Management of 3rd-degree Burns 三度烧烫伤的治疗

There are four factors that determine the depth of a burn: temperature of the contacting agent, duration of contact, thickness of skin and local blood supply. The threshold for a burn injury is around 43.5 degree C (110 degree F). Water at 66 degree C (150 degree F) will cause a full-thickness burn in only 2 seconds.

Any burn that does not penetrate the epidermis is considered to be a first-degree burn. Since the barrier is intact, the burn is dry and red. Minimal treatment (analgesia and moisturizer) or no treatment is required, and healing is very rapid.

A second-degree, or partial-thickness, burn penetrates into but not through the dermis. Because the epidermal barrier is lost, the wound forms a blister or, if uncovered, weeps interstitial fluid. Since the dermal plexus of vessels and nerves is intact, the wound will blanch with pressure and the pain will be severe.

A third-degree, or full-thickness, burn completely destroys the dermis and enters the fat.

Fourth-degree burns extend into muscle, bone, or tendon and need to be treated in burn centers, since they may require flaps or amputations.

Burn 3degree 6

A third-degree, or full-thickness, burn completely destroys the dermis and enters the fat. Since all the vasculature and nerves of the dermis are destroyed, there is no blanching and the burn is much less painful than a second-degree burn. The wounds can be any color and are drier than more superficial burns.

The local response to a burn is similar to any other injury. Cellular damage leads to release of local mediators that lead to vasodilation and increased permeability causing local edema that is proportional to the extent of injury. Once a burn exceeds 20% TBSA, a system-wide capillary leak occurs that leads to massive fluid shifts that, unless treated, may lead to death from hypovolemia.

Burn 3degree F

有四个因素决定烧伤的深度：接触剂的温度，接触的持续时间，皮肤的厚度和局部血液供应。烧伤的阈值约为43.5摄氏度（110华氏度）。 66摄氏度（150华氏度）的水会在2秒内造成全皮厚度烧伤。

任何不穿透表皮的烧伤都是一度烧伤。由于表皮屏障是完整，皮损处是干燥和红色的。只需要镇痛和保湿或者不需治疗，伤口愈合非常迅速。

二度烧伤渗入但不穿透真皮。由于表皮屏障丢失，伤口形成水疱，间质液流出。由于血管和神经的真皮丛是完整的，伤口会因压力而变白，疼痛会很严重。

三度烧伤完全破坏真皮并进入脂肪层。由于所有的血管系统和真皮神经被破坏，烧伤比二级烧伤疼痛少得多。伤口可以是任何颜色的，比浅表烧伤更干燥。

四度烧伤延伸到肌肉，骨骼或肌腱，需要在烧伤中心进行治疗，因为它们可能需要植皮或截肢。

三度烧伤完全破坏真皮并进入脂肪。由于所有的血管系统和真皮神经被破坏，烧伤比二级烧伤疼痛少得多。伤口可以是任何颜色的，创面比浅表烧伤更干燥。身体体对烧伤的局部反应与任何其他伤害反应相似。 细胞损伤导致局部介质的释放，从而导致血管舒张和血管通透性增加，引起与损伤程度成比例的局部水肿。 一旦烧伤超过身体体表面积的20％以上，就会发生系统范围的毛细血管渗漏，导致大量的液体转移，除非经过治疗，否则可能导致血容量不足致死。

Wound_healing_phases

Reference:

  1. Greenhalgh DG, Lawless MB, Chew BB, Crone WA, Fein ME, Palmieri TL. Temperature threshold for burn injury: An oximeter safety study. J Burn Care Rehabil 2004;25:411-5.
  2. Moritz AR, Henriques FC Jr. Studies of thermal injury. II. The relative importance of time and surface temperature in the causation of cutaneous burns. Am J Pathol 1947;23:695-720.
  3. David G. Greenhalgh. Management of Burns. N Engl J Med 2019;380:2349-59. DOI: 10.1056/NEJMra1807442.
  4. Demling RH. The burn edema process: current concepts. J Burn Care Rehabil 2005;26:207-27.
  5. Alvarado R, Chung KK, Cancio LC, Wolf SE. Burn resuscitation. Burns 2009;35:4-14.