Perioperative Red Blood Cell Research Articles

Soluble transferrin receptor is associated with red blood cell transfusion in infant cardiac surgery

Abstract Background Iron deficiency (ID) is linked to an increased need for perioperative red blood cell (RBC) transfusion in cardiac surgery. The soluble transferrin receptor (sTfR), an inflammation-independent marker of ID, has emerged as a potential marker for evaluating iron status. However, the relationship between sTfR level and the need for a high-volume of RBC transfusion in pediatric cardiac surgery patients has not been explored. Purpose The objective of this study was to explore the distribution of sTfRs and their association with high-volume RBC transfusion in infants during cardiac surgery. Methods From August 2021 to July 2022, 236 low-weight infants (≤10 kg) who underwent cardiac surgery were included in this study. Preoperative sTfR levels and the volume of RBCs perioperatively transfused were recorded. Receiver operating characteristic curve analysis and multivariable logistic model were used to explore the association between sTfR levels and the need for a high-volume of RBC transfusion in this study. Results In our study, 29 (12.2%) patients received more than 2 units during the perioperative period. sTfR level was the most accurate marker for predicting the need for RBC transfusion (AUC=0.643, cutoff=17.53 nmol/L, sensitivity=58.6%, specificity=73.9%). Moreover, in both the continuous and categorical variable-adjusted models, a high sTfR level was associated with a greater need for RBC transfusion (P=0.006; P<0.001). Conclusions RBC transfusion is common for low-weight infants undergoing cardiac surgery. Furthermore, a high preoperative sTfR level is associated with the need for a high-volume perioperative RBC transfusion.

Effect of perioperative erythropoietin on postoperative morbidity and mortality after cardiac surgery: A meta-analysis of randomized controlled trials

ObjectiveCardiac surgery is known to have high rates of perioperative red blood cell (RBC) transfusions which are associated with increased postoperative mortality and morbidity. Perioperative erythropoietin (EPO) has been suggested to lower perioperative RBC transfusions, and the effect on postoperative morbidity or mortality is unknown. MethodsThe registered study protocol is available on PROSPERO (CRD42022314538). We searched the Pubmed, EMbase, and Cochrane CENTRAL databases for randomized controlled trials (RCT) of EPO in cardiac surgery. Outcomes were short-term mortality, acute kidney injury (AKI), re-operation, cerebrovascular accident (CVA), perioperative myocardial infarction (MI), infectious complications, and RBC transfusions. RCT studies of perioperative EPO that reported at least one prespecified outcome of interest were included. ResultsA total of 21 RCT’s (n = 2,763 patients) were included. Mortality analysis included 17 studies (EPO 1,272 patients, control 1,235) and showed no significant difference (risk difference (RD) 0.0004, 95%CI: -0.016, 0.009). EPO did not reduce the incidence of AKI (RD -0.006, 95% CI: -0.038, 0.026) and reoperation (RD 0.001, 95% CI: -0.013, 0.015). The incidence of CVA (RD -0.004, 95% CI: -0.015, 0.007) and perioperative MI (RD -0.008, 95% CI: -0.021, 0.005) was similar between the groups. ConclusionsAlthough EPO had been proven to reduce perioperative RBC transfusions, we did not find that it reduces the incidence of postoperative short-term mortality, AKI, and reoperation. The study results support that perioperative EPO is also safe, with no rise in thrombotic events, including CVA and perioperative MI.

Effect of perioperative blood transfusion on preoperative haemoglobin levels as a risk factor for long-term outcomes in patients undergoing major noncardiac surgery: a prospective multicentre observational study

