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.

Pro-Con Debate: Anesthesiologists Should Be Responsible for Treating Preoperative Anemia.

In this Pro-Con commentary article, we discuss whether anesthesiologists should be responsible for treating preoperative anemia. This debate was proposed based on the article published in this issue of Anesthesia & Analgesia by Warner et al, which is an advisory on managing preoperative anemia endorsed by both the Society of Cardiovascular Anesthesiologists and the Society for Advancement of Patient Blood Management. All evidence suggests that anemia is not just an innocent "bystander" which can be solved by transfusion. In fact, both anemia and transfusion are independently associated with adverse outcomes, so why not avoid both? It just makes sense that patients show up for surgery with enough red blood cells to avoid needing transfusion with someone else's. Even if we agree that preoperative anemia is worth treating before surgery, the question remains who should be responsible for doing so, and therein lies the reason for this Pro-Con debate. Should it be the responsibility of the anesthesiologist, or not? Let the readers decide.

A Propensity-Matched Cohort Study of Intravenous Iron versus Red Cell Transfusions for Preoperative Iron-Deficiency Anemia.

BACKGROUND: While preoperative anemia is associated with adverse perioperative outcomes, the benefits of treatment with iron replacement versus red blood cell (RBC) transfusion remain uncertain. We used a national database to establish trends in preoperative iron-deficiency anemia (IDA) treatment and to test the hypothesis that treatment with preoperative iron may be superior to RBC transfusion. METHODS: This study is a propensity-matched retrospective cohort analysis from 2003 to 2023 using TriNetX Research Network, which included surgical patients diagnosed with IDA within 3 months preoperatively. After matching for surgery type and comorbidities, we compared a cohort of patients with preoperative IDA who were treated with preoperative intravenous (IV) iron but not RBCs (n = 77,179), with a cohort receiving preoperative RBCs but not IV iron (n = 77,179). Propensity-score matching was performed for age, ethnicity, race, sex, overweight and obesity, type 2 diabetes, hyperlipidemia, essential hypertension, heart failure, chronic ischemic heart disease, neoplasms, hypothyroidism, chronic kidney disease, nicotine dependence, surgery type, and lab values from the day of surgery including ferritin, transferrin, and hemoglobin split into low (<7 g/dL), medium (7-<12 g/dL), and high (≥12 g/dL) to account for anemia severity. The primary outcome was 30-day postoperative mortality with the secondary outcomes being 30-day morbidity, postoperative hemoglobin level, and 30-day postoperative RBC transfusion. RESULTS: Compared with RBC transfusion, preoperative IV iron was associated with lower risk of postoperative mortality (n = 2550/77,179 [3.3%] vs n = 4042/77,179 [5.2%]; relative risk [RR], 0.63, 95% confidence interval [CI], 0.60-0.66), and a lower risk of postoperative composite morbidity (n = 14,174/77,179 [18.4%] vs n = 18,632/77,179 [24.1%]; RR, 0.76, 95% CI, 0.75-0.78) (both P = .001 after Bonferroni adjustment). Compared with RBC transfusion, IV iron was also associated with a higher hemoglobin in the 30-day postoperative period (10.1 ± 1.8 g/dL vs 9.4 ± 1.7 g/dL, P = .001 after Bonferroni adjustment) and a reduced incidence of postoperative RBC transfusion (n = 3773/77,179 [4.9%] vs n = 12,629/77,179 [16.4%]; RR, 0.30, 95% CI, 0.29-0.31). CONCLUSIONS: In a risk-adjusted analysis, preoperative IDA treatment with IV iron compared to RBC transfusion was associated with a reduction in 30-day postoperative mortality and morbidity, a higher 30-day postoperative hemoglobin level, and reduced postoperative RBC transfusion. This evidence represents a promising opportunity to improve patient outcomes and reduce blood transfusions and their associated risk and costs.

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.

Clinical Outcomes, Blood Utilization, and Ethical Considerations for Pediatric Patients in a Bloodless Medicine and Surgery Program.

