A Comparative Analysis of Factors Influencing Haemoglobin Content in RBC Units

Transfus Apher Sci. 2021 Dec;60(6):103214

Background and objectives

The increment in a patient’s haemoglobin level is based upon the haemoglobin content of the transfused RBC units. The total haemoglobin present in the blood bags can vary because of the blood donor, processing method, volume and type of bag used. The study is done to analyse the factors causing variation of haemoglobin content in RBC units.

Materials and Methods

A total of 260 RBC units were tested for the haemoglobin content and analysed with the donor variables (age, gender, weight & capillary haemoglobin). The blood bags were then separated into two groups based on the donor capillary haemoglobin (normal 12.5–15.0 g/dL vs high 15.1–18.0 g/dL), volume (350 vs 450 mL), processing method (Platelet rich plasma vs buffy coat) and further analysis was carried out.


The mean haemoglobin content was 54.7 g ranging from 34.2–80 g per unit. The factors which significantly influenced (p < 0.0001) were capillary haemoglobin, gender and weight of donor, volume of blood collected and the processing method. There was a significant difference (p < 0.0001) in haemoglobin content between the two groups in all the three categories (capillary haemoglobin, volume and processing method). Regression analysis showed all three of them contributed to 80 % variability of haemoglobin content in the RBC unit.


The marked variation of haemoglobin content in our study revealed that there is a need for standardizing RBC unit. Labelling of units with haemoglobin content and transfusion based on it will result in better patient care.