BackgroundPreoperative anaemia and red blood cell (RBC) transfusions are associated with poorer clinical outcomes. It is unknown whether perioperative RBC transfusions mediate the relationship between preoperative haemoglobin levels and postoperative outcomes. MethodsThis was a prospective observational study among patients aged ≥50 yr undergoing elective major noncardiac surgery from four Swedish hospitals. The co-primary outcomes were 1-yr major adverse cardiovascular and cerebrovascular events (MACCEs) and all-cause mortality. The secondary outcome was a composite of 30-day mortality, MACCEs, acute kidney injury (AKI), pulmonary embolism, anastomotic leak, and postoperative infection. Mediation analyses were conducted with preoperative haemoglobin as the exposure and RBC transfusion as a mediator. ResultsAmong 1060 patients (mean age 70 [SD 9] yr; 472 [45%] women), 171 patients (16.1%) developed 1-yr MACCEs, and 105 patients (9.9%) died within 1 yr. Preoperative haemoglobin levels were significantly associated with both 1-yr MACCEs (b=–0.015, P=0.041) and all-cause mortality (b=–0.028, P<0.001). Volume of RBC transfusion was not directly associated with the outcomes and did not mediate the relationship between preoperative haemoglobin levels and 1-yr MACCEs (b=–0.001, P=0.451) or all-cause mortality (b=–0.002, P=0.293). For the secondary outcome, RBC transfusions had a significant mediating effect between preoperative haemoglobin and the composite 30-day outcome; however, no direct association was observed (b=0.006, P=0.554). ConclusionsPreoperative haemoglobin levels were significantly associated with 1-yr MACCEs and all-cause mortality. This effect was not mediated by perioperative RBC transfusions. Further research is needed to confirm these findings.

Impact of elevated direct factor Xa inhibitor plasma levels on perioperative blood loss in patients undergoing urgent surgery.

Data on the perioperative bleeding risk associated with elevated plasma levels of direct factor Xa inhibitors (FXa inhibitors) are limited. This study examines perioperative red blood cell (RBC) loss in patients undergoing urgent surgery with a residual FXa inhibitor level exceeding 100 mcg/L and without preoperative FXa inhibitor reversal. This retrospective analysis includes data from 32 patients who underwent urgent noncardiac surgery between 2018 and 2022. This study aims to analyze perioperative RBC loss in patients undergoing urgent surgery with a residual FXa inhibitor level exceeding 100 mcg/L and without preoperative FXa inhibitor antidote-based reversal or unspecific treatment with 4-factor prothrombin complex concentrate (PCC). All patients were managed using a watch-and-wait strategy. The last determination of FXa inhibitor plasma concentration prior to surgery showed a median of 245 mcg/L (IQR 144-345), with a median time interval of 3.8 h (IQR 2.4-7.2) before incision. Median RBC loss during surgery was 49 mL (IQR 0-253), 189 mL (IQR 104-217) until POD1 and 254 mL (IQR 58-265) until POD3. Only one patient required intraoperative treatment with 4-factor-PCC and none required reversal with andexanet alfa. Linear regression models found no significant influence of FXa inhibitor plasma levels on intraoperative RBC loss. Rivaroxaban was associated with higher RBC loss until postoperative Day 1 compared with apixaban. No thromboembolic events were observed. Despite markedly elevated plasma concentrations of residual direct FXa inhibitors, perioperative RBC loss was limited in patients undergoing urgent noncardiac surgery. The intraoperative watch-and-wait strategy with selective intraoperative FXa inhibitor reversal or treatment only when required appears to be an appropriate approach.

Comparison of Eliminating Artificial Hydronephrosis and Creating Artificial Hydronephrosis in Percutaneous Nephrolithotomy in Oblique Supine Position

Introduction: The safety and effectiveness of percutaneous nephroscopic surgery without artificial hydronephrosis remain controversial, and there are few relevant studies. This retrospective study aimed to compare the efficacy of two different methods of eliminating and creating artificial hydronephrosis in percutaneous nephrolithotomy (PCNL) in the oblique supine position. Methods: This is a retrospective study. A total of 162 patients who underwent PCNL in an oblique supine position at our hospital were divided into two groups according to the surgical method: the free artificial hydronephrosis group (group A) and the artificial hydronephrosis group (group B). Group A was directly treated with PCNL under ultrasound guidance, and group B was treated with artificial hydronephrosis before PCNL. Several outcomes were measured, including procedure time, stone clearance rate, and incidence of complications. Results: The procedure time in group A lower than that in group B, and the incidence of sepsis was significantly lower in group A than in group B (p < 0.05). There was no statistical difference in stone clearance rate, success rate of primary establishment of puncture channel, unilateral change in perioperative red blood cell count, change in perioperative renal function, and perioperative complications (except sepsis) between the two groups (p > 0.05). Conclusion: For experienced physicians, PCNL without artificial hydronephrosis in an oblique supine position can be attempted to reduce the number of surgical steps without affecting the stone clearance rate and increasing the occurrence of complications.