BACKGROUND: Pediatric patients requesting bloodless care represent a challenging clinical situation, as parents cannot legally refuse lifesaving or optimal interventions for their children. Here, we report clinical outcomes for the largest series of pediatric inpatients requesting bloodless care and also discuss the ethical considerations. METHODS: We performed a single-institution retrospective cohort study assessing 196 pediatric inpatients (<18 years of age) who requested bloodless care between June 2012 and June 2016. Patient characteristics, transfusion rates, and clinical outcomes were compared between pediatric patients receiving bloodless care and those receiving standard care (including transfusions if considered necessary by the clinical team) (n = 37,271). Families were informed that all available measures would be undertaken to avoid blood transfusions, although we were legally obligated to transfuse blood if the child's life was threatened. The primary outcome was composite morbidity or mortality. Secondary outcomes included percentage of patients transfused, individual morbid events, length of stay, total hospital charges, and total costs. Subgroup analyses were performed after stratification into medical and surgical patients. RESULTS: Of the 196 pediatric patients that requested bloodless care, 6.1% (n = 12) received an allogeneic blood component, compared to 9.1% (n = 3392) for standard care patients ( P = .14). The most common indications for transfusion were perioperative bleeding and anemia of prematurity. None of the transfusions were administered under a court order. Overall, pediatric patients receiving bloodless care exhibited lower rates of composite morbidity compared to patients receiving standard care (2.6% vs 6.2%; P = .035). There were no deaths in the bloodless cohort. Individual morbid events, length of stay, and total hospital charges/costs were not significantly different between the 2 groups. After multivariable analysis, bloodless care was not associated with a significant difference in composite morbidity or mortality (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.12-1.11; P = .077). CONCLUSIONS: Pediatric patients receiving bloodless care exhibited similar clinical outcomes compared to patients receiving standard care, although larger studies with adequate power are needed to confirm this finding. There were no mortalities among the pediatric bloodless cohort. Although a subset of our pediatric bloodless patients received an allogeneic transfusion, no patients required a court order. When delivered in a collaborative and patient-centered manner, blood transfusions can be safely limited among pediatric patients.

Recommendations From the International Consensus Conference on Anemia Management in Surgical Patients (ICCAMS).

BACKGROUND: Perioperative anemia has been associated with increased risk of red blood cell transfusion and increased morbidity and mortality after surgery. The optimal approach to the diagnosis and management of perioperative anemia is not fully established. OBJECTIVE: To develop consensus recommendations for anemia management in surgical patients. METHODS: An international expert panel reviewed the current evidence and developed recommendations using modified RAND Delphi methodology. RESULTS: The panel recommends that all patients except those undergoing minor procedures be screened for anemia before surgery. Appropriate therapy for anemia should be guided by an accurate diagnosis of the etiology. The need to proceed with surgery in some patients with anemia is expected to persist. However, early identification and effective treatment of anemia has the potential to reduce the risks associated with surgery and improve clinical outcomes. As with preoperative anemia, postoperative anemia should be treated in the perioperative period. CONCLUSIONS: Early identification and effective treatment of anemia has the potential to improve clinical outcomes in surgical patients.

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.

Ultrafiltration in cardiac surgery: Results of a systematic review and meta-analysis.

Background: Ultrafiltration is used with cardiopulmonary bypass to reduce the effects of hemodilution and restore electrolyte balance. We performed a systematic review and meta-analysis to analyze the effect of conventional and modified ultrafiltration on intraoperative blood transfusion.Methods: Utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, we systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane Library to perform a meta-analysis of studies of randomized controlled trials (RCTs) and observational studies evaluating conventional ultrafiltration (CUF) and modified ultrafiltration (MUF) on the primary outcome of intraoperative red cell transfusions.Results: A total of 7 RCTs (n = 928) were included, comparing modified ultrafiltration (n = 473 patients) to controls (n = 455 patients) and 2 observational studies (n = 47,007), comparing conventional ultrafiltration (n = 21,748) to controls (n = 25,427). Overall, MUF was associated with transfusion of fewer intraoperative red cell units per patient (n = 7); MD -0.73 units; 95% CI -1.12 to -0.35 p = 0.04; p for heterogeneity = 0.0001, I2 = 55%) compared to controls. CUF was no difference in intraoperative red cell transfusions compared to controls (n = 2); OR 3.09; 95% CI 0.26-36.59; p = 0.37; p for heterogeneity = 0.94, I2 = 0%. Review of the included observational studies revealed an association between larger volumes (>2.2 L in a 70 kg patient) of CUF and risk of acute kidney injury (AKI).Conclusion: The results of this systematic review and meta-analysis suggest that MUF is associated with fewer intraoperative red cell transfusions. Based on limited studies, CUF does not appear to be associated with a difference in intraoperative red cell transfusion.

