Evidence for pulmonary microembolization during hemodialysis.

The generation of microaggregates during the extracorporeal circulation of heparinized blood through two types of hemodialyzers was demonstrated by increased screen filtration resistance. Arterial blood deoxygenation and widening of the alveolar-arterial oxygen difference occurred following either unfiltered or inadequately filtered dialysis. These changes were consistent with pulmonary microembolization. The blood gas abnormalities and the increased screen filtration resistance were reversed or improved when venous line microemboli filters were used.