Transfusion targets and adverse events in pediatric perioperative acute Anemia

STUDY OBJECTIVE

To evaluate the association between pretransfusion and posttransfusion hemoglobin concentrations and the outcomes of children undergoing noncardiac surgery.

DESIGN

Retrospective review of patient records. We focused on initial postoperative hemoglobin concentrations, which may provide a more useful representation of transfusion adequacy than pretransfusion hemoglobin triggers (the latter often cannot be obtained during acute surgical hemorrhage).

SETTING

Single-center, observational cohort study.

PATIENTS

We evaluated all pediatric patients undergoing noncardiac surgery who received intraoperative red blood cell transfusions from January 1, 2008, through December 31, 2018.

INTERVENTIONS

None.

MEASUREMENTS

Associations between pre- and posttransfusion hemoglobin concentrations (g/dL), hospital-free days, intensive care unit admission, postoperative mechanical ventilation, and infectious complications were evaluated with multivariable regression modeling.

MAIN RESULTS

In total, 113,713 unique noncardiac surgical procedures in pediatric patients were evaluated, and 741 procedures met inclusion criteria (median [range] age, 7 [1-14] years). Four hundred ninety-eight patients (68%) with a known preoperative hemoglobin level had anemia; of these, 14% had a preexisting diagnosis of anemia in their health record. Median (IQR) pretransfusion hemoglobin concentration was 8.1 (7.4-9.2) g/dL and median (IQR) initial postoperative hemoglobin concentration was 10.4 (9.3-11.6) g/dL. Each decrease of 1 g/dL in the initial postoperative hemoglobin concentration was associated with increased odds of transfusion within the first 24 postoperative hours (odds ratio [95% CI], 1.62 [1.37-1.93]; P < .001). No significant relationships were observed between postoperative hemoglobin concentrations and hospital-free days (P = .56), intensive care unit admission (P = .71), postoperative mechanical ventilation (P = .63), or infectious complications (P = .74).

CONCLUSIONS

In transfused patients, there was no association between postoperative hemoglobin values and clinical outcomes, except the need for subsequent transfusion. Most transfused patients presented to the operating room with anemia, which suggests a potential opportunity for perioperative optimization of health before surgery.

Preoperative Anemia and Postoperative Outcomes in Cardiac Surgery: A Mediation Analysis Evaluating Intraoperative Transfusion Exposures

BACKGROUND

Preoperative anemia is associated with adverse outcomes in cardiac surgery, yet it remains unclear what proportion of this association is mediated through red blood cell (RBC) transfusions.

METHODS

This is a historical observational cohort study of adults undergoing coronary artery bypass grafting or valve surgery on cardiopulmonary bypass at an academic medical center between May 1, 2008, and May 1, 2018. A mediation analysis framework was used to evaluate the associations between preoperative anemia and postoperative outcomes, including a primary outcome of acute kidney injury (AKI). Intraoperative RBC transfusions were evaluated as mediators of preoperative anemia and outcome relationships. The estimated total effect, average direct effect of preoperative anemia, and percent of the total effect mediated through transfusions are presented with 95% confidence intervals and P -values.

RESULTS

A total of 4117 patients were included, including 1234 (30%) with preoperative anemia. Overall, 437 of 4117 (11%) patients went on to develop AKI, with a greater proportion of patients having preoperative anemia (219 of 1234 [18%] vs 218 of 2883 [8%]). In multivariable analyses, the presence of preoperative anemia was associated with increased postoperative AKI (6.4% [4.2%-8.7%] absolute difference in percent with AKI, P < .001), with incremental decreases in preoperative hemoglobin concentrations displaying greater AKI risk (eg, 11.9% [6.9%-17.5%] absolute increase in probability of AKI for preoperative hemoglobin of 9 g/dL compared to a reference of 14 g/dL, P < .001). The association between preoperative anemia and postoperative AKI was primarily due to direct effects of preoperative anemia (5.9% [3.6%-8.3%] absolute difference, P < .001) rather than mediated through intraoperative RBC transfusions (7.5% [-4.3% to 21.1%] of the total effect mediated by transfusions, P = .220). Preoperative anemia was also associated with longer hospital durations (1.07 [1.05-1.10] ratio of geometric mean length of stay, P < .001). Of this total effect, 38% (22%, 62%; P < .001) was estimated to be mediated through subsequent intraoperative RBC transfusion. Preoperative anemia was not associated with reoperation or vascular complications.

CONCLUSIONS

Preoperative anemia was associated with higher odds of AKI and longer hospitalizations in cardiac surgery. The attributable effects of anemia and transfusion on postoperative complications are likely to differ across outcomes. Future studies are necessary to further evaluate mechanisms of anemia-associated postoperative organ injury and treatment strategies.

Postoperative Transfusions after Administration of Delayed Cold-stored Platelets versus Room Temperature Platelets in Cardiac Surgery: A Retrospective Cohort Study

BACKGROUND

Delayed cold storage of room temperature platelets may extend shelf life from 5 to 14 days. The study hypothesized that the use of delayed cold-stored platelets in cardiac surgery would be associated with decreased postoperative platelet count increments but similar transfusion and clinical outcomes compared to room temperature-stored platelets.

METHODS

This is an observational cohort study of adults transfused with platelets intraoperatively during elective cardiac surgery between April 2020 and May 2021. Intraoperative platelets were either room temperature-stored or delayed cold-stored based on blood bank availability rather than clinical features or provider preference. Differences in transfusion and clinical outcomes, including a primary outcome of allogenic transfusion exposure in the first 24 h postoperatively, were compared between groups.

RESULTS

A total of 713 patient encounters were included: 529 (74%) room temperature-stored platelets and 184 (26%) delayed cold-stored platelets. Median (interquartile range) intraoperative platelet volumes were 1 (1 to 2) units in both groups. Patients receiving delayed cold-stored platelets had higher odds of allogeneic transfusion in the first 24 h postoperatively (81 of 184 [44%] vs. 169 of 529 [32%]; adjusted odds ratio, 1.65; 95% CI, 1.13 to 2.39; P = 0.009), including both erythrocytes (65 of 184 [35%] vs. 135 of 529 [26%]; adjusted odds ratio, 1.54; 95% CI, 1.03 to 2.29; P = 0.035) and platelets (48 of 184 [26%] vs. 79 of 529 [15%]; adjusted odds ratio, 1.91; 95% CI, 1.22 to 2.99; P = 0.005). There was no difference in the number of units administered postoperatively among those transfused. Platelet counts were modestly lower in the delayed cold-stored platelet group (-9 × 109/l; 95% CI, -16 to -3]) through the first 3 days postoperatively. There were no significant differences in reoperation for bleeding, postoperative chest tube output, or clinical outcomes.

CONCLUSIONS

In adults undergoing cardiac surgery, delayed cold-stored platelets were associated with higher postoperative transfusion utilization and lower platelet counts compared to room temperature-stored platelets without differences in clinical outcomes. The use of delayed cold-stored platelets in this setting may offer a viable alternative when facing critical platelet inventories but is not recommended as a primary transfusion approach.

EDITOR’S PERSPECTIVE

Coagulation Tests and Bleeding Classification After Cardiopulmonary Bypass: A Prospective Study

OBJECTIVE

No recent prospective studies have analyzed the accuracy of standard coagulation tests and thromboelastography (TEG) to identify patients with excessive microvascular bleeding following cardiopulmonary bypass (CPB). The aim of this study was to assess the value of coagulation profile tests, as well as TEG, for the classification of microvascular bleeding after CPB.

DESIGN

A prospective observational study.

SETTING

At a single-center academic hospital.

PARTICIPANTS

Patients ≥18 years of age undergoing elective cardiac surgery.

INTERVENTIONS

Qualitative assessment of microvascular bleeding post-CPB (surgeon and anesthesiologist consensus) and the association with coagulation profile tests and TEG values.

MEASUREMENTS AND MAIN RESULTS

A total of 816 patients were included in the study-358 (44%) bleeders and 458 (56%) nonbleeders. Accuracy, sensitivity, and specificity for the coagulation profile tests and TEG values ranged from 45% to 72%. The predictive utility was similar across tests, with prothrombin time (PT) (62% accuracy, 51% sensitivity, 70% specificity), international normalized ratio (INR) (62% accuracy, 48% sensitivity, 72% specificity), and platelet count (62% accuracy, 62% sensitivity, 61% specificity) displaying the highest performance. Secondary outcomes were worse in bleeders versus nonbleeders, including higher chest tube drainage, total blood loss, transfusion of red blood cells, reoperation rates (p < 0.001, respectively), readmission within 30 days (p = 0.007), and hospital mortality (p = 0.021).

CONCLUSIONS

Standard coagulation tests and individual components of TEG in isolation agree poorly with the visual classification of microvascular bleeding after CPB. The PT-INR and platelet count performed best but had low accuracy. Further work is warranted to identify better testing strategies to guide perioperative transfusion decisions in cardiac surgical patients.

Non-invasive hemoglobin estimation for preoperative anemia screening

BACKGROUND

Preoperative anemia is common and associated with adverse postoperative outcomes. Assessment of hemoglobin concentrations may facilitate optimization prior to surgery. However, phlebotomy-based hemoglobin measurement may contribute to patient discomfort and iatrogenic blood loss, which makes non-invasive hemoglobin estimation attractive in this setting.

STUDY DESIGN AND METHODS

This is a prospective study of adult patients presenting for preoperative evaluation before elective surgery at a tertiary care medical center. The Masimo Pronto Pulse CO-Oximeter was utilized to estimate blood hemoglobin concentrations (SpHb), which were then compared with hemoglobin concentrations obtained via complete blood count. Receiver operating curves were used to identify SpHb values maximizing specificity for anemia detection while meeting a minimum sensitivity of 80%.

RESULTS

A total of 122 patients were recruited with a median (interquartile range) age of 66 (58, 72) years. SpHb measurements were obtained in 112 patients (92%). SpHb generally overestimated hemoglobin with a mean (± 1.96 × standard deviation) difference of 0.8 (-2.2, 3.9) g/dL. Preoperative anemia, defined by hemoglobin <12.0 g/dL in accordance with institutional protocol, was present in 22 patients (20%). The optimal SpHb cut-point to identify anemia was 13.5 g/dL: sensitivity 86%, specificity 81%, negative predictive value 96%, and positive predictive value 53%. Utilizing this cut-point, 60% (73/122) of patients could have avoided phlebotomy-based hemoglobin assessment, while an anemia diagnosis would have been missed in <3% (3/122).

