Abstract
BACKGROUND:
Donor physiognomic characteristics play a critical role in determining the quality of packed red cell units (PRBCs), which directly impacts transfusion outcomes. This retrospective study aimed to evaluate the influence of donor physiognomic factors on PRBC quality at a tertiary care transfusion center.
METHODS:
A retrospective analysis was conducted on 250 randomly selected blood donors from January 2015 to August 2018. Donor age, gender, weight, and predonation hemoglobin (PHB) levels were assessed, along with PRBC parameters including volume (350 ml vs. 450 ml), processing method, PRBC age, and percent hemolysis during storage. Subsequent evaluations included hematocrit, per unit total hemoglobin (UTHB), and red cell mass.
RESULTS:
The mean weight among donors aged 18–28 years was 69.8 kg, compared to 74.46 kg in higher age groups. Lower PHB levels (12.5–13.0 g/dL) were associated with decreased UTHB. PRBCs prepared using the buffy coat method exhibited lower mean UTHB compared to other methods. A significant correlation (P = 0.01) was observed between PRBC age and hemolysis in all units.
CONCLUSIONS:
Donor PHB significantly influences the quality of PRBCs prepared, with lower PHB levels correlating with decreased UTHB. PRBCs prepared using the buffy coat method showed inferior UTHB, and older PRBC units displayed higher red cell hemolysis. However, donor gender, age, and weight did not significantly affect PRBC quality in this study. Larger sample sizes are necessary to confirm these findings. These results highlight the importance of donor screening and selection to optimize PRBC quality and enhance transfusion therapy outcomes.
Keywords: Buffy coat method, donor characteristics, donor physiognomic, hemolysis, packed red cell units, platelet-rich plasma method, transfusion, transfusion outcomes
Introduction
Blood transfusions are a cornerstone of modern medicine, indispensable for providing essential support to patients undergoing surgeries, suffering from trauma, or managing chronic conditions such as anemia. The safety and efficacy of blood transfusions hinge crucially on the quality of blood products, with packed red cell units (PRBCs) representing a significant component of transfused blood components due to their role in replenishing oxygen-carrying capacity.[1]
Optimal donor selection is paramount to ensure the safety and quality of blood products. Donor physiognomic characteristics, including age, gender, weight, and predonation hemoglobin (PHB) levels, play a crucial role in determining the quality of PRBCs. These factors can influence various parameters of PRBCs, such as total hemoglobin content, hematocrit levels, and susceptibility to hemolysis during storage.
While the importance of donor selection in transfusion medicine is widely acknowledged, there exists a pressing need for comprehensive studies to discern the specific impact of donor physiognomic characteristics on PRBC quality. Such investigations are imperative to elucidate the intricate relationships between donor attributes and PRBC parameters, thereby facilitating the refinement of blood donation practices and the enhancement of transfusion outcomes.[2,3]
Our study conducted a retrospective analysis at a tertiary care transfusion center in this context, with the primary objective of assessing the influence of donor physiognomic characteristics on PRBC quality. By scrutinizing donor variables and PRBC parameters, our endeavor sought to delineate key factors shaping PRBC quality and warranting attention for optimization in donor screening and selection protocols.[3]
Through our research, we endeavor to contribute valuable insights into the optimization of blood transfusion practices, fostering advancements aimed at fortifying patient safety and improving outcomes in transfusion therapy. By shedding light on the nuanced interplay between donor physiognomic characteristics and PRBC quality, we aspire to inform evidence-based strategies for refining donor selection processes, ultimately advancing the delivery of safe and effective transfusion therapy in clinical settings.[4,5]
Methods
Study design
This retrospective study was conducted to evaluate the influence of donor physiognomic characteristics on the quality of PRBCs at a tertiary care transfusion center.
Study population
A total of 250 blood donors, randomly selected from records spanning from January 2015 to August 2018, were included in the analysis. Donor data, including age, gender, weight, and PHB levels, were extracted from donor records. Information regarding PRBC parameters, such as volume of PRBC harvested from collected from whole blood, processing method, age, and hemolysis during storage, was obtained from blood bank records.
Inclusion criteria
Donors meeting specific criteria were included in the analysis. Female donors and male donors weighing <55 kg donated strictly 350 mL, while other male donors donated either 350 mL or 450 mL based on the available bag type at the blood donation camp. The lower cutoff for PHB in both male and female donors was 12.5 g/dL, with a minimum weight requirement of 45 kg.
Measurement techniques
Donor hemoglobin levels were measured using the HemoCue® Hb 301 System. PRBC parameters, including hematocrit, per unit total hemoglobin (UTHB), and red cell mass, were analyzed using a SYSMEX KX-21 Hematology Analyzer and HemoCue® Plasma/Low Hb System. Calculations were performed to determine actual UTHB and percentage hemolysis.
