1. 1.17. The Mechanism of MEBT/MEBO for Relieving the Secondary Damage to the Burn Wound
    • 2010/10/15 10:41:57
    The pathological appearances of the deep burnt skin can be divided into three zones, which are: necrotic zone, stasis zone and congestion zone. The variation of the stasis zone on the brink of death affects the mode of wound healing. However, there are many factors affecting the recovery of the stasis zone after burn and damaging the wound continuously:
    1.       The progressive damage of heat
    The heat conduction of the necrotic skin decreases after burn. Moreover, heat exchange between the skin and the outer air cant be achieved because the sweat gland is damaged. However, the heat conductivity of the tissues beneath the necrotic tissues remains nearly at the normal level so the remnant heat will conduct to the inner layer to cause secondary heat injury.
    2.       The progressive ischemia and necrosis of the stasis zone
    The peripheral circulation doesnt relieve effectively after burn and the local metabolic products cant be discharged in time, which will cause the progressive ischemia and hypoxia that will lead to necrosis. And more over, the normal skin structures are damaged so that the moisture evaporation capacity on the burn increases sharply, which will promote the permeability of the capillary and the exosmose the blood plasma. In the end, the microcirculation obstacle will be aggravated.
    3.       The infection of the burn wound invades to the inner part
    The decomposed and rancid necrotic skin is the good culture for bacterium so the amount of bacterium increases exponentially. The bacterial content in the tissues beneath the scab will reach to 105/g in 48 hours without intervention. And the wound sepsis will invade the stasis zone and the normal tissues to produce large amount of toxins, which will lead to systemic toxaemia.
    4.       Improper iatrogenic treatment
    For traditional dry exposed therapy, cold treatment using cold water is adopted after burn. The burn wound baking to promote the crust formation will not only cause the secondary heat injury to the burn wound, but also the frequent contraction and expansion of the capillary aggravates the microcirculation obstacle that leads to the irreversible necrosis of the stasis zone. The complete debridement to the burn wound, the damage of the detergent to the wound, the rough operationthe non-in time dressing changing and hemorrhage are the iatrogenic reasons that will cause secondary damage to the burn wound. We must pay attention to it.
    Using MEBT/MEBO to treat burn wound, we can achieve:
    1.       Absorb the remnant heat of the burn wound
    The melting point of MEBO is low and the heat conductivity of it is stronger than normal skin tissue, so the direction of the heat flow changes. The remnant heat of the burn wound conducts to MEBO but not to the normal tissues. Heat absorbed MEBO melts, so that the proportion decreases. The melted MEBO floats on the burn wound to bring away the remnant heat to prevent the secondary heat damage.
    2.       Reduce the amount of moisture evaporation on the burn wound, and improve wound microcirculation of the zone of stasis in the early stages after burn[17-19]
    MEBO can keep the wound in a physiologically moist environment (See Q14, Part1), which will maximally reduce the amount of moisture evaporation on the burn wound to relieve the pachemia of the stasis zone. Further damage to the burn wound is prevented.   
    3.       Bacterium variation and the descended productivity occurs (See Q21, Part1)
    The research shows that the shapes of kinds of bacterium existed on the burn wound will vary under the action of MEBO, which will lower the productivity and the invasive power. Its very effective for local infection control at the early stage after burn.
    4. Standard application of MEBT/MEBO technique for local wound management as follows:
    a)         The early application of MEBO: it will get the best curative effects to apply MEBO immediately postburn or in 4 hours postburn.
    b)        Do not use water, desiccant or any simulative disinfector to debride wounds.
    c)        Follow Three No principles to apply MEBO: no pain on wounds, no bleeding and no injury to living tissues.
    d)        When apply MEBO, follow the growth direction of lanugo and avoid the contrary direction to avoid pain caused by spasm of arrectores pilorum.
    Using MEBO following the directions and the previously mentioned rules to relieve the secondary damage maximally and shorten the healing time of the burn wound is a necessity.