Blood rheology during bacterial infection in the elderly and early middle-aged.

The aim of this study was to ascertain if the hemorheological profiles in 35 elderly and 20 young to middle-aged patients returned to normal after bacterial infection. Erythrocyte sedimentation rates, fibrinogen levels, plasma viscosity, hematocrit, white blood cell count and filterability rates (through 5 mu diameter pore filters, using a low shear positive pressure Nuclepore filtration system) of red blood cells and unfractionated leucocytes were determined at the onset of acute bacterial infection, after 3 weeks at full clinical recovery, and again 2 weeks later at the end of convalescence. Our data confirm that rheological impairments exist at the onset of bacterial infection, and persist up to clinical recovery. At the end of convalescence the unfractionated leucocyte filterability rate was still significantly higher in the elderly patients, compared not only to our normal standard, but also to average values in the younger group.