HEMOSTATIC ALTERATIONS FOLLOWING SEVERE DYSBARIC STRESS by

Hemostatic parameters were measured in the blood of mature Sprague-Dawley rats during a three day period following exposure to a compression-decompression schedule designed to produce severe dy sbaric stress. The animals were compressed on air to a pressure equivalent to 300 feet of sea water for 30 minutes and stage decompression over a 42 minute interval. Acute decompression stress produced a transient decrease in clotting time. Circulating platelet population was unchanged during the early phase of recovery from severe decompression but it had declined significantly by two days postsurfacing. It then returned to control levels by the end of the observation period. Associated with this thrombocytopenic episode was a tendency toward platelet aggregation. Core temperature measurements indicated the presence of a chronic hyperthermic condition. A significant hyperfibrinogenemia had developed by one day post-dive with a normalization of fibrinogen content occurring during the following two days. No alterations in either prothrombin time or partial thromboplastin time were detected. This animal research has much significance in the biomedical aspects of human diver safety and health.