[Blood coagulation processes in decompression sickness and hyperbaric therapy]

The hyperaggregability of platelets is remarkably important in the pathogenesis of decompression sickness. The basis of this phenomenon might consist of an excessive production of metabolites of arachidonic acid (C 20:4) whose action favours aggregation (prostaglandin endoperoxides PGG2 and PGH2 and Tromboxane A2) in respect of the synthesis of its derivatives exerting an antithrombotic action (prostacyclin I2). The antiaggregating therapy usually associated to the hyperbaric treatment involves administration of acetylsalicylic acid in low doses (3.5-5 mg/kg every three days), associated if necessary to dypyridamol. As a prophylaxis against thrombotic phenomena in "risky" subjects, a congruous dietetic assumption of polyunsaturated fatty acids is recommended, such as linoleic acid (C 18:2) and eicosapentaenoic acid (C 20:5) which are forerunners of anti-aggregating prostaglandin derivates. Hyperbaric oxygenation might finally lead to the production of lypid peroxides apt to inhibit the synthesis of PGI2. In such cases it is a rational procedure to administer vitamin E in high doses, as physiological antioxidant of lypids.