[Changes in erythrocyte structure and in platelets in elderly patients with disseminated intravascular coagulation]

We measured the platelet distribution width, the mean platelet volume, the volume percentage of platelets, and the platelet-to-large-cell ratio in 15 elderly patients with disseminated intravascular coagulation (DIC). Peripheral venous blood mixed with ehtylenediaminetetraacetic acid was analyzed with a Sysmex E-4000 analyzer. The underlying diseases were sepsis, pneumonia, pyelonephritis, and other inflammatory diseases. The mean duration of survival from the onset of DIC was 16.9 +/- 23.9 days. The distribution of red cell sizes before the onset of DIC did not differ significantly from that in patients without DIC, but fragmentation of erythrocytes on blood films was more common in the early stage of DIC (p < 0.01). Before the onset of DIC, the two groups did not differ significantly in the frequency of giant platelets on blood smears. At the onset of DIC, the platelet distribution width, the mean platelet volume, and the platelet-to-large-cell ratio were significantly higher than in patients without DIC. The concentration of glutamic-oxaloacetic transaminase and those of other serum enzymes did not change significantly, but the serum creatinine concentration and the blood urea nitrogen level increased as the platelet-to-large-cell ratio increased. No significant relation was evident between the levels of serum C-reactive protein and creatinine, between the platelet-to-large-cell ratio and the mean volume of red blood cells, or between the platelet-to-large-cell ratio and the distribution of red cell sizes. These data suggest that studies of platelets are more useful in the diagnosis of DIC at early stages of impaired organ function than are other indicators of inflammation such as the level of C-reactive protein.