Nonclinical factors affecting intraoperative red blood cell transfusion: a systematic review

PURPOSE

There is significant variability in intraoperative red blood cell (RBC) transfusion practice. We aimed to use the theoretical domains framework (TDF) to categorize nonclinical and behavioural factors driving intraoperative RBC transfusion practice in a systematic review of the literature.

SOURCE

We searched electronic databases from inception until August 2021 to identify studies evaluating nonclinical factors affecting intraoperative RBC transfusion. Using the Mixed Methods Appraisal Tool, we assessed the quality of included studies and identified relevant nonclinical factors, which were coded into TDF domains by two independent reviewers using NVivo (Lumivero, QSR International, Burlington, MA, USA). We identified common themes within domains and sorted domains based on the frequency of reported factors.

PRINCIPAL FINDINGS

Our systematic review identified 18 studies: nine retrospective cohort studies, six cross-sectional surveys, and three before-and-after studies. Factors related to the social influences, behavioural regulation, environmental context/resources, and beliefs about consequences domains of the TDF were the most reported factors. Key factors underlying the observed variability in transfusion practice included the social effects of peers, patients, and institutional culture on decision-making (social influences), and characteristics of the practice environment including case volume, geographic location, and case start time (environmental context/resources). Studies reported variable beliefs about the consequences of both intraoperative transfusion and anemia (beliefs about consequences). Provider- and institutional-level audits, educational sessions, and increased communication between surgeons/anesthesiologists were identified as strategies to optimize intraoperative transfusion decision-making (behavioural regulation).

CONCLUSION

Our systematic review has synthesized the literature on nonclinical and behavioural factors impacting intraoperative transfusion decision-making, categorized using the TDF. These findings can inform evidence-based interventions to reduce intraoperative RBC transfusion variability.

STUDY REGISTRATION

Open Science Framework ( https://osf.io/pm8zs/?view_only=166299ed28964804b9360c429b1218c1 ; first posted, 3 August 2022).

Implementation of an electronic identification system in the setting of perioperative autologous cell salvage transfusion: Experience at a university hospital

Perioperative autologous cell salvage (PACS) is one of the effective strategies in patient blood management (PBM). However, mistransfusion, in which the wrong blood is transfused to the wrong patient, of PACS units has been reported. In this study, we implemented a bar code-based electronic identification system (EIS) for blood transfusion in the setting of PACS transfusion. Between February 2009 and December 2020, a total of 12341 surgical patients (9% of whom received surgical interventions) received blood transfusion, among whom 6595 (54 %) received autologous blood transfusion alone, 2877 (23 %) both autologous and allogeneic blood transfusions, and 2869 (23 %) allogeneic blood transfusion alone. Among autologous blood conservation techniques, PACS units were transfused to 7873 patients (83 %) without a single mistransfusion. Rates of overall compliance with the electronic pre-transfusion check at the bedside for all autologous units and PACS units were 98.8 and 98.5 %, respectively. Our observations suggest that a bar code-based EIS can be successfully applied to PACS transfusion, as well as allogeneic blood transfusion in operating rooms.

Making reasonable decisions: a qualitative study of medical decision making in the care of patients with a clinically significant haemoglobin disorder

RATIONALE, AIMS AND OBJECTIVES

Therapies utilized in patients with clinically significant haemoglobin disorders appear to vary between clinicians and units. This study aimed to investigate the processes of evidence implementation and medical decision making in the care of such patients in NSW, Australia.

METHODS

Using semi-structured interviews, 11 haematologists discussed their medical decision-making processes with particular attention paid to the use of published evidence. Transcripts were thematically analysed by a single investigator on a line-by-line basis.

RESULTS

Decision making surrounding the care of patients with significant haemoglobin disorders varied and was deeply contextual. Three main determinants of clinical decision making were identified - factors relating to the patient and to their illness, factors specific to the clinician and the institution in which they were practising and factors related to the notion of evidence and to utility and role of evidence-based medicine in clinical practice.

CONCLUSIONS

Clinicians pay considerable attention to medical decision making and evidence incorporation and attempt to tailor these to particular patient contexts. However, the patient context is often inferred and when discordant with the clinician's own contexture can lead to discomfort with decision recommendations. Clinicians strive to improve comfort through the use of experience and trustworthy evidence.