Massive transfusion and severe blood shortages: establishing and implementing predictors of futility.

Massive transfusion protocols were developed to deliver blood for life-threatening haemorrhage; however, there are no guidelines to advise when massive transfusion protocols may be considered futile. Early recognition of clinical futility remains a challenge as studies have not identified variables that can accurately determine early mortality. As blood is a scarce resource, efforts to distribute it equitably to all patients who would benefit are of paramount importance. In this editorial we discuss recent data and various aspects important in developing and implementing tools that assist with determining futility in massive transfusion.

A Global Definition of Patient Blood Management.

While patient blood management (PBM) initiatives are increasingly adopted across the globe as part of standard of care, there is need for a clear and widely accepted definition of PBM. To address this, an expert group representing PBM organizations from the International Foundation for Patient Blood Management (IFPBM), the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA), the Society for the Advancement of Patient Blood Management (SABM), the Western Australia Patient Blood Management (WAPBM) Group, and OnTrac (Ontario Nurse Transfusion Coordinators) convened and developed this definition: "Patient blood management is a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment." The definition emphasizes the critical role of informed choice. PBM involves the timely, multidisciplinary application of evidence-based medical and surgical concepts aimed at (1) screening for, diagnosing, and appropriately treating anemia; (2) minimizing surgical, procedural, and iatrogenic blood losses and managing coagulopathic bleeding throughout the care; and (3) supporting the patient while appropriate treatment is initiated. We believe that having a common definition for PBM will assist all those involved including PBM organizations, hospital administrators, individual clinicians, and policy makers to focus on the appropriate issues when discussing and implementing PBM. The proposed definition is expected to continue to evolve, making this endeavor a work in progress.

Methods of Bloodless Care, Clinical Outcomes, and Costs for Adult Patients Who Decline Allogeneic Transfusions.

BACKGROUND: Providing bloodless medical care for patients who wish to avoid allogeneic transfusion can be challenging; however, previous studies have demonstrated favorable outcomes when appropriate methods are used. Here, we report one of the largest series of patients receiving bloodless care, along with the methods used to provide such care, and the resulting outcomes. METHODS: In a retrospective cohort study, 1111 adult inpatients (age ≥18 years) at a single institution who declined allogeneic transfusion for religious or personal reasons between June 2012 and June 2016 were included, and the patient blood management methods are described. Patient characteristics, laboratory data, and transfusion rates, as well as clinical outcomes (morbidity, mortality, and length of stay) were compared to all other patients in the hospital who received standard care, including transfusions if needed (n = 137,009). Medical and surgical patients were analyzed as subgroups. The primary outcome was composite morbidity (any morbid event: infectious, thrombotic, ischemic, renal, or respiratory). Secondary outcomes included individual morbid events, in-hospital mortality, length of stay, total hospital charges, and costs. RESULTS: The bloodless cohort had more females and a lower case mix index, but more preadmission comorbidities. Mean nadir hemoglobin during hospitalization was lower in the bloodless (9.7 ± 2.6 g/dL) compared to the standard care (10.1 ± 2.4 g/dL) group (P < .0001). Composite morbidity occurred in 14.4% vs 16.0% (P = .16) of the bloodless and standard care patients, respectively. Length of stay and in-hospital mortality were similar between the bloodless and standard care patients. After Bonferroni adjustment for multiple comparisons, hospital-acquired infection occurred less frequently in the bloodless compared to the standard care cohort (4.3% vs 8.3%) (P < .0001) in the medical patient subgroup, but not in the surgical subgroup. After propensity score adjustment in a multivariable model and adjustment for multiple comparisons, bloodless care was associated with less risk of hospital-acquired infection (OR, 0.56; 95% CI, 0.35-0.83; P = .0074) in the medical subgroup, but not in the surgical subgroup. Median total hospital charges (by 8.5%; P = .0017) and costs (by 8.7%; P = .0001) were lower in the bloodless compared to the standard care cohort, when all patients were included. CONCLUSIONS: Overall, adult patients receiving bloodless care had similar clinical outcomes compared to patients receiving standard care. Medical (but not surgical) bloodless patients may be at less risk for hospital-acquired infection compared to those receiving standard care. Bloodless care is cost-effective and should be considered as high-value practice.

