The protective effect of low power He-Ne laser against erythrocytic damage caused by artificial heart-lung machines.

We studied the protective effects of low power He-Ne laser irradiation on erythrocytes against the damage caused by experimental artificial heart-lung machines. The erythrocyte suspension in a closed circuit was perfused with a roller pump. One of two circuits was used for laser treatment and the other for control. The laser group demonstrated significantly higher erythrocyte deformability and erythrocyte ATP levels, and lower free hemoglobin and lipid peroxide levels. A laser output power of 8.5 mW was most effective in protecting the erythrocytes. A further morphological finding using a scanning electron microscope showed fewer echinocytes and more discocytes in the laser group. This finding was consistent with the results of physiological and biochemical tests. Low power He-Ne laser irradiation was shown to protect human erythrocytes from the damage caused by an experimental artificial heart-lung machine, raising the possibility of the clinical application of low power He-Ne laser treatment during extracorporeal circulation in cardiovascular surgery.