Veterinary Clinical Medicine-I (General and Systemic)

REWARMING TECHNIQUES

• There are three classes of rewarming techniques:

Passive external

• The animal's own metabolic processes continue to produce heat spontaneously so no external heat is required.
• Shivering is an example of thermogenesis.
• This is simplest and slowest rewarming method but is sufficient for mild hypothermic patients.

Active external

• This system includes warm water baths, hot water bottles, blankets, heating pads, radiant heaters.
• This method of rewarming is safe only for mild hypothermia because externally applied heat stimulates peripheral circulation.

Active internal

• These rewarming methods are usually more complex and need to be carried out by professionals (Veterinarians/Animal health technicians).
• These include inhalation rewarming (ventilation of patient with heated, humidified air or oxygen), circulation of heated fluids (40.5 - 43.5 C) in body cavities (gastric, thoracic and peritoneal lavage), and heated intra venous solutions preferably dextrose as this provides energy to meet increased metabolic demands (contribute little heat due to vasoconstriction in cold extremities).
• Inhalation rewarming is the only method, which can be used by a layman and does not require much training (mouth to mouth breathing). Inhalation of warm-saturated air delivers heat directly to the lungs and heart.
• The brain is also warmed from this blood flow and from conductive heat flow from the respiratory and nasal cavities.
• This method also assists in re-hydration as an added benefit.