CONCLUSION

The use of SpHb devices for anemia screening in surgical patients is feasible with the potential to reliably rule-out anemia despite limited accuracy.

Practical Anemia Bundle for Sustained Blood Recovery (PABST-BR) in critical illness: a protocol for a randomised controlled trial

INTRODUCTION

Anaemia is highly prevalent in critical illness and is associated with impaired outcomes during and after hospitalisation. However, the impact of interventions designed to attenuate or treat anaemia during critical illness on post-hospitalisation haemoglobin recovery and functional outcomes is unclear.

METHODS AND ANALYSIS

The Practical Anemia Bundle for Sustained Blood Recovery (PABST-BR) clinical trial is a pragmatic, open-label, parallel group, single-centre, randomised clinical trial assessing the impact of a multifaceted anaemia prevention and treatment strategy versus standard care for improvement of haemoglobin concentrations and functional outcomes after critical illness. The intervention, which will be delivered early in critical illness for those with moderate-to-severe anaemia (ie, haemoglobin <100 g/L), includes three components: (1) optimised phlebotomy, (2) clinical decision support and (3) pharmacological anaemia treatment directed at the underlying aetiology of anaemia. In-person assessments will occur at 1 and 3 months post-hospitalisation for laboratory evaluations and multidimensional functional outcome assessments. The primary outcome is differences in haemoglobin concentrations between groups, with secondary endpoints of anaemia-related fatigue, physical function, cognition, mental health, quality of life, phlebotomy volumes and frequency, transfusions, readmissions and mortality through 1-year post-hospitalisation.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Review Board of the Mayo Clinic in Minnesota, USA. A Data Safety Monitoring Plan has been created in accordance with the policies of the Institutional Review Board and the study funder, the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH). The study will comply with NIH data sharing and dissemination policies. Results will be presented at national and international meetings and published in peer-reviewed journals. Designing and testing strategies to optimise haemoglobin recovery and improve functional outcomes after critical illness remain important research gaps. The PABST-BR trial will inform the development of a larger multicentre clinical trial.

TRIAL REGISTRATION NUMBER

NCT05167734.

A Contemporary Analysis of Phlebotomy and Iatrogenic Anemia Development Throughout Hospitalization in Critically Ill Adults

BACKGROUND

Anemia is common in critically ill patients and may be exacerbated through phlebotomy-associated iatrogenic blood loss. Differences in phlebotomy practice across patient demographic characteristics, clinical features, and practice environments are unclear. This investigation provides a comprehensive description of contemporary phlebotomy practices for critically ill adults.

METHODS

This is an observational cohort study of adults ≥18 years of age requiring intensive care unit (ICU) admission between January 1, 2019, and December 31, 2019, at a large academic medical center. Descriptive statistics were utilized to summarize all phlebotomy episodes throughout hospitalization, with each phlebotomy episode defined by unique peripheral venous, central venous, or arterial accesses for laboratory draws, exclusive of finger sticks. Secondarily, financial costs of phlebotomy and the relationships between phlebotomy practices, hemoglobin concentrations, and red blood cell (RBC) transfusions were evaluated.

RESULTS

A total of 6194 patients were included: 59% were men with a median (interquartile range) age of 66 (54-76) years and median ICU and hospital durations of 2.1 (1.4-3.9) and 7.1 (4.3-11.8) days, respectively. The median number of unique laboratory draws was 41 (18-88) throughout hospitalization, with a median volume of 232 (121-442) mL, corresponding to 5.2 (2.6-8.8) draws and 29 (19-43) mL per day. Waste (ie, discard) volume was responsible for 10.8% of total phlebotomy volume. Surgical patients had a higher number of phlebotomy episodes and greater total phlebotomy volumes compared to nonsurgical patients. Phlebotomy practices differed across ICU types, with the greatest frequency of laboratory draws in the cardiac surgical ICU and the greatest daily phlebotomy volume in the medical ICU. Across hospitalization, ICU environments had the greatest frequency and volumes of laboratory draws, with the least intensive phlebotomy practice observed in the general hospital wards. Patients in the highest quartile of cumulative blood drawn experienced the longest hospitalizations, lowest nadir hemoglobin concentrations, and greatest RBC transfusion utilization. Differences in phlebotomy practice were limited across patient age, gender, and race. Hemoglobin concentrations declined during hospitalization, congruent with intensity of phlebotomy practice. Each 100 mL of phlebotomy volume during hospitalization was associated with a 1.15 (95% confidence interval [CI], 1.14-1.17; P < .001) multiplicative increase in RBC units transfused in adjusted analyses. Estimated annual phlebotomy costs exceeded $15 million (approximately $2500 per patient admission).

CONCLUSIONS

Phlebotomy continues to be a major source of blood loss in hospitalized patients with critical illness, and more intensive phlebotomy practices are associated with lower hemoglobin concentrations and greater transfusion utilization.

Plasma, platelet and red blood cell transfusion ratios for life-threatening non-traumatic haemorrhage in medical and post-surgical patients: An observational study

BACKGROUND AND OBJECTIVES

Despite the broad utilization of component-based transfusion strategies that aim to reconstitute whole blood during acute traumatic haemorrhage, data for haemorrhage occurring outside of trauma and surgery are limited.

METHODS

This is an observational cohort study of adults experiencing critical non-traumatic, non-intraoperative haemorrhage during hospitalization at an academic medical centre from 2011 to 2015. The primary goal was to evaluate differences in plasma and platelet to red blood cell (RBC) transfusion ratios across patient demographic, clinical and laboratory characteristics. Secondarily, associations between transfusion ratios and clinical outcomes were assessed.

RESULTS

Seven hundred nine patients were included: 498 (70.2%) medical and 211 (29.8%) post surgical. The gastrointestinal tract (36.7%) was the most common site of bleeding. Most patients received RBCs without plasma (35.5%) or platelets (54.2%). Among those receiving plasma, 82.3% received a plasma to RBC ratio < 1:1 at 24 h. For platelets, the most common ratio was 1-2:1 (52.9%). Transfusion ratios were generally consistent across comorbid disease severity, admission type and anatomic sites of bleeding. Higher plasma utilization was observed in the emergency department, while greater platelet utilization occurred in intensive care units. Higher transfusion ratios were observed in those with greater laboratory haemostatic abnormalities prior to the haemorrhagic event. Clinical outcome differences were limited, though greater platelet utilization in the first 24 h was associated with higher mortality and fewer hospital-free days.

CONCLUSIONS

Transfusion ratios for critical non-traumatic haemorrhage were primarily related to laboratory abnormalities preceding the haemorrhagic event and practice environments. Clinical outcome differences across ratios were limited.

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 screening for, diagnosing and appropriately treating anemia, minimizing surgical, procedural, and iatrogenic blood losses, managing coagulopathic bleeding throughout the care and 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.

Early Post-Hospitalization Hemoglobin Recovery and Clinical Outcomes in Survivors of Critical Illness: A Population-Based Cohort Study

Anemia is common during critical illness, is associated with adverse clinical outcomes, and often persists after hospitalization. The goal of this investigation is to assess the relationships between post-hospitalization hemoglobin recovery and clinical outcomes after survival of critical illness. This is a population-based observational study of adults (≥18 years) surviving hospitalization for critical illness between January 1, 2010 and December 31, 2016 in Olmsted County, Minnesota, United States with hemoglobin concentrations and clinical outcomes assessed through one-year post-hospitalization. Multi-state proportional hazards models were utilized to assess the relationships between 1-month post-hospitalization hemoglobin recovery and hospital readmission or death through one-year after discharge. Among 6460 patients that survived hospitalization for critical illness during the study period, 2736 (42%) were alive, not hospitalized, and had available hemoglobin concentrations assessed at 1-month post-index hospitalization. Median (interquartile range) age was 69 (56, 80) years with 54% of male gender. Overall, 86% of patients had anemia at the time of hospital discharge, with median discharge hemoglobin concentrations of 10.2 (9.1, 11.6) g/dL. In adjusted analyses, each 1 g/dL increase in 1-month hemoglobin recovery was associated with decreased instantaneous hazard for hospital readmission (HR 0.87 [95% CI 0.84-0.90]; p < 0.001) and lower mortality (HR 0.82 [95% CI 0.75-0.89]; p < 0.001) through one-year post-hospitalization. The results were consistent in multiple pre-defined sensitivity analyses. Impaired early post-hospitalization hemoglobin recovery is associated with inferior clinical outcomes in the first year of survival after critical illness. Additional investigations are warranted to evaluate these relationships.

Implementation of a Comprehensive Patient Blood Management Program for Hospitalized Patients at a Large United States Medical Center

OBJECTIVE

To assess changes in inpatient transfusion utilization and patient outcomes with implementation of a comprehensive patient blood management (PBM) program at a large US medical center.

PATIENTS AND METHODS

This is an observational study of graduated PBM implementation for hospitalized adults (age ≥18 years) from January 1, 2010, through December 31, 2017, at two integrated hospital campuses at a major academic US medical center. Allogeneic transfusion utilization and clinical outcomes were assessed over time through segmented regression with multivariable adjustment comparing observed outcomes against projected outcomes in the absence of PBM activities.

RESULTS

In total, 400,998 admissions were included. Total allogeneic transfusions per 1000 admissions decreased from 607 to 405 over the study time frame, corresponding to an absolute risk reduction for transfusion of 6.0% (95% confidence interval [CI]: 3.6%, 8.3%; P<.001) and a 22% (95% CI: 6%, 37%; P=.006) decrease in the rate of transfusions over projected. The risk of transfusion decreased for all blood components except cryoprecipitate. Transfusion reductions were experienced for all major surgery types except liver transplantation, which remained stable over time. Hospital length of stay (multiplicative increase in geometric mean 0.85 [95% CI: 0.81, 0.89]; P<.001) and incident in-hospital adverse events (absolute risk reduction: 1.5% [95% CI: 0.1%, 3.0%]; P=.04) were lower than projected at the end of the study time frame.

