050 Amplification of the Hypoxic Wound Signal by Treprostinil Sodium (Remodulin®) as Measured by PeriWound Tcpo2 and Laser Doppler Signals

Abstract

Introduction: As an initial pilot effort a prospective, case-controlled trial examining the effects of treprostinil sodium (Remodulin®), by continuous, subcutaneous infusion, was performed in diabetic patients with recalcitrant lower extremity wounds. While the primary outcomes for the trial were wound healing and limb preservation, evaluation of local tissue perfusion with transcutaneous oximetry and laser Doppler analysis (TcPO2/LD) were included as secondary objectives, and with the expectation they would be useful monitors of any interventional modality. Methods: All patients enrolled had nonhealing wounds (>3 months) in critically ischemic lower extremities (Fontaine Stage III-IV or Rutherford Stage 4, 5, or 6). Hyperbaric oxygen exposures were included as diagnostic/monitoring indices. In the last four enrolled subjects TcPO2/LD measurements were made at ambient pressure and at 2.0 or 2.4 ATA before Remodulin® was begun and at various points during drug infusion. Results: Early, observational evaluation of the TcPO2/LD data shows: 1 – These examinations prognostically profile healing in ischemic limbs. 2 – TcPO2/LD values demonstrate the efficacy of Remodulin® in augmenting perfusion in ischemic wounds. While there is a broad range, all measured parameters increased on the drug (resting TcPO2 5–30 mmHg, the rate of TcPO2 rise following ambient pressure O2-challenge 25–150% and periwound TcPO2 90–300 mmHg at 2.0 and 2.4 ATA). 3 – The in-chamber TcPO2 on Remodulin® further defines patients who will not benefit from HBO2 therapy. 4 – The TcPO2/LD data will assist in determining dosages, duration, and maintenance requirements for this drug both as a single agent and when used as an adjuvant to HBO2 therapy. Conclusions: Treprostinil sodium (Remodulin®) has significant laudatory effects on local wound perfusion in ischemic lower extremities. Acknowledgments: United Therapeutics, Inc provided support for this study through an unrestricted educational grant.