FPIN’s Help Desk Answers

Reducing Amputation Rates After Severe Frostbite JENNIFER TAVES, MD, and THOMAS SATRE, MD, University of Minnesota/St. Cloud Hospital Family Medicine Resi- dency Program, St. Cloud, Minnesota

Help Desk Answers pro- Clinical Question in the tPA plus iloprost group with severe vides answers to questions submitted by practicing Is tissue plasminogen activator (tPA) effec- disease and only three and nine digits in the family physicians to the tive in reducing digital amputation rates in other treatment arms. Thus, no conclusions Family Physicians Inquiries patients with severe frostbite? can be reached about the effect of tPA plus Network (FPIN). Members iloprost compared with iloprost alone. of the network select Evidence-Based Answer questions based on their A 2007 retrospective cohort trial evalu- relevance to family medi- In patients with severe frostbite, tPA plus a ated the use of tPA in six patients with severe cine. Answers are drawn prostacyclin may be used to decrease the risk of frostbite.2 After rapid rewarming, patients from an approved set of digital amputation. (Strength of Recommen- underwent digital angiography, and those evidence-based resources and undergo peer review. dation [SOR]: B, based on a single randomized with significant perfusion defects received controlled trial [RCT].) tPA can be used alone intraarterial tPA (0.5 to 1 mg per hour IV The complete database of evidence-based ques- and is associated with lower amputation rates infusion) and heparin (500 units per hour tions and answers is compared with local wound care. (SOR: C, IV infusion) for up to 48 hours. Patients who copyrighted by FPIN. If based on lower-quality cohort studies.) presented after 24 hours and had normal or interested in submit- A 2011, open-label RCT (n = 47) compared uninterpretable angiography results (n = 26) ting questions or writing answers for this series, tPA plus iloprost (Ventavis), iloprost alone, received local wound care. The tPA group go to http://www.fpin. and buflomedil (not available in the United had a lower amputation rate (10% vs. 41%; org or email: questions@ States) in patients with frostbite extending P < .05), but patients in the control group fpin.org. just past the proximal phalanx or injury were not matched for injury severity. This series is coordinated proximal to the metacarpal or metatarsal A 2005 prospective cohort trial evaluated by John E. Delzell, Jr., MD, joint.1 Digital perfusion was not assessed the use of tPA in 19 patients with severe MSPH, Assistant Medical Editor. before treatment. All patients underwent frostbite (no perfusion on technetium-99m rapid tissue rewarming and received 250 mg bone scan).3 In patients who received intra- Copyright Family Physi- cians Inquiries Network. of aspirin and 400 mg of intravenous (IV) arterial or IV tPA, 33 of 174 affected digits Used with permission. buflomedil. Patients then received 100 mg of (19%) were amputated. In eight historical IV tPA plus an IV infusion of iloprost (0.5 to control patients who had undergone local 2 ng per kg per minute) for six hours per day, wound care alone, at least 60 of 65 affected iloprost alone, or 400 mg of IV buflomedil digits (92%) were amputated. per day. After eight days, a technetium-99m Address correspondence to Jennifer Taves, MD, at scan was used to identify digits at risk of [email protected]. Reprints are not avail- amputation. In the buflo-medil group, nine able from the authors. of 15 patients were at risk of amputation com- Author disclosure: No relevant financial affiliations. pared with zero of 16 in the iloprost group (P < .001) and three of 16 in the tPA plus REFERENCES iloprost group (P < .03). After three months, 1. Cauchy E, et al. A controlled trial of a prostacyclin and four patients in the iloprost group had ampu- rt-PA in the treatment of severe frostbite. N Engl J Med. tations compared with three in the tPA plus 2011;364 (2):189-190. 2. Bruen KJ, et al. Reduction of the incidence of amputa- iloprost group. Statistical testing between tion in frostbite injury with thrombolytic therapy. Arch the tPA plus iloprost and the iloprost alone Surg. 2007;142(6):546-551. groups was not reported, and comparisons 3. Twomey JA, et al. An open-label study to evaluate the safety and efficacy of tissue plasminogen activator in between groups were complicated by unbal- treatment of severe frostbite. J Trauma. 2005;59(6): anced randomization; there were 25 digits 1350-1354. ■

716 American Family Physician www.aafp.org/afp Volume 92, Number 8 ◆ October 15, 2015