pyrophosphate and Frostbite

Experiments were conducted in 32 rabbits to determine whether treatment with IV streptokinase can effectively limit the extent of tissue damage associated with frostbite injury of the hind limbs. Other variables studied were the temperature of the tissue during freezing, the time taken to rewarm the exposed limbs, and the delay between the initiation of treatment with streptokinase and cessation of freezing. A control group of 16 rabbits was not given streptokinase. The extent of tissue damage was estimated by sequential radionuclide perfusion scans of the exposed limbs. This estimate was based on the proportional loss of tissue perfusion on subsequent twice-weekly nuclear scans in comparison with that shown by scans performed immediately after thawing. Pathologic changes in exposed tissues were studied by histology. Streptokinase treatment and rapid rewarming both resulted in less tissue damage at all freezing temperatures. Streptokinase was most beneficial when given 12 hr after freezing, but was effective even when treatment was delayed up to 48 hr.

Topics: Animals; Diphosphates; Frostbite; Hindlimb; Injections, Intravenous; Rabbits; Radionuclide Imaging; Streptokinase; Technetium; Technetium Tc 99m Pyrophosphate

Early diagnosis of the extent of bone and soft tissue damage is a very important step in treating a frostbite victim. The diagnostic use of Tc-99m-phosphates in assessing the viability of soft tissue and bone in frostbite was evaluated in the early post-thaw period. Four patients were treated with a combination of warm baths, rehydration, vasodilators, epidural block, fasciotomy, and debridement. Six scans were done to stage involvement. In three of the four cases, final involvement could be determined as early as the third day. When a specific level of soft tissue or bone uptake was determined, future scanning showed either improvement, or no change in three of the four patients. In our experience, Tc-99m-phosphate scans represent an improvement over other diagnostic tests for viability of tissues.

Topics: Adult; Child; Diphosphates; Female; Frostbite; Humans; Male; Radionuclide Imaging; Technetium; Technetium Tc 99m Medronate; Technetium Tc 99m Pyrophosphate

We designed an experimental model using a new method of freezing to study the pathogenesis and treatment of frostbite. Frostbite was simulated in a manner that closely resembles that which occurs in a natural environment. We used a radionuclide imaging technique to monitor the evolution and extent of tissue damage relative to temperature, rate of freezing, and controlled rewarming. Characteristic sequential changes were demonstrated on sequential nuclear scans. Nonperfusion, followed by perfusion, and finally again by nonperfusion occurred in all areas in which necrosis developed. The reappearance of nonperfusion corresponded to vascular injury and thrombosis evidenced at pathologic examination. We determined that lack of tissue perfusion corresponded to tissue injury. We believe that our experimental model provides an effective means of evaluating potential therapeutic regimens.

Topics: Animals; Diphosphates; Frostbite; Hindlimb; Rabbits; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Adolescent; Adult; Aged; Arm; Child; Diphosphates; Frostbite; Gangrene; Humans; Leg; Middle Aged; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Xeroradiography

Topics: Diphosphates; Foot Diseases; Frostbite; Hand; Humans; Radionuclide Imaging; Technetium; Time Factors