Human model of burn injury that quantifies the benefit of cooling as a first aid measure.

BACKGROUND: Burn injuries are a major cause of morbidity and mortality worldwide. Cooling is widely practised as a first aid measure, but the efficacy of cooling burns in human skin has not been demonstrated. A safe, consistent, ethically acceptable model of burning and cooling in live human skin in vivo was developed, and used to quantify the effects of cooling. METHODS: Novel apparatus was manufactured to create and cool burns in women who were anaesthetized for breast reconstruction surgery using a deep inferior epigastric artery perforator flap. Burns were excised between 1 and 3 h after creation, and analysed using histopathological assessment. RESULTS: All 25 women who were approached agreed to take part in the study. There were no adverse events. Increased duration of contact led to increased burn depth, with a contact time of 7·5 s at 70°C leading to a mid-dermal burn. Burn depth progressed over time following injury, but importantly this was modified by cooling the burn at 16°C for 20 min. On average, cooling salvaged 25·2 per cent of the dermal thickness. CONCLUSION: This study demonstrated the favourable effects of cooling on human burns. Public heath messaging should emphasize cooling as first aid for burns. This model will allow analysis of the molecular effects of cooling burns, and provide a platform for testing novel therapies aimed at reducing the impact of burn injury.

ANTECEDENTES: Las lesiones por quemadura son una causa importante de morbilidad y mortalidad en todo el mundo. El enfriamiento de las quemaduras se practica ampliamente como medida de primeros auxilios, pero no se ha demostrado su eficacia en la piel de los seres humanos. Para cuantificar los efectos del enfriamiento, se desarrolló un modelo de quemadura y enfriamiento en piel humana in vivo, seguro, estable y éticamente aceptable. MÉTODOS: Se construyó un dispositivo nuevo para crear y enfriar quemaduras en pacientes que fueron anestesiadas para una reconstrucción mamaria utilizando un colgajo perforante de la arteria epigástrica inferior profunda. Las quemaduras se extirparon entre una y tres horas después de su producción y se analizaron por evaluación histopatológica. Para determinar la significación estadística entre grupos se utilizó las pruebas de ANOVA o de t pareadas, según correspondiera. RESULTADOS: Aceptaron participar en el estudio las 25 pacientes a las que se propuso. No hubo efectos adversos. La mayor duración del contacto conllevó un aumento en la profundidad de la quemadura: con un tiempo de contacto de 7,5 segundos a 70°C se obtuvo una quemadura dérmica de segundo grado. La profundidad de la quemadura aumentó con el tiempo de exposición, pero mejoró de forma sustancial al enfriar la quemadura a 16°C durante 20 minutos. El enfriamiento salvó el 25% del espesor dérmico como promedio. CONCLUSIÓN: Este es el primer estudio que demuestra los efectos favorables del enfriamiento sobre las quemaduras humanas. Los consejos de salud deberían hacer más énfasis en el enfriamiento como forma de primeros auxilios en las quemaduras. Este modelo permitirá identificar los efectos moleculares del enfriamiento en las quemaduras y proporcionará una plataforma para probar nuevos tratamientos encaminados a reducir el impacto de las lesiones por quemadura.

Cooling of burns: Mechanisms and models.

The role of cooling in the acute management of burns is widely accepted in clinical practice, and is a cornerstone of basic first aid in burns. This has been underlined in a number of animal models. The mechanism by which it delivers its benefit is poorly understood, but there is a reduction in burns progression over the first 48 h, reduced healing time, and some subjective improvements in scarring when cooling is administered after burning. Intradermal temperature normalises within a matter of seconds to a few minutes, yet the benefits of even delayed cooling persist, implying it is not simply the removal of thermal energy from the damaged tissues. Animal models have used oedema formation, preservation of dermal perfusion, healing time and hair retention as indicators of burns severity, and have shown cooling to improve these indices, but pharmacological or immunological blockade of humoural and cellular mediators of inflammation did not reproduce the benefit of cooling. More recently, some studies of tissue from human and animal burns have shown consistent, reproducible, temporal changes in gene expression in burned tissues. Here, we review the experimental evidence of the role and mechanism of cooling in burns management, and suggest future research directions that may eventually lead to improved treatment outcomes.

Guidelines for the excision of cutaneous squamous cell cancers in the United Kingdom: the best cut is the deepest.

