Internal Flashcards
Treatment of frost bite
Frozen tissue should be thawed rapidly and completely by immersion in circulating water at 37°–40°C (99°–104°F). Rapid rewarming often produces an initial hyperemia. The early formation of large clear distal blebs is more favorable than that of smaller proximal dark hemorrhagic blebs. A common error is the premature termination of thawing, since the reestablishment of perfusion is intensely painful. Parenteral narcotics will be necessary with deep frostbite. If cyanosis persists after rewarming, the tissue compartment pressures should be monitored carefully.
Numerous experimental antithrombotic and vasodilatory treatment regimens have been evaluated. There is no conclusive evidence that dextran, heparin, steroids, calcium channel blockers, hyperbaric oxygen, or prostaglandin inhibitors salvage tissue. Intraarterial thrombolysis may reduce the need for digital and more proximal amputations when administered within 24 h of severe injuries.
Sterily drain clear vesicles, don’t drain hemorrhagic one.
Types of non freezing cold injuries?
The two most common nonfreezing peripheral cold injuries are chilblain (pernio) and immersion (trench) foot. Chilblain results from neuronal and endothelial damage induced by repetitive exposure to dry cold. Young females, particularly those with a history of Raynaud’s phenomenon, are at greatest risk. Persistent vasospasticity and vasculitis can cause erythema, mild edema, and pruritus. Eventually plaques, blue nodules, and ulcerations develop. These lesions typically involve the dorsa of the hands and feet. In contrast, immersion (trench) foot results from repetitive exposure to wet cold above the freezing point. The feet initially appear cyanotic, cold, and edematous. The subsequent development of bullae is often indistinguishable from frostbite. This vesiculation rapidly progresses to ulceration and liquefaction gangrene. Patients with milder cases complain of hyperhidrosis, cold sensitivity, and painful ambulation for many years.
