An open-label study to evaluate the safety and efficacy of tissue plasminogen activator in treatment of severe frostbite.
ABSTRACT Severe frostbite can have devastating consequences with loss of limbs and digits. One of the mechanisms of cold injury to human tissue is vascular thrombosis. The effect of tissue plasminogen activator (tPA) and heparin in limb and digit preservation in severe frostbite patients has not been previously studied.
Intra-arterial (6 patients) or intravenous (i.v., 13 patients) tPA and IV heparin were used in patients with severe frostbite. All patients between January 1, 1989 and February 1, 2003 with severe frostbite not improved by rapid rewarming, with absent Doppler pulses in distal limb or digits, without perfusion by Technetium (Tc) 99m three-phase bone scan, and no contraindication to tPA use were eligible. Efficacy was assessed on the basis of predicted digit amputation before therapy, given the clinical and Tc-99m scan results, versus partial or complete digits removed.
There were no complications with i.v. tPA. Two patients with intra-arterial TPA had bleeding complications. We know from historical Tc-99m scan data which digits were at risk for amputation. In this study, there were 174 digits at risk in 18 patients and only 33 were amputated.
Intravenous tPA and heparin after rapid rewarming is safe and reduced predicted digit amputations considerably. Patients with no response to thrombolytic therapy were those with more than 24 hours of cold exposure, warm ischemia times greater than 6 hours, or evidence of multiple freeze-thaw cycles. Our algorithm for treatment of severe frostbite now includes use of i.v. tPA for patients without contraindications.
SourceAvailable from: Oscar R. MirandaClinical Pharmacology & Therapeutics 11/2014; 97(3). DOI:10.1002/cpt.33 · 6.85 Impact Factor
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ABSTRACT: The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2011;22(2):156-166.Wilderness and Environmental Medicine 12/2014; 25(4). DOI:10.1016/j.wem.2014.09.001 · 0.79 Impact Factor
Article: Frostbite of the Hand[Show abstract] [Hide abstract]
ABSTRACT: Frostbite is damage caused by the freezing of tissue owing to exposure to extreme cold. Clinically, it is often difficult to identify the severity of frostbite injury. There may be a wide discrepancy between the extent of damage to the skin versus that to the deeper structures. The initial clinical impression is usually worse than actual tissue damage. In addition to physical examination, diagnostic imaging, especially triple-phase bone scan, has been proposed to help differentiate between superficial and deep damage. Principles of treatment involve rapid rewarming to thaw the tissues and halt direct cellular damage, methods to minimize progressive dermal ischemia, and active wound care to promote timely healing. Pharmacological adjuncts, such as fibrinolytics, have been proposed to minimize tissue damage. Surgical therapy is postponed until there is clear demarcation between healthy and necrotic tissue.The Journal Of Hand Surgery 09/2014; 39(9):1863–1868. DOI:10.1016/j.jhsa.2014.01.035 · 1.66 Impact Factor