Effect of local anesthetics on red blood cell deformability.

The deformability of human red blood cells under the influence of local anesthetics is studied in vitro. Red blood cells obtained from blood samples of healthy adult volunteers are treated with two local anaesthetics, procain and tetracaine, at varied concentrations. Deformability of red blood cells, in terms of its elongation index, were then examined by laser light shear stress diffractometer both at low and high shear forces. Results show that the deformability of local anesthetic-treated red blood cells is decreased when compared to that of control samples. At low shear forces and at low concentrations of the anesthetic agent, the decrease in deformability is not significant, whereas it is significant for high shear forces and at high concentrations. These effects are similar for both anesthetic agents studied.