Burns

Assessing antibacterial efficacy of a polyhexanide hydrogel versus alginate-based wound dressing in burns

OBJECTIVE

Burn injuries pose a heightened risk of infection, which is primarily responsible for increased morbidity and mortality. Factors such as extensive skin damage and compromised immunity exacerbate this vulnerability. Pseudomonas aeruginosa and Staphylococcus aureus are frequently identified in burns, with Gram-negative Pseudomonas aeruginosa often resistant to antibacterial agents. While Flaminal, an alginate-based wound dressing (Flen Health, Belgium), aids wound healing, its antibacterial effects are limited compared with 1% silver sulfadiazine (1% SSD). In contrast, Prontosan Wound Gel X, a betaine and polyhexanide-based hydrogel (B. Braun Medical AG, Switzerland), has been shown to effectively combat various microbes and promotes wound healing.

METHOD

In this study, two research cohorts were retrospectively established (control group: patients receiving standard of care with the alginate-based wound dressing; intervention group: patients receiving the polyhexanide hydrogel wound dressing), comprising patients admitted to a burn centre between 2019 and 2022. Patients were eligible when continuous wound treatment with either of the two wound dressings was performed. Laser Doppler imaging (LDI) scans were conducted. Regions of interest (ROIs) were selected based on LDI scans and divided into healing time categories. Wound swabs were collected and the presence of Pseudomonas aeruginosa and Staphylococcus aureus was documented. Bacterial load was evaluated using a semiquantitative scale. Wound healing was recorded.

RESULTS

The control group consisted of 31 patients with 93 ROIs, while the intervention group had 67 ROIs involving 29 patients. Both groups exhibited similar proportions of healing time categories (p>0.05). The polyhexanide hydrogel dressing outperformed the alginate-based dressing in antiseptic efficacy by significantly reducing the incidence of Pseudomonas aeruginosa- and Staphylococcus aureus-positive cultures in patients' wounds. Wound healing time for conservative treatment was comparable between groups.

CONCLUSION

In this study, the polyhexanide hydrogel dressing minimised Pseudomonas aeruginosa and Staphylococcus aureus colonisation in burn wounds, demonstrating strong antibacterial properties, emphasising its potential to minimise infections in burn injuries.

Radiation dermatitis, burns, and recall phenomena: Meaningful instances of immunocompromised district

Ionizing and ultraviolet radiations, as well as burns, can selectively damage and immunologically mark the cutaneous area they act on through direct and indirect mechanisms. After the causal event has disappeared, the affected skin district may appear clinically normal, but its immune behavior is often compromised forever. In fact, irradiated or burned skin areas undergo a destabilization of the immune control, which can lead to either a reduction of immunity (as suggested by the facilitated local occurrence of tumors and infections) or an excess of it (as suggested by the possible local onset of disorders with exaggerated immune response). In other words, these areas become typical immunocompromised districts (ICD). Also, in recall phenomena the damaged skin area usually behaves as an ICD with an exaggerated immune response toward a wide range of drugs (especially chemotherapeutic agents) that prove to be harmless on the undamaged skin surface. The occurrence of any skin disorder on an irradiated, photoexposed, or burned skin area can be defined as an isoradiotopic, isophototopic, or isocaumatopic response, respectively; however, the opposite may also occur when elsewhere generalized cutaneous diseases or eruptions selectively spare irradiated, photoexposed, or burned skin sites (isoradiotopic, isophototopic, and isocaumatopic nonresponse, respectively). The pathomechanisms involved in any secondary disorder occurring on irradiated or burned skin areas may be linked to locally decreased or altered lymph flow (with dysfunction of lymph drainage) on the one hand, and to fibrotic throttling or reduction of peptidergic nerve fibers (with dysfunction of neuroimmune signaling) on the other hand, resulting in a significant dysregulation of the local immune response. Future clinical observations and experimental investigations on radiation dermatitis, sunburns, and thermal or chemical skin injuries should shed new light on the mechanisms regulating regional resistance to infectious agents, local oncogenesis, and district propensity to dysimmune reactions.

A reappraisal of the role of cerium in burn wound management

A rare earth element, cerium, was introduced as an antibacterial agent in 1976 but has rarely been used due to the emphasis on wound excision. Used in combination with silver sulphadiazine, it may improve patient survival when excision is not possible.