Risk factors for allogeneic red blood cell transfusion in adult spinal deformity surgery.

Retrospective study. To investigate the risk factors for allogeneic red blood cell (RBC) transfusion in adult spinal deformity (ASD) surgery. Studies have not thoroughly explored the roles of intraoperative hypothermia, autologous blood donation, and hemostatic agent administration, which would provide a better understanding of the risk for perioperative RBC transfusion in ASD surgery. The medical records of 151 patients with ASD who underwent correction surgery between 2012 and 2021 were retrospectively reviewed. Estimated blood loss and perioperative allogeneic transfusion were examined. Patients were categorized into two groups based on whether they received perioperative allogeneic blood transfusion. Logistic regression analysis was employed to investigate the effect of age, sex, blood type, body mass index, American Society of Anesthesiologists' physical status, preoperative hemoglobin level, autologous blood donation, global spine alignment parameters, preoperative use of anticoagulants or antiplatelet medicine and nonsteroidal anti-inflammatory drugs, number of instrumented fusion levels, total operative duration, three-column osteotomy, lateral interbody fusion, pelvic fixation, intraoperative hypothermia, use of gelatin-thrombin based hemostatic agents, and intraoperative tranexamic acid (TXA) with simultaneous exposure by two attending surgeons. The estimated blood loss was 994.2±754.5 mL, and 71 patients (47.0%) received allogeneic blood transfusion. In the logistic regression analysis, the absence of intraoperative TXA use and simultaneous exposure (odds ratio [OR], 26.3; 95% confidence interval [CI], 7.6-90.9; p<0.001), lack of autologous blood donation (OR, 21.2; 95% CI, 4.4-100.0; p<0.001), and prolonged operative duration (OR, 1.6; 95% CI, 1.3-1.9; p<0.001) were significant independent factors for perioperative allogeneic blood transfusion in ASD surgery. Autologous blood storage, intraoperative TXA administration, and simultaneous exposure should be considered to minimize perioperative allogeneic blood transfusion in ASD surgery, particularly in patients with anticipated lengthy surgeries.

Better prognosis in surgical aortic valve replacement patients with lower red cell distribution width: A MIMIC-IV database study.

Surgical aortic valve replacement (SAVR) currently stands as a primary surgical intervention for addressing aortic valve disease in patients. This retrospective study focused on the role of the red blood cell distribution width (RDW) in predicting adverse outcomes among SAVR patients. The subjects for this study were exclusively derived from the Medical Information Mart for Intensive Care database (MIMIC IV 2.0). Kaplan‒Meier (K-M) curves and Cox proportional hazards regression models were employed to assess the correlation between RDW, one-year mortality, and postoperative atrial fibrillation (POAF). The smooth-fitting curves were used to observe the relative risk (RR) of RDW in one-year mortality and POAF. Furthermore, time-dependent receiver operating characteristic (ROC) curves, the continuous-net reclassification index (NRI), and integrated discrimination improvement (IDI) were employed for comprehensive assessment of the prognostic value of RDW. Analysis of RDW revealed a distinctive inverted U-shaped relationship with one-year mortality, while its association with POAF appeared nearly linear. Cox multiple regression models showed that RDW > 14.35%, along with preoperative potassium concentration and perioperative red blood cell transfusion, were significantly linked to one-year mortality (K-M curves, log-rank P < 0.01). Additionally, RDW was associated with both POAF and prolonged hospital stays (P < 0.05). There was no significant difference in length of stay in ICU. Notably, the inclusion of RDW in the predictive models substantially enhanced its performance. This was evidenced by the time-dependent ROC curve (AUC = 0.829), NRI (P< 0.05), IDI (P< 0.05), and K-M curves (log-rank P< 0.01). RDW serves as a robust prognostic indicator for SAVR patients, offering a novel means of anticipating adverse postoperative events.

