Association of Perioperative Red Blood Cell Transfusions With Venous Thromboembolism in a North American Registry

Evaluation of the efficacy of perioperative tranexamic acid in patients with pelvic and acetabular fractures: A systematic review and meta-analysis

BACKGROUND

Tranexamic acid (TXA) is commonly used to reduce perioperative bleeding in various surgeries, including acetabular and pelvic fractures treated with open reduction and internal fixation (ORIF). However, research on TXA's effectiveness and safety in this context is conflicting. To address this, we conducted a systematic review and meta-analysis on TXA's efficacy and safety in patients with acetabular and pelvic fractures undergoing ORIF.

METHODS

We systematically searched Cochrane, PubMed, and EMBASE databases until August 30, 2023. Our evaluation of TXA focused on 6 domains: estimated blood loss (EBL), blood transfusion units, transfusion rates, thromboembolic events, other complications, and surgery duration. Data from these studies were analyzed using RevMan Manager 5.4.

RESULTS

This study included 4 randomized controlled trials with 179 patients with acetabular and pelvic fractures treated with TXA. The analysis showed that TXA did not significantly reduce EBL, packed red blood cell transfusion units, blood transfusion rates, or surgery duration. There was no significant difference in thromboembolic events or other postoperative complications, like surgical wound issues, pneumonia, heterotopic ossification, and sciatic nerve injuries, between the TXA and control groups.

CONCLUSION

TXA did not demonstrate a significant benefit in reducing perioperative bleeding or complications in patients treated with ORIF for acetabular and pelvic fractures. The utilization of TXA in such clinical scenarios remains a topic necessitating further rigorous investigation to delineate its role in this clinical setting.

Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion in Obese Patients : A Propensity Score-Matched Study

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVES

This study aimed to compare the clinical outcomes of obese patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and open TLIF.

SUMMARY OF BACKGROUND DATA

The perioperative benefits of minimally invasive surgery in obese patients have been described. However, there is limited literature on the patient-reported outcomes (PROs), satisfaction and return to work following MIS-TLIF and open TLIF in this subgroup of patients.

MATERIALS AND METHODS

Obese patients (BMI ≥30.0 kg/m 2 ) who underwent a primary, one-level to two-level open and MIS-TLIF were stratified and matched using propensity scoring. Operative time, length of stay, and perioperative outcomes were recorded. Patient-reported outcomes (PROs) including Oswestry disability index, Short Form-36 physical component score, mental component score, visual analogue scale for back pain and leg pain were compared at each postoperative time point. Achievement of minimal clinically important difference (MCID), patient satisfaction and return to work were also assessed. Revision procedures were recorded at mean 10±3.3 years follow-up.

RESULTS

In total, 236 obese patients were included: 118 open TLIF and 118 MIS-TLIF. Length of stay was longer in the open TLIF cohort and there was a trend toward a higher complication rate. However, there was no difference in operative time, transfusions, or readmissions. Patients who underwent open TLIF reported worse ODI ( P =0.043) and VAS leg pain at two years, although the latter did not reach statistical significance ( P =0.095). Achievement of MCID for each PRO, patient satisfaction, and return to work were also comparable.

CONCLUSIONS

Obese patients who underwent MIS-TLIF had a shorter length of stay and improved functional disability at two years compared those who underwent open TLIF. However, a similar proportion achieved a clinical meaningful improvement. Patient satisfaction and return to work were also comparable at two years.

LEVEL OF EVIDENCE

Level III.

Use of preoperative erythropoietin-stimulating agents is associated with decreased thrombotic adverse events compared to red blood cell transfusion in surgical patients with anaemia

BACKGROUND AND OBJECTIVES

Preoperative red blood cell (RBC) transfusions increase post-operative venous thromboembolic (VTE) events. Erythropoietin-stimulating agents (ESAs) increase VTE risk in cancer patients; we aimed to assess ESA versus RBC-associated VTE risks in a broad population of surgical patients.

MATERIALS AND METHODS

We queried TriNetX Diamond Network from 2006 to 2023, comparing patients with anaemia within 3 months preoperatively who received preoperative ESAs with or without intravenous (IV) iron to patients who received preoperative RBCs. Sub-analyses included (1) all surgeries and (2) cardiovascular surgeries. We propensity score matched for demographics, comorbidities, medical services, post-treatment haemoglobin (g/dL) and, for all-surgery comparisons, surgery type. Outcomes included 30-day post-operative mortality, VTE, pulmonary embolism (PE), disseminated intravascular coagulation (DIC) and haemoglobin.

RESULTS

In our 19,548-patient cohorts, compared with preoperative RBC transfusion, ESAs without IV iron were associated with lower mortality (relative risk [RR] = 0.51 [95% confidence interval (CI), 0.45-0.59]), VTE (RR = 0.57 [0.50-0.65]) and PE (RR = 0.67 [0.54-0.84]). Post-operative haemoglobin was higher in the ESA without IV iron cohort compared with the transfusion cohort (10.0 ± 1.4 vs. 9.4 ± 1.8 g/dL, p = 0.002). Cardiac surgical patients receiving ESAs with or without IV iron had lower risk for post-operative mortality, VTE and PE (p < 0.001) than those receiving RBCs. Post-operative haemoglobin differed between patients receiving ESAs with IV iron versus RBCs (10.1 ± 1.5 vs. 9.4 ± 1.9 g/dL, p = 0.0009).

CONCLUSION

Compared with surgical patients who were transfused RBCs, ESA recipients had reduced 30-day post-operative risk of mortality, VTE, PE and DIC and increased haemoglobin levels. IV iron given with ESAs improved mortality.

Associations between transfusion reactions and thromboembolism development in blood-transfused patients: A retrospective cohort study

BACKGROUND

Blood transfusion (BT) may be associated with an increased risk of thromboembolism. The associations between transfusion reactions (TRs) during BTs and potential risk factors for the development of thromboembolism in patients underwent blood transfusion have not been analyzed. Therefore, this study aimed to compare risk factors associated with the development of venous thromboembolism (VTE) or pulmonary embolism (PE) between patients underwent blood transfusion with and without TRs.

STUDY DESIGNS AND METHODS

The retrospective study was conducted between April 1, 2017, and March 31, 2020, at a medical center in Taiwan. Blood-transfused patients were grouped into two cohorts as follows: those who experienced TRs and those who did not experience TRs. Both cohorts were subjected to follow-up until March 31, 2021. The endpoints for both groups were the occurrence of VTE or PE or the date of March 31, 2021. To investigate between-cohort risk differences, a Kaplan-Meier survival analysis and multiple Cox proportional hazard model was used.

RESULTS

A total of 10,759 patients underwent 59,385 transfusion procedures, with 703 patients in the TR group, and 10,056 patients in the non-TR group. The risk of VTE or PE was twice as high in the TR group than in the non-TR group (adjusted hazard ratio 2.53, 95% confidence interval 1.49-4.29, p = .001). Meanwhile, age, female sex, transfusion frequency increment, and being nondiabetic was associated with an increased risk of developing thromboembolism.

CONCLUSION

TRs are associated with increased long-term thromboembolism risk in patients underwent blood transfusion. It is imperative for clinicians to acknowledge this and maintain rigorous follow-up.

Perioperative Plasma in Addition to Red Blood Cell Transfusions Is Associated With Increased Venous Thromboembolism Risk Postoperatively

BACKGROUND

Perioperative red blood cell (RBC) transfusions increase venous thromboembolic (VTE) events. Although a previous study found that plasma resuscitation after trauma was associated with increased VTE, the risk associated with additional perioperative plasma is unknown.

METHODS

A US claims and EHR database (TriNetX Diamond Network) was queried. We compared surgical patients who received perioperative plasma and RBC to patients who received perioperative RBC but not plasma. Subanalyses included (1) all surgeries (n = 48,580) and (2) cardiovascular surgeries (n = 38,918). Propensity score matching was performed for age at surgery, ethnicity, race, sex, overweight and obesity, type 2 diabetes, disorders of lipoprotein metabolism, essential hypertension, neoplasms, nicotine dependence, coagulopathies, sepsis, chronic kidney disease, liver disease, nonsteroidal anti-inflammatory analgesics, platelet aggregation inhibitors, anticoagulants, hemoglobin level, outpatient service utilization, and inpatient services; surgery type was included for "all surgeries" analyses. Outcomes included 30-day mortality, postoperative VTE, pulmonary embolism (PE), and disseminated intravascular coagulation (DIC).

RESULTS

After matching the surgical cohorts, compared to only RBC, plasma + RBC was associated with higher risk of postoperative mortality (4.52% vs 3.32%, risk ratio [RR]: 1.36 [95% confidence interval, 1.24-1.49]), VTE (3.92% vs 2.70%, RR: 1.36 [1.24-1.49]), PE (1.94% vs 1.33%, RR: 1.46 [1.26-1.68]), and DIC (0.96% vs 0.35%, RR: 2.75 [2.15-3.53]). Among perioperative cardiovascular patients, adding plasma to RBC transfusion was associated with similar increased risk.

CONCLUSIONS

When compared with perioperative RBC transfusion, adding plasma was associated with increased 30-day postoperative mortality, VTE, PE, and DIC risk among surgical and cardiovascular surgical patients. Reducing unnecessary plasma transfusion should be a focus of patient blood management to improve overall value in health care.

