Impact of body weight on hemoglobin increments in adult red blood cell transfusion

A randomized controlled clinical trial to compare the clinical outcome of random-based versus formula-based blood transfusion in a tertiary care hospital setting

BACKGROUND AND OBJECTIVES

Red cell transfusion is the mainstay of therapy for anemia and it is important to transfuse adequate dosage of red cells to maintain tissue oxygen demands. Additionally, it is also important to avoid overload of red cells to prevent adverse effects. Therefore, we compared the rise in hemoglobin and hematocrit for random-Based transfusion (RBT) and formula-based blood transfusion (FBBT) among patients to get a better understanding of differences in clinical outcome between the two methods.

MATERIALS AND METHODS

In this study 752 patients were included who were admitted in the hospital and required transfusion of a single unit of PRBC. Patients included in the study were randomized in two categories, RBT and FBBT, using stratified random sampling without any bias. In RBT category, patients received blood transfusion according to standard practice i.e. patient received the full red cell unit without any modifications in volume. All odd number request in cross-match register during the study period who fulfilled the eligibility were included in this group. In FBBT group, even numbered requests in the crossmatch register were randomized to receive FBBT. In this category, patients received transfusion according to the following formula: Volume of PRBCs to be transfused = TBV × (Desired Hct - Current Hct of patient)/ Hct of donor unit (where the desired rise of Hct is 3%).

RESULTS

In our study we found that the rise in hemoglobin and hematocrit levels were significantly higher for patients receiving FBBT as compared to the patients receiving RBT. Pre-transfusion hemoglobin and hematocrit did not have a significant difference whereas the post transfusion hemoglobin and hematocrit showed a higher rise in the FBBT group as compared to the RBT group. (Welch corrected t = 2.633, p value = 0.0086).

CONCLUSION

This study re-emphasizes the value of FBBT over the routinely used RBT. This study found that FBBT had an edge over RBT, providing significantly higher increase in post-transfusion Hb and Hct. The authors therefore are of the opinion that use of FBBT may be considered in routine clinical practice to optimize transfusions for the patients.

Association of antepartum anemia and red blood cell mass with racial and ethnic disparities in transfusion rates after cesarean delivery: A retrospective cohort study

BACKGROUND

Antepartum anemia among patients undergoing cesarean deliveries has increased over the past decades in the United States. We hypothesized that red blood cell (RBC) mass, reflecting both prepartum anemia and body mass index (BMI), predicts transfusion risk after cesarean delivery beyond racial/ethnic categories.

STUDY DESIGN AND METHODS

A retrospective analysis of cesarean deliveries from 2019 to 2021 was performed using the National Surgical Quality Improvement Program database. The outcome of interest was perioperative transfusion within 72 h of surgery. Multivariable logistic regression models evaluated the potential added predictive value of race and RBC mass, alongside other known predictors of transfusion.

RESULTS

Among 43,869 cesarean deliveries, the perioperative RBC transfusion rate was 3.3%. Anemia and high BMI were the most prominent in Blacks and Native Americans. These two racial groups had a significantly larger RBC mass difference between non-transfused and transfused individuals (ΔRBC mass, 360-400 mL). Cesarean deliveries for placental complications had six-fold higher transfusion odds than those with only a history of cesarean delivery. While race remained a significant predictor, a 400 mL increase in RBC mass was associated with a 35% decrease in transfusion odds.

DISCUSSION

Antepartum anemia prevalence and BMI varied significantly by race/ethnicity, influencing peripartum RBC mass and transfusion rates. Despite the association of races or placental factors, our predictive model demonstrated a significant reduction of transfusion odds with increased antepartum RBC mass. As a parameter that accounts for varied hemoglobin levels and BMI, estimated RBC mass may be a useful metric for assessing transfusion risk in diverse populations.

The association of donor and recipient sex on sepsis rates and hemoglobin increment among critically ill patients receiving red cell transfusions in a retrospective study

Background

Existing research presents conflicting results on the influence of blood donor sex on hemoglobin (Hb) change and transfusion-associated infection and mortality in transfusion recipients.

Aim

This retrospective study explored the association between donor and recipient sex on hospital-onset sepsis (HO-sepsis) and Hb changes in critically ill patients receiving red blood cell (RBC) transfusions.

