Abstract
Erythropoiesis is affected during deep saturation dives. The mechanism should be related
to a downregulation of serum Erythropoietin (s-EPO) concentration or to a toxic effect
of the hyperbaric hyperoxia. We evaluated s-EPO and other haematological parameters
in 6 scuba divers before, during and after a 14-days guinness saturation dive (8–10 m).
Athletes were breathing air at 1.8–2 ATA, under the control of a team of physicians.
Serum parameters were measured before diving (T0) and: 7 days (T1), 14 days (T2) after
the beginning of the dive and 2 h (T3) and 24 h (T4) after resurfacing. Hgb, and many
other haematological parameters did not change whereas Ht, s-EPO, the ratio between
s-EPO predicted and that observed and reticulocytes (absolute, percent) declined progressively
from T0 to T3. At T4 a significant rise in s-EPO was observed. Hgb did not vary but
erythropoiesis seemed to be affected as s-EPO and reticulocyte counts showed. All
these changes were statistically significant. The experiment, conducted in realistic
conditions of dive length, oxygen concentration and pressure, allows us to formulate
some hypotheses about the role of prolonged hyperbarism on erythropoiesis. The s-EPO
rise, 24 h after resurfacing, is clearly documented and related to the “Normobaric
Oxygen Paradox”. This evidence suggests interesting hypotheses for new clinical applications
such as modulation of s-EPO production and Hgb content triggered by appropriate O2 administration in pre-surgical patients or in some anemic disease.
Key words
erythropoietin (EPO) - hyperbarism - hyperoxia - reactive oxygen species (ROS) - normobaric
oxygen paradox (NOP) - diving - scuba dive - free radicals