CONCLUSION

Patient blood management implementation for hospitalized patients in a large academic center was associated with substantial reductions in transfusion utilization and improved clinical outcomes. Broad-scale implementation of PBM in US hospitals is feasible without signal for patient harm.

Quantifying the Importance of COVID-19 Vaccination to Our Future Outlook

Predictive models have played a critical role in local, national, and international response to the COVID-19 pandemic. In the United States, health care systems and governmental agencies have relied on several models, such as the Institute for Health Metrics and Evaluation, Youyang Gu (YYG), Massachusetts Institute of Technology, and Centers for Disease Control and Prevention ensemble, to predict short- and long-term trends in disease activity. The Mayo Clinic Bayesian SIR model, recently made publicly available, has informed Mayo Clinic practice leadership at all sites across the United States and has been shared with Minnesota governmental leadership to help inform critical decisions during the past year. One key to the accuracy of the Mayo Clinic model is its ability to adapt to the constantly changing dynamics of the pandemic and uncertainties of human behavior, such as changes in the rate of contact among the population over time and by geographic location and now new virus variants. The Mayo Clinic model can also be used to forecast COVID-19 trends in different hypothetical worlds in which no vaccine is available, vaccinations are no longer being accepted from this point forward, and 75% of the population is already vaccinated. Surveys indicate that half of American adults are hesitant to receive a COVID-19 vaccine, and lack of understanding of the benefits of vaccination is an important barrier to use. The focus of this paper is to illustrate the stark contrast between these 3 scenarios and to demonstrate, mathematically, the benefit of high vaccine uptake on the future course of the pandemic.

Red blood cell transfusion threshold and mortality in cardiac intensive care unit patients

BACKGROUND

The benefit of red blood cell (RBC) transfusion in anemic critically-ill patients with cardiovascular disease is uncertain, as is the optimal threshold at which RBC transfusion should be considered. We sought to examine the association between RBC transfusion and mortality stratified by nadir Hgb level and admission diagnosis among cardiac intensive care unit (CICU) patients.

METHODS

Retrospective single-center cohort of 11,754 CICU patients admitted between 2007 and 2018. The association between RBC transfusion and hospital mortality at each nadir Hgb (<8 g/dL, 8-9.9 g/dL, ≥10 g/dL) was assessed using multivariable logistic regression adjusted for the propensity to receive RBC transfusion.

RESULTS

The study population had a mean age of 68±15 years, including 38% females; 1,134 (11.4%) received RBC transfusion. Admission diagnoses included: acute coronary syndrome , 42%; heart failure, 50%; cardiac arrest , 12%; and cardiogenic shock , 12%. Patients who received RBC transfusion had higher crude hospital mortality (19% vs. 8%, P<.001). RBC transfusion was associated with lower adjusted hospital mortality in patients with nadir Hgb <8 g/dL after propensity adjustment, including subgroups with acute coronary syndrome, cardiac arrest, or cardiogenic shock (all P <.01). RBC transfusion was not associated with lower adjusted hospital mortality in any subgroup of patients with nadir Hgb ≥8 g/dL.

CONCLUSIONS

These observational data suggest the use of a Hgb threshold <8 g/dL for RBC transfusion in most CICU patients, although we could not exclude a potential benefit of RBC transfusion at a nadir Hgb of 8 to 9.9 g/dL; we did not observe any benefit from RBC transfusion at a nadir Hgb ≥10 g/dL.

Sex-Specific Associations Between Preoperative Anemia and Postoperative Clinical Outcomes in Patients Undergoing Cardiac Surgery

BACKGROUND

Preoperative anemia is common in cardiac surgery, yet there were limited data describing the role of sex in the associations between anemia and clinical outcomes. Understanding these relationships may guide preoperative optimization efforts.

METHODS

This is an observational cohort study of adults undergoing isolated coronary artery bypass grafting or single- or double-valve surgery from 2008 to 2018 at a large tertiary medical center. Multivariable regression assessed the associations between preoperative hemoglobin concentrations and a primary outcome of postoperative acute kidney injury (AKI) and secondary outcomes of perioperative red blood cell (RBC) transfusion, reoperation, vascular complications (ie, stroke, pulmonary embolism, and myocardial infarction), and hospital length of stay (LOS). Each outcome was a single regression model, using interaction terms to assess sex-specific associations between hemoglobin and outcome.

RESULTS

A total of 4117 patients were included (57% men). Linear splines with sex-specific knots (13 g/dL in women and 14 g/dL in men) provided the best overall fit for preoperative hemoglobin and outcome relationships. In women, each 1 g/dL decrease in hemoglobin <13 g/dL was associated with increased odds of AKI (odds ratio = 1.49; 95% confidence interval [CI], [1.23-1.81]; P < .001), and there was no significant association between hemoglobin per 1 g/dL >13 g/dL and AKI (0.90 [0.56-1.45]; P = .67). The association between hemoglobin and AKI in men did not meet statistical significance (1.10 [0.99-1.22]; P = .076, per 1 g/dL decrease <14 g/dL; 1.00 [0.79-1.26]; P = .98 for hemoglobin per 1 g/dL >14 g/dL). In women, lower preoperative hemoglobin (per 1 g/dL decrease <13 g/dL) was associated with increased odds of RBC transfusion (2.90 [2.33-3.60]; P < .001), reoperation (1.27 [1.11-1.45]; P < .001) and a longer hospital LOS (multiplicative increase in geometric mean 1.05 [1.03-1.07]; P < .001). In men, preoperative hemoglobin (per 1 g/dL decrease <14 g/dL) was associated with increased odds of perioperative RBCs (2.56 [2.27-2.88]; P < .001) and longer hospital LOS (multiplicative increase in geometric mean 1.02 [1.01-1.04] days; P < .001) but not reoperation (0.94 [0.85-1.04]; P = .256). Preoperative hemoglobin per 1 g/dL >13 g/dL in women and 14 g/dL in men were associated with lower odds of RBCs transfusion (0.57 [0.47-0.69]; P < .001 and 0.74 [0.60-0.91]; P = .005, respectively).

CONCLUSIONS

Preoperative anemia was associated with inferior clinical outcomes after cardiac surgery. The associations between hemoglobin and outcomes were distinct for women and men, with different spline knot points identified (13 and 14 g/dL, respectively). Clinicians should consider data-driven approaches to determine preoperative hemoglobin values associated with increasing risk for adverse perioperative outcomes across sexes.

The Prevalence and Clinical Significance of Preoperative Thrombocytopenia in Adults Undergoing Elective Surgery: An Observational Cohort Study

BACKGROUND

Preoperative thrombocytopenia is associated with inferior outcomes in surgical patients, though concurrent anemia may obfuscate these relationships. This investigation assesses the prevalence and clinical significance of preoperative thrombocytopenia with thorough consideration of preoperative anemia status.

METHODS

This is an observational cohort study of adults undergoing elective surgery with planned postoperative hospitalization from January 1, 2009 to May 3, 2018. Patients were designated into 4 groups: normal platelet and hemoglobin concentrations, isolated thrombocytopenia (ie, platelet count <100 × 109/L), isolated anemia (ie, hemoglobin <12 g/dL women, <13.5 g/dL men), and thrombocytopenia with anemia. Thrombocytopenia was further defined as incidental (ie, previously undiagnosed) or nonincidental. Multivariable regression analyses were utilized to assess the relationships between thrombocytopenia status and clinical outcomes, with a primary outcome of hospital length of stay.

RESULTS

A total of 120,348 patients were included for analysis: 72.3% (95% confidence interval [CI], 72.1-72.6) normal preoperative laboratory values, 26.3% (26.1-26.6) isolated anemia, 0.80% (0.75-0.86) thrombocytopenia with anemia, and 0.52% (0.48-0.56) isolated thrombocytopenia (0.38% [0.34-0.41] nonincidental, 0.14% [0.12-0.17] incidental). Thrombocytopenia was associated with longer hospital length of stay in those with concurrent anemia (multiplicative increase of the geometric mean 1.05 [1.00, 1.09] days; P = .034) but not in those with normal preoperative hemoglobin concentrations (multiplicative increase of the geometric mean 1.02 [0.96, 1.07] days; P = .559). Thrombocytopenia was associated with increased odds for intraoperative transfusion regardless of anemia status (nonanemic: 3.39 [2.79, 4.12]; P < .001 vs anemic: 2.60 [2.24, 3.01]; P < .001). Thrombocytopenia was associated with increased rates of intensive care unit (ICU) admission in nonanemic patients (1.56 [1.18, 2.05]; P = .002) but not in those with preoperative anemia (0.93 [0.73, 1.19]; P = .578).

CONCLUSIONS

Preoperative thrombocytopenia is associated with clinical outcomes in elective surgery, both in the presence and absence of concurrent anemia. However, isolated thrombocytopenia is rare (0.5%) and is usually identified before preoperative testing. It is unlikely that routine thrombocytopenia screening is indicated for most patients.

Deployment of an Interdisciplinary Predictive Analytics Task Force to Inform Hospital Operational Decision-Making During the COVID-19 Pandemic

In March 2020, our institution developed an interdisciplinary predictive analytics task force to provide coronavirus disease 2019 (COVID-19) hospital census forecasting to help clinical leaders understand the potential impacts on hospital operations. As the situation unfolded into a pandemic, our task force provided predictive insights through a structured set of visualizations and key messages that have helped the practice to anticipate and react to changing operational needs and opportunities. The framework shared here for the deployment of a COVID-19 predictive analytics task force could be adapted for effective implementation at other institutions to provide evidence-based messaging for operational decision-making. For hospitals without such a structure, immediate consideration may be warranted in light of the devastating COVID-19 third-wave which has arrived for winter 2020-2021.

Renal Function Parameters and Serum Sodium Enhance Prediction of Wait-List Outcomes in Pediatric Liver Transplantation

BACKGROUND AND AIMS

Reliance on exception points to prioritize children for liver transplantation (LT) stems from concerns that the Pediatric End-Stage Liver Disease (PELD) score underestimates mortality. Renal dysfunction and serum sodium disturbances are negative prognosticators in adult LT candidates and various pediatric populations, but are not accounted for in PELD. We retrospectively evaluated the effect of these parameters in predicting 90-day wait-list death/deterioration among pediatric patients (<12 years) listed for isolated LT in the United States between February 2002 and June 2018.

