Abstract: 　Objective　To investigate the efficacy of different ratios of red blood cells (RBC) to plasma in neonatal exchange transfusion (ET) and the effect on internal environment (blood cell counts, electrolyte, blood glucose and acid-base balance). Methods　The clinical data of 149 neonates with hyperbilirubinemia treated with ET from January 2015 to December 2018 were analyzed retrospectively. According to the ratio of RBC to plasma during blood exchange, the patients were divided into the 2:1 group (RBC 2U: plasma 100mL, 62 cases) and the 3:1 group (RBC 3U: plasma 100ml, 87 cases). The decreases of serum total bilirubin (TSB) at 0-hour and 12-hour after ET, the duration of continuous phototherapy after ET and the percentage of recurrent ET were compared between the two groups. Before and after the ET, the changes in blood cell counts, serum electrolytes, blood glucose and blood gas results were compared between the two groups. Results　There were no significant differences between the two groups in gestational age, birth weight, gender and age of ET (all P > 0.05). There were no significant differences between the two groups in the decrease of TSB at 0-hour and 12-hour after ET, the duration of continuous phototherapy and the ratio of recurrent ET (all P> 0.05). After ET, RBC (3.7 ± 0.4 vs 4.7 ± 0.3) and Hb (118.9 ± 12.1 vs 157.8 ± 14.3) in the 3:1 group were increased significantly. Meanwhile, the white blood cell, platelet, sodium and HCO－ 3 levels were significantly decreased after ET, while the concentrations of potassium, calcium, and glucose were significantly increased in both groups (all P<0.05) after ET. However, these differences were not significant between the two groups (all P>0.05). Furthermore, the incidence of ET-related complications, acute bilirubin encephalopathy and kernicterus were similar between the two groups (all P>0.05). Conclusions　Neonatal hyperbilirubinemia can be effectively treated using mixed RBC and plasma in a ratio of either 2:1 or 3:1. A 3:1 ratio of mixed blood can effectively correct anemia, and does not aggravate the disorder of the internal environment after ET.

Key words: hyperbilirubinemia;　red blood cell;　plasma;　exchange transfusion;　newborn