In the recent several years, it is necessary to use the preserved blood in the surgical procedures because of the reasons that the dvelopements of surgical techniques have demended the great amounts of blood transfusions. But it may be said that the preserved blood transfusion has many unknown clinical problems, even its clinical usefulness. The author studied on the relation of hemolysis of preserved blood to untoward reactions of transfusion in Part Ⅰ of this studies. 1. On the clinical investigations of hemolytic reactions by preserved blood transfusion: The hemolytic reaction is the most important and severe untoward reaction. In this reaction, the patient shows the so-called hemolytic shock and, in the latter, studium, has the crisis due to renal failure. The causes of this reaction, which shows the destruction of blood cells in the patient, may be said in (1) incompatible blood transfusion, (2) massive transfusion of O-type blood and (3) transfusion of hemolysed blood. The statistical analysis of the untoward reactions due to preserved blood transfusion in
the Tsuda's Surgical Department shows that 80% of untoward reactions are fever or allergic ones and 0.8% , 14 cases, are hemolytic reactions. 6 cases of these hemolytic reaetions are occurred in incompatible blood transfusions and other 8 cases are seen in compatible blood transfusions. The main causes of latter 8 cases have the intimate relations to the hemolysis of preserved blood But, it is remarkable that the clinical severity of this reaction is not identified the grade of hemolysis or the quantity of incompatible blood transfusion and is in the more intimate relations to the patho-physiological states of the patients. 2. The grade of hemolysis and the untoward reactions; There are seen no definite intimate relations between the grade of hemolysis, ocurrences of untoward reactions and the kinds of untoward reactions. 3. The patho-physiological states of the patients and the untoward reactions; The author classified the next four groups in the meanings of patho-physiology. (1) nearly normal state, (2) anemia, (3) hypoproteinemia and (4) dehydrated state. In the latter 3 groups there are shown the untoward reactions in the ratio of over twice numbers than the group of nearly normal state. The allergic reactions are seen in hypoproteinemia group in the most high ratio. On the contrary, the fever and hemolytic reactions are often seen in the groups of anemia and dehydrated state. 4. Experimental studies on the hemolysis of preserved blood: The atuthor has the experimental studies on the hemolysis of preserved blood, especially on the influences of preservation days, transportation, shaking, filtratron, temperature, mixtures with many other physiological transfued solutions etc.. All over mentioned mechanical procedures show the unexpected important influences on the hemolysis of preserved blood, and especially show the marked hemolysis in the longer preservation days. These hemolytic tendencies are seen most intense in the duration of 1 week of preservation. In the conclusions of these clinical and experimental studies, there must be said that it should be taken the most careful handling in the presereved blood transfusions even mechanically as well as criticizing of hemolytic states of preserved blood itself and shonld use the preserved blood of duration of within one week to the poor risked patients.