Calculating unit total hemoglobin
Multiply the hemoglobin concentration (in g/dL) of the PRBC unit by the volume of the PRBC unit (in mL).
Formula: UTHB = (HB of the PRBC unit × Volume of the PRBC unit)/100
Calculating percentage hemolysis
This is calculated using the following formula:
Percentage Hemolysis = [(1 − Hematocrit) × Plasma-free hemoglobin]/total hemoglobin of the unit × 100
where:
Hematocrit is the fraction of blood volume occupied by red blood cells.
Plasma-free hemoglobin is the amount of free hemoglobin in the plasma.
The total hemoglobin of the unit is the total hemoglobin content of the PRBC unit (g/dL).
Statistical analysis
Statistical analysis was performed using SPSS software version 21 (IBM Corp. USA). Descriptive statistics, including mean, median, standard deviation, and range, were calculated for relevant variables. Differences between groups were assessed using independent sample t-tests or Mann–Whitney U-tests, as appropriate. Correlation coefficients were calculated using Pearson’s and Spearman’s rho tests.
Ethical considerations
Before the commencement of the study, donor consent was obtained during the donation process, wherein donors were informed that their donation blood data may be utilized by the institution for quality and improvement purposes. This consent process ensured that donors were aware of and agreed to the potential use of their data for research purposes.
Throughout the study, strict adherence to ethical standards and data protection regulations was maintained to safeguard the confidentiality and privacy of participant information. All data were handled and stored securely, with access restricted to authorized personnel only. In addition, measures were implemented to anonymize data to prevent the identification of individual donors.
Results
Demographic characteristics of blood donors
The study included 250 blood donors with a median age of 33 years (range: 18–55 years). From Figure 1, it is evident that the largest portion of our donor population falls within the 29–38 years of age range with 38%. Figure 2 illustrates the weight distribution among our donor population, indicating the percentage of donors falling within each weight range. Donors aged 18–28 years had a mean weight of 69.8 kg, while those in higher age groups had a mean weight of 74.46 kg.
Figure 1.
The age distribution of a donor population
Figure 2.
The weight distribution of our donor population
This comparison highlights a difference in mean weight between younger donors and those in higher age groups. Donors in the 18–28 years of age range exhibit a slightly lower mean weight compared to older age groups.
Effect of predonation hemoglobin on packed red cell unit quality
Donors with lower PHB levels (12.5–13.0 g/dL) were associated with decreased per UTHB in PRBCs. Figure 3 illustrates the distribution of PHB levels among donors with PHB levels >13.6. Among these donors, the majority, comprising 137 individuals, had PHB levels falling within the range of 14.1–16.
Figure 3.
Distribution of predonation hemoglobin levels among donors
No significant difference in UTHB was observed between donors with PHB levels of 12.5–13.0 g/dL and 13.1–13.5 g/dL, compared to those with PHB levels exceeding 13.6 g/dL. The Whole blood volume collected showed significant correlation with UTHB, as indicated by a p-value of 0.05, presented in Table 1.
Table 1.
Whole blood volume and the measurement of unit hemoglobin before component separation
| Bag type | 350 mL, mean (range) | 450 mL, mean (range) | ||
|---|---|---|---|---|
| Whole blood (volume in mL) | 358 (325–367) | 457 (410–490) | ||
| UTHB (g) | 55.3 (48.0–52.4) | 64.17 (50.5–78.3) |
A significant correlation at the p-value of 0.05 level is seen between whole blood volume and UTHB. UTHB: Unit total hemoglobin
Impact of packed red cell unit preparation methods
PRBCs prepared using the buffy coat method exhibited lower mean UTHB compared to those prepared using the platelet-rich plasma (PRP) method.
Units separated by the buffy coat method in 450 ml bags showed lower mean UTHB compared to those separated in 350 ml bags. Figure 4 illustrates the distribution of blood collection bags utilized for blood donation.
Figure 4.
Distribution of blood collection bags utilized for blood donation
Association between packed red cell unit age and hemolysis
A significant correlation (P = 0.01) was found between the age of PRBC units and hemolysis, with older units demonstrating higher rates of red cell hemolysis during storage.
Gender variation in packed red cell unit quality
No significant difference in UTHB was observed between male and female donors, indicating that gender did not significantly influence PRBC quality in this study.[5]
However, units from female donors had lower hematocrit levels compared to units from male donors.
Effect of manufacturing conditions on packed red cell unit quality
Manufacturing conditions, such as the type of bags used for collection and processing methods, significantly impacted PRBC quality.
Units processed using the buffy coat method in 450 ml bags exhibited lower UTHB and higher hemolysis compared to those processed using the PRP method.