APPROACH AND RESULTS

Among 4,765 patients, 2,303 (49.3%) were transplanted, and 231 (4.8%) died or deteriorated beyond transplantability within 90 days of listing. Estimated glomerular filtration rate (eGFR) (hazard ratio [HR] 1.09 per 5-unit decrease, 95% confidence interval [CI] 1.06-1.10) and dialysis (HR 7.24, 95% CI 3.57-14.66) were univariate predictors of 90-day death/deterioration (P < 0.001). The long-term benefit of LT persisted in patients with renal dysfunction, with LT as a time-dependent covariate conferring a 2.4-fold and 17-fold improvement in late survival among those with mild and moderate-to-severe dysfunction, respectively. Adjusting for PELD, sodium was a significant nonlinear predictor of outcome, with 90-day death/deterioration risk increased at both extremes of sodium (HR 1.20 per 1-unit decrease below 137 mmol/L, 95% CI 1.16-1.23; HR per 1-unit increase above 137 mmol/L 1.13, 95% CI 1.10-1.17, P < 0.001). A multivariable model incorporating PELD, eGFR, dialysis, and sodium demonstrated improved performance and superior calibration in predicting wait-list outcomes relative to the PELD score.

CONCLUSIONS

Listing eGFR, dialysis, and serum sodium are potent, independent predictors of 90-day death/deterioration in pediatric LT candidates, capturing risk not accounted for by PELD. Incorporation of these variables into organ allocation systems may highlight patient subsets with previously underappreciated risk, augment ability of PELD to prioritize patients for transplantation, and ultimately mitigate reliance on nonstandard exceptions.

Transition from room temperature to cold-stored platelets for the preservation of blood inventories during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic has placed great strain on blood resources. In an effort to extend platelet (PLT) shelf life and minimize waste, our institution transitioned room temperature to cold-stored PLTs for administration to bleeding patients.

STUDY DESIGN AND METHODS

We describe the administrative and technical processes involved in transitioning room temperature PLTs to cold storage in April 2020. Additionally, we describe the clinical utilization of cold-stored PLTs in the first month of this practice change, with a focus on changes in PLT counts after transfusion, hemostasis, and safety outcomes.

RESULTS

A total of 61 cold-stored PLT units were transfused to 40 bleeding patients, with a median (interquartile range [IQR]) of 1 (1-2) units per patient. The median age was 68 (59-73) years; 58% male. Median pretransfusion and posttransfusion PLTs counts were 88 (67-109) and 115 (93-145). A total of 95% of transfusions were administered in the operating room: 57% cardiac surgery, 20% vascular surgery, 8% general surgery, and 5% solid organ transplantation. Hemostasis was deemed to be adequate in all cases after transfusion. There were no transfusion reactions. One patient (3%) experienced a fever and infection within 5 days of transfusion, which was unrelated to transfusion. Median (IQR) hospital length of stay was 8.5 (6-17) days. Two patients (5%) died in the hospital of complications not related to transfusion.

CONCLUSION

Cold-stored PLT utilization was associated with adequate hemostasis and no overt signal for patient harm. Conversion from room temperature to cold-stored PLTs may be one method of reducing waste in times of scarce blood inventories.

Transfusion in the mechanically ventilated patient

Red blood cell transfusions are a frequent intervention in critically ill patients, including in those who are receiving mechanical ventilation. Both these interventions can impact negatively on lung function with risks of transfusion-related acute lung injury (TRALI) and other forms of acute respiratory distress syndrome (ARDS). The interactions between transfusion, mechanical ventilation, TRALI and ARDS are complex and other patient-related (e.g., presence of sepsis or shock, disease severity, and hypervolemia) or blood product-related (e.g., presence of antibodies or biologically active mediators) factors also play a role. We propose several strategies targeted at these factors that may help limit the risks of associated lung injury in critically ill patients being considered for transfusion.

NT-proBNP levels in the identification and classification of pulmonary transfusion reactions

BACKGROUND

Consensus definitions for transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) have recently been revised; however, pulmonary transfusion reactions remain difficult to diagnose. We hypothesized that N-terminal pro-brain natriuretic peptide (NT-proBNP) levels could have utility in the identification and classification of pulmonary transfusion reactions.

STUDY DESIGN AND METHODS

We performed a secondary analysis of a case-control study of pulmonary transfusion reactions at four academic hospitals. We evaluated clinical data and measured NT-proBNP levels prior to and following transfusion in patients with TACO (n = 160), transfused acute respiratory distress syndrome (ARDS) [n = 51], TRALI [n = 12], TACO/TRALI [n = 7], and controls [n = 335]. We used Wilcoxon Rank-Sum tests to compare NT-proBNP levels, and classification and regression tree (CART) algorithms to produce a ranking of covariates in order of relative importance for differentiating TACO from transfused controls.

RESULTS

Pre-transfusion NT-proBNP levels were elevated in cases of transfused ARDS and TACO (both P < .001) but not TRALI (P = .31) or TACO/TRALI (P = .23) compared to transfused controls. Pre-transfusion NT-proBNP levels were higher in cases of transfused ARDS or TRALI with a diagnosis of sepsis compared to those without (P < .05 for both). CART analyses resulted in similar differentiation of patients with TACO from transfused controls for models utilizing either NT-proBNP levels (AUC 0.83) or echocardiogram results (AUC 0.80).

CONCLUSIONS

NT-proBNP levels may have utility in the classification of pulmonary transfusion reactions. Prospective studies are needed to test the predictive utility of pre-transfusion NT-proBNP in conjunction with other clinical factors in identifying patients at risk of pulmonary transfusion reactions.

Ratios of Plasma and Platelets to Red Blood Cells in Surgical Patients With Acute Intraoperative Hemorrhage

BACKGROUND

The relationships between the ratios of transfused allogeneic blood products and clinical outcomes in patients with acute intraoperative hemorrhage are poorly defined.

METHODS

To better define these ratios, we undertook a single-center, observational cohort study of all surgical patients (≥18 years) who received rapid transfusion defined by a critical administration threshold of 3 or more units of red blood cells (RBCs) intraoperatively within 1 hour between January 1, 2011 and December 31, 2015. Multivariable regression analyses were used to assess relationships between ratios of plasma to RBCs and platelets to RBCs at 3, 12, and 24 hours and clinical outcomes. The primary outcome was hospital mortality, with secondary outcomes of intensive care unit and hospital-free days.

RESULTS

The study included 2385 patients, of whom 14.9% had a plasma-to-RBC ratio of 1.0+, and 47.6% had a platelet-to-RBC ratio of 1.0+. Higher plasma-to-RBC and platelet-to-RBC ratios were observed for patients who underwent cardiac, transplant, and vascular surgery and in patients with greater derangements in hemostatic laboratory values. Ratios did not differ by patient age or severity of illness. Higher ratios were not associated with improved clinical outcomes. Mortality differed by platelet-to-RBC but not plasma-to-RBC ratio, with the highest mortality observed with a platelet-to-RBC ratio of 0.1-0.9 at 24 hours (odds ratio, 3.34 [1.62-6.88]) versus no platelets (P= .001). Higher plasma-to-RBC ratios were associated with decreased hospital-free days, although differences in clinical outcomes were not significant after exclusion of patients receiving only RBCs without component therapies.

CONCLUSIONS

Transfusion ratios in surgical patients with critical intraoperative hemorrhage were largely related to surgical and hemostatic features rather than baseline patient characteristics. Higher ratios were not associated with improved outcomes.

Prevalence of and Recovery From Anemia Following Hospitalization for Critical Illness Among Adults

IMPORTANCE

Anemia is common and has been associated with poor outcomes in the critically ill population, yet the timing and extent of hemoglobin recovery remains incompletely described, which may have important implications for clinical outcomes following discharge from intensive care.

OBJECTIVES

To describe longitudinal changes in anemia status during and after critical illness and assess the associations between hemoglobin concentrations and postdischarge mortality.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted from January 1, 2010, to December 31, 2016, in Olmsted County, Minnesota; data analysis was performed from June 1 to December 30, 2019. Participants included 6901 adults (age ≥18 years) admitted to intensive care.

MAIN OUTCOMES AND MEASURES

Hemoglobin concentrations in the 12 months before hospitalization, during hospitalization, and in the 12 months after discharge, categorized by anemia severity (mild, hemoglobin ≥10.0 to <12.0 g/dL in women or ≥10.0 to <13.5 g/dL in men; moderate, hemoglobin ≥8.0 to <10.0 g/dL; and severe, hemoglobin <8.0 g/dL). Complete recovery from anemia, defined as attainment of nonanemic status by 12 months post hospitalization, and 12-month mortality were also evaluated.

RESULTS

Of the 6901 patients included in the study, 3792 were men (55%); median (interquartile range [IQR]) age was 67 (IQR, 52-79) years. Prehospitalization hemoglobin concentrations were available in 83% of the population (n = 5694), with median hemoglobin concentrations of 13.1 (IQR, 11.6-14.4) g/dL. Forty-one percent of the patients (n = 2320) had anemia preceding hospitalization. Hemoglobin values at hospital discharge were 10.8 g/dL (IQR, 9.5-12.4 g/dL), with 80% (n = 5182 of 6460) having anemia: 58% mild, 39% moderate, and 3% severe. The prevalence of anemia post hospitalization was 56% (95% CI, 55%-58%) at 3 months, 52% (95% CI, 50%-54%) at 6 months, and 45% (95% CI, 43%-47%) at 12 months among those alive with available hemoglobin measurements. Rates of complete recovery from anemia at 12 months were 58% (95% CI, 56%-61%) for mild anemia, 39% (95% CI, 36%-42%) for moderate anemia, and 24% (95% CI, 15%-34%) for severe anemia. Of those without baseline anemia surviving hospitalization, 74% of the patients were anemic at hospital discharge, with rates of complete 12-month recovery of 73% (95% CI, 69%-76%) for mild anemia, 62% (95% CI, 57%-68%) for moderate anemia, and 59% (95% CI, 35%-82%) for severe anemia. Higher hospital discharge hemoglobin concentrations were associated with decreased mortality after multivariable adjustment (hazard ratio, 0.95 per 1-g/dL increase; 95% CI, 0.90-0.99, P = .02).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that anemia is common and often persistent in the first year after critical illness. Further studies are warranted to identify distinct anemia recovery profiles and assess associations with clinical outcomes.

