Hematology and blood chemistry in saturation diving: II. Open-sea vs. hyperbaric chamber.

Hematograms, platelet function, and blood-enzyme chemistry were compared in two similar saturation-excursion dives, one conducted in a hyperbaric chamber and the other in the open sea. The chamber dive was more stressful in that it was preceded by a series of bounce decompression dives (one of which produced a 100% incidence of cutaneous pruritus in four subjects) and in that the excursions from saturation depth (60 fsw or 2.818 ATA) were longer and deeper (producing one case of O2 convulsions, one of confirmed decompression sickness, and several of Doppler-detected vascular bubbles). The chamber dive was associated with a marked and significant reduction in circulating platelet count; significant increases in plasma enzyme activities in the victim of O2 toxicity (LDH, CPK) and in one subject with Doppler bubbles and questionable bends symptoms (LDH, GOT, GPT) but not in another; and mild but significant anemia. In the open-water dive, one subject, who developed symptoms of gastroenteritis, showed moderate elevation of LDH, GOT, and GPT activity. No significant change in platelet counts occurred. Both dives were associated with elevated white-cell counts, apparently as a result of numerous minor infections, and reduced sensitivity of platelets of ADP-induced aggregation.