An Interdisciplinary Education Initiative to Promote Blood Conservation in Cardiac Surgery

Transfusion practices vary extensively for patients undergoing cardiac surgical procedures, leading to high utilization of blood products despite evidence that transfusions negatively impact outcomes. An important factor affecting transfusion practice is recognition of the importance of teams in cardiac surgery care delivery. This article reports an evidenced-based practice (EBP) initiative constructed using the Society of Thoracic Surgery (STS) 2011 Blood Conservation Clinical Practice Guidelines (CPGs) to standardize transfusion practice across the cardiac surgery team at a large academic medical center. Project outcomes included: a) Improvement in clinician knowledge related to the STS Blood Conservation CPGs; and b) Decreased blood product utilization for patients undergoing cardiac surgical procedures. Participants' scores reflected an improvement in the overall knowledge of the STS CPGs noting a 31.1% (p = 0.012) increase in the number of participants whose practice reflected the Blood Conservation CPGs post intervention. Additionally, there was a reduction in overall blood product utilization for all patients undergoing cardiac surgery procedures post intervention (p = 0.005). Interdisciplinary education based on the STS Blood Conservation CPGs is an effective way to reduce transfusion practice variability and decrease utilization of blood products during cardiac surgery.

Geographic variability in potentially discretionary red blood cell transfusions after coronary artery bypass graft surgery

OBJECTIVE

A number of established regional quality improvement collaboratives have partnered to assess and improve care across their regions under the umbrella of the Cardiac Surgery Quality Improvement (IMPROVE) Network. The first effort of the IMPROVE Network has been to assess regional differences in potentially discretionary transfusions (<3 units red blood cells [RBCs]).

METHODS

We examined 11,200 patients undergoing isolated nonemergent coronary artery bypass graft surgery across 56 medical centers in 4 IMPROVE Network regions between January 2008 and June 2012. Each center submitted the most recent 200 patients who received 0, 1, or 2 units of RBC transfusion during the index admission. Patient and disease characteristics, intraoperative practices, and percentage of patients receiving RBC transfusions were collected. Region-specific transfusion rates were calculated after adjusting for pre- and intraoperative factors among region-specific centers.

RESULTS

There were small but significant differences in patient case mix across regions. RBC transfusions of 1 or 2 units occurred among 25.2% of coronary artery bypass graft procedures (2826 out of 11,200). Significant variation in the number of RBC units used existed across regions (no units, 74.8% [min-max, 70.0%-84.1%], 1 unit, 9.7% [min-max, 5.1%-11.8%], 2 units, 15.5% [min-max, 9.1%-18.2%]; P < .001). Variation in overall transfusion rates remained after adjustment (9.1%-31.7%; P < .001).

CONCLUSIONS

Delivery of small volumes of RBC transfusions was common, yet varied across geographic regions. These data suggest that differences in regional practice environments, including transfusion triggers and anemia management, may contribute to variability in RBC transfusion rates.

The need to label red blood cell units with their haemoglobin content: a single centre study on haemoglobin variations due to donor-related factors

BACKGROUND

Red blood cell (RBC) transfusions are given as "number of units" without considering the haemoglobin (Hb) content of these units. Donor factors influencing Hb level in whole blood donors and, ultimately, in RBC units have not been studied.

MATERIALS AND METHODS

Donor data for a period of 1.5 years were retrospectively analysed and the effects of age, gender and weight on the Hb level of the donors were determined. The correlation between donor's Hb concentration with total Hb in the RBC unit was analysed. Additionally, actual Hb content of 125 RBC units was determined. The total Hb content of these RBC units was also mathematically calculated based on the blood donors' Hb. The ability of this mathematically calculated Hb to predict actual Hb content per RBC unit was then analysed.

RESULTS

The mean Hb level in female donors was 1.79 g/dL lower than in the male donors (p<0.001). Increasing age was associated with a lower mean Hb in the donors (p<0.01), while a higher body weight correlated weakly (r=0.06) but significantly with increased mean Hb (p<0.01). Logistic regression analysis showed that in blood donors, female gender had a stronger influence on lowering the mean Hb than either older age or lower weight. A variation of nearly 100% (42.3-80.8 g Hb per unit) was seen in the total Hb content of the RBC units tested. Mathematically calculated Hb content correlated well (r=0.6; p<0.01) with the actual Hb content of the RBC units.

