Risk factors for massive transfusion in obstetrical hemorrhage and consideration of a whole blood program

Background

Postpartum hemorrhage (PPH) is one of the leading causes of obstetric complications. The goal of this study was to identify risk factors for obstetric (OB) massive transfusion (MT) and determine the feasibility of developing a low-titer group O RhD-positive whole blood (LTO + WB) protocol for OB hemorrhage.

Study Design and Methods

A retrospective study of OB patients who received transfusion within 24 h. MT patients were those who received >3 U of pRBC within 1 h or > 10 U in 24 h. Patient demographics, OB history, comorbidities, blood type, antibody status, and known risk factors for PPH and maternal-fetal outcomes were compared. Logistic regression was used for univariate and multivariate analyses.

Results

Of the 610 transfused OB patients, 12.0% (n = 73) required MT. Groups were well matched for body mass index (BMI), maternal comorbidities, and history of spontaneous vaginal deliveries. The incidence of the previous cesarean section was higher in the MT group. Exactly 93.9% of patients were RhD-positive and 3.77% of all patients possessed an antibody on pretransfusion testing. Patients with MT had a longer length of stay (LOS), higher rate of intensive care unit (ICU) admission, fetal death, and hysterectomy. Multivariate analysis found age >35, PPH, placenta percreta, accreta, and increta to be significant (p < .05) risk factors for MT.

Discussion

Patients over 35 years and those with abnormal placentation are at increased risk of requiring MT. With a time to delivery of 2 days, potential MT patients can be identified early, and with a 94% rate of RhD-positive+, they are eligible to receive low-titer O whole blood (LTOWB) providing hemostatic resuscitation with reduced donor exposure.     

A narrative review of prehospital hemorrhagic shock treatment with non-blood product medications

Background

Hemorrhagic shock remains a leading cause of death in both military and civilian trauma casualties. While standard of care involves blood product administration, maintaining normothermia, and restoring hemostatic function, alternative strategies to treat severe hemorrhage at or near the point of injury are needed. We reviewed adjunct solutions for managing severe hemorrhage in the prehospital environment.

Methods

We performed a literature review by searching PubMed with a combination of several keywords. Additional pertinent studies were identified by crossreferencing primary articles. Clinical experience of each author was also considered.

Results

We identified several promising antishock therapies that can be utilized in the prehospital setting: ethinyl estradiol sulfate (EES), polyethylene glycol 20,000 (PEG20K), C1 esterase inhibitors (e.g. Berinert, Cinryze), cyclosporin A, niacin, bortezomib, rosiglitazone, icatibant, diazoxide, and valproic acid (VPA).

Conclusion

Several studies show promising adjunct treatment options in the management of severe prehospital hemorrhage. While some are rarely used, many others are readily available and commonly utilized for other indications. This suggests the potential for future use in resourcelimited settings. Human studies and case reports supporting their use are currently lacking.     

Conservation of Rh negative Low Titer O Whole Blood (LTOWB) and the need for a national conversation to define its use in trauma transfusion protocols

Low-titer group O whole blood (LTOWB) use is growing steadily in the United States. Although the percentage of O negative LTOWB use by Red Cross hospitals has remained steady at ~23% over the last 2 years, this elevated use rate is twice that of O negative RBC components. Given the more restricted group O donor pool, this level of use will make it difficult to expand the use of this product. Evaluation of hospital practices regarding females of childbearing potential show significant variability with some hospitals transfusing O positive, with others choosing to restrict this population to O negative LTOWB or only O negative RBC component therapy. To ensure access of LTOWB to all patients who may benefit and to maintain sufficient supplies, we recommend developing standardized practice recommendations for its use.     

Would doctors dream of electric blood bankers? Large language model-based artificial intelligence performs well in many aspects of transfusion medicine

Background

Large language models (LLMs) excel at answering knowledge-based questions. Many aspects of blood banking and transfusion medicine involve no direct patient care and require only knowledge and judgment. We hypothesized that public LLMs could perform such tasks with accuracy and precision.

Study Design and Methods

We presented three sets of tasks to three publicly-available LLMs (Bard, GPT-3.5, and GPT-4). The first was to review short case presentations and then decide if a red blood cell transfusion was indicated. The second task was to answer a set of consultation questions common in clinical transfusion practice. The third task was to take a multiple-choice test experimentally validated to assess internal medicine postgraduate knowledge of transfusion practice (the BEST-TEST).

Results

In the first task, the area under the receiver operating characteristic curve for correct transfusion decisions was 0.65, 0.90, and 0.92, respectively for Bard, GPT-3.5 and GPT-4. All three models had a modest rate of acceptable responses to the consultation questions. Average scores on the BEST-TEST were 55%, 40%, and 87%, respectively.

Conclusion

When presented with transfusion medicine tasks in natural language, publicly available LLMs demonstrated a range of ability, but GPT-4 consistently scored very well in all tasks. Research is needed to assess the utility of LLMs in transfusion medicine practice. Transfusion Medicine physicians should consider their role alongside such technologies, and how they might be used for the benefit and safety of patients.     

