• Freezing injury, or “frostbite,” is the development of cold injury in which tissues actually become frozen, with crystallization (ice formation) of tissue and cell water. Frostbite is seen at environmental temperatures below 32° F and primarily affects the distal extremities, ears, nose, scrotum, and tail. Frostbite varies in severity from superficial (1st degree frostbite) to deep injury (4th degree frostbite).
  • Clinical signs of superficial frostbite (1st and 2nd degree frostbite) include a grey-to-white, waxy appearance of affected skin; blistering of affected skin may be present with 2nd degree frostbite. Clinical signs of deep frostbite (3rd and 4th degree frostbite) include involvement of the entire epidermis, but no subcutaneous tissues (3rd degree) to involvement of subcutaneous tissues, to possibly include muscle and bone (4th degree frostbite). Tissues affected with deep frostbite may be black and friable. In all cases of frostbite, pain may be intense, especially during rewarming of tissues.
  • Management of MWDs with freezing injury is summarized in Table 14. Treatment of frostbite involves rapid warming of affected tissues, overall patient management (e.g., treatment of whole-body hypothermia, trauma, or shock as appropriate), analgesia, and protection of affected tissues.
  • Affected tissues may be warmed by immersion in a water bath that is 104-108° F for at least 20 minutes or until thawing has occurred, or by wrapping the affected tissue with warm, wet towels for 15 to 20 minutes, changing the towels every 5 minutes.
    • Do not use dry heat to warm tissues, and never rub or massage the tissues, as further injury may occur.
    • Provide systemic analgesia (See CPG 16), as frostbite is extremely painful.
    • Protect the affected tissues by applying loose protective bandages, minimizing movement (confine to a cage), and attaching a bucket-collar device (See Figure 21 and Figure 22) to prevent self-trauma.
    • Antibiotic use is not recommended.
    • Aseptically aspirate large blisters that develop.

 

Table 14.  Management of Freezing Injury (Frostbite) in MWDs

Table 14.  Management of Freezing Injury (Frostbite) in MWDs