DISCUSSION

We demonstrated the effect of gender, age and weight on Hb levels in whole blood donors. Dissimilarities in the donor Hb caused nearly 100% variations in the Hb content of the RBC units. It would, therefore, be prudent to label RBC units with their total Hb content. This total Hb content can be predicted fairly accurately from the donor's pre-donation Hb level.

Blood transfusions in cardiac surgery: indications, risks, and conservation strategies

Although red blood cell (RBC) transfusions are frequently used in cardiac operations, an increasing amount of data has demonstrated deleterious consequences. Consequently, the appropriate use of this limited resource is unclear. In this review, we discuss the relationship between anemia and the outcomes of cardiac surgical procedures, the risks associated with RBC transfusion, and the impact of blood transfusions on mortality and morbidity after cardiac operations. The review concludes with a discussion of randomized trials comparing restrictive versus liberal transfusion strategies and a consideration of blood conservation techniques.

RBC transfusion practices among critically ill patients: has evidence changed practice?

OBJECTIVE

Increasing evidence, including publication of the Transfusion Requirements in Critical Care trial in 1999, supports a lower hemoglobin threshold for RBC transfusion in ICU patients. However, little is known regarding the influence of this evidence on clinical practice over time in a large population-based cohort.

DESIGN

Retrospective population-based cohort study.

SETTING

Thirty-five Maryland hospitals.

PATIENTS

Seventy-three thousand three hundred eighty-five nonsurgical adults with an ICU stay greater than 1 day between 1994 and 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The unadjusted odds of patients receiving an RBC transfusion increased from 7.9% during the pre-Transfusion Requirements in Critical Care baseline period (1994-1998) to 14.7% during the post-Transfusion Requirements in Critical Care period (1999-2007). A logistic regression model, including 40 relevant patient and hospital characteristics, compared the annual trend in the adjusted odds of RBC transfusion during the pre- versus post-Transfusion Requirements in Critical Care periods. During the pre-Transfusion Requirements in Critical Care period, the trend in the adjusted odds of RBC transfusion did not differ between hospitals averaging>200 annual ICU discharges and hospitals averaging≤200 annual ICU discharges (odds ratio, 1.07 [95% CI, 1.01-1.13] annually and 1.03 [95% CI, 0.99-1.07] annually, respectively; p=0.401). However, during the post-Transfusion Requirements in Critical Care period, the adjusted odds of RBC transfusion decreased over time in higher ICU volume hospitals (odds ratio, 0.96 [95% CI, 0.93-0.98] annually) but continued to increase in lower ICU volume hospitals (odds ratio, 1.10 [95% CI, 1.08-1.13] annually), p<0.001.

CONCLUSIONS

In this population-based cohort of ICU patients, the unadjusted odds of RBC transfusion increased in both higher and lower ICU volume hospitals both before and after Transfusion Requirements in Critical Care publication. After adjusting for relevant characteristics, the odds continued to increase in lower ICU volume hospitals in the post-Transfusion Requirements in Critical Care period, but it decreased in higher ICU volume hospitals. This suggests that evidence supporting restrictive RBC transfusion thresholds may not be uniformly translated into practice in different hospital settings.

Variation of blood transfusion in patients undergoing major noncardiac surgery

OBJECTIVE

To examine the hospital variability in use of red blood cells (RBCs), fresh-frozen plasma (FFP), and platelet transfusions in patients undergoing major noncardiac surgery.

BACKGROUND

Blood transfusion is commonly used in surgical procedures in the United States. Little is known about the hospital variability in perioperative transfusion rates for noncardiac surgery.

METHODS

We used the University HealthSystem Consortium database (2006-2010) to examine hospital variability in use of allogeneic RBC, FFP, and platelet transfusions in patients undergoing major noncardiac surgery. We used regression-based techniques to quantify the variability in hospital transfusion practices and to study the association between hospital characteristics and the likelihood of transfusion.