Hospital discharge hemoglobin values and posthospitalization clinical outcomes in transfused patients undergoing noncardiac surgery

BACKGROUND

Red blood cell (RBC) transfusion is common in surgical patients, yet optimal transfusion targets are incompletely defined in the perioperative period. Hemoglobin levels at the time of hospital discharge may provide insight into transfusion practices, anemia management, and patient outcomes.

STUDY DESIGN AND METHODS

This is an observational cohort study of adults receiving RBC transfusion during noncardiac surgery from 2010 to 2014. Multivariable regression was used to assess the relationships between hospital discharge hemoglobin concentrations, anemia severity (severe: <8 g/dL; moderate: 8-10 g/dL; mild/none: ≥10 g/dL), and clinical outcomes, including a primary outcome of 30-day hospital readmission and secondary outcomes of posthospitalization RBC transfusion, composite stroke or myocardial infarction, and mortality.

RESULTS

A total of 3129 patients were included: 165 (5%) with severe discharge anemia, 1962 (63%) moderate, and 1002 (32%) with mild/none. Five hundred ninety-two (19%) were readmitted, with the highest rates observed with severe anemia (26% vs 19% for mild/none). Readmissions were not significantly different after multivariable adjustment (overall P = .216); however, in those receiving postoperative intensive care, severe anemia was associated with increased readmission rates (hazard ratio [HR], 1.72; 95% confidence interval [CI], 1.09-2.71; reference mild/none]. Posthospitalization RBC transfusion rates were highest with severe anemia (25% vs 10% for mild/none; adjusted HR, 2.2; 95% CI, 1.5-3.3; P < .001). There were no significant differences in composite stroke/myocardial infarction, or mortality. RBC transfusion volumes did not modify anemia-outcome relationships.

CONCLUSION

Hospital discharge hemoglobin values for transfused surgical patients were not associated with hospital readmission rates except for those receiving postoperative intensive care. Further evaluation is warranted to understand downstream consequences of postsurgical anemia.

Essential Role of Patient Blood Management in a Pandemic: A Call for Action

The World Health Organization (WHO) has declared coronavirus disease 2019 (COVID-19), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a pandemic. Global health care now faces unprecedented challenges with widespread and rapid human-to-human transmission of SARS-CoV-2 and high morbidity and mortality with COVID-19 worldwide. Across the world, medical care is hampered by a critical shortage of not only hand sanitizers, personal protective equipment, ventilators, and hospital beds, but also impediments to the blood supply. Blood donation centers in many areas around the globe have mostly closed. Donors, practicing social distancing, some either with illness or undergoing self-quarantine, are quickly diminishing. Drastic public health initiatives have focused on containment and "flattening the curve" while invaluable resources are being depleted. In some countries, the point has been reached at which the demand for such resources, including donor blood, outstrips the supply. Questions as to the safety of blood persist. Although it does not appear very likely that the virus can be transmitted through allogeneic blood transfusion, this still remains to be fully determined. As options dwindle, we must enact regional and national shortage plans worldwide and more vitally disseminate the knowledge of and immediately implement patient blood management (PBM). PBM is an evidence-based bundle of care to optimize medical and surgical patient outcomes by clinically managing and preserving a patient's own blood. This multinational and diverse group of authors issue this "Call to Action" underscoring "The Essential Role of Patient Blood Management in the Management of Pandemics" and urging all stakeholders and providers to implement the practical and commonsense principles of PBM and its multiprofessional and multimodality approaches.

Computerized Advisory Decision Support for Cardiovascular Diseases in Primary Care: A Cluster Randomized Trial

PURPOSE

The purpose of this research was to evaluate the impact of an outpatient computerized advisory clinical decision support system (CDSS) on adherence to guideline-recommended treatment for heart failure, atrial fibrillation, and hyperlipidemia.

METHODS

Twenty care teams (109 clinicians) in a primary care practice were cluster-randomized to either access or no access to an advisory CDSS integrated into the electronic medical record. For patients with an outpatient visit, the CDSS determined if they had heart failure with reduced ejection fraction, hyperlipidemia, or atrial fibrillation; and if so, was the patient receiving guideline-recommended treatment. In the intervention group, an alert was visible in the medical record if there was a discrepancy between current and guideline-recommended treatment. Clicking the alert displayed the treatment discrepancy and recommended treatment. Outcomes included prescribing patterns, self-reported use of decision aids, and self-reported efficiency. The trial was conducted between May 1 and November 15, 2016, and incorporated 16,310 patient visits.

RESULTS

The advisory CDSS increased adherence to guideline-recommended treatment for heart failure (odds ratio [OR] 7.6, 95% confidence interval [CI], 1.2, 47.5) but had no impact in atrial fibrillation (OR 0.94, 95% CI 0.15, 5.94) or hyperlipidemia (OR 1.1, 95% CI 0.6, 1.8). Clinicians with access to the CDSS self-reported greater use of risk assessment tools for heart failure (3.6 [1.1] vs 2.7 [1.0], mean [standard deviation] on a 5-point scale) but not for atrial fibrillation or hyperlipidemia. The CDSS did not impact self-assessed efficiency. The overall usage of the CDSS was low (19%).

CONCLUSIONS

A computerized advisory CDSS improved adherence to guideline-recommended treatment for heart failure but not for atrial fibrillation or hyperlipidemia.

Anemia in Critically Ill Patients With Acute Respiratory Distress Syndrome and Posthospitalization Physical Outcomes

Objective:

Anemia is common during critical illness and often persists after hospital discharge; however, its potential association with physical outcomes after critical illness is unclear. Our objective was to assess the associations between hemoglobin at intensive care unit (ICU) and hospital discharge with physical status at 3-month follow-up in acute respiratory distress syndrome (ARDS) survivors.

Methods:

This is a secondary analysis of a multisite prospective cohort study of 195 mechanically ventilated ARDS survivors from 13 ICUs at 4 teaching hospitals in Baltimore, Maryland. Multivariable regression was utilized to assess the relationships between ICU and hospital discharge hemoglobin concentrations with measures of physical status at 3 months, including muscle strength (Medical Research Council sumscore), exercise capacity (6-minute walk distance [6MWD]), and self-reported physical functioning (36-Item Short-Form Health Survey [SF-36v2] Physical Function score and Activities of Daily Living [ADL] dependencies).

Results:

Median (interquartile range) hemoglobin concentrations at ICU and hospital discharge were 9.5 (8.5-10.7) and 10.0 (9.0-11.2) g/dL, respectively. In multivariable regression analyses, higher ICU discharge hemoglobin concentrations (per 1 g/dL) were associated with greater 3-month 6MWD mean percent of predicted (3.7% [95% confidence interval 0.8%-6.5%]; P = .01) and fewer ADL dependencies (−0.2 [−0.4 to −0.1]; P = .02), but not with percentage of maximal muscle strength (0.7% [−0.9 to 2.3]; P = .37) or SF-36v2 normalized Physical Function scores (0.8 [−0.3 to 1.9]; P = .15). The associations of physical outcomes and hospital discharge hemoglobin concentrations were qualitatively similar, but none were statistically significant.

Conclusions:

In ARDS survivors, higher hemoglobin concentrations at ICU discharge, but not hospital discharge, were significantly associated with improved exercise capacity and fewer ADL dependencies. Future studies are warranted to further assess these relationships.

Intraoperative Plasma Transfusion Volumes and Outcomes in Cardiac Surgery

OBJECTIVE

Assess outcomes after intraoperative plasma transfusion in patients undergoing cardiac surgery.

DESIGN

Retrospective study of adult cardiac surgical between 2011 and 2015. Relationships between plasma transfusion volume, coagulation test values, and a primary outcome of early postoperative red blood cell (RBC) transfusion were assessed via multivariable regression analyses. Secondary outcomes included hospital mortality, intensive care unit and hospital-free days, intraoperative RBCs, estimated blood loss, and reoperation for bleeding.

SETTING

Academic tertiary referral center.

PARTICIPANTS

A total of 1,794 patients received intraoperative plasma transfusions during the study period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Higher plasma transfusion volumes were associated with worse clinical outcomes, with each 1-unit increase being associated with greater odds for postoperative RBCs [odds ratio (OR) 1.12 (confidence interval [CI] 1.04-1.20); p = 0.002], intraoperative [OR 1.85 (CI 1.69-2.03); p < 0.001], and fewer hospital-free days [mean -0.20 (-0.39, -0.01); p = 0.04]. Each 0.1 increase in pretransfusion International Normalized Ratio (INR) was associated with increased odds of postoperative and intraoperative RBCs, reoperation for bleeding, and fewer intensive care unit and hospital-free days. For given plasma volumes, patients achieving greater reduction in elevated pretransfusion INR values experienced more favorable outcomes.

CONCLUSIONS

In patients undergoing cardiac surgery who received intraoperative plasma transfusion, higher plasma transfusion volumes were associated with inferior clinical outcomes. Higher pretransfusion INR values also were associated with worse outcomes; however, those achieving a greater degree of INR correction after plasma transfusion demonstrated more favorable outcomes. Prospective studies related to plasma transfusion are needed to address this important topic.

The Value of Aggregated High-Resolution Intraoperative Data for Predicting Post-Surgical Infectious Complications at Two Independent Sites

Surgical procedures carry the risk of postoperative infectious complications, which can be severe, expensive, and morbid. A growing body of evidence indicates that high-resolution intraoperative data can be predictive of these complications. However, these studies are often contradictory in their findings as well as difficult to replicate, suggesting that these predictive models may be capturing institutional artifacts. In this work, data and models from two independent institutions, Mayo Clinic and University of Minnesota-affiliated Fairview Health Services, were directly compared using a common set of definitions for the variables and outcomes. We built perioperative risk models for seven infectious post-surgical complications at each site to assess the value of intraoperative variables. Models were internally validated. We found that including intraoperative variables significantly improved the models' predictive performance at both sites for five out of seven complications. We also found that significant intraoperative variables were similar between the two sites for four of the seven complications. Our results suggest that intraoperative variables can be related to the underlying physiology for some infectious complications.