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

BACKGROUND: Though weight is a major consideration when transfusing blood in pediatric patients, it is generally not considered when dosing transfusions in adults. We hypothesized that the change in hemoglobin (Hb) concentration is inversely proportional to body weight when transfusing red blood cells (RBC) in adults. METHODS: A total of 13,620 adult surgical patients at our institution were assessed in this retrospective cohort study (2009-2016). Patients were stratified based on total body weight (kg): 40-59.9 (16.6%), 60-79.9 (40.4%), 80-99.9 (28.8%), 100-119.9 (11.3%), and 120-139.9 (2.9%). The primary outcome was the change in Hb per RBC unit transfused. Subgroup analyses were performed after stratification by sex (male/female) and the total number of RBC units received (1/2/≥3 units). Multivariable models were used to assess the association between weight and change in Hb. RESULTS: As patients' body weight increased, there was a decrease in the mean change in Hb per RBC unit transfused (40-59.9 kg: 0.85 g/dL, 60-79.9 kg: 0.73 g/dL, 80-99.9 kg: 0.66 g/dL, 100-119.9 kg: 0.60 g/dL, 120-139.9 kg: 0.55 g/dL; p < .0001). This corresponded with a 35% difference in the change in Hb between the lowest and highest weight categories on univariate analysis. Similar trends were seen after subgroup stratification. On multivariable analysis, for every 20 kg increase in patient weight, there was a ~6.5% decrease in the change in Hb per RBC unit transfused (p < .0001). CONCLUSIONS: Patient body weight differentially impacts the change in Hb after RBC transfusion. These findings justify incorporating body weight into the clinical decision-making process when transfusing blood in adult surgical patients.

Assessing predictors of futility in patients receiving massive transfusions.

BACKGROUND: Massive transfusions are associated with a high mortality rate, but there is little evidence indicating when such efforts are futile. The purpose of this study was to identify clinical variables that could be used as futility indicators in massively transfused patients. METHODS: We retrospectively analyzed 138 adult surgical patients at our institution receiving a massive transfusion (2016-2019). Peak lactate and nadir pH within 24 h of massive transfusion initiation, along with other clinical variables, were assessed as predictors of the primary outcome, in-hospital mortality. RESULTS: The overall rate of in-hospital mortality among our patient population was 52.9% (n = 73). Increasing lactate and decreasing pH were associated with greater mortality among massively transfused patients. Mortality rates were ~2-fold higher for patients in the highest lactate category (≥10.0 mmol/L: 25 of 37; 67.6%) compared to the lowest category (0.0-4.9 mmol/L: 17 of 48; 35.4%) (p = .005), and ~2.5-fold higher for patients in the lowest pH category (<7.00: 8 of 9; 88.9%) compared to the highest category (≥7.40: 8 of 23; 34.7%) (p = .016). Increasing age was also associated with higher mortality (≥65 years: 24 of 33; 72.7%) when compared to younger patients (18-64 years: 49 of 105; 46.7%) (p = .010). CONCLUSIONS: Peak lactate ≥10.0 mmol/L, nadir pH <7.00, and age ≥65 years were significantly associated with higher rates of in-hospital mortality among massively transfused patients. Incorporating these clinical parameters into a futility index for massive transfusions will be useful in situations where blood products are scarce and/or mortality may be unavoidable.

Blood transfusions in gunshot-wound-related emergency department visits and hospitalizations in the United States.

BACKGROUND: The United States (US) leads all high-income countries in gunshot wound (GSW) deaths. However, previous US studies have not evaluated the national blood transfusion utilization patterns in hospitalized GSW patients. METHODS: Data from 2016 to 2017 were analyzed from the Nationwide Emergency Department Sample (NEDS) and Nationwide Inpatient Sample (NIS), the largest all-payer emergency department (ED) and inpatient databases, respectively. Using stratified probability sampling, weights were applied to generate nationally representative estimates. Multivariable Poisson-regression models were used to estimate prevalence ratios (PR) of blood transfusion. RESULTS: There were 168,315 ED visits and 58,815 hospitalizations (age = 18-90 years) following a GSW. The majority of hospitalizations were men (88.5%), age 18-24 years (31.8%), and assault-related GSW (51.3%). Blacks had the largest proportion (48.7%) overall of all GSW hospitalizations; Whites accounted for the highest proportion of intentional self-harm injuries (72.4%). Blood transfusions occurred in 12.7% of hospitalizations (12.0% red blood cell [RBC], 4.9% plasma, and 2.5% platelet transfusions). Only 1.9% of cases were associated with transfusion of all three blood components. Hospitalizations with major/extreme severity of illness had significantly higher prevalence of transfusion versus those with mild/moderate severity [crude PR = 4.79 (95%CI:4.15-5.33, p < .001)]. Overall, 8.2% of hospitalizations with GSW died, of whom 26.8% required blood transfusions, which was significantly higher than survivors [crude PR = 2.34 (95%CI:2.10-2.61, p < .001)]. The vast majority (95%) of the transfusions among those who died were within 48 h since admission. CONCLUSIONS: Gun-related violence is a public health emergency in the US, and GSWs are a source of significant mortality, blood utilization, and health care costs.