RESULTS

After adjusting for patient risk factors, hospital transfusion rates varied widely for patients undergoing total hip replacement (THR), colectomy, and pancreaticoduodenectomy. Compared with patients undergoing THR in average-transfusion hospitals, patients treated in high-transfusion hospitals have a greater than twofold higher odds of being transfused with RBCs [adjusted odds ratio (AOR) = 2.41; 95% confidence interval (CI), 1.89-3.09], FFP (AOR = 2.81; 95% CI, 2.02-3.91), and platelets (AOR = 2.52; 95% CI, 1.95-3.25), whereas patients in low-transfusion hospitals have an approximately 50% lower odds of receiving RBCs (AOR = 0.45; 95% CI, 0.35-0.57), FFP (AOR = 0.37; 95% CI, 0.27-0.51), and platelets (AOR = 0.42; 95% CI, 0.29-0.62). Similar results were obtained for colectomy and pancreaticoduodenectomy.

CONCLUSIONS

There was dramatic hospital variability in perioperative transfusion rates among patients undergoing major noncardiac surgery at academic medical centers. In light of the potential complications of transfusion therapy, reducing this variability in hospital transfusion practices may result in improved surgical outcomes.

Effect of hospital culture on blood transfusion in cardiac procedures

BACKGROUND

In our effort to reduce the use of blood products in cardiac operations in a health care system, we noted variations in transfusion practices among facilities. Interestingly, surgeons practicing at the same hospital had similar transfusion rates. We sought to quantitate the contribution of hospital influence on individual surgeons' transfusion practices.

METHODS

Blood transfusion data for coronary artery bypass graft operations at 12 Providence Health & Services facilities between January 2008 and June 2011 were reviewed. Frequency of perioperative blood transfusion, amount of transfusion, components transfused, and timing of transfusions were compared. Variation among surgeons at the same institution vs between institutions was computed based on multilevel mixed-effect logistic and linear regression models. Intraclass correlation coefficients were calculated.

RESULTS

A total of 5,744 nonemergency first-time coronary artery bypass graft procedures were performed by 42 not-low volume (n>30 in 2.5 years) surgeons at 12 Providence Health & Services hospitals during the 3.5-year study period. Frequency, amount, timing, and blood component usage were different among facilities but relatively similar for surgeons within a facility. The variance of red blood cell transfusion rate among hospitals (.82) is more than two times that among surgeons practicing within the same hospital (.35). Thus, surgeons contribute 30% to the variation, and 70% of the total variation can be explained by the hospital effect.

CONCLUSIONS

In our multihospital system, the hospital that a surgeon practices at plays a larger role in determining blood utilization than the individual surgeon's preference.

An evolution in blood management: past, present, and future

Blood management is a concept that adopts a principle of improving patient outcome by integrating all available techniques to ensure safety, availability, and appropriate allocation of blood products. This constitutes a model of multidisciplinary care where the changes in culture are system directed on the basis of evidence-based medicine. There are about 14% US hospitals where any kind of blood management program exists, although the idea remains the same but the programs vary in their execution, implementation, and ultimately providing the value to patients. In this article, we have described our experience of creating a patient-centric, cost-effective, evidence-based, and multipronged program creation with scalable results. The use of data, education, process improvement, engagement, and accountability of caregivers have resulted in sustained results and helped in creating a comprehensive blood management program.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines

BACKGROUND

Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.

METHODS

The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.

RESULTS

In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.

CONCLUSIONS

Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.

Thrombelastography (TEG) or thromboelastometry (ROTEM) to monitor haemotherapy versus usual care in patients with massive transfusion

BACKGROUND

Severe bleeding and coagulopathy as a result of massive transfusion are serious clinical conditions that are associated with high mortality. Thromboelastography (TEG) and thromboelastometry (ROTEM) are increasingly used to guide transfusion strategy but their roles remain disputed.

OBJECTIVES

To systematically assess the benefits and harms of a TEG or ROTEM guided transfusion strategy in randomized trials involving patients with severe bleeding.

SEARCH STRATEGY

Randomized clinical trials (RCTs) were identified from electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 9); MEDLINE; EMBASE; Science Citation Index Expanded; International Web of Science; CINAHL; LILACS; and the Chinese Biomedical Literature Database (up to 31st October 2010). We contacted trial authors, authors of previous reviews, and manufacturers in the field.

SELECTION CRITERIA

We included all RCTs, irrespective of blinding or language, that compared transfusion guided by TEG or ROTEM to transfusion guided by clinical judgement and standard laboratory tests, or both.