Predictive Value of Thromboelastography for Postoperative Blood Loss in Infants Undergoing Cardiac Surgery

Thromboelastography (TEG) has emerged as a critical tool in promptly identifying the risk of postoperative bleeding, especially in infants and young children undergoing cardiac surgery. By meticulously analyzing TEG parameters, clinicians gain a profound understanding of patients&amp;apos; coagulation status, enabling timely intervention to minimize and manage postoperative bleeding risks. The present study adopts a rigorous, prospective, and observational approach to explore the relationship between intraoperative TEG test results and postoperative blood loss. Furthermore, it aims to assess the potential of intraoperative TEG testing as an early predictor of postoperative bleeding in high-risk pediatric patients. In this process, a key focus is placed on perioperative red blood cell suspension and platelet transfusion volume, as well as their association with TEG testing outcomes. Our findings reveal a significant correlation between the volume of red blood cell suspension and platelet transfusion and the MA value derived from TEG testing. The MA value, a pivotal indicator in TEG test results, represents the maximum clotting strength. Notably, during perioperative red blood cell suspension and platelet transfusion, the MA value often exhibits corresponding changes. These changes not only reflect improvements in coagulation function but also provide clinicians with an objective basis for evaluating the effectiveness of blood transfusion. However, despite the notable impact of blood transfusion on MA values, our study did not detect statistically significant associations between blood transfusion and other TEG parameters, including TEG-ACT values, α-Angle, and LY30. This absence of significant associations may be attributed to the differential effects of various transfusion components on the coagulation process, as well as the influence of confounding factors such as patient age, comorbidities, and surgical procedure type.

Influence of thromboelastography-guided hemostatic algorithm on allogeneic transfusion requirements during pediatric hemispherectomy

Objective: To evaluate the influence of thromboelastography-guided hemostatic algorithm on allogeneic transfusion requirements during pediatric hemispherectomy. Methods: Clinical data of 38 children who underwent hemispherectomy from January 1, 2011 to October 31, 2023 at Xuanwu Hospital of Capital Medical University were retrospective collected. Patients were divided into study group (n=17) and control group (n=21) according to whether thromboelastography was employed to guide hemostatic algorithm. Demographic data and surgical data were recorded. The primary outcomes were allogeneic transfusion rates, including RBC transfusion rate, plasma transfusion rate, and platelets transfusion rate. The second outcomes were estimated blood loss, postoperative seizures during hospitalization, thromboembolic events, and length of hospital stay. Results: There were 13 boys and 4 girls with mean age of (5.7±3.3) years old in study group, and 16 boys and 5 girls with mean age of (7.4±3.4) years old in control group. The surgery duration, anesthesia duration and the proportion of prophylactic administration of tranexamic acid in study group were (424.5±98.5) min, (542.8±106.9) min, and 94.1% (16/17), which were higher than (353.1±85.3) min, (445.3±87.9) min, and 47.6% (10/21) in control group (all P<0.05). The rates of intra- and perioperative allogeneic plasma transfusion in study group were 52.9% (9/17) and 64.7% (11/17) respectively, which were lower than 90.5% (19/21) and 95.2% (20/21) in control group (all P<0.05). The ratio of fibrinogen concentrates administration in study group was 58.8% (10/17), which was higher than that in control group [4.8% (1/21), P=0.001]. There were no statistically differences in intra- and perioperative allogeneic RBC transfusion rates between the two groups (all P>0.05). No platelets were transfused in both groups. There were no statistically differences in estimated blood loss, postoperative seizures during hospitalization and the length of hospital stay between the two groups (all P>0.05). No postoperative thromboembolic events were observed. Conclusion: Thromboelastography-guided hemostatic algorithm can reduce allogeneic plasma transfusion requirements but not RBC transfusion requirements during pediatric hemispherectomy.

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.

