Effects of red blood cell transfusions during the first week of life on acid-base, glucose, and electrolytes in preterm neonates

BACKGROUND: More than 90 percent of extremely low‐birth‐weight infants receive one or more transfusions of red blood cells (RBCs). The objective was to assess if RBC transfusions may induce significant changes of plasma acid‐base, electrolyte, and glucose status in extremely preterm infants. STUDY DESIGN AND METHODS: Records of infants with gestational age of less than 31 weeks who were transfused with RBCs during the first week of life were reviewed (n = 61). Blood samples were collected from infants before and after transfusions to evaluate hemoglobin (Hb) level, hematocrit, acid‐base, electrolyte, and glucose status. Then infants were stratified into four groups that received a RBC volume of less than 15, 15 to 20, more than 20 to 25, or more than 25 mL per kg. RESULTS: Infants received 20.7 (±1.5) mL per kg RBCs. After transfusions, a significant increase of pO₂ (p < 0.0001) and decrease of Ca²⁺ (p = 0.047) and glycemia (p < 0.0001) were observed. Infants who were transfused with more than 25 mL per kg were significantly less immature, heavier, and more anemic than infants in other groups. A positive relationship was found between changes of patients' potassium plasma level and K⁺ intake through RBC transfusion (r = 0.442, p = 0.008). Three (4.9%) infants developed hyperkalemia, one (1.6%) had an exacerbation of his hypocalcemia, and another (1.6%) of his hypoglycemia. CONCLUSIONS: RBC transfusions were effective in correcting anemia in our patients and induced a slight increase of pH and pO₂ and decrease of Ca²⁺ and glycemia, which were not clinically relevant. A linear direct correlation was observed between potassium intake by RBC transfusions and changes of kalemia in our infants, but there was not an increase of K⁺ plasma level after transfusions.