R. W. Lewis

Predicting survival in an elderly burn patient population

The purpose of this study was to analyze the outcome of elderly burn victims and to determine an instrument to predict survival in this population. Charts of three hundred and eight burn patients > or =60 yr of age who were admitted to a university-based hospital between the years of 1977-1996 were retrospectively analyzed. The mean age of the population was 71.5+/-8.6, with a male predominance (1.8 to 1, P < 0.001). The majority of the burns were secondary to flame injuries (210, 68.6%). The median body surface area (BSAB) was 13.0% with an in-hospital mortality rate of 30.2%. We demonstrated improved survival in patients aged 60-74 yr as compared to 1965-1971 national burn survival data. A similar trend could not be shown in the very old (> 75 yr of age). Only age and BSAB were related to death by multiple stepwise forward linear regression. The Baux score, which adds age and BSAB, was predictive of outcome in 87.0% of our population. In conclusion, this study reinforces the high mortality associated with burn injuries in the elderly and the superior ability of the Baux score (age + percent burn) in predicting outcome in this population.

Prospective, randomized study of the efficacy of pressure garment therapy in patients with burns

A randomized, prospective study was undertaken to determine the efficacy of pressure garment therapy in patients with burns. Patients were randomly assigned to receive either pressure garment therapy or no pressure garment therapy. Patients were observed by use of the Vancouver Burn Scar Assessment Scale to assess the maturity of all involved areas. One hundred and twenty-two consecutive patients were enrolled in the study; 64 were assigned to pressure garment therapy and 58 to no pressure garment therapy. Eight of the patients receiving pressure garment therapy and nine receiving no pressure garment therapy were not involved in the follow-up. No significant differences were found between the two groups when age, body surface area burn, length of hospital stay, or time to wound maturation were compared.

Prospective Randomized Comparison of Two Types of Pressure Therapy Garments

A prospective randomized study was undertaken to compare compliance efficacy and cost of the elastic nylon pressure garment (Jobst Institute, Inc., Toledo, Ohio) with the cotton elastic pressure garment (Tubigrip, SePro Healthcare Inc., Montgomeryville, Penn.). Of 110 patients enrolled, 54 received Jobst pressure garments and 56 received Tubigrip pressure garments. Time spent in pressure-therapy garments was the same for both groups. Comparable clinical results were achieved with either Tubigrip or Jobst garments. A significantly greater percentage of patients were compliant with Tubigrip pressure-garment therapy than with Jobst pressure-garment therapy. The cost of the Tubigrip garments was significantly lower than that of Jobst garments. These data suggest that the use of elasticized cotton pressure garments results in significantly better patient compliance, a lower cost, and equal therapeutic efficacy when compared with the elasticized nylon pressure garments.

Our chemical burn experience: exposing the dangers of anhydrous ammonia.

Although chemical injuries account for only a small number of one burn units cases, the diversity, resulting complications, and sequelae of these burns pose special problems. We reviewed a 19-year period of the chemical burn experience of our burn unit. The population of patients with these types of burns consisted of young men (mean age: 29.8 years), the majority of whom were injured on the job. Unique to our series is the largest collection of injuries (30%) resulting from the common fertilizer anhydrous ammonia. Another population of concern, accounting for 14% of the injuries in our unit, is that of patients injured at home with routine household cleaners. Nearly one half of those patients injured at home incurred injuries that required grafting. The cornerstone of chemical burn prevention and treatment involves education regarding the caustic nature of chemicals, proper handling, adequate protection, and copious irrigation of the wound at the scene. From the analysis of our retrospective review, adequate education and treatment at the scene appear to be well implemented in the industrial and farming communities. The focus of our education efforts should be directed toward the public and emphasize the safe use of household chemicals. Finally our review illuminated the potential benefit of immediate excision and grafting for decreasing the length of stay, complications, and loss of productivity.

A prospective safety study of femoral vein versus nonfemoral vein catheterization in patients with burns.

A prospective study was undertaken to determine the safety of femoral vein catheterization in patients with burns. Forty-two patients had a total of 275 catheterizations and were divided into two groups: group 1, femoral vein catheterization = 80 catheters and group 2, nonfemoral vein catheterization = 195 catheters (180 subclavian, 8 internal jugular, and 7 supraclavicular). All catheters were changed to new sites every 48 hours, and dressings were changed every 24 hours. Bacteriologic surveillance was accomplished by submitting the tip and subcutaneous segment of the catheter for semiquantitative cultures. Skin exit-site cultures were obtained, and blood was drawn through the catheters for fungal-isolator cultures before removal. Catheter colonization was defined as greater than or equal to 5 colony-forming units on either the subcutaneous segment or the catheter tip. Catheter-related sepsis was diagnosed when the same organism was recovered from the fungal isolator bottle and either part of the catheter and when there was no other identifiable source of sepsis. The rate of occurrence of colonized catheters was 7.5% (6 of 80) in the femoral vein catheterization group and 13.8% (27 of 195) in the nonfemoral vein catheterization group. Catheter-related sepsis occurred in 2.5% (2 of 80) of femoral and 1% (2 of 195) of nonfemoral catheters. None of these differences are statistically significant. There were no noninfectious complications from femoral vein catheterization. Two subclavian catheters had to be repositioned. This study suggests that central venous access in patients with burns can be safely employed with the use of the femoral vein.

