Alterations in erythrocytes in hyperosmolar diabetic decompensation: a pathophysiological basis for impaired blood flow and for an improved design of fluid therapy.

In a study of 10 diabetic patients, each of whom was in a severely decompensated state, notable alteration of blood flow properties was observed in those six patients who were hyperosmolar. In this form of diabetic decompensation, whole blood filtration was distinctly impaired. The additional impairment was shown to be due to an accumulation of solute within the erythrocytes occurring as a consequence of hyperosmolarity. The alterations in erythrocytes were revealed by Coulter blood count abnormalities and confirmed by osmotic fragility studies. When biochemical improvement was achieved in these patients, rapid resolution of the erythrocyte abnormalities occurred. Microvascular ischaemia due to such erythrocyte alterations may be a possible explanation for the characteristic cerebral disturbances of the hyperosmolar diabetic state. Altered blood flow properties would also promote vascular thrombosis, a common terminal event in the hyperosmolar non-ketotic syndrome with associated 50 per cent mortality. An improved design of the insulin and fluid replacement therapy for patients in hyperosmolar diabetic coma might be based on the findings of these and further studies.