Initial Postoperative Hemoglobin Values and Clinical Outcomes in Transfused Patients Undergoing Noncardiac Surgery

BACKGROUND

Intraoperative red blood cell (RBC) transfusion is common, yet transfusion strategies remain controversial as pretransfusion hemoglobin triggers are difficult to utilize during acute bleeding. Alternatively, postoperative hemoglobin values may provide useful information regarding transfusion practices, though optimal targets remain undefined.

METHODS

This is a single-center observational cohort study of adults receiving allogeneic RBCs during noncardiac surgery from 2010 through 2014. Multivariable regression analyses adjusting for patient illness, laboratory derangements, and surgical features were used to assess relationships between initial postoperative hemoglobin values and a primary outcome of hospital-free days.

RESULTS

A total of 8060 patients were included. Those with initial postoperative hemoglobin <7.5 or ≥11.5 g/dL had decreased hospital-free days [mean (95% confidence interval [CI]), -1.45 (-2.50 to -0.41) and -0.83 (-1.42 to -0.24), respectively] compared to a reference range of 9.5-10.4 g/dL (overall P value .003). For those with hemoglobin <7.5 g/dL, the odds (95% CI) for secondary outcomes included acute kidney injury (AKI) 1.43 (1.03-1.99), mortality 2.10 (1.18-3.74), and cerebral ischemia 3.12 (1.08-9.01). The odds for postoperative mechanical ventilation with hemoglobin ≥11.5 g/dL were 1.33 (1.07-1.65). Secondary outcome associations were not significant after multiple comparisons adjustment (Bonferroni P < .0056).

CONCLUSIONS

In transfused patients, postoperative hemoglobin values between 7.5 and 11.5 g/dL were associated with superior outcomes compared to more extreme values. This range may represent a target for intraoperative transfusions, particularly during active bleeding when pretransfusion hemoglobin thresholds may be impractical or inaccurate. Given similar outcomes within this range, targeting hemoglobin at the lower aspect may be preferable, though prospective validation is warranted.

Changes in International Normalized Ratios After Plasma Transfusion of Varying Doses in Unique Clinical Environments

BACKGROUND

Plasma transfusion is commonly performed for the correction of abnormal coagulation screening tests. The goal of this investigation was to assess the relationship between the dose of plasma administered and changes in coagulation test results in a large and diverse cohort of patients with varying levels of coagulation abnormalities and comorbid disease and in a variety of clinical settings.

METHODS

In this single-center historical cohort study, all plasma transfusion episodes in adult patients with abnormal coagulation screening tests were extracted between 2011 and 2015. The primary outcome was the proportion of patients attaining normal posttransfusion international normalized ratio (INR ≤ 1.1) with secondary outcomes including the proportion of patients attaining partial normalization of INR (INR ≤ 1.5) or at least 50% normalization in pretransfusion values with respect to an INR of 1.1.

RESULTS

In total, 6779 unique patients received plasma with a median (quartiles) pretransfusion INR of 1.9 (1.6-2.5) and a median transfusion volume of 2 (2-3) units. The majority (85%) of transfusions occurred perioperatively, with 20% of transfusions administered prophylactically before a procedure. The median decrease in INR was 0.4 (0.2-0.8). Complete INR normalization was obtained in 12%. Reductions in INR were modest with pretransfusion INR values <3. Patients receiving ≥3 units of plasma were more likely to achieve at least 50% normalization in INR than those receiving ≤2 units (68% vs 60%; P < .001).

CONCLUSIONS

Changes in INR after plasma transfusion were modest at typically used clinical doses, particularly in those with less severely deranged baseline coagulation screening tests. Further studies are necessary to assess the relationships between plasma-mediated changes in INR and clinical outcomes.

Improvements in red blood cell transfusion utilization following implementation of a single-unit default for electronic ordering

BACKGROUND

The prevention of excessive allogeneic red blood cell (RBC) transfusion is an important component of patient blood management initiatives. In this investigation, changes in transfusion behaviors following modification of computerized physician order entry (CPOE) procedures for RBC transfusions to a single-unit default quantity were assessed.

STUDY DESIGN AND METHODS

This is an observational cohort study of adults for whom nonemergency allogeneic RBC transfusions were ordered in the 2 years before and 2 years after the date of modification of the CPOE system to a single-unit default (June 18, 2015). Changes in the frequency of single- versus multiunit RBC transfusion orders and other transfusion metrics were compared between preintervention and postintervention cohorts.

RESULTS

A total of 52,773 unique transfusion orders for 61,989 RBC units were included, of which 60,045 (96.9%) were transfused. Single-unit orders increased annually, from 10,404 (74.1%) in the first year to 11,645 (88.6%) in the last year, while multiunit orders decreased by more than half (p < 0.0001). The number of RBC units transfused decreased by 13.9% from 32,528 in the preintervention cohort to 27,497 in the post intervention cohort (p < 0.0001) with an estimated reduction in transfusion-related expenditures of nearly $4 million. The percentage of transfusions associated with a posttransfusion hemoglobin of10 g/dL or greater decreased by 34.5% (p < 0.0001).

CONCLUSION

Modification of the CPOE process such that nonemergency RBC transfusion orders were defaulted to a single unit was associated with decreased rates of multiunit RBC transfusion orders, lower transfusion volumes, and substantial cost savings.

Implementation of a patient blood management program in hematopoietic stem cell transplantation (Editorial, p. 2763)

BACKGROUND

Recipients of hematopoietic stem cell transplantation (HSCT) are among the highest consumers of allogeneic red blood cell (RBC) and platelet (PLT) components. The impact of patient blood management (PBM) efforts on HSCT recipients is poorly understood.

STUDY DESIGN AND METHODS

This observational study assessed changes in blood product use and patient-centered outcomes before and after implementing a multidisciplinary PBM program for patients undergoing HSCT at a large academic medical center. The pre-PBM cohort was treated from January 1 through September 31, 2013; the post-PBM cohort was treated from January 1 through September 31, 2015.

RESULTS

We identified 708 patients; 284 of 352 (80.7%) in the pre-PBM group and 225 of 356 (63.2%) in the post-PBM group received allogeneic RBCs (p < 0.001). Median (interquartile range [IQR]) RBC volumes were higher before PBM than after PBM (3 [2-4] units vs. 2 [1-4] units; p = 0.004). A total of 259 of 284 pre-PBM patients (91.2%) and 57 of 225 (25.3%) post-PBM patients received RBC transfusions when hemoglobin levels were more than 7 g/dL (p < 0.001). The median (IQR) PLT transfusion quantities was 3 (2-5) units for pre-PBM patients and 2 (1-4) units for post-PBM patients (p < 0.001). For patients with PLT counts of more than 10 × 10⁹ /L, a total of 1219 PLT units (73.4%) were transfused before PBM and 691 units (48.8%) were transfused after PBM (p < 0.001). Estimated transfusion expenditures were reduced by $617,152 (18.3%). We noted no differences in clinical outcomes or transfusion-related adverse events.

CONCLUSION

Patient blood management implementation for HSCT recipients was associated with marked reductions in allogeneic RBC and PLT transfusions and decreased transfusion-related costs with no detrimental impact on clinical outcomes.

A consensus redefinition of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a serious complication of blood transfusion and is among the leading causes of transfusion-related morbidity and mortality in most developed countries. In the past decade, the pathophysiology of this potentially life-threatening syndrome has been increasingly elucidated, large cohort studies have identified associated patient conditions and transfusion risk factors, and preventive strategies have been successfully implemented. These new insights provide a rationale for updating the 2004 consensus definition of TRALI.

STUDY DESIGN AND METHODS

An international expert panel used the Delphi methodology to develop a redefinition of TRALI by modifying and updating the 2004 definition. Additionally, the panel reviewed issues related to TRALI nomenclature, patient conditions associated with acute respiratory distress syndrome (ARDS) and TRALI, TRALI pathophysiology, and standardization of reporting of TRALI cases.

RESULTS

In the redefinition, the term "possible TRALI" has been dropped. The terminology of TRALI Type I (without an ARDS risk factor) and TRALI Type II (with an ARDS risk factor or with mild existing ARDS) is proposed. Cases with an ARDS risk factor that meet ARDS diagnostic criteria and where respiratory deterioration over the 12 hours before transfusion implicates the risk factor as causative should be classified as ARDS. TRALI remains a clinical diagnosis and does not require detection of cognate white blood cell antibodies.

CONCLUSIONS

Clinicians should report all cases of posttransfusion pulmonary edema to the transfusion service so that further investigation can allow for classification of such cases as TRALI (Type I or Type II), ARDS, transfusion-associated circulatory overload (TACO), or TRALI or TACO cannot distinguish or an alternate diagnosis.

Red blood cell transfusion in acute brain injury subtypes: An observational cohort study

PURPOSE

Optimal red blood cell (RBC) transfusion thresholds in acute brain injury (ABI) are poorly defined.

MATERIALS AND METHODS

We conducted a retrospective cohort study of adult patients with ABI and moderate anemia (Hb 7-10 g/dL) in a neurological intensive care unit (ICU) at an academic medical center between 2008 and 2015. Transfused and non-transfused patients were matched based on age, ABI subtype, pre-transfusion hemoglobin, and ICU length of stay (LOS) at the time of RBC transfusion. Multivariable regression analyses were performed to assess the relationship between RBC transfusion and hospital LOS, hospital mortality, ICU LOS, ICU mortality, and 24 h change in sequential organ failure assessment (SOFA) scores.

RESULTS

2638 patients met inclusion criteria, with 225 (8.5%) receiving RBC transfusion. Acute ischemic stroke was the most prevalent ABI diagnosis (43.3%) then intracranial hemorrhage (25.6%), subarachnoid hemorrhage (16.5%), and traumatic brain injury (TBI) (14.6%). In multivariable analyses, RBC transfusion was associated with longer hospital and ICU LOS, and higher SOFA scores. Each ABI subtype had similar results, except for TBI which showed no difference in hospital LOS. Mortality was not significantly different.