Perioperative Transfusion Practices in Adults Having Noncardiac Surgery

Surgical patients are often transfused to manage bleeding and anemia. Best practices for red blood cell (RBC) transfusion administration in patient having noncardiac surgery remains controversial and a robust evaluation and description of perioperative transfusion practices is lacking. We characterized perioperative hemoglobin concentrations and transfusion practices from the prospective VISION cohort which included 39,222 patients aged ≥45 years who had inpatient noncardiac surgery. Variations in transfusion practices were analyzed using hierarchical mixed models, and associations with mortality and complications were evaluated using a nested frailty survival model. Within the cohort, 16.1% (n = 6296) were given perioperative RBC transfusions, with the fraction declining from 20% to 13% over the 6-year study period. The proportion of patients transfused varied by surgery type from 6.4% for low-risk operations (i.e., minor surgery) to 31.5% for orthopedic surgeries. Variations were largely associated with patient hemoglobin concentrations, but also with center (range: 3.7%-27.3%) and country (0.4%-25.3%). Even after adjusting for baseline hemoglobin, comorbidities and type of surgery, both center and country were significant sources of variation in transfusion practices. Among transfused participants, 60.4% (n = 3728/6170) had at least 1 hemoglobin concentration ≤80g/L and 86.0% (n = 5305/6170) had at least 1 hemoglobin concentration ≤90g/L, suggesting that relatively restrictive transfusion strategies were used in most. The proportion of patients receiving at least 1 RBC transfusion declined from 20% to 13% over 6 years. However, there was considerable unexplained variation in transfusion practices.

Blood transfusion is correlated with elevated adult all-cause mortality and cardiovascular mortality in the United States: NHANES 1999 to 2018 population-based matched propensity score study

BACKGROUND AND AIMS

The association of blood transfusion with an increase in medium- and short-term mortality in specific populations has been confirmed. However, the correlation between blood transfusion and long-term mortality in the general population remains unclear. This cohort study evaluated the correlation between blood transfusion and overall and cause-specific mortality in the general American adult population.

METHODS

The authors utilized 10 sets of 2-year cycle data (1999-2018) from the National Health and Nutrition Examination Survey on the outcomes of adults who did and did not receive blood transfusions. Propensity score-matching (1:1) was performed based on age, sex, race, education level, marital status, poverty-income ratio, arteriosclerotic cardiovascular disease, cancer, anemia, hypertension, and diabetes status. After controlling for demographic characteristics and clinical risk factors, Cox regression analysis was performed to evaluate the correlation between blood transfusion and all-cause and cause-specific mortality.

RESULTS

The study included 48,004 adult participants. The risk of all-cause mortality increased by 101 % with blood transfusion, and the risk of cardiovascular mortality increased by 165 %. After propensity score-matching, 6,116 pairs of cases were retained, and the risk of all-cause mortality increased by 84 % with blood transfusion, and the risk of cardiovascular mortality increased by 137 %. The sensitivity analysis results were robust.

CONCLUSIONS

In the general American population, blood transfusion significantly impacts long-term all-cause and cardiovascular mortality and may be an unacknowledged risk factor for death. Thus, the effective management of blood transfusion in the general population may be beneficial.

Venous Thromboembolic Events in Adult Trauma Patients Receiving Balanced Hemostatic Resuscitation (BHR): An Analysis of Their Incidence, Predictors, and Associated Mortality Rates at a Level 1 Trauma Center

Background and objective Studies assessing the incidence of venous thromboembolic (VTE) events in the setting of massive balanced transfusions and/or tranexamic acid (TXA) infusion have yielded varied outcomes. In light of this, we conducted this study to examine the incidence of VTEs in trauma patients requiring blood products, and to identify the risk factors for VTE and mortality in this population. Methods We performed a retrospective analysis of trauma patients admitted to our level 1 trauma center from January 2013 to September 2023. Clinical characteristics were compared between patients who developed VTE and those who did not. A regression analysis of potential variables associated with the development of VTEs and mortality was performed. Results Among 1305 patients (mean age: 42.4 ± 18.8 years) receiving blood products within the initial 24 hours, 4.3% (56 patients) developed a VTE. Patients with VTE experienced prolonged ICU and hospital stays and ventilation duration (p<0.001). They were also noted to have delayed initiation of VTE prophylaxis (104.2 vs. 50.3 hours, p<.001). Prolonged ventilation >7 days was the sole significant factor associated with VTE in multivariate regression analysis [odds ratio (OR): 6.2, p=0.004]. Early TXA administration (within four hours) showed a higher association with VTE than TXA within 24 hours (OR: 2.1, p=0.07 vs. OR 1.6, p=0.22). Massive transfusion was found to increase VTE risk (OR: 2.65, p<0.001). Severe head and neck (OR: 6.0, p=0.002) and chest (OR: 3.8, p=0.01) injuries were key predictors of mortality, while TXA was not significantly associated with mortality in the multivariate model. Conclusions Our study revealed an elevated risk of VTE in patients requiring massive transfusion protocol (MTP, ≥6 units). Early TXA administration was neither associated with increased VTE risk in MTP patients nor increased mortality risk. Strategies directed at reducing the risk of VTE in massively transfused patients while maintaining the survival benefits of balanced resuscitation and TXA need to be devised.

Association between perioperative red blood cell transfusions and postoperative venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Whether perioperative red blood cell transfusions increases the risk of postoperative venous thromboembolism is controversial and uncertain.We aims to explore the relationship between perioperative red blood cell transfusions and the risk of postoperative venous thromboembolism by conducting a meta-analysis.

OBJECTIVE

To conduct a meta-analysis to systematically evaluate the relationship between perioperative red blood cell transfusions and the risk of postoperative venous thromboembolism.

METHODS

PubMed, Embase, Cochrane, and Web of Science databases were searched to identify studies examining the relationship between perioperative red blood cell transfusions and the risk of postoperative venous thromboembolism. The databases were searched from establishment to August 2023.Two researchers independently screened literature and extracted data according to inclusion and exclusion criteria. Newcastle-ottawa Scale was used for quality assessment. Meta-analysis of data was performed using RevMan 5.4 software.

RESULTS

A total of 15 studies involving 1,880,990 patients were included in this study.Meta-analysis showed that perioperative red blood cell transfusions increased the risk of postoperative venous thromboembolism [OR = 1.61, 95%CI (1.37, 1.89), P < 0.001]. Subgroup analyses showed that the transfusion dose,transfusion timing,study population and follow-up time were closely related to the risk of postoperative venous thromboembolism.

CONCLUSIONS

In summary, this meta-analysis demonstrated a significant positive association between perioperative red blood cell transfusions and postoperative venous thromboembolism.Healthcare professionals should pay attention to the influence of blood transfusions on postoperative venous thromboembolism, strengthen management and prevention.

'Door-to-prophylaxis' as a novel quality improvement metric in prevention of venous thromboembolism following traumatic injury

Objective

Venous thromboembolism (VTE) risk reduction strategies include early initiation of chemoprophylaxis, reducing missed doses, weight-based dosing and dose adjustment using anti-Xa levels. We hypothesized that time to initiation of chemoprophylaxis would be the strongest modifiable risk for VTE, even after adjusting for competing risk factors.

Methods

A prospectively maintained trauma registry was queried for patients admitted July 2017-October 2021 who were 18 years and older and received emergency release blood products. Patients with deep vein thrombosis or pulmonary embolism (VTE) were compared to those without (no VTE). Door-to-prophylaxis was defined as time from hospital arrival to first dose of VTE chemoprophylaxis (hours). Univariate and multivariate analyses were then performed between the two groups.

Results

2047 patients met inclusion (106 VTE, 1941 no VTE). There were no differences in baseline or demographic data. VTE patients had higher injury severity score (29 vs 24), more evidence of shock by arrival lactate (4.6 vs 3.9) and received more post-ED transfusions (8 vs 2 units); all p<0.05. While there was no difference in need for enoxaparin dose adjustment or missed doses, door-to-prophylaxis time was longer in the VTE group (35 vs 25 hours; p=0.009). On multivariate logistic regression analysis, every hour delay from time of arrival increased likelihood of VTE by 1.5% (OR 1.015, 95% CI 1.004 to 1.023, p=0.004).

Conclusion

The current retrospective study of severely injured patients with trauma who required emergency release blood products found that increased door-to-prophylaxis time was significantly associated with an increased likelihood for VTE. Chemoprophylaxis initiation is one of the few modifiable risk factors available to combat VTE, therefore early initiation is paramount. Similar to door-to-balloon time in treating myocardial infarction and door-to-tPA time in stroke, "door-to-prophylaxis time" should be considered as a hospital metric for prevention of VTE in trauma.

Level of evidence

Level III, retrospective study with up to two negative criteria.

Blood Transfusion Procedure: Assessment of Serbian Intensive Care Nurses' Knowledge

Many patients require administering one or more blood components during hospitalisation in the Intensive Care Unit (ICU). Therefore, nurses' knowledge of who is responsible for immediately administering blood transfusions, monitoring patients, and identifying and managing transfusion reactions is crucial. This cross-sectional descriptive-analytical study aimed to assess the knowledge of ICU nurses in tertiary healthcare institutions about blood transfusion procedures. The questionnaire about the transfusion procedure was designed and reviewed by experts. The questionnaire consisted of 29 items divided into three domains. The scores on the knowledge test ranged from 10 to 27. Generally, 57.7% of nurses had moderate, 23.4% low, and 18.9% high levels of knowledge about the transfusion procedure. Most nurses answered correctly about refreezing fresh frozen plasma, verifying the transfusion product, and identifying the patient. Of the nurses, 91.0% would recognise mild allergic reactions, and 98.2% knew about the supervision of sedated patients. Nurses showed poor knowledge of the length of usage of the same transfusion system for red blood cells, labelling, and transfusion administration in febrile patients. Nurses with higher education and longer working experience had significantly better outcomes (p = 0.000) on the knowledge test. Continuous education of ICU nurses on safe transfusion usage is recommended.

