The moorLDI2-BI (Moor Instruments Ltd) is a laser doppler blood flow imaging system for the non-invasive mapping of blood flow in an area of skin that has been burned. This can be used in addition to clinical evaluation to guide decisions about the need for surgical treatment of burn wounds.
The moorLDI2-BI includes a scan head, scan controller and a touch-screen panel computer, all mounted on a mobile stand that can be used in a ward, operating theatre or consulting room as well as in rooms designed specifically for laser equipment.
The moorLDI2-BI uses a low-power laser beam, directed at the burn wound using a mirror. The laser beam scans across the burn wound by rotating the mirror and there is no direct contact with the burned skin. Laser light scattered from moving blood cells in the tissue undergoes a doppler frequency shift, proportional to the average speed of the blood cells. Some of the scattered laser light is focused onto photodiode detectors and the resulting photocurrent is processed to calculate the blood flow in the tissue. Results are displayed as a colour-coded blood flow image and a colour video image of the burn wound. Depending on the size of the burn wound and required resolution of the image, the scan takes from 80 seconds to about 5 minutes. Healing potential results based on the blood-flow image are calculated and reported in three categories: less than 14 days, 14 to 21 days and more than 21 days.
The moorLDI2-BI can be purchased at a cost of approximately £53,942 with an annual servicing cost of approximately £8,301, or it can be leased at an inclusive cost of approximately £22,000 per year. [2017]
Current provision for inpatient treatment of burn injuries within England and Wales, based on the recommendation of the National Burn Care Review, is by specialised burn care services which consist of burn centres, burn units and burn facilities.
The assessment of burn wound depth and healing potential is fundamental in planning burn wound management. An experienced clinician can easily identify a burn that is epidermal and will heal without surgery, or a full thickness burn that requires surgical excision and grafting. However, it is often difficult to distinguish the superficial dermal burns that will heal well, from deep dermal burns, when a prolonged healing time will result in hypertrophic scarring (when the scar is swollen and red). It is difficult to assess burn wound depth and healing time in children because of the prevalence of mixed-depth scald burns and their thin skin.
Diagnosis of burn wound depth and healing potential is also difficult in patients with dark skin (including those with suntan, birthmarks or tattoos). Identifying the level of burn injury can be complicated by other factors such as oedema, tissue hypoxia and burn wound conversion, when superficial burns progress into deeper wounds because of the death of severely injured cells.
Clinical evaluation is the most widely used method of assessing burn wound depth and healing potential. This method is based on visual and tactile assessment of the external characteristics of the burn. The accuracy of clinical examination depends on the experience of the clinician. Other less widely used methods such as thermography and fluoroscein injections are also available for burn wound assessment.
The surgical procedure for treatment of burn wounds usually involves removing the damaged skin (using excision or debridement) followed by skin grafting. Skin grafting is the transplantation of skin from a healthy part of the body. This procedure is used for deep dermal wounds because it reduces the wound healing time and wound complications. Even after excision and skin grafting there will be scarring, and hypertrophic scarring may occur.