028) compared to those intubated in the field or in the burn center. The incidence of associated injuries was significantly greater (P < .0001) in the initial ED group. Only a small percentage of burn patients also sustain blunt trauma. VAP occurs in 50% of the patients requiring urgent intubation. Independent risk factors appear to be intubation at an initial ED before transfer and associated injuries.

Analysis of functional outcomes in patients discharged from an acute burn center

Burn patients require careful consideration of their post-discharge needs to maximize their recovery. Patient-specific variables or a combination of variables that might allow clinicians to develop pathways and objective endpoints for appropriate discharge would assist in expediting the patient's post-discharge care. While there have been numerous studies examining a single variable and its ability to predict outcomes, these studies may not be directly applicable to burn patients. A burn clinician must incorporate a number of variables into their prediction of discharge disposition and outcomes. Our study included 202 burn patients aged 16 and older discharged from the acute burn unit from February 2004 to June 2005. Descriptive data collection included age, total body surface area, location of burn, presence/absence of inhalation injury, gender, length of stay, discharge disposition, insurance status, and presence/absence of social support. The analysis that also incorporated data containing functional status consisted of FIM scores for locomotion, transfers, dressing, and feeding. The classification tree analysis was utilized to demonstrate what variables could predict discharge disposition. The only variable that could strongly predict those patients that went home versus another setting was the FIM locomotion score. Of the patients who went home, 87.2% were at or above a supervision level for locomotion, whereas 85.2% of the patients not discharged to home were at or below a maximal assist level. The level of functional independence at the time of a patient's discharge as assessed by the patient's ability to walk was the most powerful identifier of their ongoing needs.

Comparison between civilian burns and combat burns from Operation Iraqi Freedom and Operation Enduring Freedom

OBJECTIVE

To assess outcome differences between locally burned civilians and military personnel burned in a distant combat zone treated in the same facility.

SUMMARY BACKGROUND DATA

The United States Army Institute of Surgical Research (USAISR) Burn Center serves as a referral center for civilians and is the sole center for significant burns in military personnel. We made the hypothesis that outcomes for military personnel burned in the current conflict in Iraq and Afghanistan would be poorer because of delays to definitive treatment, other associated injury, and distance of evacuation.

METHODS

We reviewed the civilian and military records of patients treated at the USAISR from the outset of hostilities in Iraq in April 2003 to May 2005. Demographics, injury data, mortality, and clinical outcomes were compared.

RESULTS

: We cared for 751 patients during this time period, 273 of whom were military (36%). Military injuries occurred in a younger population (41 +/- 19 vs. 26 +/- 7 years for civilian and military respectively, P < 0.0001) with a longer time from injury to burn center arrival (1 +/- 5 days vs. 6 +/- 5, P < 0.0001), a higher Injury Severity Score (ISS 5 +/- 8 vs. 9 +/- 11, P < 0.0001), and a higher incidence of inhalation injury (8% vs. 13%, P = 0.024). Total burn size did not differ. Mortality was 7.1% in the civilian and 3.8% in the military group (P = 0.076). When civilians outside the age range of the military cohort were excluded, civilian mortality was 5.0%, which did not differ from the military group (P = 0.57). Total body surface area (TBSA) burned, age > or =40 years, presence of inhalation injury, and ventilator days were found to be important predictors of mortality by stepwise regression, and were used in a final predictive model with the area under receiver operator characteristic curve of 0.97 for both populations considered together. No significant effect of either group was identified during development.

CONCLUSIONS

Mortality does not differ between civilians evacuated locally and military personnel injured in distant austere environments treated at the same center.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.

Comparison of combat and non-combat burns from ongoing U.S. military operations

BACKGROUND

Military burns result from either combat or non-combat causes. We compared these etiologies from patients involved in ongoing conflicts to evaluate their impact and provide prevention recommendations.

METHODS

All military patients with significant burns treated at the United States Army Institute of Surgical Research from April 2003 to May 2005 were reviewed. Injuries were categorized as having resulted from combat or non-combat causes. Demographics, burn severity and pattern, mortality, and early outcomes were compared.

RESULTS

There were 273 burn patients seen with 63% injured in combat. A high early rate of non-combat injuries was noted. Feedback on non-combat burn prevention was provided to the combat theater, and the incidence of non-combat burns decreased. Mean age and time from injury to admission did not differ. The majority of combat injuries resulted from explosive device detonation. Waste burning, ammunition handling, and gasoline caused most non-combat injuries. Combat casualties had more associated and inhalation injuries and greater full-thickness burn size; total body surface area burned was equivalent. The hands and the face were the most frequently burned body areas. Mortality was 5% in combat and 2% in non-combat patients. The majority of survivors in both groups returned to military duty.

CONCLUSIONS

The disparity in full-thickness burn size and incidence of inhalation and associated injuries resulted from differing mechanisms of injury, with explosions and penetrating trauma more common in combat wounds. Despite the severity of combat burns, mortality was low and outcomes generally good. Non-combat burns are preventable and have decreased in incidence.

Outcome and changes over time in survival following severe burns from 1985 to 2004

OBJECTIVE

To investigate outcome in severely burned patients over a 20-year period and to evaluate survival over time.

DESIGN AND SETTING

Historical cohort in a six-bed burn unit of a 1060-bed university hospital.

PATIENTS

1385 patients admitted to the burn unit over a 20-year period.

MEASUREMENTS AND RESULTS

Outcome was evaluated in relation to the presence of three major risk factors for death: age 60 years or over, total burned surface area 40% or more, and the presence of inhalation injury. Overall mortality was 7.1%. When zero, one, two, or three risk factors were present, mortality was respectively 0.5%, 9.9%, 48.0%, and 90.5%. Over the study period the average proportional total burned surface area decreased as did mortality. The survival benefit was significant among patient groups with one or two risk factors present. Multivariate regression analysis adjusting for risk factors for death confirmed that survival improved over time (odds ratio 0.73 per 5-year period).

CONCLUSIONS

Global mortality following burns is low, and nearly all patients who die had at least one risk factor present. In the presence of three risk factors the prognosis following burns is particularly compromised. Taking into account that our patients over the past 20 years have been progressively less extensively burned and hence have a lesser at risk for death, survival following severe burns has continued to improve.