Nomogram for predicting postoperative deep vein thrombosis in patients with spinal fractures caused by high-energy injuries

OBJECTIVE

Deep venous thrombosis (DVT) is a common complication in patients with spinal fractures caused by high-energy injuries. Early identification of patients at high risk of postoperative DVT is essential for the prevention of thrombosis. This study aimed to develop and validate a prediction model based on a nomogram to predict DVT in patients with spinal fractures caused by high-energy injuries.

METHODS

Clinical data were collected from 936 patients admitted to our hospital between January 2016 and December 2021 with spinal fractures caused by high-energy injuries. Multivariate logistic regression analysis was used to identify the risk factors for postoperative DVT and to develop a nomogram. The predictive performance of the nomogram was evaluated by the receiver operating characteristic (ROC) curve and calibration curve.

RESULTS

The incidence of preoperative DVT was 15.38% (144/936). The postoperative incidence of DVT was 20.5% (192/936). The multivariate analysis revealed that age, operation time, blood transfusion, duration of bed rest, American Spinal Injury Association (ASIA) score and D-dimer were risk factors for postoperative DVT. The area under the ROC curve of the nomogram was 0.835 and the calibration curve showed good calibration.

CONCLUSIONS

The nomogram showed a good ability to predict postoperative DVT in patients with spinal fractures caused by high-energy injuries, which may benefit pre- and postoperative DVT prophylaxis strategy development.

Low-molecular-weight heparin is associated with lower venous thromboembolism events than factor Xa inhibitors in patients with severe blunt trauma: a cohort study from the Trauma Quality Improvement Program

BACKGROUND

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common complication of major trauma. Pharmacological VTE prophylactics are widely used, and low-molecular-weight heparin (LMWH) is recommended. Factor Xa inhibitors are increasingly being used for VTE prophylaxis in both medical and surgical patients. Evidence comparing LMWH and factor Xa inhibitors as VTE prophylactics for severe blunt trauma is lacking. This study aims to compare the efficacy and safety of factor Xa inhibitors and LMHW in VTE prophylaxis.

MATERIALS AND METHODS

Patients with severe blunt trauma who received LMWH or a factor Xa inhibitor for VTE prophylaxis in the Trauma Quality Improvement Program between 2017 and 2019 were included. The comparison was performed after using propensity score matching. The outcomes included mortality and incidence of DVT, PE, post-prophylactics haemorrhage control procedures and length of stay.

RESULTS

After 2:1 propensity score matching, 1128 patients ( n =752, LMHW group; n =376, factor Xa inhibitor group) were included in the analysis. Patients in the LMWH group had fewer VTE events than those in the factor Xa inhibitor group (DVT, 3.7% vs. 7.2%, P =0.013; PE, 0.4% vs. 3.2%, P <0.001). VTE risk was higher in the factor Xa group (DVT: odds ratio, 1.97; 95% CI, 1.12-3.44; P =0.018 and PE: odds ratio, 9.65; 95% CI, 2.91-44.12; P =0.001). The mortality rate was higher in the LMWH group; however, there was no significant difference (4.0% vs. 1.9%; P =0.075). The difference in the risk of undergoing haemorrhage control surgery after VTE prophylaxis between both groups was insignificant (0.3% vs. 0.0%; P =0.333).

CONCLUSIONS

LMWH was associated with a lower risk of VTE than factor Xa inhibitors in patients with severe blunt trauma. The mortality rate was higher in the LMWH group; however, there was no statistically significant difference observed.

Outcomes following perioperative red blood cell transfusion in patients undergoing elective major abdominal surgery: a systematic review and meta-analysis

BACKGROUND

Perioperative red blood cell transfusion is a double-edged sword for surgical patients. While transfusion of red cells can increase oxygen delivery by increasing haemoglobin levels, its impact on short- and long-term postoperative outcomes, particularly in patients undergoing elective major abdominal surgery, is unclear.

METHODS

We conducted a systematic review and meta-analysis on the effect of perioperative blood transfusions on postoperative outcomes in elective major abdominal surgery. PubMed, Cochrane, and Scopus databases were searched for studies with data collected between January 1, 2000 and June 6, 2020. The primary outcome was short-term mortality, including all-cause 30-day or in-hospital mortality. Secondary outcomes included long-term all-cause mortality, any morbidity, infectious complications, overall survival, and recurrence-free survival. No randomised controlled trials were found. Thirty-nine observational studies were identified, of which 37 were included in the meta-analysis.

RESULTS

Perioperative blood transfusion was associated with short-term all-cause mortality (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.89-3.91, P<0.001), long-term all-cause mortality (hazard ratio 1.35, 95% CI 1.09-1.67, P=0.007), any morbidity (OR 2.18, 95% CI 1.81-2.64, P<0.001), and infectious complications (OR 1.90, 95% CI 1.60-2.26, P<0.001). Perioperative blood transfusion remained associated with short-term mortality in the sensitivity analysis after excluding studies that did not control for preoperative anaemia (OR 2.27, 95% CI 1.59-3.24, P<0.001).

CONCLUSIONS

Perioperative blood transfusion in patients undergoing elective major abdominal surgery is associated with poorer short- and long-term postoperative outcomes. This highlights the need to implement patient blood management strategies to manage and preserve the patient's own blood and reduce the need for red blood cell transfusion.

TRIAL REGISTRATION

PROSPERO (CRD42021254360).

Intraoperative Blood Pressure Variability and Early Postoperative Stroke: A Case-Control Study

BACKGROUND

This study aims to assess the association of postoperative stroke with intraoperative hemodynamic variability and transfusion management.

METHODS

In this case-control study, adult patients (≥ 18 years) who had a stroke within 72 hours of a surgical procedure were matched to 2 control patients according to age, sex, and procedure type. Primary risk factors assessed were intraoperative fluid administration, blood product transfusion, vasopressor use, and measures of variability in systolic and diastolic blood pressure and heart rate: maximum, minimum, range, SD, and average real variability. The variables were analyzed with conditional logistic regression, which accounted for the 1:2 matched case-control study design.

RESULTS

Among 687 581 procedures, we identified 64 postoperative strokes (incidence, 9.3 [95% CI, 7.2-11.9] strokes per 100 000 procedures). These cases were matched with 128 controls. Stroke cases had higher Charlson cmorbidity index scores than did controls (P = .046). Blood pressure and heart rate variability measures were not associated with stroke. The risk of stroke was increased with red blood cell (RBC) transfusion (odds ratio [OR], 14.82; 95% CI, 3.40-64.66; P < .001), vasopressor use (OR, 3.91; 95% CI, 1.59-9.60; P = .003), and longer procedure duration (OR, 1.23/h; 95% CI, 1.01-1.51; P = .04). Multivariable analysis of procedure duration, RBC transfusion, and vasopressor use showed that only RBC transfusion was independently associated with an increased risk of stroke (OR, 10.10; 95% CI, 2.14-47.72; P = .004).

CONCLUSIONS

Blood pressure variability was not associated with an increased risk of postoperative stroke; however, RBC transfusion was an independent risk factor.

Trends and predictions of perioperative transfusion and venous thromboembolism in hepatectomy using a North American Registry

BACKGROUND

Studies indicate a link between allogeneic blood transfusion and venous thromboembolism (VTE) post-major surgery. Analyzing trends and predictors of these outcomes after hepatectomy can inform risk management.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used for a retrospective analysis. Primary outcomes were perioperative red blood cell (RBC) transfusion and VTE events within 30 days of hepatectomy. Seven-year trends and predictors were evaluated.

RESULTS

Among 29,131 hepatectomy patients, transfusion rates showed no statistically significant decreasing trends (p = .122) from 2014 to 2020 (18.13%-16.71%), while VTE rates showed a downward trend over the 7 years (p = .021); 17.2% received RBC transfusion, with higher rates in surgeries lasting ≥282 min (median: 220 min). Calculated RBC mass [hematocrit (%) × body weight (kg) × 10-5  × 70/ √ (body mass index/22)] at or below 1.5 L substantially increased transfusion odds. VTE was reported postoperatively in 2.6% of cases more frequently in longer cases involving transfusions. The adjusted odds ratio (aOR) of VTE escalated from the shortest operative time to the longest (3.17; 95% confidence interval [CI], 2.37-4.22). The adjusted odds of VTE doubled for transfused patients compared to non-transfused patients (aOR, 2.19; 95% CI, 1.86-2.57).

CONCLUSIONS

Rates of RBC transfusion and VTE rates hepatectomy have minimally changed in the recent years. VTE prevention is challenging in extended surgeries at increased risk of bleeding and RBC transfusions. Patient-level data on coagulation and thromboprophylaxis can potentially refine risk assessment for postoperative VTE.