Red blood cell storage duration and peri-operative outcomes in paediatric cardiac surgery.

BACKGROUND: Prior research on red blood cell (RBC) storage duration and clinical outcomes in paediatric cardiac surgery has shown conflicting results. The purpose of this study was to evaluate whether blood stored for a longer duration is harmful in these patients. METHODS: We performed a retrospective cohort study of paediatric patients undergoing cardiac surgery at our institution between January 2011 and June 2015. Patients were stratified based on whether they were transfused RBCs stored for ≤15 days (fresher blood) or >15 days (older blood). The primary outcome was composite morbidity, with prolonged length of stay (LOS) as a secondary outcome. Subgroup analyses were performed after stratification by RBC transfusion volume (≤2 vs. >2 RBC units). Multivariable logistic regression models were used to assess the impact of RBC storage duration on composite morbidity and prolonged LOS. RESULTS: Of 461 patients, 122 (26·5%) received fresher blood and 339 (73·5%) received older blood. The overall rate of composite morbidity was 18·0% (n = 22) for patients receiving fresher blood and 13·6% (n = 46) for patients receiving older blood (P = 0·24). In the risk-adjusted model, patients receiving older blood did not exhibit an increased risk of composite morbidity (OR: 0·74, 95% CI: 0·37-1·47, P = 0·40) or prolonged LOS (OR: 0·72, 95% CI: 0·38-1·35, P = 0·30) compared to patients receiving fresher blood. Similar results were seen after stratification by RBC transfusion volume. CONCLUSIONS: Transfusing RBCs stored for a longer duration was not associated with an increased risk of morbidity or prolonged LOS in paediatric cardiac surgery patients.

Balancing the Blood Component Transfusion Ratio for High- and Ultra High-Dose Cell Salvage Cases.

OBJECTIVE: To assess the ratio of non-red blood cell to red blood cell components required to avoid coagulopathy when transfusing large amounts of salvaged blood using laboratory test-guided therapy. DESIGN: Retrospective cohort study. SETTING: Single-center, academic hospital. PARTICIPANTS: Thoracoabdominal and abdominal open aortic surgery patients. MEASUREMENT AND MAIN RESULTS: Thirty-eight patients in whom at least 1,000 mL of salvaged red blood cells were transfused were identified and divided into the following 2 cohorts: 1,000-to-2,000 mL of salvaged red blood cells (high dose) (n = 20) and >2,000 mL of salvaged red blood cells (ultra-high dose) (n = 18). Compared with the high-dose cohort, the ultra high-dose cohort received ∼4 times more salvaged red blood cells (1,240 ± 279 mL v 5,550 ± 3,801 mL). With transfusion therapy guided by intraoperative coagulation tests and thromboelastography, the adjusted ratio of non-red blood cell to red blood cell components (plasma + platelets + cryoprecipitate:allogeneic + salvaged red blood cells) was 0.59 ± 0.66 in the high-dose and 0.93 ± 0.27 in the ultra high-dose cohorts. Multiple coagulation parameters were normal and similar between cohorts at the end of surgery, as determined by the mean, median, and 95% confidence intervals. CONCLUSIONS: When transfusing large volumes of salvaged blood, it is important to balance the ratio between non-red blood cell and red blood cell components. Through a laboratory test-guided approach, coagulopathy was not detected when transfusing blood in ratios of approximately 1:2 for patients receiving 1,000-to-2,000 mL of salvaged blood and 1:1 for patients receiving >2,000 mL of salvaged blood.

Utility of viscoelastic coagulation testing in liver surgery: a systematic review.