Correlation analysis
A significant correlation was observed between UTHB and red cell mass, highlighting the relationship between these parameters in determining PRBC quality, which was shown in Table 2.
Table 2.
The effect of manufacturing methods on product quality
| Preparation method | Triple 350 mL (PRP) | Triple 450 mL (PRP) | Quadruple (buffy coat) | |||
|---|---|---|---|---|---|---|
| PRBC volume (mL), mean (range) | 272 (185–318) | 349 (256–386) | 274 (247–300) | |||
| Hematocrit (%), mean (range) | 56.96 (53.3–66.9) | 59.04 (53.6–65.1) | 58.68 (54.0–62.7) | |||
| Red cell mass (mL), mean (range) | 164 (130–208) | 206 (175–245) | 161 (141–176) | |||
| UTHB (g), mean (range) | 55.3 (48.0–52.4) | 64.17 (50.5–78.3) | 51.19 (45.13–63.7) | |||
| Hemolysis (%), median (range) | 0.17 (0.048–0.36) | 0.18 (0.04–0.68) | 0.15 (0.08–0.35) |
UTHB: Unit total hemoglobin, PRP: Platelet-rich plasma, PRBC: Packed red cell unit
Discussion
The findings of our study contribute significantly to the understanding of how donor physiognomic characteristics influence the quality of PRBCs and thereby impact transfusion outcomes. By examining various donor factors and PRBC parameters, we gained valuable insights into the complex interplay between donor characteristics and blood product quality.[6,7] Here, we discuss our findings in relation to existing literature, highlighting similarities, discrepancies, and areas for further investigation.
Impact of donor hemoglobin levels on packed red cell unit quality
Our study revealed a clear association between lower PHB levels and decreased per UTHB in PRBCs.[8,9,10]
This highlights the importance of stringent donor screening protocols to ensure that the donor has a minimum hemoglobin level also helps ensure that there is a reasonably consistent level of therapeutic material in the PRBC unit.[11,12]
Effect of packed red cell unit preparation methods
We observed significant differences in UTHB between PRBCs prepared using different processing methods, particularly the buffy coat method and the PRP method. Our findings are consistent with studies[13,14] which also reported variations in hemoglobin content and hemolysis rates between PRBCs prepared using different techniques. These differences highlight the need for standardized processing protocols to ensure consistency and optimize PRBC quality across blood centers.[15,16,17,18]
Association between packed red cell unit age and hemolysis
Our study demonstrated a significant correlation between PRBC age and hemolysis, indicating the impact of storage duration on red cell integrity. Similar findings were reported by Janatpour et al.,[19,20] who also observed increased hemolysis rates in older PRBC units. These consistent findings highlight the importance of strict inventory management practices to minimize storage duration and mitigate the risk of hemolysis-related complications in transfusion recipients.
Gender variation in packed red cell unit quality
While our study did not find a significant difference in UTHB between male and female donors, units from female donors exhibited lower hematocrit levels compared to those from male donors. This finding is consistent with previous research by Neufeld et al.[14] and García-Roa et al.,[21] which reported similar gender-based differences in red cell mass and hematocrit levels. These findings emphasize the importance of considering gender-specific factors in blood donor screening and selection to optimize PRBC quality.
Limitations
Our study has certain limitations that include a relatively small sample size, which may limit the generalizability of the findings to a broader population. Additionally, the retrospective nature of the study introduces potential biases, such as reliance on existing records that may not capture all relevant donor or PRBC parameters. Despite these limitations, the methodology employed aimed to maintain rigor and validity, offering valuable insights into the relationship between donor physiognomic characteristics and PRBC quality.
Future directions
Future research endeavors should aim to address these limitations by conducting prospective, multicenter studies with larger and more diverse patient populations. In addition, further investigation is warranted to explore the underlying mechanisms driving the observed associations and to develop targeted interventions aimed at optimizing PRBC quality and improving transfusion outcomes.
Conclusions
In summary, our study highlights the crucial role of donor characteristics in determining the quality of PRBCs and, consequently, the effectiveness of transfusion therapy. We found that lower PHB levels were associated with decreased hemoglobin content in PRBCs, highlighting the importance of rigorous donor screening to ensure optimal hemoglobin levels. In addition, differences in processing methods and storage duration significantly influenced PRBC quality, emphasizing the need for standardized protocols and strict inventory management practices. While gender-based differences in PRBC quality were minimal, consideration of gender-specific factors in donor selection remains important.
Overall, our findings contribute valuable insights to the field of blood transfusion, informing strategies to optimize PRBC quality and improve patient outcomes. Further research is needed to refine our understanding and implement evidence-based interventions for enhanced transfusion therapy efficacy and safety.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
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