Prevention of perioperative stroke in patients undergoing non-cardiac surgery

About 300 million adults undergo non-cardiac surgery annually. Although, in this setting, the incidence of perioperative stroke is low, the absolute number of patients experiencing a stroke is substantial. Furthermore, most patients with this complication will die or end up with severe disability. Covert brain infarctions are more frequent than overt strokes and are associated with postoperative delirium, cognitive decline, and cerebrovascular events at 1 year after surgery. Evidence shows that traditional stroke risk factors including older age, hypertension, and atrial fibrillation are also associated with perioperative stroke; previous stroke is the strongest risk factor for perioperative stroke. Increasing evidence also suggests the pathogenic role of perioperative events, such as hypotension, new atrial fibrillation, paradoxical embolism, and bleeding. Clinicians involved in perioperative care should be aware of this evidence on prevention strategies to improve patient outcomes after non-cardiac surgery.

How do we build a comprehensive Vein-to-Vein (V2V) database for conduct of observational studies in transfusion medicine? Demonstrated with the Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric V2V database protocol

BACKGROUND

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) is the fourth iteration of the National Heart, Lung, and Blood Institute's REDS program and includes a focus on pediatric populations. The REDS-IV-P Vein-to-Vein (V2V) database encompasses linked information from blood donors, blood components, and patients to facilitate studies in transfusion medicine.

STUDY DESIGN AND METHODS

The V2V database is an Observational Medical Outcomes Partnership Common Data Model database. The study period is April 1, 2019 through December 31, 2023. Data from all donors and donations at participating blood centers, all blood components derived from the donations, and all inpatient visits and selected outpatient visits at participating hospitals are included. The database captures all information within patient data domains not restricting data to a preselected subset of medical records.

RESULTS

The V2V database contains data from 7 blood centers and 22 hospitals. We project the database will have over 2 billion pieces of information from 1.3 million patients with 20.6 million healthcare encounters. The database will include data on approximately 1 million transfused units and 2.3 million donors with approximately 6.8 million donation visits.

CONCLUSION

The REDS-IV-P V2V database is a comprehensive database with data from millions of blood donors, blood components, and patients. A diverse set of data from the encounters are included in the database such that emerging questions can likely be addressed. The Observational Medical Outcomes Partnership Common Data Model is an efficient, flexible, and increasingly used common data model. The final de-identified database will be publicly available.

Association of Intraoperative Red Blood Cell Transfusions With Venous Thromboembolism and Adverse Outcomes After Cardiac Surgery

OBJECTIVE

We determined whether intraoperative packed red blood cell (PRBC) transfusion was associated with a higher incidence of hospital-acquired venous thromboembolic (HA-VTE) complications and adverse outcomes after isolated coronary artery bypass grafting (CABG) surgery.

BACKGROUND

Intraoperative PRBC has been associated with increased risk for postoperative deep venous thrombosis after cardiac surgery, but validation of these findings in a large, multi-institutional, national cohort of cardiac surgery patients has been lacking.

METHODS

A registry-based cohort study of 751,893 patients with isolated CABG between January 1, 2015, to December 31, 2019. Using propensity score-weighted regression analysis, we analyzed the effect of intraoperative PRBC on the incidence of HA-VTE and adverse outcomes.

RESULTS

Administration of 1, 2, 3, and ≥4 units of PRBC transfusion was associated with increased odds for HA-VTE [odds ratios (ORs): 1.27 (1.22-1.32), 1.21 (1.16-1.26), 1.93 (1.85-2.00), 1.82 (1.75-1.89)], deep venous thrombosis [ORs: 1.39 (1.33-1.46), 1.38 (1.32-1.44), 2.18 (2.09-2.28), 1.82 (1.74-1.91], operative mortality [ORs: 1.11 (1.08-1.14), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], readmission within 30 days [ORs: 1.05 (1.04-1.06), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], and a prolonged postoperative length of stay [mean difference in days, 0.23 (0.19-0.27), 0.34 (0.30-0.39), 0.69 (0.64-0.74), 0.77 (0.72-0.820]. The odds of pulmonary venous thromboembolism were lower for patients transfused with 1 or 2 units [ORs: 0.98 (0.91-1.06), 0.75 (0.68-0.81)] of PRBC but remained significantly elevated for those receiving 3 and ≥4 units [ORs: 1.19 (1.09-1.29), 1.35 (1.25-1.48)].

CONCLUSIONS

Intraoperative PRBC transfusion was associated with HA-VTE and adverse outcomes after isolated CABG surgery.

Just What the Doctor Ordered: Missed Ordering of Venous Thromboembolism Chemoprophylaxis Is Associated With Increased VTE Events in High-risk General Surgery Patients

OBJECTIVE

To define the impact of missed ordering of venous thromboembolism (VTE) chemoprophylaxis in high-risk general surgery populations.

BACKGROUND

The primary cause of preventable death in surgical patients is VTE. Although guidelines and validated risk calculators assist in dosing recommendations, there remains considerable variability in ordering and adherence to recommended dosing.

METHODS

All adult inpatients who underwent a general surgery procedure between 2016 and 2019 and were entered into Atrium Health National Surgical Quality Improvement Program registry were identified. Patients at high risk for VTE (2010 Caprini score ≥5) and without bleeding history and/or acute renal failure were included. Primary outcome was 30-day postoperative VTE. Electronic medical record identified compliance with "perfect" VTE chemoprophylaxis orders (pVTE): no missed orders and no inadequate dose ordering. Multivariable analysis examined association between pVTE and 30-day VTE events.

RESULTS

A total of 19,578 patients were identified of which 4252 were high-risk inpatients. Hospital compliance of pVTE was present in 32.4%. pVTE was associated with shorter postoperative length of stay and lower perioperative red blood cell transfusions. There was 50% reduced odds of 30-day VTE event with pVTE (odds ratio: 0.50; 95% CI, 0.30-0.80) and 55% reduction in VTE event/mortality (odds ratio: 0.45; 95% CI, 0.31-0.63). After controlling for relevant covariates, pVTE remained significantly associated with decreased odds of VTE event and VTE event/mortality.

CONCLUSIONS

pVTE ordering in high-risk general surgery patients was associated with 42% reduction in odds of postoperative 30-day VTE. Comprehending factors contributing to missed or suboptimal ordering and development of quality improvement strategies to reduce them are critical to improving outcomes.

Treatment Options for Anemia in Kidney Transplant Patients: A Review

Anemia is common after kidney transplantation. The etiology may be multifactorial, such as causes of anemia in the general population and causes that are unique to the kidney transplant setting. Posttransplant anemia, particularly when severe, may be associated with adverse effects such as graft failure, mortality, and a decline in kidney function. After careful investigation, that is, having excluded or treated reversible causes of anemia, treatment of anemia in patients with a kidney transplant is based on iron supplementation or erythropoiesis-stimulating agents (ESA), although there are no specific guidelines on anemia management in this patient population. Iron therapy is often needed, but optimal and safe iron-deficiency management strategies remain to be defined. Evidence suggests that ESAs are safe and potentially associated with favorable outcomes. Better graft function has been reported with ESA use targeting hemoglobin levels higher than those recommended in the general population with chronic kidney disease and with no apparent increased risk of cardiovascular events. These results require further investigation. Data on the use of hypoxia-inducible factor inhibitors are limited. Prevention and treatment of anemia in kidney transplantation can improve patients' quality of life, life expectancy, allograft function, and survival.

A nomogram to predict postoperative deep vein thrombosis in patients with femoral fracture: a retrospective study

OBJECTIVE

The implementation of more active anticoagulant prevention and treatment measures has indeed led to a significant reduction in the incidence of perioperative deep vein thrombosis (DVT) among patients with bone trauma. However, it is important to note that despite these efforts, the incidence of DVT still remains relatively high. According to the Caprini score, all patients undergoing major orthopedic surgery were defined as the high-risk group for DVT. Stratifying the risk further within high-risk groups for DVT continues to present challenges. As a result, the commonly used Caprini score during the perioperative period is not applicable to orthopedic patients. We attempt to establish a specialized model to predict postoperative DVT risk in patients with femoral fracture.

METHODS

We collected the clinical data of 513 patients undergoing femoral fracture surgery in our hospital from May 2018 to December 2019. According to the independent risk factors of DVT obtained by univariate and multivariate logistic regression analysis, the corresponding nomogram model was established and verified internally. The discriminative capacity of nomogram was evaluated by receiver operating characteristic (ROC) curve and area under the curve (AUC). The calibration curve used to verify model consistency was the fitted line between predicted and actual incidences. The clinical validity of the nomogram model was assessed using decision curve analysis (DCA) which could quantify the net benefit of different risk threshold probabilities. Bootstrap method was applied to the internal validation of the nomogram model. Furthermore, a comparison was made between the Caprini score and the developed nomogram model.

RESULTS

The Caprini scores of subjects ranged from 5 to 17 points. The incidence of DVT was not positively correlated with the Caprini score. The predictors of the nomogram model included 10 risk factors such as age, hypoalbuminemia, multiple trauma, perioperative red blood cell infusion, etc. Compared with the Caprini scale (AUC = 0.571, 95% CI 0.479-0.623), the calibration accuracy and identification ability of nomogram were higher (AUC = 0.865,95% CI 0.780-0.935). The decision curve analysis (DCA) indicated the clinical effectiveness of nomogram was higher than the Caprini score.

CONCLUSIONS

The nomogram was established to effectively predict postoperative DVT in patients with femoral fracture. To further reduce the incidence, more specialized risk assessment models for DVT should take into account the unique risk factors and characteristics associated with specific patient populations.

