The effect of the perfluorocarbon emulsion Oxycyte on platelet count and function in the treatment of decompression sickness in a swine model

Decompression from elevated ambient pressure is associated with platelet activation and decreased platelet counts. Standard treatment for decompression sickness (DCS) is hyperbaric oxygen therapy. Intravenous perfluorocarbon (PFC) emulsion is a nonrecompressive therapy being examined that improves mortality in animal models of DCS. However, PFC emulsions are associated with a decreased platelet count. We used a swine model of DCS to study the effect of PFC therapy on platelet count, function, and hemostasis. Castrated male swine (n=50) were fitted with a vascular port, recovered, randomized, and compressed to 180 feet of sea water (fsw) for 31min followed by decompression at 30fsw/min. Animals were observed for DCS, administered 100% oxygen, and treated with either emulsified PFC Oxycyte (DCS-PFC) or isotonic saline (DCS-NS). Controls underwent the same procedures, but were not compressed (Sham-PFC and Sham-NS). Measurements of platelet count, thromboelastometry, and coagulation were obtained 1h before compression and 1, 24, 48, 96, 168 and 192h after treatment. No significant changes in normalized platelet counts were observed. Prothrombin time was elevated in DCS-PFC from 48 to 192h compared with DCS-NS, and from 96 to 192h compared with Sham-PFC. Normalized activated partial thromboplastin time was also elevated in DCS-PFC from 168 to 192h compared with Sham-PFC. No bleeding events were noted. DCS treated with PFC (Oxycyte) does not impact platelet numbers, whole blood clotting by thromboelastometry, or clinical bleeding. Late changes in prothrombin time and activated partial thromboplastin time associated with PFC use in both DCS therapy and controls warrant further investigation.