Transfusion-associated adverse events incidence and severity after the implementation of an active hemovigilance program with 24 h follow-up. A prospective cohort study

Background

Hemovigilance (HV) is usually based on voluntary reports (passive HV). Our aim is to ascertain credible incidence, severity, and mortality of transfusion-associated adverse events (TAAEs) using an active HV program.

Study Design and Methods

Prospective cohort study to estimate transfusion risk after 46,488 transfusions in 5830 patients, using an active HV program with follow-up within the first 24 h after transfusion. We compared these results to those with the previously established passive HV program during the same 30 months of the study. We explored factors associated with the occurrence of TAAEs using generalized estimating equations models.

Results

With the active HV program TAAEs incidence was 57.3 (95% CI, 50.5–64.2) and mortality 1.1 (95% CI, 0.13–2.01) per 10,000 transfusions. Incidence with the new surveillance model was 14.0 times higher than with the passive. Most events occurred when transfusions had already finished (60.2%); especially pulmonary events (80.4%). Three out of five deaths and 50.3% of severe TAAEs were pulmonary. In the multivariate analysis surgical patients had half TAAEs risk when compared to medical patients (OR, 0.53; 95% CI, 0.34–0.78) and women had nearly twice the risk of a pulmonary event compared to men (OR, 1.84; 95% CI, 1.03–3.32). Patient's age, blood component type, or blood component shelf-life were unrelated to TAAEs risk.

Discussion

Active hemovigilance programs provide additional data which may lead to better recognition and understanding of TAAEs and their frequency and severity.     

Results from a type two hybrid-effectiveness study to implement a preoperative anemia and iron deficiency screening,evaluation, and management pathway

Background

Implementation of pathways to screen surgical patients for preoperative anemia and iron deficiency remains limited. This study sought to measure the impact of a theoretically informed, bespoke change package on improving the uptake of a Preoperative Anemia and Iron Deficiency Screening, Evaluation, and Management Pathway.

Study Design and Methods

Pre-post interventional study using a type two hybrid-effectiveness design evaluated implementation. Four hundred (400) patient medical record reviews provided the dataset (200 pre- and 200-post implementation). The primary outcome measure was compliance with the pathway. Secondary outcome measures (clinical outcomes) were anemia on day of surgery, exposure to a red blood cell (RBC) transfusion, and hospital length of stay. Validated surveys facilitated data collection of implementation measures. Propensity score-adjusted analyses determined the effect of the intervention on clinical outcomes, and a cost analysis determined the economic impact.

Results

For the primary outcome, compliance improved significantly post-implementation (Odds Ratio 10.6 [95% CI 4.4–25.5] p < .000). In secondary outcomes, adjusted analyses point estimates showed clinical outcomes were slightly improved for anemia on day of surgery (Odds Ratio 0.792 [95% CI 0.5–1.3] p = .32), RBC transfusion (Odds Ratio 0.86 [95% CI 0.41–1.78] p = .69) and hospital length of stay (Hazard Ratio 0.96 [95% CI 0.77–1.18] p = .67), although these were not statistically significant. Cost savings of $13,340 per patient were realized. Implementation outcomes were favorable for acceptability, appropriateness, and feasibility.

Conclusion

The change package significantly improved compliance. The absence of a statistically significant change in clinical outcomes may be because the study was powered to detect an improvement in compliance only. Further prospective studies with larger samples are needed. Cost savings of $13,340 per patient were achieved and the change package was viewed favorably.     

Transfusion of red blood cells in venoarterial extracorporeal membrane oxygenation: A multicenter retrospective observational cohort study

Background

Evidence-based recommendations for transfusion in patients with venoarterial extracorporeal membrane oxygenation (VA ECMO) are scarce. The current literature is limited to single-center studies with small sample sizes, therefore complicating generalizability. This study aims to create an overview of red blood cell (RBC) transfusion in VA ECMO patients.

Methods

This international mixed-method study combined a survey with a retrospective observational study in 16 centers. The survey inventoried local transfusion guidelines. Additionally, retrospective data of all adult patients with a VA ECMO run >24 h (January 2018 until July 2019) was collected of patient, ECMO, outcome, and daily transfusion parameters. All patients that received VA ECMO for primary cardiac support were included, including surgical (i.e., post-cardiotomy) and non-surgical (i.e., myocardial infarction) indications. The primary outcome was the number of RBC transfusions per day and in total. Univariable logistic regressions and a generalized linear mixed model (GLMM) were performed to assess factors associated with RBC transfusion.

Results

Out of 419 patients, 374 (89%) received one or more RBC transfusions. During a median ECMO run of 5 days (1st–3rd quartile 3–8), patients received a median total of eight RBC units (1st–3rd quartile 3–17). A lower hemoglobin (Hb) prior to ECMO, longer ECMO-run duration, and hemorrhage were associated with RBC transfusion. After correcting for duration and hemorrhage using a GLMM, a different transfusion trend was found among the regimens. No unadjusted differences were found in overall survival between either transfusion status or the different regimens, which remained after adjustment for potential confounders.

Conclusion

RBC transfusion in patients on VA ECMO is very common. The sum of RBC transfusions increases rapidly after ECMO initiation, and is dependent on the Hb threshold applied. This study supports the rationale for prospective studies focusing on indications and thresholds for RBC transfusion.