title: Hematologic changes after two exposures to 6.7 ATA air at three-day intervals.
abstract: Hematologic parameters were studied in human subjects exposed to various diving regimens. A series of exposures in a dry chamber to a simulated depth of 188 ft of seawater gauge (fswg), 6.7 ATA, utilizing compressed air, were carried out according to standard Navy diving tables. The subjects were serially followed for a control period prior to diving and subsequently for up to 1 wk. Little significant change occurred except for alterations in some platelet factors. In another series of experiments, the single excursion was followed by a second dive to 188 fswg 3 days later, again with appropriate hematologic monitoring. A pronounced eosinopenia and increased clotting times were observed soon after reaching the surface. Platelet depletion associated with increased clumping and elevated megathrombocyte levels persisted long after the second excursion. A latent hemodilution also developed 3--5 after the second dive. These findings clearly demonstrate that repeated hyperbaric exposures produce additive effects and further suggest that no diving procedure is completely innocuous.
mesh_terms: D000328:Adult; D000399:Air Pressure; D001772:Blood Cell Count; D001777:Blood Coagulation; D001792:Blood Platelets; D001810:Blood Volume; D004242:Diving; D004906:Erythrocyte Count; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D010974:Platelet Aggregation; D014867:Water / Q000032:analysis
chemical_list: D006454:Hemoglobins; D014867:Water