Development of machine learning models to predict perioperative blood transfusion in hip surgery

BackgroundAllogeneic Blood transfusion is common in hip surgery but is associated with increased morbidity. Accurate prediction of transfusion risk is necessary for minimizing blood product waste and preoperative decision-making. The study aimed to develop machine learning models for predicting perioperative blood transfusion in hip surgery and identify significant risk factors.MethodsData of patients undergoing hip surgery between January 2013 and October 2021 in the Peking Union Medical College Hospital were collected to train and test predictive models. The primary outcome was perioperative red blood cell (RBC) transfusion within 72 h of surgery. Fourteen machine learning algorithms were established to predict blood transfusion risk incorporating patient demographic characteristics, preoperative laboratory tests, and surgical information. Discrimination, calibration, and decision curve analysis were used to evaluate machine learning models. SHapley Additive exPlanations (SHAP) was performed to interpret models.ResultsIn this study, 2431 hip surgeries were included. The Ridge Classifier performed the best with an AUC = 0.85 (95% CI, 0.81 to 0.88) and a Brier score = 0.21. Patient-related risk factors included lower preoperative hemoglobin, American Society of Anesthesiologists (ASA) Physical Status > 2, anemia, lower preoperative fibrinogen, and lower preoperative albumin. Surgery-related risk factors included longer operation time, total hip arthroplasty, and autotransfusion.ConclusionsThe machine learning model developed in this study achieved high predictive performance using available variables for perioperative blood transfusion in hip surgery. The predictors identified could be helpful for risk stratification, preoperative optimization, and outcomes improvement.

A survey on perioperative red blood cell transfusion trigger strategies for pediatric patients in the Nordic countries.

Transfusion of red blood cells (RBC) to rapidly increase hemoglobin levels have been associated with increased risks and worse outcomes in critically ill children. The international TAXI consensus from 2018 (pediatric critical care transfusion and anemia expertise initiative) recommended restrictive RBC transfusion strategies in pediatric patients. To elucidate physicians perioperative RBC transfusion trigger strategies for pediatric patients in the Nordic countries and to investigate what factors influence the decision to transfuse this group of patients. An electronic web-based survey designed by the TransfUsion triggers in Pediatric perioperAtive Care (TUPAC) initiative including six different clinical scenarios was sent to anesthesiologist treating pediatric patients at university hospitals in the Nordic countries on February 1, 2023 and closed May 1, 2023. The study had a response rate of 67.7% (180 responders out of 266 contacted). Median hemoglobin thresholds triggering RBC transfusions were 7.0 [IQR, 7.0-7.3] g/dL in a stable young child (1-year-old), 7.0 [IQR, 7.0-7.0] g/dL in the stable older child (5-year-old), 8.5 [IQR, 8.0-9.0] g/dL in the older child with cardiac disease, 9.0 [IQR, 8.0-10.0] g/dL the older child with traumatic brain injury, 8.0 [IQR, 7.3-9.0] g/dL in stabilized older child with septic shock and 8.0 [IQR, 7.0-9.0] g/dL in the older child with active but non-life-threatening bleeding. Apart from specific hemoglobin level, RBC transfusions were mostly triggered by high lactate level (74.2%), increasing heart rate (68.0%), prolonged capillary refill time (48.3%), and lowered blood pressure (47.8%). No statistical difference was found between the Nordic countries, work experience, or enrollment in a pediatric anesthesia fellowship program regarding RBC transfusion strategies. Anesthesiologists in the Nordic countries report restrictive perioperative RBC transfusion strategies for children that are mostly in agreement with the international TAXI recommendations. However, RBC transfusions strategies were modified to be guided by more liberal trigger levels when pediatric patients presented with severe comorbidity such as severe sepsis, septic shock, and non-life-threatening bleeding.

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

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. 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). 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. 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.

Monitoring of Perioperative Microcirculation Dysfunction by Near-Infrared Spectroscopy for Neurological Deterioration and Prognosis of Aneurysmal Subarachnoid Hemorrhage: An Observational, Longitudinal Cohort Study.

