Rewarming of a localized area should only be considered if the risk of refreezing is unlikely. Avoid rubbing the frozen area which may cause further damage to the area (Grieve et al, 2011; Hallam et al, 2010).

Do not institute rewarming unless complete rewarming can be assured; refreezing thawed tissue increases tissue damage. Place affected area in a water bath with a temperature of 40 to 42 degrees Celsius for 15 to 30 minutes until thawing is complete. The bath should be large enough to permit complete immersion of the injured part, avoiding contact with the sides of the bath. A whirlpool bath would be ideal. Some authors suggest a mild antibacterial (ie, chlorhexidine, hexachlorophene or povidone-iodine) be added to the bath water. Tissues should be thoroughly rewarmed and pliable; the skin will appear a red-purple color (Grieve et al, 2011; Hallam et al, 2010; Murphy et al, 2000).

Correct systemic hypothermia which can cause cold diuresis due to suppression of antidiuretic hormone; consider IV fluids (Grieve et al, 2011).

Rewarming may be associated with increasing acute pain, requiring narcotic analgesics.

For severe frostbite, clinical trials have shown that pentoxifylline, a phosphodiesterase inhibitor, can enhance tissue viability by increasing blood flow and reducing platelet activity (Hallam et al, 2010).

Digits should be separated by sterile absorbent cotton; no constrictive dressings should be used. Protective dressings should be changed twice per day.

Perform twice daily hydrotherapy for 30 to 45 minutes in warm water at 40 degrees Celsius. This helps debride devitalized tissue and maintain range of motion. Keep the area warm and dry between treatments (Hallam et al, 2010; Murphy et al, 2000).

The injured extremities should be elevated and should not be allowed to bear weight.

In patients at risk for infection of necrotic tissue, prophylactic antibiotics and tetanus toxoid have been recommended by some authors (Hallam et al, 2010; Murphy et al, 2000).

Non-tense clear blisters should be left intact due to the risk of infection; tense or hemorrhagic blisters may be carefully aspirated in a setting where aseptic technique is provided (Hallam et al, 2010).

Further surgical debridement should be delayed until mummification demarcation has occurred (60 to 90 days). Spontaneous amputation may occur.

Analgesics may be required during the rewarming phase; however, patients with severe pain should be evaluated for vasospasm.

IMAGING: Arteriography and noninvasive vascular techniques (e.g., plain radiography, laser Doppler studies, digital plethysmography, infrared thermography, isotope scanning), have been useful in evaluating the extent of vasospasm after thawing and assessing whether debridement is needed (Hallam et al, 2010). In cases of severe frostbite, Technetium 99 (triple phase scanning) and MRI angiography have been shown to be the most useful to assess injury and determine the extent or need for surgical debridement (Hallam et al, 2010).

TOPICAL THERAPY: Topical aloe vera may decrease tissue destruction and should be applied every 6 hours (Murphy et al, 2000).

IBUPROFEN THERAPY: Ibuprofen, a thromboxane inhibitor, may help limit inflammatory damage and reduce tissue loss (Grieve et al, 2011; Murphy et al, 2000). DOSE: 400 mg orally every 12 hours is recommended (Hallam et al, 2010).

THROMBOLYTIC THERAPY: Thrombolysis (intra-arterial or intravenous thrombolytic agents) may be beneficial in those patients at risk to lose a digit or a limb, if done within the first 24 hours of exposure. The use of tissue plasminogen activator (t-PA) to clear microvascular thromboses can restore arterial blood flow, but should be accompanied by close monitoring including angiography or technetium scanning to evaluate the injury and to evaluate the effects of t-PA administration. Potential risk of the procedure includes significant tissue edema that can lead to a rise in interstitial pressures resulting in compartment syndrome (Grieve et al, 2011).

CONTROVERSIAL: Adjunct pharmacological agents (ie, heparin, vasodilators, prostacyclins, prostaglandin synthetase inhibitors, dextran) are controversial and not routinely recommended. The role of hyperbaric oxygen therapy, sympathectomy remains unclear (Grieve et al, 2011).

CHRONIC PAIN: Vasomotor dysfunction can produce chronic pain. Amitriptyline has been used in some patients; some patients may need a referral for pain management. Inability to tolerate the cold (in the affected area) has been observed following a single episode of frostbite (Hallam et al, 2010).

MORBIDITIES: Frostbite can produce localized osteoporosis and possible bone loss following a severe case. These events may take a year or more to develop. Children may be at greater risk to develop more severe events (ie, early arthritis) (Hallam et al, 2010).

2.2: Non-flammable compressed gas. See 49 CFR section 173.115 for definitions.

2.2: Non-Flammable Gas.

T50: Applicable liquefied compressed gases are authorized to be transported in portable tanks in accordance with the requirements of sxn. 173.313 of this subchapter.

Exceptions: 306

Non-bulk packaging: 304

Bulk packaging: 314, 315

Passenger aircraft or railcar: 75 kg

Cargo aircraft only: 150 kg

Vessel stowage location: A

Vessel stowage other: Not Listed

SETIQ:

CENACOM:

CIQUIME:

PRÓ-QUÍMICA:

CISPROQUIM:

CANUTEC:

CHEMTREC®:

CHEM-TEL, INC.:

INFOTRAC:

3E COMPANY:

NATIONAL RESPONSE CENTER (NRC):

MILITARY SHIPMENTS:

NATIONWIDE POISON CONTROL CENTER (United States only):