Net haemoglobin increase from reinfusion of refrigerated vs. frozen red blood cells after autologous blood transfusions

BACKGROUND AND OBJECTIVES Two main blood storage procedures can be used for storing red blood cells: refrigeration and freezing. Nevertheless, the efficiency of these procedures measured as the increase in haemoglobin after reinfusion compared with baseline has never been examined. The main objective was to examine which storage procedure yielded the largest increase in circulating haemoglobin after reinfusion compared to baseline. MATERIALS AND METHODS Equal volumes of blood from 15 men were withdrawn and stored either frozen or refrigerated as packed red blood cells. Serial measures of circulating haemoglobin by carbon monoxide rebreathing provided an opportunity to monitor recovery from anaemia, as well as the net increase in circulating haemoglobin after transfusion. RESULTS The post-thaw yield of haemoglobin in the bags was 72% after refrigerated storage compared with only 52% after freezing. Nevertheless, frozen storage allowed haemoglobin to fully recover before reinfusion, while the haemoglobin was 10% lower in the refrigerated group compared with baseline. After reinfusion, the haemoglobin levels were 11·5% higher than the baseline values in the group reinfused with frozen blood, while for the refrigerated group, haemoglobin levels were only 5·2% higher than baseline. CONCLUSION The relatively larger recovery from anaemia in the frozen group during storage more than compensated for the larger loss of haemoglobin during freezing and resulted in a larger net gain in haemoglobin. Based on the average 23 g per week recovery of haemoglobin, extending refrigerated storage to 7-8 weeks may yield sufficient time for patients to fully replenish harvested haemoglobin from three bags of blood without reliance on frozen storage of RBC.