No evidence has established a direct causal relationship between early microcirculation disturbance after aneurysmal subarachnoid hemorrhage (aSAH) and neurological function prognosis, which is the key pathophysiological mechanism of early brain injury (EBI) in patients with aSAH. A total of 252 patients with aSAH were enrolled in the Neurosurgical Intensive Care Unit of Southwest Hospital between January 2020 and December 2022 and divided into the no neurological deterioration, early neurological deterioration, and delayed neurological deterioration groups. Indicators of microcirculation disorders in EBI included regional cerebral oxygen saturation (rSO2) measured by near-infrared spectroscopy (NIRS), brain oxygen monitoring, and other clinical parameters for evaluating neurological function and determining the prognosis of patients with aSAH. Our data suggest that the rSO2 is generally lower in patients who develop neurological deterioration than in those who do not and that there is at least one time point in the population of patients who develop neurological deterioration where left and right cerebral hemisphere differences can be significantly monitored by NIRS. An unordered multiple-classification logistic regression model was constructed, and the results revealed that multiple factors were effective predictors of early neurological deterioration: reoperation, history of brain surgery, World Federation of Neurosurgical Societies (WFNS) grade4-5, Fisher grade3-4, SAFIRE grade 3-5, abnormal serum sodium and potassium levels, and reduced rSO2 during the perioperative period. However, for delayed neurological deterioration in patients with aSAH, only a history of brain surgery and perioperative RBC count were predictive indicators. The rSO2 concentration in patients with neurological deterioration is generally lower than that in patients without neurological deterioration, and at least one time point in the population with neurological deterioration can be significantly monitored via NIRS. However, further studies are needed to determine the role of microcirculation and other predictive factors in the neurocritical management of EBI after aSAH, as these factors can reduce the incidence of adverse outcomes and mortality during hospitalization.

Impact of peri-operative red blood cell transfusions for treatment of anemia on acute rejection in renal transplant recipients

IntroductionAnemia occurs before and after kidney transplantation. Determining the impact of perioperative transfusion on post-transplant outcomes can help determine best management of anemia. Project aimThe current study aims to describe clinical outcomes associated with packed red blood cell transfusions in the peri-operative management of anemia after transplantation. DesignThis was a single-center, retrospective study of adult kidney recipients with anemia at the time of transplantation. 1271 patients were stratified by donor-type due to the potential variability in underlying recipient and transplant characteristics; living donor (n = 698, 62%) or deceased donor (n = 573, 38%). ResultsLiving donor recipients that received blood during the index hospitalization were more likely to experience rejection within 30 days (18% vs. 10%, p = 0.008) and 1 year of transplant (32% vs. 16%, p = 0.038). In multivariate analysis, receiving both blood and darbepoetin (HR: 1.89 [1.20,3.00], p = 0.006), age at transplant (HR: 0.98 [0.97, 0.99], p = 0.02), number of HLA mismatches (HR: 1.17 [1.05,1.30], p = 0.003), and whether the case was a repeat transplant (HR: 2.77 [1.93,3.97], p < 0.01) were significantly associated with hazard of rejection. For deceased donor recipients, there were no differences in acute rejection, graft failure or mortality at 30 days or 1 year. When analyzing hazard of rejection in a multivariate model, treatment received was not found to be significantly associated with rejection. ConclusionOur findings suggest there may be a role for more aggressive pre-transplant treatment of anemia for those patients undergoing living donor transplants.

Development and validation of a machine learning prediction model for perioperative red blood cell transfusions in cardiac surgery

ObjectiveSeveral machine learning (ML) models have been used in perioperative red blood cell (RBC) transfusion risk for cardiac surgery with limited generalizability and no external validation. Hence, we sought to develop and comprehensively externally validate a ML model in a large dataset to estimate RBC transfusion in cardiac surgery with cardiopulmonary bypass (CPB). DesignA retrospective analysis of a multicenter clinical trial (NCT03782350). PatientsThe study patients who underwent cardiac surgery with CPB came from four cardiac centers in China and Medical Information Mart for Intensive Cared (MIMIC-IV) dataset. MeasurementsData from Fuwai Hospital were used to develop an individualized prediction model for RBC transfusion. The model was externally validated in the data from three other centers and MIMIC-IV dataset. Twelve models were constructed. Main resultsA total of 11,201 eligible patients were included in the model development (2420 in Fuwai Hospital) and external validation (563 in the other three centers and 8218 in the MIMIC-IV dataset). A significant difference was observed between the Logistic Regression and CatboostClassifier (0.72 Vs. 0.74, P = 0.031) or RandomForestClassifier (0.72 Vs. 0.75 p = 0.012) in the external validation and MIMIV-IV datasets (age ≤ 70:0.63 Vs. 0.71, p < 0.001; age > 70:0.63 Vs. 0.70, 0.63 Vs. 0.71, p < 0.001). The CatboostClassifier and RandomForestClassifier model was comparable in development (0.83 Vs. 0.82, p = 0.419), external (0.74 Vs. 0.75, p = 0.268), and MIMIC-IV datasets (age ≤ 70: 0.71 Vs. 0.71, p = 0.574; age > 70: 0.70 Vs. 0.71, p = 0.981). Of note, they outperformed other ML models with excellent discrimination and calibration. The CatboostClassifier and RandomForestClassifier models achieved higher area under precision-recall curve and lower brier loss score in validation and MIMIC-IV datasets. Additionally, we confirmed that low preoperative hemoglobin, low body mass index, old age, and female sex increased the risk of RBC transfusion. ConclusionsIn our study, enrolling a broad range of cardiovascular surgeries with CPB and utilizing a restrictive RBC transfusion strategy, robustly validates the generalizability of ML algorithms for predicting RBC transfusion risk. Notably, the CatboostClassifier and RandomForestClassifier exhibit strong external clinical applicability, underscoring their potential for widespread adoption. This study provides compelling evidence supporting the efficacy and practical value of ML-based approaches in enhancing transfusion risk prediction in clinical practice.

