Original Article

Arterial-Venous Perfusion Without Anticoagulation to Reverse Accidental Hypothermia

Department of Surgery and School of Cardiovascular Perfusion, Cooper HospitaVUniversity Medical Center, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden, Camden, NJ

^* Address correspondence to: Anthony J. DelRossi, MD, Head, Div. of Cardiothoracic Surgery, Cooper Hospital/University Medical Center, Three Cooper Plaza, Suite 411, Camden, NJ 08103

Abstract

To investigate a means of rewarming individuals suffering from accidental hypothermia, five Yucatan swine were topically cooled to a core body temperature of 30#x00B0;C. No heparin or any other means of anticoagulation was administered. An extracorporeal circuit consisting of polyvinylchloride tubing, a Bio-Pump and an external stainless steel heat exchanger was utilized and primed with an albuminized Ringers solution. An arterial-venous circuit was employed with oxygenation being provided by the animals' lungs. A series of aliquots of blood were taken and analyzed for coagulation prior to cannulation, after stabilization of blood flows, at a rectal rewarming temperature of 32°C and post-decannulation.

All subjects were effectively rewarmed to 34°C, with a mean perfusion time of 64.8 ± 8.5 minutes. Coagulation parameters showed very little alteration from the control values taken: PT (11.9 ± .5), PTT (16.0 ± .9), platelet count (456.0 ± 105.6) and normal fibrinogen levels. Necropsy examination revealed only minimal clot formation within either the extracorporeal circuit or the animals' vascular system.

Our results support the hypothesis that circulatory assistance and ultimately, extracorporeal circulation may be possible without anticoagulation.