A rapid section technique for burn wound biopsy

Burn Wound Sepsis

Wound sepsis remains perhaps the most feared sequela in the patient who has suffered major burn injuries and leads to overwhelming mortality among patients with extensive burn wounds. The presence of large areas of devitalized, necrotic tissue, coupled with the profound immunosuppression that usually follows major injury, sets the stage for rapid microbial proliferation in the wound; when microbes invade subjacent, previously vi able tissues, invasive burn wound sepsis is defined. Top ical antimicrobial drugs probably have only a limited effect in preventing wound sepsis, and organisms now frequently emerge that are resistant to the commonly used topical agents. Salient factors in the diagnosis and treatment of invasive wound sepsis are discussed in this review. Prevention of wound sepsis, however, is one of the primary objectives of current burn care. Early burn wound excision and immediate wound closure with autograft or a suitable biologic dressing has emerged as the best means for prevention of generalized wound sepsis.

The changing epidemiology of infection in burn patients

Topical chemotherapy, prompt excision, and timely closure of the burn wound have significantly reduced the occurrence of invasive burn wound infection and its related mortality. Since wound protection is imperfect and invasive wound infection may still occur in patients with massive burns in whom wound closure is delayed, scheduled wound surveillance and biopsy monitoring are necessary to assess the microbial status of the burn wound and identify wound infections caused by resistant bacteria or non-bacterial opportunists at a stage when therapeutic intervention can control the process. As a reflection of the systemic immunosuppressive effects of burn injury, infection remains the most common cause of morbidity and mortality even though the occurrence of wound infections has been significantly decreased. Pneumonia is the most frequent infection occurring in burn patients today but the improvements in patient management, wound care, and infection control have made bronchopneumonia the most common form of this infection and gram-positive organisms the most common causative agents. The organisms causing bacteremia that exert a species specific effect on the mortality related to extent of burn injury and patient age have changed in concert with changes in wound flora. Infection control procedures, including scheduled surveillance cultures, utilization of cohort patient care methodology, strict enforcement of patient and staff hygiene, and patient monitoring have been effective in eliminating endemic resistant microbial strains, preventing the establishment of newly introduced resistant organisms, diagnosing infection in a timely fashion, instituting antibiotic and other necessary therapy in a prompt manner, and documenting the effectiveness of present day burn patient care and the improved survival of burn patients.

Rapid quantification of bacterial and fungal growth in burn wounds: biopsy homogenate Gram stain versus microbial culture results

A prospective analysis of 370 burn wound biopsies was done to correlate Gram-stain results from biopsy homogenates with quantitative culture results. The number of bacteria seen in a total of 10 oil immersion microscope fields of Gram-stained homogenates was correlated with significant microbial growth (1 x 10(5) organisms/gram of tissue) of the same biopsy homogenate plated on trypticase soy agar. Of the biopsies examined, Gram-negative rods were present in 36.8 per cent, Gram-positive cocci in 49.7 per cent and yeast in 15.9 per cent. Mixtures of organisms were present in 24.3 per cent. When Gram stains showed one or more organisms per oil immersion microscope field, the correlation with significant microbial growth was 94.5 per cent or more. When five or more organisms were seen per field, the correlation with significant growth became 97 per cent or greater. When no organism was seen on Gram stain, the cultures grew significant numbers of organisms 19.1 per cent of the time or less. This false-negative rate was considered to be high. It is believed, however, that this method of early detection of significant burn wound microbial growth may prove to be valuable in the management of severely burned patients.