The Hemoglobin Function and 2,3-DPG Levels of Blood Stored at 4 degrees C in ACD and CPD. The pH Effect.

Normal hemoglobin function depends on adequate red cell levels of 2,3-diphosphoglycerate 2,3-DPG, a compound which is poorly maintained during blood bank storage in acid-citrate-dextrose ACD. Since 2,3-DPG is better maintained in citrate-phosphate-dextrose CPD and this preservative has a higher pH 5.5 than ACD pH - 5.0, these preservatives were prepared at each pH and studied. The CPD preservatives pH 5.0, 5.5 had similar amounts of phosphate so the differences between them, obtained by altering the buffer ratio, should relate to pH. The ACD solutions pH 5.0, 5.5 contained no phosphate. Hemoglobin function, expressed as P50 the p02 at 50 oxygenation, an inverse but direct measure of oxygen affinity, and 2,3-DPG were better maintained in ACD and CPD of pH 5.5. The lower pH 5.0 preservatives, whether ACD or CPD, showed rapidly declining hemoglobin function and 2,3-DPG levels. The values at the higher pH remained close to normal for 2 weeks and above those of the lower pH preservatives for most of the 4-week storage period. Author