The effect of acute and short term normobaric hyperoxia on hemorheologic parameters.

Backround:Possible toxic effects of hyperoxia have been reported previously. However, the number of studies investigating the influence of hyperoxia on blood cells is limited and there are no data regarding its hemorheological effects.

Objective: The aim of this study was to investigate the effects of acute hyperoxia, performed in human subjects at normal atmospheric pressure, on the rheological properties of blood.

Method: The study was conducted with 12 brain death patients mechanically ventilated in the intensive care unit. The patients were ventilated with 21%, 40%, and 100% oxygen before induction of apnea testing performed for diagnosis of brain death. Blood samples were obtained at each oxygen concentration value for all patients.

Result: The results of the study indicated no significant change of red blood cell aggregation, deformability and plasma or whole blood viscosity associated with acute hyperoxia at normobaric conditions.

Conclusion: The results of the study suggest that application of normobaric hyperoxia does not have detrimental effects on hemorheological parameters in brain death patients, and that organs considered for donation from such subjects are not adversely affected by abnormalities of blood flow and tissue perfusion.