BACKGROUND: The objective of the current study was to summarize and evaluate all published evidence regarding viscoelastic testing in the field of liver surgery. METHODS: A systematic search of the literature was performed using Medline/PubMed, Scopus, Cochrane Library Central, Google Scholar, and clinicaltrials.gov databases. The following keywords were used:"Thromboelastography", "Thromboelastometry", "Viscoelastic tests OR testing", "Sonoclot Devices", "Point-of-care tests OR testing", "Coagulation OR Haemostasis OR Hemostasis", "Liver OR Hepatic Surgery", "Cirrhosis." RESULTS: A total of 12 studies analyzing 348 patients who underwent viscoelastic testing of coagulation during liver surgery for benign or malignant diseases were included; 7 (58.3%) studies reported on the use of thromboelastography (TEG), and 5 (41.7%) reported on rotational thromboelastometry (ROTEM). Viscoelastic testing (TEG and ROTEM) identified normo-, hyper- and hypo-coagulable status in 77% (n = 268/348), 18.4% (n = 64/348), and 4.6% (n = 16/348) of patients, respectively. In contrast, conventional coagulation tests indicated normo-coagulability in 111 patients (34.2% out of 325) and hypo-coagulability in 214 (65.8% out of 325) patients following liver resection. No patient (0% out of 291) experienced postoperative hemorrhage, whereas 5.8% (n = 17/291) experienced postoperative thromboembolic events. CONCLUSIONS: Global viscoelastic testing may be a reasonable adjunct to conventional coagulation testing to provide a more robust assessment of the coagulation status of patients undergoing liver surgery.

Factors that influence flow through intravascular catheters: the clinical relevance of Poiseuille's law.

BACKGROUND: The physics of ideal fluid flow is well characterized. However, the effect of catheter size, tubing types, injection port adjuncts, and viscosity on flow is not well described. We used a simulated environment to determine how various permutations of common elements affect fluid flow. STUDY DESIGN AND METHODS: We tested 16 peripheral and central venous catheters to assess flow through several standard infusion sets and a rapid infuser set; tested flow through standard and blood infusion sets with the addition of intravenous extension tubing, stopcocks, and a needleless connector; and compared the relative viscosity of commonly used blood products and colloids to that of normal saline. RESULTS: The maximal flow rate was 200 mL/min for the standard infusion set but 800 mL/min for the rapid infusion set. Choice of infusion tubing was the rate-limiting component for many larger catheters. A 14-gauge, single-lumen central venous catheter (CVC) and 18-gauge peripheral intravenous catheter (PIV) had equivalent flow rates with all infusion sets. A 16-gauge single-lumen CVC allowed a flow rate that was slower than that of a 20-gauge PIV, and faster than that of a 22-gauge PIV. The addition of adjuncts slowed flow rate. Needleless connectors had the greatest impact, reducing flow by 75% for the blood infusion set. Packed red blood cells had a viscosity 4.5 times that of normal saline and thereby reduced flow. CONCLUSION: Catheter and tubing choice, adjuncts, and fluid viscosity influence flow rates. Our results will help inform adequate vascular access planning in the perioperative environment.

Anemia, sex, and race as predictors of morbidity or mortality after knee arthroplasty surgery.

BACKGROUND: Anemia is associated with poor outcome after major joint replacement surgery, but it is unclear whether sex and race modify its impact on outcome. We hypothesized that anemia would be associated with increased morbidity or mortality after knee arthroplasty surgery and that sex and race would be effect modifiers for this relationship. STUDY DESIGN AND METHODS: We performed a retrospective cohort study of elective knee arthroplasty patients between 2013 and 2018 using data from the National Surgical Quality Improvement Program. Morbidity or mortality after surgery was compared between patients without anemia, with mild anemia, and with moderate to severe anemia. Multivariable logistic regression was used to determine adjusted odds for morbidity or mortality with anemia. Interaction terms were entered into the model to test for effect modification by sex and race. RESULTS: 243 491 patients were included and 30 135 patients (12.4%) were anemic. Morbidity or mortality occurred in 3.7% of patients without anemia, 5.2% of patients with mild anemia, and 7.1% of patients with moderate to severe anemia (P < .001). After adjustment for confounding variables, mild anemia OR = 1.36 (95% CI = 1.28-1.45), and moderate to severe anemia OR = 1.92 (95% CI = 1.72-2.13) were associated with increased odds of morbidity or mortality. Sex, but not race, was a significant effect modifier with men having a greater increase in morbidity or mortality when anemic (P = .02). CONCLUSIONS: Anemia is associated with increased morbidity or mortality after knee arthroplasty surgery and men have a greater increase in perioperative risk than women when anemic.