CONCLUSIONS

In moderately anemic patients with ABI, RBC transfusion was associated with longer hospital and ICU LOS. Prospective investigations are necessary to further assess these relationships.

Higher intraoperative plasma transfusion volumes are associated with inferior perioperative outcomes

BACKGROUND

Intraoperative plasma transfusion is common, yet little is known regarding its effects on perioperative coagulation tests or clinical outcomes.

STUDY DESIGN AND METHODS

This is a retrospective cohort study of adults receiving intraoperative plasma transfusion at a single center from 2011 to 2015. Relationships between plasma transfusion volume, changes in coagulation test values, and clinical outcomes, including a primary outcome of early postoperative red blood cell (RBC) transfusion, were assessed with multivariable regression analyses. Secondary outcomes included hospital mortality, intensive care unit (ICU)- and hospital-free days, intraoperative RBC transfusions, and estimated blood loss.

RESULTS

A total of 3393 unique patients were included, with median (IQR) transfusion of 2 (2-4) units. In multivariable analyses, higher plasma volumes were associated with worse outcomes, with each 1 mL/kg increase associated with increased odds for postoperative (1.02 [1.01-1.03], p < 0.001) and intraoperative RBCs (1.17 [1.16-1.19], p < 0.001) and fewer ICU- and hospital-free days (mean difference [95% CI], -0.08 [-0.12 to -0.05], p < 0.001; and -0.09 [-0.13 to -0.06], p < 0.001, respectively). Greater decreases in international normalized ratio (INR) following plasma transfusion were associated with decreased odds of postoperative RBCs (0.35 [0.25-0.47], p < 0.001), decreased mortality (0.50 [0.31-0.83], p = 0.007), and increased mean ICU- (1.31 [0.41-2.21], p = 0.004) and hospital-free days (1.15 [0.19-2.10], p = 0.018).

CONCLUSION

In patients receiving intraoperative plasma transfusion, higher transfusion volumes were associated with inferior clinical outcomes; however, greater improvements in INR were associated with improved outcomes. Future prospective studies are necessary to better define these relationships and to explore plasma transfusion triggers beyond the limitations of INR.

Bleeding Complications in Patients Undergoing Intrathecal Drug Delivery System Implantation

Introduction

Intrathecal drug delivery systems (IDDSs) have dramatically improved analgesia and the functional status of cancer patients and those with chronic pain states. However, given the close proximity to the neuraxis and frequent concomitant use of antiplatelet or anticoagulant medications, this intervention is not without risk. The goal of this investigation was to determine the incidence of bleeding complications following IDDS placement.

Methods

This is a retrospective review from 2005 through 2014 of adult patients undergoing IDDS implantation or revision at a tertiary care center. The primary outcome was a bleeding-related neurological complication requiring emergency medicine, neurology, or neurosurgical evaluation within 31 days.

Results

A total of 247 procedures were performed on 216 unique patients. Patients received aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) within seven days of needle placement for 64 procedures (25.9%). A preprocedural platelet count or international normalized ratio (INR) was available within 30 days for 138 procedures (55.9%). Of these, two patients had a platelet count lower than 100 x 109/L and one patient had an INR of 1.5 or higher at the time of the procedure. One neurological complication was identified (0.4%) that was not related to procedural bleeding. Similarly, three patients (1.2%) received a periprocedural red blood cell transfusion, none of which were related to procedural bleeding.

Conclusion

No cases of bleeding-related neurological complications were identified following IDDS placement or revision, including in those receiving aspirin or NSAIDs. Future investigations with larger numbers are needed to further explore the safety of antithrombotic therapy continuation or discontinuation periprocedurally.

Evolution of Validated Biomarkers and Intraoperative Parameters in the Development of Postoperative ARDS

BACKGROUND

Patients who develop ARDS from medical or traumatic causes typically present after the inciting event has already occurred. Postoperative ARDS is unique in that the inciting insult potentially responsible for ARDS is known ahead of time, which provides an opportunity to study the early pathophysiology of ARDS. The objective of this study was to better understand the early pathophysiology of postoperative ARDS through a temporal analysis of key biomarkers of interest.

METHODS

We performed a case-control study of adults undergoing elective thoracic, aortic vascular, or cardiac surgery, which placed them at increased risk of developing postoperative ARDS. Biomarkers were measured at baseline, 2 h, and 6 h after the key intraoperative event believed to be responsible for ARDS.

RESULTS

Of the 467 subjects enrolled, 26 developed ARDS and were matched to non-ARDS controls 1:2 based on age, sex, surgical procedure, and surgical lung injury prediction score. Patients with ARDS were more likely to have lower preoperative albumin (P = .029), longer surgery (P = .007), larger amounts of intraoperative fluid (P = .036), and higher intraoperative peak inspiratory pressures (P = .006). Baseline plasminogen activator inhibitor-1 levels were higher in the ARDS group (P = .03). Changes in postoperative biomarker levels from baseline were greater in the ARDS group for interleukin-8 (baseline to 6 h, P = .02) and surfactant protein-D (baseline to 2 h, P = .009).

CONCLUSIONS

Our study supported the hypothesis that dysregulated coagulation, inflammation, and epithelial injury are pathophysiologic features of early postoperative ARDS. Interleukin-8, plasminogen activator-1, and surfactant protein-D may help predict development of postoperative ARDS.

Early Intravascular Events Are Associated with Development of Acute Respiratory Distress Syndrome. A Substudy of the LIPS-A Clinical Trial

RATIONALE

Acute respiratory distress syndrome (ARDS) is a devastating illness with limited therapeutic options. A better understanding of early biochemical and immunological events in ARDS could inform the development of new preventive and treatment strategies.

OBJECTIVES

To determine select peripheral blood lipid mediator and leukocyte responses in patients at risk for ARDS.

METHODS

Patients at risk for ARDS were randomized as part of a multicenter, double-blind clinical trial of aspirin versus placebo (the LIPS-A [Lung Injury Prevention Study with Aspirin] trial; NCT01504867). Plasma thromboxane B2 (TXB2), aspirin-triggered lipoxin A4 (15-epi-LXA4, ATL), and peripheral blood leukocyte number and activation were determined on enrollment and after treatment with either aspirin or placebo.

MEASUREMENTS AND MAIN RESULTS

Thirty-three of 367 subjects (9.0%) developed ARDS after randomization. Baseline ATL levels, total monocyte counts, intermediate monocyte counts, and monocyte-platelet aggregates were associated with the development of ARDS. Peripheral blood neutrophil count and monocyte-platelet aggregates significantly decreased over time. Of note, nine subjects developed ARDS after randomization yet before study drug initiation, including seven subjects assigned to aspirin treatment. Subjects without ARDS at the time of first dose demonstrated a lower incidence of ARDS with aspirin treatment. Compared with placebo, aspirin significantly decreased TXB2 and increased the ATL/TXB2 ratio.

CONCLUSIONS

Biomarkers of intravascular monocyte activation in at-risk patients were associated with development of ARDS. The potential clinical benefit of early aspirin for prevention of ARDS remains uncertain. Together, results of the biochemical and immunological analyses provide a window into the early pathogenesis of human ARDS and represent potential vascular biomarkers of ARDS risk. Clinical trial registered with www.clinicaltrials.gov (NCT01504867).

Optimizing Blood Transfusion Practices Through Bundled Intervention Implementation in Patients With Gynecologic Cancer Undergoing Laparotomy

OBJECTIVE

To examine blood transfusion practices and develop a standardized bundle of interventions to address the high rate of perioperative red blood cell transfusion among patients with ovarian and endometrial cancer.

METHODS

This was a retrospective cohort study. Our primary aim was to determine whether an implemented bundled intervention was associated with a reduction in perioperative red blood cell transfusions among cases of laparotomy for cancer. Secondary aims included comparing perioperative demographic, surgical, complication, and cost data. Interventions included blood transfusion practice standardization using American Society of Anesthesiologists guidelines, an intraoperative hemostasis checklist, standardized intraoperative fluid status communication, and evidence-based use of tranexamic acid. Prospective data from women undergoing laparotomy for ovarian or endometrial cancer from September 28, 2015, to May 31, 2016, defined the study cohort and were compared with historical controls (September 1, 2014, to September 25, 2015). Outcomes were compared in the full unadjusted cohorts and in propensity-matched cohorts.

RESULTS

In the intervention and historical cohorts, respectively, 89 and 184 women underwent laparotomy for ovarian cancer (n=74 and 152) or advanced endometrial cancer (n=15 and 32). Tranexamic acid was administered in 54 (60.7%) patients. The perioperative transfusion rate was lower for the intervention group compared with historical controls (18.0% [16/89] vs 41.3% [76/184], P<.001), a 56.4% reduction. This improvement in the intervention group remained significant after propensity matching (16.2% [13/80] vs 36.2% [29/80], P=.004). The hospital readmission rate was also lower for the intervention group compared with historical controls (1.1% [1/89] vs 12.5% [23/184], P=.002); however, this improvement did not attain statistical significance after propensity matching (1.2% [1/80] vs 7.5% [6/80], P=.12). Cost analysis demonstrated that this intervention was cost-neutral during index hospitalization plus 30-day follow-up.

CONCLUSION

Application of a standardized bundle of evidence-based interventions was associated with reduced blood use in our gynecologic oncology practice.

Identification of Clinically Meaningful Plasma Transfusion Subgroups Using Unsupervised Random Forest Clustering

Statistical techniques such as propensity score matching and instrumental variable are commonly employed to "simulate" randomization and adjust for measured confounders in comparative effectiveness research. Despite such adjustments, the results of these methods apply essentially to an "average" patient. However, as patients show significant heterogeneity in their responses to treatments, this average effect is of limited value. It does not account for individual level variabilities, which can deviate substantially from the population average. To address this critical problem, we present a framework that allows the discovery of clinically meaningful homogeneous subgroups with differential effects of plasma transfusion using unsupervised random forest clustering. Subgroup analysis using two blood transfusion datasets show that considerable variablilities exist between the subgroups and population in both the treatment effect of plasma transfusion on bleeding and mortality and risk factors for these outcomes. These results support the customization of blood transfusion therapy for the individual patient.

