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 activation of intrinsic and extrinsic coagulation pathways. Thirty-one male divers divided into two groups were tested in decompression habitat LSH-200. The 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 divers, exposed to a pressure of 400 kPa with a heliox breathing mixture (helium-oxygen mixture: pO2, 40 kPa; pN2, 40 kPa; pHe, 420 kPa). The concentrations 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 decompression. There was a statistically significant decrease in platelet counts and factor I, XII and X concentrations after air-diving, and a potent and statistically significant increase of PAP concentration in both groups of divers. We suggest that saturated air or heliox diving followed by decompression have little if any effect on thrombin generation. Saturated air diving, however, may induce a decrease in platelet count and factor XII concentration. The observed elevation of PAP concentrations in both groups of divers suggests possible activation of fibrinolysis. The exact effect of diving and decompression on fibrinolytic system has to be further investigated.