Novel insights into negative pressure wound healing from an in situ porcine perspective.

Negative pressure wound therapy (NPWT) is used clinically to promote tissue formation and wound closure. In this study, a porcine wound model was used to further investigate the mechanisms as to how NPWT modulates wound healing via utilization of a form of NPWT called the vacuum-assisted closure. To observe the effect of NPWT more accurately, non-NPWT control wounds containing GranuFoam™ dressings, without vacuum exposure, were utilized. In situ histological analysis revealed that NPWT enhanced plasma protein adsorption throughout the GranuFoam™, resulting in increased cellular colonization and tissue ingrowth. Gram staining revealed that NPWT decreased bacterial dissemination to adjacent tissue with greater bacterial localization within the GranuFoam™. Genomic analysis demonstrated the significant changes in gene expression across a number of genes between wounds treated with non-NPWT and NPWT when compared against baseline tissue. However, minimal differences were noted between non-NPWT and NPWT wounds, including no significant differences in expression of collagen, angiogenic, or key inflammatory genes. Similarly, significant increases in immune cell populations were observed from day 0 to day 9 for both non-NPWT and NPWT wounds, though no differences were noted between non-NPWT and NPWT wounds. Furthermore, histological analysis demonstrated the presence of a foreign body response (FBR), with giant cell formation and encapsulation of GranuFoam™ particles. The unique in situ histological evaluation and genomic comparison of non-NPWT and NPWT wounds in this pilot study provided a never-before-shown perspective, offering novel insights into the physiological processes of NPWT and the potential role of a FBR in NPWT clinical outcomes.

Reimbursement for out-of-state burn patients is not always lower than that for in-state patients at regional burn centers.

Because burn care in the United States is regionalized, burn patients are often transported across state lines to receive their burn treatment. The authors hypothesized that there are differences between in-state and out-of-state reimbursement for burn care. This project was conducted by the American Burn Association (ABA) Government Affairs Committee through the ABA Multicenter Trials Group. Participation was open to any member of the ABA. This retrospective observational study was approved by the institutional review boards of each participating institution. Subjects were identified using registry of each site, selecting patients hospitalized for burn injuries during FY2004-FY2006 of the hospitals. Once identified by the registry, the ID numbers were used to collect billing and reimbursement data from the financial offices. Data were sorted by age (adult and pediatric), location (in state and out of state), and payor source (Medicare, Medicaid, commercial, workers compensation, and self-pay). The rate of reimbursement was calculated based on charges and recoveries. Comparisons on data of each center were performed using Student's t-test with type I error <1%. Six facilities contributed data. A total of 4850 burn patients were reviewed, of whom 3941 were in-state burn patients and 909 were out-of-state burn patients. When the results from all six states were analyzed together, reimbursement for adults from Medicaid and Medicare was higher for in-state patients than for out-of-state patients. However, when analyzed by state, Medicare reimbursement between in-state and out-of-state patients did not differ significantly. In one state (Kansas), in-state Medicaid reimbursement was higher, but in two others (Arizona and Pennsylvania), in-state Medicaid reimbursement was lower than that for out-of-state reimbursement. Reimbursement for the care of children did not differ significantly based on state of residence. From these data, we conclude that there are indeed variations between in-state and out-of-state reimbursement, but those variations differ regionally. Indeed, in some cases, out-of-state reimbursement exceeds in-state reimbursement. Careful examination of these data is necessary before recommending policy change, although consideration should be given to a national policy that guarantees uniformity of reimbursement across all payors for burn patients regardless of their state of residence.

Incidence of cardiac events in burned patients.

Given the increased level of adrenergic stimulation in burn patients, it would be expected that they would experience an increased incidence of cardiac arrhythmias and other cardiac events. We performed a retrospective chart review of 56 acute burn patients matched by age, length of hospital stay, and sex to 56 trauma patients, all of whom had been continuously monitored electrocardiographically. Burn and trauma patients were similar in injury severity, admission laboratory values, and prior history of cardiopulmonary diseases. Arrhythmias were noted in 34% of burn patients and 28% of trauma patients. One myocardial infarction and six deaths occurred in burn patients. No myocardial infarctions or deaths were observed in trauma patients. A past history of cardiopulmonary disease increased the risk of myocardial infarction or death by 6.6 times. Cardiac arrhythmias and other events are relatively infrequent and benign in burn patients and are similar to those experienced by other patients with acute injuries.

Biomechanical failure of metacarpal fracture resorbable plate fixation.

Metacarpal fractures are a relatively common hand injury that may require operative intervention to ensure adequate reduction and stabilization. The use of permanent hardware, although acceptable, may lead to complications and an increased number of surgical procedures. The use of resorbable hardware such as poly-L-lactic acid and polyglycolic acid copolymer plates and screws may circumvent some of these complications. In vitro studies have demonstrated that the biomechanical characteristics of these resorbable plates may provide the rigid fixation necessary to allow for union of metacarpal fractures in vivo. However, limited clinical data are available regarding the success of their use in this application. The authors present what they believe is the first reported case of the failure of a poly-L-lactic acid and polyglycolic acid copolymer miniplate after use in the fixation of a metacarpal shaft fracture.

Mafenide acetate allergy presenting as recurrent chondritis.

Acute chondritis has a strong predilection for recurrence. Mafenide acetate has been implicated in causing reactions that mimic this condition; however, these hypersensitivity reactions lack fever, fluctuance, and pain. The authors report a case of mafenide acetate allergy presenting as recurrent chondritis in a patient who had previously been treated successfully for this condition. In this patient, the allergic response resolved within 3 days after cessation of mafenide acetate. If unappreciated, it may have led to unnecessary operative intervention. Therefore, auricular edema and erythema, without fever, fluctuance, and pain, must be recognized by surgeons as a possible mafenide acetate allergy and must be considered in the differential diagnosis for patients who present with recurrent acute suppurative chondritis.