Red Blood Cell Transfusions Are Not Associated With Incident Complications or Poor Outcomes in Patients With Intracerebral Hemorrhage

Background Anemia is associated with poor intracerebral hemorrhage (ICH) outcomes, yet the relationship of red blood cell (RBC) transfusions to ICH complications and functional outcomes remains unclear. We investigated the impact of RBC transfusion on hospital thromboembolic and infectious complications and outcomes in patients with ICH. Methods and Results Consecutive patients with spontaneous ICH enrolled in a single-center, prospective cohort study from 2009 to 2018 were assessed. Primary analyses assessed relationships of RBC transfusions on incident thromboembolic and infectious complications occurring after the transfusion. Secondary analyses assessed relationships of RBC transfusions with mortality and poor discharge modified Rankin Scale score 4 to 6. Multivariable logistic regression models adjusted for baseline demographics and medical disease severity (Acute Physiology and Chronic Health Evaluation II), and ICH severity (ICH score).Of 587 patients with ICH analyzed, 88 (15%) received at least one RBC transfusion. Patients receiving RBC transfusions had worse medical and ICH severity. Though patients receiving RBC transfusions had more complications at any point during the hospitalization (64.8% versus 35.9%), we found no association between RBC transfusion and incident complications in our regression models (adjusted odds ratio [aOR], 0.71 [95% CI, 0.42-1.20]). After adjusting for disease severity and other relevant covariates, we found no significant association between RBC transfusion and mortality (aOR, 0.87 [95% CI, 0.45-1.66]) or poor discharge modified Rankin Scale score (aOR, 2.45 [95% CI, 0.80-7.61]). Conclusions In our cohort with ICH, RBC transfusions were expectedly given to patients with higher medical and ICH severity. Taking disease severity and timing of transfusions into account, RBC transfusion was not associated with incident hospital complications or poor clinical ICH outcomes.

Development and validation of a newly developed nomogram for predicting the risk of deep vein thrombosis after surgery for lower limb fractures in elderly patients

Background

Prevention of deep vein thrombosis (DVT) is indispensable in the treatment of lower limb fractures during the perioperative period. This study aimed to develop and validate a novel model for predicting the risk of DVT in elderly patients after orthopedic surgeries for lower limb fractures.

Methods

This observational study included 576 elderly patients with lower limb fractures who were surgically treated from January 2016 to December 2018. Eleven items affecting DVT were optimized by least absolute shrinkage and selection operator regression analysis. Multivariable logistic regression analysis was performed to construct a predictive model incorporating the selected features. C-index was applied to evaluate the discrimination. Decision curve analysis was employed to determine the clinical effectiveness of this model and calibration plot was applied to evaluate the calibration of this nomogram. The internal validation of this model was assessed by bootstrapping validation.

Results

Predictive factors that affected the rate of DVT in this model included smoking, time from injury to surgery, operation time, blood transfusion, hip replacement arthroplasty, and D-dimer level after operation. The nomogram showed significant discrimination with a C-index of 0.919 (95% confidence interval: 0.893-0.946) and good calibration. Acceptable C-index value could still be reached in the interval validation. Decision curve analysis indicated that the DVT risk nomogram was useful within all possibility threshold.

Conclusion

This newly developed nomogram could be used to predict the risk of DVT in elderly patients with lower limb fractures during the perioperative period.

How do I reduce variation in red blood cell transfusion practices in a large integrated health care system?

BACKGROUND

Reducing variation in transfusion practices can prevent unwarranted transfusions, an outcome that improves quality of care and patient safety, while lowering costs and eliminating waste of blood. We developed and assessed a system-wide initiative to reduce variation in red blood cell (RBC) transfusion in terms of both transfusion utilization and the number of units transfused.

INTERVENTION DESIGN AND METHODS

Our initiative combined a single-unit default order for RBC transfusion in hemodynamically stable, non-bleeding patients with a "Why Give 2 When 1 Will Do?" Choosing Wisely campaign, while also promoting a restrictive hemoglobin threshold (Hb <7 g/dl). This multimodal intervention was implemented across an academic medical center (AMC) with over 950 beds and 10 community hospitals.

RESULTS

Between our baseline (CY 2020) and intervention period (CY 2021), single-unit orders increased from 57% to 70% of all RBC transfusion orders (p < .001). The greatest change in ordering practices was at community hospitals, where single-unit orders increased from 46% to 65% (p < .001). Over the same time period, the system-wide mean (SD) Hb result prior to transfusion fell from 7.3 (0.05) to 7.2 g/dl (0.04) (p < .05). We estimate this effort saved over 4000 units of blood and over $4 million in direct and indirect costs in its first year.

DISCUSSION

By combining a single-unit default setting in the RBC order with a restrictive hemoglobin threshold, we significantly reduced variation in ordering practices. This effort demonstrates the value of single-unit policies and "nudges" in system-wide patient blood management initiatives.

The interaction effect of transfusion history and previous stroke history on the risk of venous thromboembolism in stroke patients: a prospective cohort study

BACKGROUND

Blood transfusion and previous stroke history are two independent risk factors of venous thromboembolism (VTE) in stroke patients. Whether the potential interaction of transfusion history and previous stroke history is associated with a greater risk of VTE remains unclear. This study aims to explore whether the combination of transfusion history and previous stroke history increases the risk of VTE among Chinese stroke patients.

METHODS

A total of 1525 participants from the prospective Stroke Cohort of Henan Province were enrolled in our study. Multivariate logistic regression models were used to explore the associations among transfusion history, previous stroke history and VTE. The interaction was evaluated on both multiplicative and additive scales. The odds ratio (95% CI), relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (S) of interaction terms were used to examine multiplicative and additive interactions. Finally, we divided our population into two subgroups by National Institutes of Health Stroke Scale (NIHSS) score and re-evaluated the interaction effect in both scales.

RESULTS

A total of 281 (18.4%) participants of 1525 complicated with VTE. Transfusion and previous stroke history were associated with an increased risk of VTE in our cohort. In the multiplicative scale, the combination of transfusion and previous stroke history was statistically significant on VTE in both unadjusted and adjusted models (P<0.05). For the additive scale, the RERI shrank to 7.016 (95% CI: 1.489 ~ 18.165), with the AP of 0.650 (95% CI: 0.204 ~ 0.797) and the S of 3.529 (95% CI: 1.415 ~ 8.579) after adjusting for covariates, indicating a supra-additive effect. In subgroups, the interaction effect between transfusion history and previous stroke history was pronouncedly associated with the increased risk of VTE in patients with NIHSS score > 5 points (P<0.05).

CONCLUSIONS

Our results suggest that there may be a potential synergistic interaction between transfusion history and previous stroke history on the risk of VTE. Besides, the percentage of VTE incidence explained by interaction increased with the severity of stroke. Our findings will provide valuable evidence for thromboprophylaxis in Chinese stroke patients.

Incidence and Impact of a Single-Unit Red Blood Cell Transfusion: Analysis of The Society of Thoracic Surgeons Database 2010-2019

BACKGROUND

As the adverse effects of blood transfusions are better understood, recommendations support single-unit red blood cell (RBC) transfusions (SRBCT). However, an isolated SRBCT across the entire index admission suggests even the single unit may be avoidable. We sought to identify the characteristics of cardiac surgery patients receiving an isolated SRBCT and analyze the impact on outcomes.

METHODS

The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for the period between January 1, 2010, and December 31, 2019. Patients aged >18 years undergoing isolated coronary artery bypass grafting or isolated aortic valve replacement were included. A total of 2,151,430 encounters were analyzed.

RESULTS

Of the 847,442 patients (39.3%) receiving any RBC transfusion during their index admission, 206,555 (24.4%) received only 1 unit. Propensity-matching analysis determined SRBCT patients were significantly older (67.26 vs 64.02 years; odds ratio [OR], 1.02; P < .001), female (39.1% vs 17.8%; OR, 1.57; P < .001), non-White (18.2% vs 13.1%; OR, 0.81; P < .001), and had a smaller body surface area (1.94 vs 2.07 m2; OR, 0.20; P < .001). They also had higher mortality (1.4% vs 1.0%, P < .001), stroke (1.7% vs 1.2%, P < .001), prolonged ventilation (6.4% vs 3.4%, P < .001), renal failure (1.8% vs 0.9%, P < .001), and reoperations (1.3% vs. 0.5%, P < .001) than patients who received 0 RBCs.

CONCLUSIONS

SRBCT is a common occurrence in adult cardiac surgery. This low-volume transfusion is strongly associated with higher morbidity, even after controlling for preoperative risk factors.

Perioperative management of acetabular and pelvic fractures: evidence-based recommendations

PURPOSE

The American Academy of Orthopaedic Surgeons does not currently provide clinical practice guidelines for management of PAF. Accordingly, this article aims to review and consolidate the relevant historical and recent literature in important topics pertaining to perioperative management of PAF.

METHODS

A thorough literature review using PubMed, Cochrane and Embase databases was performed to assess preoperative, intraoperative and postoperative management of PAF fracture. Topics reviewed included: time from injury to definitive fixation, the role of inferior vena cava filters (IVCF), tranexamic acid (TXA) use, intraopoperative cell salvage, incisional negative pressure wound therapy (NPWT), intraoperative antibiotic powder use, heterotopic ossification prophylaxis, and pre- and postoperative venous thromboembolism (VTE) prophylaxis.