Surgical excision remains the gold standard for the management of cutaneous squamous cell cancers (SCC) and national guidelines for operative radial margins predict 95% oncological clearance with a margin of 4 mm for low-risk and 6 mm for high-risk tumours. We retrospectively analysed all cutaneous SCC excisions performed across 4 regional Plastic surgical units in England over a consecutive 24-month period and collected data on tumour characteristics, operative and histological margins and completeness of excision. We identified 633 eligible SCC excisions of which 265 (42%) were over 2 cm in diameter with 37 recurrent tumours (5.8%). The mean radial operative margin was 6.5 mm across all tumours and 8.4 mm for tumours greater than 2 cm. The mean histological tumour diameter was 21 mm. The overall incomplete excision rate was 7.6% (7.9% for tumours >2 cm). Ninety-four percent (45/48) of incomplete excisions involved the deep margin and only 3 out of 633 excisions (0.47%) were incomplete at a radial margin only. No differences were observed in tumour size or excision margin between incompletely and completely excised tumours. Incomplete excisions were most common on the ear, nose and cheek. In summary our analysis demonstrates that despite adherence to recommended surgical margins for cutaneous SCCs the incomplete excision rate remains higher than expected. We believe that this is because most incomplete excisions are incomplete at the deep margin and question the utility of performing increasingly wide excisions, and, the generalisability of the evidence upon which recommendations for radial margins are based.

Serum complement-reactive protein (CRP) trends following local and free-tissue reconstructions for traumatic injuries or chronic wounds of the lower limb.

BACKGROUND: Soft-tissue reconstructions of the lower limb for open fractures, chronic infections and nonunion carry a high risk of infection, nonunion, osteomyelitis and amputation. Inflammatory markers can be difficult to interpret in the context of recent surgery and trauma and little is known of their behaviour. AIM: To profile the behaviour of complement-reactive protein (CRP) following soft-tissue reconstructions for the lower limb performed for acute injuries(open fractures) and chronic wounds(nonunion and osteomyelitis). PATIENTS AND METHODS: Patients who had soft-tissue reconstructions following open fractures of the lower limbs, chronic infection, osteomyelitis and nonunion were identified and their notes and postoperative CRP levels reviewed. RESULTS: 52 patients were identified. 41 reached peak CRP < or =4 days of surgery. A peak CRP >4 days indicated infection or further surgery (p<0.01). Acute and chronic groups showed a peak in mean CRP at day 2. Chronic wound patients showed significantly elevated CRP levels compared to acute wound patients at day 7 (p=0.05) and 8 (p<0.001). Muscle and fasciocutaneous flaps showed similar CRP profiles. Patients with nonunion or deep infections showed persistently elevated CRP levels. CONCLUSIONS: CRP peaks on day 2 following soft-tissue coverage and falls thereafter. Peaks after day 4 indicate infective complications or further surgery. Patients with chronic wounds show a slower decrease in their CRP. Persistently elevated CRP following surgery is associated with infection and nonunion.

Functional and oncological outcomes after limb-salvage surgery for primary sarcomas of the upper limb.

The surgical treatment of upper limb sarcoma poses an oncological and reconstructive challenge. Limb-salvage surgery aims to balance adequate excision margins for disease control and preservation of all important structures to retain maximum function. Reported here is an assessment of the functional and oncological outcomes of limb salvage surgery for primary sarcoma of the upper limb and limb girdle in 72 patients referred to a specialist musculoskeletal tumour unit over 9 years. All patients underwent excision of the sarcoma with reconstruction and adjuvant treatment as needed. Functional outcome was assessed using the Toronto Extremity Salvage Score (TESS) after discharge from hospital. The upper limb sarcomas treated by limb-salvage surgery achieved planned margins of excision in 85% of cases with primary surgery. This increased to 100% with re-excision, resulting in local recurrence in 15% and survival of 75% among those at 5 years or more after surgery, while retaining good to excellent function (TESS mean of 87 out of 100). A total of 38 patients completed TESS questionnaires and, as a single group, had a mean TESS of 87. Patient age, anatomical site of tumour and adjuvant treatment made no significant difference to TESS. Liposarcomas had a significantly better TESS than leiomyosarcomas, chondrosarcomas and malignant peripheral nerve sheath tumours. Oncological outcome was assessed in terms of excision margins achieved, local recurrence, re-excision and disease-free survival. Eight patients died of disease, all with high-grade primary tumours. Fourteen had local recurrence, four low-grade disease and the remaining high-grade disease. All four low-grade recurrences were successfully re-excised, as were five of the high-grade recurrences. The remaining five died of disease, with or without further recurrences. Consistently good functional results as measured by TESS were reported by responders, but high-grade disease and early recurrence were identified as predictors of recurrence and death from disease, respectively.

The problem of toxic chemical wastes and their deposition in Developing Countries

This paper examines the nature and origin of toxic wastes that eventually find themselves in the environment - the land; sea; acean and the atmosphere. It discusses the problems of waste accumulation; waste treatment and waste disposal in both the industrialised and the developing countries and highlights the adverse effects on plants; animals and human lives of these toxic chemicals. The socio-economic and other factors; which make developing countries targets for the dumping exercises; are highlighted and strategies for combatting such activities are proposed. In conclusion the paper makes general recommendations on environmental issues; stressing the seriousness of the specific hazardous effects of selected types of toxic chemicals and also of substances which on their own; can decompose to yield toxic principles when subjected to atmosphere or microbial interactions