Changes in the extrinsic and intrinsic coagulation pathways in humans after decompression following saturation diving

We have investigated the effect of simulated saturation diving on the activ ation of intrinsic and extrinsic coagulation pathways. Thirty-one male dive rs divided into two groups were tested in decompression habitat LSH-200. Th e first group of 16 divers was subjected to hyperbaric exposure at pressure of 180 kPa with air as a breathing mixture, and the second group of 15 div ers, exposed to a pressure of 400 kPa with a heliox breathing mixture (heli um-oxygen mixture: pO(2), 40 kPa; pN(2), 40 kPa; pHe, 420 kPa). The concent rations of tissue factor, tissue factor pathway inhibitor, factors XII, X, VII, and I, prothrombin fragment F1+2, and thrombin-antithrombin complex as well as platelet count, prothrombin time, activated partial thromboplastin time, plasmin-antiplasmin complex (PAP) and D-dimers were measured. We did not detect activation of the extrinsic coagulation pathway after decompres sion. There was a statistically significant decrease in platelet counts and factor I, XII and X concentrations after air-diving, and a potent and stat istically significant increase of PAP concentration in both groups of diver s. We suggest that saturated air or heliox diving followed by decompression have little if any effect on thrombin generation. Saturated air diving, ho wever, may induce a decrease in platelet count and factor XII concentration . The observed elevation of PAP concentrations in both groups of divers sug gests possible activation of fibrinolysis. The exact effect of diving and d ecompression on fibrinolytic system has to be further investigated. (C) 200 1 Lippincott Williams & Wilkins.