Predictors for postoperative dysphagia in liver transplant recipients.

Liver transplant recipients are at a heightened risk for oropharyngeal dysphagia; identification of those who are at high risk for postoperative dysphagia could reduce hospital costs and length of stay. We sought to identify predictors of dysphagia, in a large cohort of patients who underwent liver transplantation. Electronic medical records were queried for patients undergoing liver transplantation, who underwent instrumental swallowing evaluations. Demographics, functional outcomes, and interventions were collected. Logistic regression analyses were performed to identify predictors of dysphagia. Seven hundred and ninety-five patients met inclusionary criteria. Multivariate analyses found ethnic group (p = .0191), MELD Score (p < 0001), cold ischemia time (p = .0123), and length of intubation (p < .0001) to be predictors of post-operative development of dysphagia. Pre-transplant dialysis (p < .0001), dysphagia related to end stage liver disease (p < .0001), Karnofsky Performance Status Scale (p < .0001), wait time to transplant (p = 0.0173), surgery time (p = 0.0095), tracheostomy (p < 0.0001), and transfusion of intraoperative RBC (p < .0001), intraoperative platelets (p = 0.0018), intraoperative FFP (p = 0.0495), perioperative FFP (p = 0.0002), perioperative platelets (p = 0.0151) and perioperative RBC (p = 0.0002) were variables of significance associated with the development of postoperative dysphagia from univariate analysis. Our results propose a set of predictors that should be considered when identifying post-operative critically ill patients at risk for dysphagia.

Safety and efficacy of tranexamic acid in major non-cardiac vascular surgery: a systematic review and meta-analysis

Background: Tranexamic acid (TXA) is a synthetic lysine analogue that inhibits fibrinolysis. The effectiveness of TXA in obstetrics, trauma and orthopaedic and cardiac surgery is well established. However, concerns regarding its prothrombotic potential remain, which is an important consideration for vascular surgery. We aimed to evaluate the safety and efficacy of TXA in adults undergoing major non-cardiac vascular surgery. Methods: A pre-specified protocol (PROSPERO CRD42023427282) was followed. Relevant databases (PubMed, MEDLINE, EMBASE) were searched for randomised controlled trials (RCTs). Data extraction and risk of bias assessments were performed in duplicate. A random effects model was used to synthesise data from RCTs. Measures of effect were reported as relative risk (RR) with 95% confidence intervals (CIs). The primary safety outcome was a composite of arterial and venous thromboembolic events (composite of myocardial infarction, non-haemorrhagic stroke, peripheral arterial thrombosis and symptomatic proximal venous thromboembolism). Certainty of evidence was assessed using the GRADE approach. Results: After screening 1989 records, three RCTs were included, cumulatively enrolling 1,560 participants. In all trials, patients received either TXA (intravenously or orally) compared with placebo. There was no evidence of the effect of intravenous TXA on thromboembolic events (RR 1.10, 95% CI 0.89 to 1.36, two RCTs, 1460 participants, low certainty of evidence) or on critical bleeding (composite of life-threatening, critical and major organ bleed) (RR 0.85, 95% CI 0.65 to 1.11, two RCTs, 1460 participants, low certainty of evidence). TXA may reduce postoperative blood loss, especially at 0–4 hours (Cliff’s delta −0.41, 95% CI −0.19 to −0.59) and 0–24 hours (Cliff’s delta −0.37, 95% CI −0.14 to −0.55) after surgery. There was no evidence of an effect of TXA on reducing perioperative red blood cell (RBC) transfusion requirements (RR 0.66, 95% CI 0.11 to 3.95, one RCT, 100 participants). One RCT assessed oral TXA and found no evidence of an effect on type II endoleak post endovascular aneurysm repair. No thrombotic complications were reported in this RCT during the study period. Conclusions: We found no evidence of an effect of TXA on thromboembolic complications. While TXA appears to reduce early postoperative bleeding, the clinical relevance of this is uncertain. Due to limitations of study design and the variety of vascular procedures, the role of TXA in vascular surgery is still unclear. Ongoing trials may reduce this uncertainty. Registration: Prospectively registered on PROSPERO (CRD42023427282)