DATA COLLECTION AND ANALYSIS

Two authors independently abstracted data; they resolved any disagreements by discussion. We presented pooled estimates of the intervention effects on dichotomous outcomes as relative risks (RR) and on continuous outcomes as mean differences, with 95% confidence intervals (CI). Our primary outcome measure was all cause mortality. We performed subgroup and sensitivity analyses to assess the effect of TEG or ROTEM in adults and children on various clinical and physiological outcomes. We assessed the risk of bias through assessment of trial methodological components and the risk of random error through trial sequential analysis.

MAIN RESULTS

We included nine RCTs with a total of 776 participants; only one trial had a low risk of bias. We found two ongoing trials but were unable to retrieve any data from them. Compared with standard treatment, TEG or ROTEM showed no statistically significant effect on overall mortality (3.78% versus 5.11%, RR 0.77, 95% CI 0.35 to 1.72; I(2) = 0%) but only five trials provided data on mortality. Our analyses demonstrated a statistically significant effect of TEG or ROTEM on the amount of bleeding (MD -85.05 ml, 95% CI -140.68 to -29.42; I(2) = 26%) but failed to show any statistically significant effect on other predefined outcomes.

AUTHORS' CONCLUSIONS

There is an absence of evidence that TEG or ROTEM improves morbidity or mortality in patients with severe bleeding. Application of a TEG or ROTEM guided transfusion strategy seems to reduce the amount of bleeding but whether this has implications for the clinical condition of patients is still uncertain. More research is needed.

Utilization of blood transfusion among older adults in the United States

BACKGROUND

While there have been epidemiologic studies of blood donors, the characteristics of individuals who receive transfusions have not been well described for the US population.

STUDY DESIGN AND METHODS

Subjects were from the nationally representative Health and Retirement Study whose data were linked to Medicare files from 1991 through 2007 (n = 16,377). A cohort study was conducted to assess the frequency of transfusion in older Americans over time and to describe the characteristics of blood recipients.

RESULTS

Thirty-one percent (95% confidence interval [CI], 30%-33%) of older Americans received at least one transfusion within a 10-year period and 5.8% (95% CI, 5.4%-6.2%) experienced repeated transfusion-related visits within 30 days. The mean number of transfusion-related visits was 2.3 over a 10-year period (95% CI, 2.2-2.4). Older Americans who lived in the South were most likely to receive a transfusion (34%), independent of demographic and health-related factors, while those who lived in the western United States were the least likely (26%). Predictors of transfusion included smoking, low body mass index, and a history of cancer, diabetes mellitus, end-stage renal disease, and heart disease. African-Americans and Mexican-Americans had greater rates of blood utilization than other races and other Hispanics (respectively). There were also differences in transfusion utilization by education, marital status, religion, and alcohol use.

CONCLUSIONS

Transfusion is common in older Americans. Regional variations in blood use are not explained by patient characteristics alone.

Early results from a novel quality outcomes program: the American Society Of Breast Surgeons' Mastery of Breast Surgery

BACKGROUND

In 2008, the American Society for Breast Surgeons launched its Mastery in Breast Surgery Pilot Program to demonstrate feasibility of a Web-based tool for breast surgeons to document and monitor quality outcomes.

METHODS

Participating surgeons report performance of three quality measures for breast procedures: Was a needle biopsy performed to evaluate the breast lesion before the procedure? Was the surgical specimen oriented? For nonpalpable lesions localized with image guidance, was there intraoperative confirmation of removal? Data are collected through the American Society for Breast Surgeons' Web-based software using a secure server and encrypted identification numbers. Surgeon demographic/practice characteristic data were collected, and logistic regression models were used to identify factors that affected quality measures.

RESULTS

From October 2008 to December 2009, a total of 696 surgeons entered data for 28,798 breast procedures. Participants were diverse in years in practice, geographic location, practice setting and type, and proportion of practice made up of breast procedures. Delivery of "optimal care" (defined as delivery of all quality measures for which there was no valid clinical reason for nonperformance) was high for all surgeon demographic/practice characteristics, ranging from 81% to 94%. Statistically significant differences in delivery of quality measures were observed within all physician demographic/practice characteristic variables, but many absolute differences were small.

CONCLUSIONS

The high level of participation and volume of breast procedures for which quality measure data was entered demonstrate this is a feasible means of collecting quality performance data. Future development will include identifying/developing additional quality measures and establishing evidence-based benchmarks for care on the basis of data collected.