RESULTS

A total of 126 articles pertaining to the preoperative, intraoperative and postoperative management of PAF were reviewed. Articles reviewed by topic include 13 articles pertaining to time to fixation, 23 on IVCF use, 14 on VTE prophylaxis, 20 on TXA use, 10 on cell salvage, 10 on iNPWT 14 on intraoperative antibiotic powder and 20 on HO prophylaxis. An additional eight articles were reviewed to describe background information. Five articles provided information for two or more treatment modalities and were therefore included in multiple categories when tabulating the number of articles reviewed per topic.

CONCLUSION

The literature supports the use of radiation therapy for HO prophylaxis, early (< 5 days from injury) surgical intervention and the routine use of intraoperative TXA. The literature does not support the routine use of iNPWT or IVCF. There is inadequate information to make a recommendation regarding the use of cell salvage and wound infiltration with antibiotic powder. While the routine use of chemical VTE prophylaxis is recommended, there is insufficient evidence to recommend the optimal agent and duration of therapy.

Patient Blood Management, Anemia, and Transfusion Optimization Across Surgical Specialties

Patient blood management (PBM) is a systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood and minimizing allogenic transfusion need and risk. According to the PBM approach, the goals of perioperative anemia management include early diagnosis, targeted treatment, blood conservation, restrictive transfusion except in cases of acute and massive hemorrhage, and ongoing quality assurance and research efforts to advance overall blood health.

Blood donor, component, and recipient-specific factors associated with venous thromboembolism in transfused hospitalized adult patients: Data from the recipient epidemiology and donor evaluation Study-III (REDS-III)

OBJECTIVE

Growing evidence suggests multiple pathophysiological mechanisms linking red blood cells (RBC) transfusions to thrombosis. This study examined blood donor, component, and recipient factors which may be associated with thromboembolic outcomes following RBC transfusion.

METHODS

We utilized the Recipient Epidemiology Donor Evaluation Study-III (REDS-III) database on patients transfused in 12 hospitals between 2013-2016. Stratified Cox proportional hazards regression models with time-dependent exposures were used to examine associations of donor and component modification characteristics on venous thromboembolism (VTE) in patients transfused RBC units.

RESULTS

59,603 patients were transfused 229,500 RBC units during 79,298 hospitalizations with post-transfusion VTE occurring in 1869 (2.4%) of patients. In adjusted regression analyses, a per RBC-unit risk of VTE was present for gamma irradiation (HR = 1.03; 95% CI: 1.02-1.03), female donor sex (HR = 1.01; 95% CI: 1.00-1.01), storage duration greater than 5 weeks (HR = 1.01; 95% CI: 1.01-1.02), AS-1 storage solution (HR = 1.01; 95% CI: 1.00-1.01), and apheresis-derived collections (HR = 1.01; 95% CI: 1.01-1.02). Among recipient factors, male sex (HR = 1.03; 95% CI: 1.02-1.04), pre-transfusion hemoglobin level (HR = 0.94; 95% CI: 0.94-0.94), body mass index strata (HR = 1.11; 95% CI: 1.08-1.14), and principal diagnoses including malignancy (HR = 1.13; 95% CI: 1.10-1.16), cardiac arrest (HR = 1.38; 95% CI:1.07-1.77) and hip fracture (HR = 1.59; 95% CI:1.53-1.66) were associated with VTE in adjusted analyses.

DISCUSSION

We identified several donor, component, and recipient-specific factors associated with VTE in transfused hospitalized adult patients. In adjusted models, the dose-dependent associations of donor and component-specific factors with VTE were modest and unlikely to be clinically significant in the majority of transfused patients. Additional mechanistic and clinical studies linking blood donor and component factors with thrombotic outcomes are needed.

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.

Red blood cell transfusion is associated with an increased risk of splanchnic vein thrombosis in patients with cirrhosis

BACKGROUND

Haemorrhage and coagulation disorders are common complications in cirrhotic patients, which cause blood products transfusion, and mounting evidence suggested that red blood cells (RBCs) were associated with pathologic thrombosis and RBC transfusion increased the risk of venous thromboembolism (VTE).

AIMS

The aim of the study was to investigate the association of RBC transfusion with splanchnic vein thrombosis (SVT) in cirrhotic patients.

MATERIALS & METHODS

We retrospectively reviewed patients with cirrhosis admitted in the Hunan Provincial People's Hospital between January 2010 and September 2020. Demographic data, the development of SVT, blood transfusion product type and RBC transfusion dose were collected. Multivariate logistic regression analyses and propensity matching analysis (PSM) were performed to identify the association between RBC transfusion and development of SVT.

RESULTS

A total of 4479 patients with cirrhosis were enrolled in the study. SVT occurred in 48 (12.4%) cirrhotic patients in RBC transfusion group, and 233 (5.7%) cirrhotic patients in non-RBC transfusion group. RBC transfusion was significantly associated with an increased risk of SVT (unadjusted odds ratio [OR] 2.345, 95% confidence interval [CI] 1.686-3.262, p < 0.001). Notably, this association remained robust after PSM, and the volume of RBC transfusion was associated with SVT in a dose-dependent manner.

CONCLUSION

This study suggested that RBC transfusion was associated with an increased risk of SVT in cirrhotic patients. High quality clinical study will be needed to further validate the association between RBC transfusion and SVT.

Risk factor analysis and a new prediction model of venous thromboembolism after pancreaticoduodenectomy

AIM

The present study aimed to identify risk factors for venous thromboembolism (VTE) after pancreaticoduodenectomy (PD) and to develop and internally validate a predictive model for the risk of venous thrombosis.

METHODS

We retrospectively collected data from 352 patients who visited our hospital to undergo PD from January 2018 to March 2022. The number of patients recruited was divided in an 8:2 ratio by using the random split method, with 80% of the patients serving as the training set and 20% as the validation set. The least absolute shrinkage and selection operator (Lasso) regression model was used to optimize feature selection for the VTE risk model. Multivariate logistic regression analysis was used to construct a prediction model by incorporating the features selected in the Lasso model. C-index, receiver operating characteristic curve, calibration plot, and decision curve were used to assess the accuracy of the model, to calibrate the model, and to determine the clinical usefulness of the model. Finally, we evaluated the prediction model for internal validation.

RESULTS

The predictors included in the prediction nomogram were sex, age, gastrointestinal symptoms, hypertension, diabetes, operative method, intraoperative bleeding, blood transfusion, neutrophil count, prothrombin time (PT), activated partial thromboplastin time (APTT), aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AST/ALT), and total bilirubin (TBIL). The model showed good discrimination with a C-index of 0.827, had good consistency based on the calibration curve, and had an area under the ROC curve value of 0.822 (P < 0.001, 95%confidence interval:0.761-0.882). A high C-index value of 0.894 was reached in internal validation. Decision curve analysis showed that the VTE nomogram was clinically useful when intervention was decided at the VTE possibility threshold of 10%.

CONCLUSION

The novel model developed in this study is highly targeted and enables personalized assessment of VTE occurrence in patients who undergo PD. The predictors are easily accessible and facilitate the assessment of patients by clinical practitioners.

Dose-dependent effects of red blood cell transfusion and case mix index on venous thromboembolic events in spine surgery

BACKGROUND AND OBJECTIVES

Venous thromboembolic (VTE) events represent a major source of morbidity and mortality in spine surgery. Our goal was to assess whether a dose-response relationship exists between red blood cell (RBC) transfusion and postoperative VTE events among spine surgery patients.

MATERIALS AND METHODS

A total of 786 spine surgery patients at a single institution who received at least 1 RBC unit perioperatively were included (2016-2019). Patients were stratified based on RBC transfusion volume: 1-2 units (39.3%), 3-4 units (29.4%), 5-6 units (15.9%) and ≥7 units (15.4%). Subgroup analyses were performed after stratification by case mix index, a standardized surrogate for patients' disease severity and comorbidities. Multivariable regression was used to assess risk factors for the development of postoperative VTE events.

RESULTS

The overall VTE event rate was 2.4% (n = 19). A dose-response relationship was seen between RBC transfusion volume and VTE events (1-2 units: 0.97%, 3-4 units: 1.30%, 5-6 units: 3.20%, ≥7 units: 7.44%; p < 0.01). Similar dose-response relationships were seen between case mix index and VTE events (1.00-3.99: 0.52%, 4.00-6.99: 2.68%, ≥7.00: 9.00%; p < 0.01). On multivariable regression, larger RBC transfusion volumes (adjusted odds ratio [OR] 1.18 per RBC unit, 95% confidence interval [CI] 1.07-1.29; p < 0.01) and higher case mix index scores (adjusted OR 1.39 per unit increase, 95% CI 1.14-1.69; p < 0.01) were associated with an increased risk of thrombosis.

CONCLUSION

Larger RBC transfusion volumes and higher case mix index scores were associated with an increased risk of VTE events. Physicians should be aware of how these dose-response relationships can influence a patient's risk of developing thrombotic complications postoperatively.

Incidence of venous thromboembolism in patients with sickle cell disease undergoing noncardiovascular surgery

OBJECTIVE

Patients with sickle cell disease (SCD) will have a baseline hypercoagulable state and an increased risk of venous thromboembolism (VTE). Few data are available regarding the efficacy of standard prophylaxis in preventing VTE after noncardiovascular surgery for patients with SCD. Our objective was to investigate the incidence of VTE in patients with SCD who had undergone noncardiovascular surgery.