The additive effects of anaemia and transfusion on long-term survival after coronary artery bypass surgery.

To compare the independent and combined effects of anaemia and red blood cell transfusion on late survival after isolated coronary artery bypass grafting. Retrospective analysis of 5243 consecutive patients undergoing primary isolated coronary artery bypass grafting, performed from 2000 to 2015, in a Portuguese Academic Hospital. We identified 1649 patients with preoperative anaemia (A+) and 1422 patients who received a perioperative transfusion (T+)-the 4 possible combinations allowed for the creation of 4 subgroups (A-/T-, A-/T+, A+/T- and A+/T+). The primary endpoint was all-cause mortality at 10 years. We employed inverse probability weighting to control for confounding variables. Thirty-one percent of the patients had preoperative anaemia, and 27.0% had at least one packed red blood cell transfusion. Inverse probability weighting was effective in eliminating differences in all significant baseline characteristics. The primary endpoint of all-cause mortality at 10 years occurred in 568 patients (20.5%) in the A-/T- group, as compared with 204 (24.4%) in the A-/T+ group (hazard ratio, 1.14; 95% confidence interval, 1.00 to 1.31; P = 0.053), 358 (33.8%) in the A+/T- group (hazard ratio, 1.53; 95% confidence interval, 1.38 to 1.71; P < 0.001), 254 (43.6%) in the A+/T+ group (hazard ratio, 2.25; 95% confidence interval, 1.97 to 2.56; P < 0.001). This longitudinal, population-level study emphasizes the adverse long-term outcomes of preoperative anaemia and perioperative red blood cell transfusion. It stresses the importance of an evidence-based, multimodal and multidisciplinary approach to conserving blood resources and optimizing outcomes in patients at high risk for transfusion.

Clinical Risk Factors of Perioperative Pressure Injury in Older Adult Patients with a Hip Fracture.

To examine the clinical risk factors of perioperative pressure injury (PrI) in older adults with a hip fracture, including preoperative chronic comorbidities and postoperative complications. In this retrospective study, the authors queried the PearlDiver Patient Records database between January 2011 and January 2020. Data from 54,194 patients without preexisting PrI were included for analyses. Patients were separated into two groups: (1) one or more perioperative PrI and (2) no PrI. Clinical factors as outcome variables include 21 comorbidities and 10 complications. Univariate analyses were computed to compare the variables between groups, and two logistic regression models were developed to find comorbidity predictors and complication predictors. Of all patients, 1,362 (2.5%) developed one or more perioperative PrI. Patients with perioperative PrIs were more likely to be older men. One-year mortality for patients with perioperative PrI was 2.5 times that of patients without PrI. The regression models showed that predictors of perioperative PrI are malnutrition, hypoalbuminemia, frailty, peripheral vascular disease, dementia, urinary tract infection, perioperative red blood cell transfusion, and atrial fibrillation. Screening for these comorbidities and complications may assist in determining the risk of PrI in older adults undergoing hip fracture surgery. Determining PrI risk enables the appropriate prevention strategies to be applied perioperatively.