Methods

Data from 2010-2020 were extracted from an academic hospital's clinical database and a blood supplier's donor database. HO-sepsis was determined based on the International Classification of Diseases and Related Health Problems 10th Revision (ICD-10) diagnostic codes without requiring a microbiology test within the first 48 h of admission. Hb increments were determined by comparing the last Hb result in the 24-h period prior to RBC unit issue and the first Hb result within 4-24 h after RBC unit issued for transfusion.

Results

25,585 critically ill patients received one or more RBC transfusions; 3,410 were included in the HO-sepsis and 3,487 in the Hb increment analysis. There was no significant differences in the HO-sepsis rate among the four groups, but female recipients were more prone to HO-sepsis than males (OR 1.48, p = 0.04). Multivariate analysis found that the number of RBC unit transfused (p = 0.001) and recipient age (p = 0.03), but not recipient sex (p = 0.63), were significant contributors to HO-sepsis. Male blood was associated with higher Hb than female blood in female recipients (p = 0.007), but not in male recipients (p = 0.75). Variables such as donor Hb levels and recipient Hb level influenced Hb increments.

Conclusion

Blood donor sex was not associated with HO-sepsis in critically ill patients receiving RBC transfusion. Male to female transfusions were associated with a higher Hb increment in recipients. Further exploration of the impact of sex mis-matched transfusion on recipient outcomes is warranted.

From Unit to Dose: A Machine Learning Approach for Precise Prediction of Hemoglobin and Iron Content in Individual Packed Red Blood Cell Units

Transfusion of packed red blood cells (pRBCs) saves lives, but iron overload limits survival of chronically transfused patients. Quality control methods, which involve entering pRBC units and removing them from the blood supply, reveal that hemoglobin (38.5-79.9 g) and heme iron (133.42-276.89 mg) vary substantially between pRBCs. Yet, neither hemoglobin nor iron content can be quantified for individual clinically used pRBCs leading to rules of thumb for pRBC transfusions. Keeping their integrity, the authors seek to predict hemoglobin/iron content of any given pRBC unit applying eight machine learning models on 6,058 pRBCs. Based on thirteen features routinely collected during blood donation, production and quality control testing, the model with best trade-off between performance and complexity in hemoglobin/iron content prediction is identified. Validation of this model in an independent cohort of 2637 pRBCs confirms an adjusted R2 > 0.9 corresponding to a mean absolute prediction error of ≤1.43 g hemoglobin/4.96 mg iron (associated standard deviation: ≤1.13 g hemoglobin/3.92 mg iron). Such unprecedented precise prediction enables reliable pRBC dosing per pharmaceutically active agent, and monitoring iron uptake in patients and individual iron loss in donors. The model is implemented in a free open source web application to facilitate clinical application.

Assessing predictors of futility in patients receiving massive transfusions

BACKGROUND

Massive transfusions are associated with a high mortality rate, but there is little evidence indicating when such efforts are futile. The purpose of this study was to identify clinical variables that could be used as futility indicators in massively transfused patients.

METHODS

We retrospectively analyzed 138 adult surgical patients at our institution receiving a massive transfusion (2016-2019). Peak lactate and nadir pH within 24 h of massive transfusion initiation, along with other clinical variables, were assessed as predictors of the primary outcome, in-hospital mortality.

RESULTS

The overall rate of in-hospital mortality among our patient population was 52.9% (n = 73). Increasing lactate and decreasing pH were associated with greater mortality among massively transfused patients. Mortality rates were ~2-fold higher for patients in the highest lactate category (≥10.0 mmol/L: 25 of 37; 67.6%) compared to the lowest category (0.0-4.9 mmol/L: 17 of 48; 35.4%) (p = .005), and ~2.5-fold higher for patients in the lowest pH category (<7.00: 8 of 9; 88.9%) compared to the highest category (≥7.40: 8 of 23; 34.7%) (p = .016). Increasing age was also associated with higher mortality (≥65 years: 24 of 33; 72.7%) when compared to younger patients (18-64 years: 49 of 105; 46.7%) (p = .010).

CONCLUSIONS

Peak lactate ≥10.0 mmol/L, nadir pH <7.00, and age ≥65 years were significantly associated with higher rates of in-hospital mortality among massively transfused patients. Incorporating these clinical parameters into a futility index for massive transfusions will be useful in situations where blood products are scarce and/or mortality may be unavoidable.