METHODS

We performed a retrospective medical record review of 352 patients with SCD who had undergone noncardiovascular surgery from August 2009 to August 2019 at Beaumont Hospitals. An equal number of control patients without SCD were propensity matched for age, sex, race, body mass index, and specific surgery. The data collected included demographics, comorbidities, VTE prophylaxis used, occurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE), hospital length of stay, and 30-day mortality.

RESULTS

We found no differences in age, race, sex, ethnicity, operative time, or hospital length of stay between the SCD and propensity-matched control patients. DVT prophylaxis was used more frequently for the SCD patients than for the controls (96.0% vs 88.6%; P < .001). Four SCD patients (1.1%) had developed DVT vs five control patients (1.4%; P > .999). One patient in each group had developed PE (0.3%; P > .999). No difference was found in 30-day mortality between the SCD group and the control group (1 [0.3%] vs 3 [0.9%]; P = .312). Of those with a diagnosis of VTE ≤30 days postoperatively, no differences were present in age, sex, race, BMI, or procedure type. DVT had been diagnosed significantly later in the SCD patients than in the controls (median, postoperative day 12 vs 5; P = .014). None of the five SCD patients with VTE was a smoker compared with four of the six non-SCD patients with VTE, who were current or former tobacco users (P = .061). All the patients who had developed VTE had received DVT prophylaxis at surgery.

CONCLUSIONS

We found no differences in the perioperative rates of DVT, PE, or mortality between the SCD patients and matched control patients after noncardiovascular surgery. Vigilant attention to routine VTE prophylaxis seemed to effectively reduce the VTE risk for these hypercoagulable patients. SCD patients might need VTE prophylaxis for a longer period postoperatively compared with those without SCD.

The association of venous thromboembolism with blood transfusion in kidney transplant patients

BACKGROUND

Red blood cell transfusion (RBCT) is common after kidney transplantation and could have pro-thrombotic effects predisposing to venous thromboembolism (VTE). The risks for developing of VTE after RBCT in kidney transplant patients are unknown.

STUDY DESIGN AND METHODS

This was a retrospective cohort study of adult kidney transplant recipients from 2002 to 2018. The exposure of interest was receipt of RBCT after transplant. Cox proportional hazards models were used to calculate hazard ratios (HR) for the outcomes of venous thromboembolism [VTE] (deep venous thrombosis [DVT] or pulmonary embolism [PE]) using RBCT as a time-varying, cumulative exposure.

RESULTS

Out of 1258 kidney transplants recipients, 468 (37%) were transfused during the study period. Seventy-nine study participants (6.3%) developed VTE, 72 DVT (5.7%), and 22 PE (1.8%). For the receipt of 1, 2, 3-5, and >5 RBCT, compared to individuals never transfused, the number of events and adjusted HR (95%CI) for VTE were 6 (6.2%) HR 1.57 (0.69-3.58), 9 (7.6%) HR 2.54 (1.30-4.96), 15 (11.9%) HR 2.73 (1.38-5.41), and 23 (18.1%) HR 5.77 (2.99-11.14) respectively; for DVT, it was 6 (6.2%) HR 1.94 (0.84-4.48), 9 (7.6%) HR 2.92 (1.44-5.94), 14 (11.1%) HR 3.29 (1.63-6.65), and 21 (16.5%) HR 6.97 (3.53-13.76), respectively. For PE, among transfused individuals, there were 14 events (3.0%) and the HR was 2.40 (1.02-5.61).

CONCLUSION

The risks for developing VTE, DVT, and PE were significantly increased in kidney transplant patients receiving RBCT after transplant. Receipt of RBCT should prompt considerations for judicious monitoring and assessment for thrombosis.

Storage of packed red blood cells impairs an inherent coagulation property of erythrocytes

Storage of packed red blood cells is associated with changes in erythrocytes that over time increasingly impair cellular function and potentially contribute to adverse effects associated with blood transfusion. Exposure of phosphatidylserine at the outer membrane leaflet of erythrocytes and shedding of microvesicles (MVs) during packed red blood cell storage are alterations assumed to increase the risk of prothrombotic events in recipients. Here, we used rotational thromboelastometry to study the coagulation process in blood samples with erythrocytes from stored PRBCs reconstituted with freshly prepared platelet-rich plasma. We explored the influence of following effects on the coagulation process: 1) PRBC storage duration, 2) differences between erythrocytes from stored PRBCs compared to freshly drawn erythrocytes, and 3) the contribution of added MVs. Interestingly, despite of a higher fraction of PS-positive cells, erythrocytes from PRBCs stored for 6 weeks revealed longer clotting times than samples with erythrocytes stored for 2 or 4 weeks. Further, clotting times and clot formation times were considerably increased in samples reconstituted with erythrocytes from stored PRBCs as compared to fresh erythrocytes. Moreover, MVs added to reconstituted samples elicited only comparably small and ambiguous effects on coagulation. Thus, this study provides no evidence for an amplified clotting process from prolonged storage of PRBCs but on the contrary implicates a loss of function, which may be of clinical significance in massive transfusion. Our observations add to the increasing body of evidence viewing erythrocytes as active players in the clotting process.

Indications and hemoglobin thresholds for red blood cell transfusion and iron replacement in adults with gastrointestinal bleeding: An algorithm proposed by gastroenterologists and patient blood management experts

Gastrointestinal (GI) bleeding is associated with considerable morbidity and mortality. Red blood cell (RBC) transfusion has long been the cornerstone of treatment for anemia due to GI bleeding. However, blood is not devoid of potential adverse effects, and it is also a precious resource, with limited supplies in blood banks. Nowadays, all patients should benefit from a patient blood management (PBM) program that aims to minimize blood loss, optimize hematopoiesis (mainly by using iron replacement therapy), maximize tolerance of anemia, and avoid unnecessary transfusions. Integration of PBM into healthcare management reduces patient mortality and morbidity and supports a restrictive RBC transfusion approach by reducing transfusion rates. The European Commission has outlined strategies to support hospitals with the implementation of PBM, but it is vital that these initiatives are translated into clinical practice. To help optimize management of anemia and iron deficiency in adults with acute or chronic GI bleeding, we developed a protocol under the auspices of the Spanish Association of Gastroenterology, in collaboration with healthcare professionals from 16 hospitals across Spain, including expert advice from different specialties involved in PBM strategies, such as internal medicine physicians, intensive care specialists, and hematologists. Recommendations include how to identify patients who have anemia (or iron deficiency) requiring oral/intravenous iron replacement therapy and/or RBC transfusion (using a restrictive approach to transfusion), and transfusing RBC units 1 unit at a time, with assessment of patients after each given unit (i.e., “don’t give two without review”). The advantages and limitations of oral versus intravenous iron and guidance on the safe and effective use of intravenous iron are also described. Implementation of a PBM strategy and clinical decision-making support, including early treatment of anemia with iron supplementation in patients with GI bleeding, may improve patient outcomes and lower hospital costs.

Effectiveness of intraoperative cell salvage in aseptic revision total hip arthroplasty: a single-center retrospective study

Background and study aim: Revision of total hip arthroplasty (rTHA) is associated with significant blood loss. We have used intraoperative cell savage (ICS) systematically in these patients for the last ten years. We sought to determine how often re-suspended red blood cells could be re-transfused and to identify predictors of re- transfusion. Materials and methods: Patients who underwent aseptic rTHA between January 2011 and December 2020 at our center were enrolled in this retrospective observational study. Exclusion criteria were revision for infection or tumor. The primary outcome was the successful use of ICS defined as the ability to re-transfuse at least 125 mL of ICS blood. Secondary outcome measures included re-transfused ICS blood volume, aspirated blood volume, allogenic blood transfusion, and post-operative hemoglobin level. Uni- and multi-variable logistic regressions were used to identify patients and procedure characteristics associated with successful ICS. Mann-Whitney U tests, Student’s t tests and Chi-square tests were used to compare outcomes between patients with and without successful ICS. A P value < 0.05 was considered statistically significant. Results: ICS was successful in 93 (69.9%) out of 133 patients. The extent of revision, categorized as isolated acetabulum, isolated femur, or combined revision was the only predictor of successful ICS. Postoperative hemoglobin levels as well as rate and amount of allogenic red blood cells transfusion did not differ between the groups. Conclusions: ICS is useful in most patients undergoing rTHA. Those requiring a combined revision have the greatest chance of successful re-infusion.

Red Blood Cell Transfusions and Risk of Postoperative Venous Thromboembolism

INTRODUCTION

Postoperative venous thromboembolism (VTE) is a major risk for orthopaedic surgery and associated with notable morbidity and mortality. Knowing a patient's risk for VTE may help guide the choice of perioperative VTE prophylaxis. Recently, red blood cells (RBCs) have been implicated for their role in pathologic thrombosis. Therefore, we examine the association between perioperative RBC transfusion and postoperative VTE after orthopaedic surgery.

METHODS

A retrospective cohort study was done by conducting a secondary analysis of data obtained from the 2016 American College of Surgeons National Surgical Quality Improvement Program database. Our population consisted of 234,608 adults who underwent orthopaedic surgery. The exposure was whether patients received a perioperative RBC transfusion. The primary outcome was postoperative VTE within 30 days of surgery that warranted therapeutic intervention, which was subsequently split into symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE). Odds ratios (ORs) were estimated using a multivariate logistic regression model.