An experimental study to determine the effects of Dermagraft* on skin graft viability in the presence of bacterial wound contamination

Dermagrafts (Advanced Tissue Science, La Jolla, Calif.) is a possible dermal substitute currently in early stages of clinical trials. It consists of polyglycolic acid mesh impregnated with viable, human, neonatal fibroblasts. The randomized prospective study with the mouse model was undertaken to determine the effect of Dermagraft on skin graft viability in the presence of wound contamination with controlled concentrations of commonly encountered burn wound pathogens. Appropriate controlled series were run concurrently. Placement of Dermagraft, or polyglycolic acid mesh, had no significant effect on skin graft viability when compared with simple skin grafts. Controlled bacterial contamination of skin grafts with Dermagraft did not significantly change the occurrence of graft viability when compared with control groups of skin grafts with controlled bacterial contamination. These studies suggest that Dermagraft does not increase the occurrence of graft loss in the face of wound bed contamination.

A study of functional viability and metabolic degeneration of human skin stored at 4° C

We sought to ascertain whether an in vitro assay could be as reliable as an in vivo assay in determining the viability of human skin stored at 4 degrees C. Allografts from six human donors were stored in RPMI 1640 tissue culture medium at 4 degrees C. At fixed intervals during the storage period, all skin specimens were tested concurrently by two different viability assays: (1) transplantation onto surgically created defects on nude mice, and (2) intracellular enzyme activity with use of a 4-hour semiquantitative micromethod system activity (API ZYM; Biomerieux Vitek Inc., Hazelwood, Mo.). Human graft survival on the nude mice was 100% for the first 15 days of storage, and then declined to 50% on storage day 30. The API ZYM assay showed a comparable progressive decrease in enzyme activity over skin storage time. The API ZYM assay is a simple, rapid system that produces reproducible results and is cost-effective when compared to the biologic model.

A retrospective study of the incidence and prevalence of thermal corneal injury in patients with burns

The clinical course of thermal corneal injuries is not well described. A review of 1750 burn admissions to a regional burn center between 1979 through 1993 was done to determine the clinical course of thermal corneal injuries. Twenty-five out of 1750 burn admissions (1%) presented with a thermal corneal injury. Corneal injuries were identified with use of a fluorescein dye and a Woods lamp. Ophthalmologic consultation was obtained for those identified. Data were analyzed with the Fishers exact test and the unpaired two-tailed Students t test. Patients with thermal corneal injury did not differ demographically from other patients with burn injury. Open-flame burns were the most common cause of injury. Improvement of corneal injury occurred in all survivors who had an intact globe on initial examination. Initial visual acuity was not a good predictor of outcome, and long-term complications were uncommon.

Value of the Candida antigen assay in diagnosis of systemic candidiasis in burn patients.

The Cand-tec latex agglutination test was used to analyze 2,575 serum samples from 47 consecutive burn patients at risk for systemic candidiasis and serum samples from 24 nonhospitalized control subjects. One burn patient had systemic candidiasis documented by culture of a deep biopsy specimen. In addition, blood culture produced positive results in one patient with no other evidence of systemic candidiasis. Wound, sputum, mucous membrane, or gastrointestinal tract specimens were cultured in 25 of 47 (53%) patients with no evidence of systemic candidiasis. Surveillance cultures were negative in 19 (40%) patients and there were no signs of systemic candidial infection. The sensitivity of the Candida antigen titer was 100% at titers of greater than or equal to 1:2, greater than or equal to 1:4, greater than or equal to 1:8, and greater than or equal to 1:16. Specificity was 77% at titers of greater than or equal to 1:4, 94% at titers of greater than or equal to 1:8, and 100% at titers of greater than or equal to 1:16. The positive predictive value ranged from 6.0% at greater than or equal to 1:4 to 100% at greater than or equal to 1:16. The negative predictive value was 100% for all titer values. The Cand-tec antigen test shows poor specificity and poor positive predictive value for the detection of systemic candidiasis in burn patients.

Effectiveness of universal screening for vancomycin-resistant enterococcus and methicillin-resistant Staphylococcus aureus on admission to a burn-trauma step-down unit.

Vancomycin-resistant enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) are significant healthcare-associated pathogens. We sought to identify factors that could be used to predict which patients carry or are infected with VRE or MRSA on admission so that we could obtain cultures selectively from high-risk patients on our burn-trauma unit. We conducted a case–control study of patients admitted to our burn-trauma unit from September 2000 to March 2005 who were colonized or infected with either VRE or MRSA (cases) and patients who were not colonized or infected with one of these organisms (controls). We used logistic regression to construct a model that we subsequently validated based on data collected prospectively from patients admitted from September 2006 to August 2007. In the case–control study, colonization or infection with MRSA or VRE on admission were independently associated with the total days of antimicrobial treatment, age, prior hospitalization, prior operations, and admitting diagnosis (admission for a burn injury was protective). In the cohort study, a prior hospitalization with a length of stay ≥7 days and operations within the past 6 months were significantly associated with colonization or infection on admission. The latter model was 59.3% sensitive. If, we used this model to identify which patients should be cultured on admission, we would have missed 24 (39.3%) of the colonized or infected patients. These patients would not have been placed in isolation (434 missed isolation days, 71.0%) and may have been the source of transmission to other patients. Our model lacked the sensitivity to identify patients colonized or infected with VRE or MRSA. We recommend that units, which care for patients who are at high risk of hospital-acquired infection and having prevalence and transmission rates of VRE or MRSA similar to those in our study, screen all patients for these organisms on admission to the unit.