RESULTS

At baseline, 1,952 patients (0.83%) had postoperative VTE (DVT in 1,299 [0.55%], PE in 801 [0.34%], and both DVT and PE in 148 [0.06%]). Seven hundred ninety-five patients (0.3%) received preoperative RBC transfusions only, 11,587 patients (4.9%) received postoperative RBC transfusions only, and 848 patients (0.4%) received both preoperative and postoperative RBC transfusions. Postoperative RBC transfusion was associated with higher odds of VTE (adjusted OR [aOR], 1.47; 95% confidence interval [CI], 1.19-1.81), DVT (aOR, 1.40; 95% CI, 1.09-1.79), PE (aOR, 1.59; 95% CI, 1.14-2.22), and 30-day mortality (aOR, 1.21; 95% CI, 1.01-1.45) independent of various presumed risk factors. When creating subgroups within orthopaedics by Current Procedural Terminology codes, postoperative transfusions in spine (aOR, 2.03; 95% CI, 1.13-3.67) and trauma (aOR, 1.40; 95% CI, 1.06-1.86) were associated with higher odds of postoperative VTE.

CONCLUSION

Our results suggest that postoperative RBC transfusion may be associated with an increased risk of postoperative VTE, both symptomatic DVT and life-threatening PE, independent of confounders. Additional prospective validation in cohort studies is necessary to confirm these findings. In addition, careful perioperative planning for patients deemed to be at high risk of requiring blood transfusion may reduce these postoperative complications in orthopaedic patients.

LEVEL OF EVIDENCE

III.

Efficacy and Safety of Tranexamic Acid in Cancer Surgery. An Update of Clinical Findings and Ongoing Research

In cancer patients undergoing surgery, tumor biology and anticancer treatments can increase the risk of perioperative bleeding and blood transfusions. Notably, blood transfusions can be potentially associated with an increased risk of life-threatening immune responses, acute lung injury, postoperative infections, and thromboembolism. Moreover, the link between perioperative transfusion and increased risk of cancer recurrence cannot be excluded. On the other hand, cancer patients have an increased risk of thromboembolism due to cancer itself and antineoplastic systemic treatments including chemotherapy and anti-angiogenic drugs. In this complex scenario, effective and safe strategies aimed at the prevention of blood transfusions are warranted. This narrative review addresses the efficacy, and the safety of the synthetic antifibrinolytic agent tranexamic acid (TXA) when used perioperatively in cancer surgery. Although in not oncologic surgery the use of TXA has been extensively studied, in the setting of cancer patients requiring surgery, the evidence is scarce. An overview of the ongoing clinical research is also provided.

Prevalence and risk factor of post-operative lower extremities deep vein thrombosis in patients undergoing gynecologic surgery: a single-institute cross-sectional study

Background and aim

The study of prevalence and risk factors of postoperative lower limb deep vein thrombosis (DVT) in Thai gynecologic patients was limited. The present study was conducted to evaluate this issue.

Methods

The patients were age > 15 years old without a history of DVT or pulmonary emboli (PE) scheduled for laparotomy or vaginal gynecologic surgery between May and November 2020 were invited to participate. All of these patients were scheduled for a complete duplex ultrasound to detect lower limb DVT 72 h before and within 14 days after the operation. The patients without DVT were scheduled for an interview by telephone about DVT symptoms 30 days after the operation. The clinical variables were compared using univariate and multivariate analysis to identify the independent factors related to the development of DVT.

Results

One hundred and twelve patients met the inclusion criteria. Of these patients, 44 cases (39.3%) were diagnosed as malignancy and 102 patients underwent a hysterectomy. Post-operative DVTs were detected in six patients (5.4%) and all except one had a malignancy. Thus, the prevalence of DVT in malignancy cases was five in 44 patients (11.4%). The independent risk factors for postoperative DVT were age > 60-year-old and receiving a perioperative blood transfusion. Five of six DVT patients received low molecular-weight heparin for treatment of DVT and none developed PE. The rest of the participants reported no symptom-related DVTs from the interview 30 days after the operation.

Conclusion

The prevalence of postoperative DVT in gynecologic patients was 5%, and the independent risk factors were elderly patients and receiving a perioperative blood transfusion.

Impact of restrictive red blood cell transfusion strategy on thrombosis-related events: A meta-analysis and systematic review

BACKGROUND AND OBJECTIVES

There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated.

MATERIALS AND METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data.

RESULTS

Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I²  = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I²  = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I²  = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups).

CONCLUSIONS

A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.

Preoperative Anemia Is Associated With 30-Day Morbidity in Total Knee Arthroplasty

Given the heightened focus on decreasing length of stay and readmissions following total joint arthroplasty, meticulous preoperative optimization has become increasingly important. The goal of this study was to evaluate the association between preoperative anemia and postoperative morbidity and mortality at 30 days. We used the National Surgical Quality Improvement Program database to identify patients who underwent primary total knee arthroplasty (TKA) between 2006 and 2016. Cohorts were defined based on preoperative hemoglobin and were evaluated for 30-day complications as well as 30-day readmission and non-home discharge. The survey of the National Surgical Quality Improvement Program database yielded 198,233 patients who underwent TKA between 2006 and 2016. Preoperative anemia was found to be a risk factor for all complications (4.73% vs 3.22%, P<.001) as well as non-home discharge (37.0% vs 24.2%, P<.001) and unplanned readmission (4.99% vs 3.14%, P<.001) using both bivariate analysis and multivariate analysis. Meticulous optimization of patients at risk for complications is critical in the era of bundled care and increased focus on rapid transition from inpatient to outpatient care. Preoperative anemia was associated with the total postoperative complication rate at 30 days following TKA as well as non-home discharge and unplanned readmission. Surgeons should attempt to identify patients with preoperative anemia and correct underlying low blood levels to help minimize the rate of postoperative complications. [Orthopedics. 2022;45(2):e86-e90.].

Treatment through a preoperative anemia clinic is associated with a reduction in perioperative red blood cell transfusion in patients undergoing orthopedic and gynecologic surgery

BACKGROUND

Preoperative anemia is associated with increased morbidity, mortality, and risk of transfusion. Treatment through a preoperative anemia clinic (PAC) may improve outcomes.

STUDY DESIGN AND METHODS

Adult patients undergoing elective orthopedic and gynecologic surgery with preoperative anemia were identified and referred for hemoglobin optimization with iron and/or erythropoietin from a single-site academic health center. Treated patients were propensity matched to untreated controls and compared on outcomes of erythrocyte transfusion, length of stay (LOS), and readmission. Changes in hemoglobin relative to treatment time before surgery were also measured in the treated cohort.

RESULTS

One thousand three hundred thirty-two patients were evaluated between July 2015 and March 2021, of which 161 underwent optimization through the PAC. After propensity matching, 127 (98 orthopedic and 29 gynecology) PAC-treated patients were compared to 127 (98 orthopedic and 29 gynecology) control patients who did not undergo treatment. The primary outcome of perioperative transfusion was significantly lower in treated patients compared with matched controls (12.60% vs. 26.77%, p = .005). A lower LOS was demonstrated in the gynecologic PAC subgroup (2.2 [1.5, 2.4] vs. 3.1 [2.2, 3.4], p = .002). Each day of treatment time before surgery was associated with an increase of 0.040 g/dL hemoglobin (p < .001) until 65 days, after which further time did not increase hemoglobin.

CONCLUSION

Treatment through a preoperative anemia clinic is associated with a reduction in perioperative transfusion and possible reduction in LOS and readmission compared with matched controls. Additionally, treatment time before surgery is correlated with a greater increase in hemoglobin up until 2 months prior to surgery.

Novel characteristics of soluble fibrin: hypercoagulability and acceleration of blood sedimentation rate mediated by its generation of erythrocyte-linked fibers

Soluble fibrin (SF) in blood consists of monomers lacking both fibrinopeptides A with a minor population in multimeric clusters. It is a substantial component of isolated fibrinogen (fg), which spontaneously self-assembles into protofibrils progressing to fibers at sub-physiologic temperatures, a process enhanced by adsorption to hydrophobic and some metal surfaces. Comparisons of SF-rich (FR) and SF-depleted (FD) fg isolates disclosed distinct molecular imprints of each via an adsorption/desorption procedure using gold surfaced silica microplates. Accelerated plasminogen activator-induced lysis and decreased stiffness (G′) of thrombin-induced FR fg clots were revealed by thomboelastography. Erythrocyte sedimentation (ESR) in afibrinogenemic plasma (Hematocrit 25–33%) was accelerated by FR fg nearly threefold that of FD fg. Stained smears disclosed frequent rouleaux formations and fibers linking stacked erythrocytes in contrast to no rouleaux by FD fg. Rouleaux formations were more pronounced at 4 °C than at ambient temperatures and at fiber-membrane contacts displayed irregular, knobby membrane contours. One of several FR fg isolates also displayed incomplete fiber networks in cell-free areas. What is more, pre-mixing FR fg with each of three monoclonal IgG anti-fg antibodies at 1.5 mol/mol fg, that inhibited fibrin polymerization, prevented rouleaux formation save occasional 2–4 erythrocyte aggregates. We conclude that spontaneously generated SF fibers bound to erythrocytes forming intercellular links culminating in rouleaux formation and ensuing ESR acceleration which in clinical settings reflects hypercoagulability. Also, the results can explain the reported fg binding to erythrocytes via ligands such as CD47, stable in vivo RBC aggregates in capillaries, and red areas of pathologic thrombi.