Intra-Operative Inspired Fraction of Oxygen and the Risk of Surgical Site Infections in Patients with Type 1 Surgical Incisions

BACKGROUND

Whether the fraction of inspired oxygen (F_IO₂) influences the risk of surgical site infection (SSI) is controversial. The World Health Organization and the World Federation of Societies of Anesthesiologists offer conflicting recommendations. In this study, we evaluate simultaneously three different definitions of F_IO₂ exposure and the risk of SSI in a large surgical population.

PATIENTS AND METHODS

Patients with clean (type 1) surgical incisions who developed superficial and deep organ/space SSI within 30 days after surgery from January 2003 through December 2012 in five surgical specialties were matched to specialty-specific controls. Fraction of inspired oxygen exposure was defined as (1) nadir F_IO₂, (2) percentage of operative time with F_IO₂ greater than 50%, and (3) cumulative hyperoxia exposure, calculated as the area under the curve (AUC) of F_IO₂ by time for the duration in which F_IO₂ greater than 50%. Stratified univariable and multivariable logistic regression models tested associations between F_IO₂ and SSI.

RESULTS

One thousand two hundred fifty cases of SSI were matched to 3,248 controls. Increased oxygen exposure, by any of the three measures, was not associated with the outcome of any SSI in a multivariable logistic regression model. Elevated body mass index (BMI; 35+ vs. <25, odds ratio [OR] 1.78, 95% confidence interval [CI] 1.43-2.24), surgical duration (250+ min vs. <100 min, OR 1.93, 95% CI 1.48-2.52), diabetes mellitus (OR 1.37, 95% CI 1.13-1.65), peripheral vascular disease (OR 1.52, 95% CI 1.10-2.10), and liver cirrhosis (OR 2.48, 95% CI 1.53-4.02) were statistically significantly associated with greater odds of any SSI. Surgical sub-group analyses found higher intra-operative oxygen exposure was associated with higher odds of SSI in the neurosurgical and spine populations.

CONCLUSION

Increased intra-operative inspired fraction of oxygen was not associated with a reduction in SSI. These findings do not support the practice of increasing F_IO₂ for the purpose of SSI reduction in patients with clean surgical incisions.

Demographic and epidemiologic characterization of transfusion recipients from four US regions: evidence from the REDS-III recipient database

BACKGROUND

Blood transfusion is one of the most common medical procedures during hospitalization in the United States. To understand the benefits of transfusion while mitigating potential risks, a multicenter database containing detailed information on transfusion incidence and recipient outcomes would facilitate research.

STUDY DESIGN AND METHODS

The Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) program has developed a comprehensive transfusion recipient database utilizing data from hospital electronic health records at 12 participating hospitals in four geographic regions. Inpatient and outpatient data on transfusion recipients from January 1, 2013 to December 31, 2014 included patient age, sex, ethnicity, primary diagnosis, type of blood product provided, issue location, pretransfusion and post-transfusion hemoglobin (Hgb), and hospital outcomes. Transfusion incidence per encounter was calculated by blood product and various patient characteristics.

RESULTS

During the 2-year study period, 80,362 (12.5%) inpatient encounters involved transfusion. Among inpatients, the most commonly transfused blood products were red blood cells (RBCs; 10.9% of encounters), followed by platelets (3.2%) and plasma (2.9%). Among patients who received transfusions, the median number of RBC units was one, the pretransfusion Hgb level was 7.6 g/dL, and the Hgb increment per unit was 1.4 g/dL. Encounter mortality increased with patient age, the number of units transfused, and the use of platelet or plasma products. The most commonly reported transfusion reaction was febrile nonhemolytic.

CONCLUSION

The database contains comprehensive data regarding transfusion use and patient outcomes. The current report describes an evaluation of the first 2 years of a planned, 4-year, linked blood donor-component-recipient database, which represents a critical new resource for transfusion medicine researchers.

Point-of-care washing of allogeneic red blood cells for the prevention of transfusion-related respiratory complications (WAR-PRC): a protocol for a multicenter randomised clinical trial in patients undergoing cardiac surgery

INTRODUCTION

The transfusion-related respiratory complications, transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), are leading causes of transfusion-related morbidity and mortality. At present, there are no effective preventive strategies with red blood cell (RBC) transfusion. Although mechanisms remain incompletely defined, soluble biological response modifiers (BRMs) within the RBC storage solution may play an important role. Point-of-care (POC) washing of allogeneic RBCs may remove these BRMs, thereby mitigating their impact on post-transfusion respiratory complications.

METHODS AND ANALYSIS

This is a multicenter randomised clinical trial of standard allogeneic versus washed allogeneic RBC transfusion for adult patients undergoing cardiac surgery testing the hypothesis that POC RBC washing is feasible, safe, and efficacious and will reduce recipient immune and physiologic responses associated with transfusion-related respiratory complications. Relevant clinical outcomes will also be assessed. This investigation will enrol 170 patients at two hospitals in the USA. Simon's two-stage design will be used to assess the feasibility of POC RBC washing. The primary safety outcomes will be assessed using Wilcoxon Rank-Sum tests for continuous variables and Pearson chi-square test for categorical variables. Standard mixed modelling practices will be employed to test for changes in biomarkers of lung injury following transfusion. Linear regression will assess relationships between randomised group and post-transfusion physiologic measures.

ETHICS AND DISSEMINATION

Safety oversight will be conducted under the direction of an independent Data and Safety Monitoring Board (DSMB). Approval of the protocol was obtained by the DSMB as well as the institutional review boards at each institution prior to enrolling the first study participant. This study aims to provide important information regarding the feasibility of POC washing of allogeneic RBCs and its potential impact on ameliorating post-transfusion respiratory complications. Additionally, it will inform the feasibility and scientific merit of pursuing a more definitive phase II/III clinical trial.

REGISTRATION

ClinicalTrials.gov registration number is NCT02094118 (Pre-results).

Prophylactic Plasma Transfusion Is Not Associated With Decreased Red Blood Cell Requirements in Critically Ill Patients

BACKGROUND

Critically ill patients frequently receive plasma transfusion under the assumptions that abnormal coagulation test results confer increased risk of bleeding and that plasma transfusion will decrease this risk. However, the effect of prophylactic plasma transfusion remains poorly understood. The objective of this study was to determine the relationship between prophylactic plasma transfusion and bleeding complications in critically ill patients.

METHODS

This is a retrospective cohort study of adults admitted to the intensive care unit (ICU) at a single academic institution between January 1, 2009 and December 31, 2013. Inclusion criteria included age ≥18 years and an international normalized ratio measured during ICU admission. Multivariable propensity-matched analyses were used to evaluate associations between prophylactic plasma transfusion and outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of hospital- and ICU-free days and mortality within 30 days of ICU discharge.

RESULTS

A total of 27,561 patients were included in the investigation with 2472 (9.0%) receiving plasma therapy and 1105 (44.7%) for which plasma transfusion was prophylactic in nature. In multivariable propensity-matched analyses, patients receiving plasma had higher rates of red blood cell transfusion (odds ratio: 4.3 [95% confidence interval: 3.3-5.7], P < .001) and fewer hospital-free days (estimated % increase: -11.0% [95% confidence interval: -11.4, -10.6%], P < .001). There were no significant differences in ICU-free days or mortality. These findings appeared robust, persisting in multiple predefined sensitivity analyses.

CONCLUSIONS

Prophylactic administration of plasma in the critically ill was not associated with improved clinical outcomes. Further investigation examining the utility of plasma transfusion in this population is warranted.

Postoperative Pulmonary Complications, Early Mortality, and Hospital Stay Following Noncardiothoracic Surgery: A Multicenter Study by the Perioperative Research Network Investigators

Importance

Postoperative pulmonary complications (PPCs), a leading cause of poor surgical outcomes, are heterogeneous in their pathophysiology, severity, and reporting accuracy.

Objective

To prospectively study clinical and radiological PPCs and respiratory insufficiency therapies in a high-risk surgical population.

Design, Setting, and Participants

We performed a multicenter prospective observational study in 7 US academic institutions. American Society of Anesthesiologists physical status 3 patients who presented for noncardiothoracic surgery requiring 2 hours or more of general anesthesia with mechanical ventilation from May to November 2014 were included in the study. We hypothesized that PPCs, even mild, would be associated with early postoperative mortality and use of hospital resources. We analyzed their association with modifiable perioperative variables.

Exposure

Noncardiothoracic surgery.

Main Outcomes and Measures

Predefined PPCs occurring within the first 7 postoperative days were prospectively identified. We used bivariable and logistic regression analyses to study the association of PPCs with ventilatory and other perioperative variables.

Results

This study included 1202 patients who underwent predominantly abdominal, orthopedic, and neurological procedures. The mean (SD) age of patients was 62.1 (13.8) years, and 636 (52.9%) were men. At least 1 PPC occurred in 401 patients (33.4%), mainly the need for prolonged oxygen therapy by nasal cannula (n = 235; 19.6%) and atelectasis (n = 206; 17.1%). Patients with 1 or more PPCs, even mild, had significantly increased early postoperative mortality, intensive care unit (ICU) admission, and ICU/hospital length of stay. Significant PPC risk factors included nonmodifiable (emergency [yes vs no]: odds ratio [OR], 4.47, 95% CI, 1.59-12.56; surgical site [abdominal/pelvic vs nonabdominal/pelvic]: OR, 2.54, 95% CI, 1.67-3.89; and age [in years]: OR, 1.03, 95% CI, 1.02-1.05) and potentially modifiable (colloid administration [yes vs no]: OR, 1.75, 95% CI, 1.03-2.97; preoperative oxygenation: OR, 0.86, 95% CI, 0.80-0.93; blood loss [in milliliters]: OR, 1.17, 95% CI, 1.05-1.30; anesthesia duration [in minutes]: OR, 1.14, 95% CI, 1.05-1.24; and tidal volume [in milliliters per kilogram of predicted body weight]: OR, 1.12, 95% CI, 1.01-1.24) factors.

Conclusions and Relevance

Postoperative pulmonary complications are common in patients with American Society of Anesthesiologists physical status 3, despite current protective ventilation practices. Even mild PPCs are associated with increased early postoperative mortality, ICU admission, and length of stay (ICU and hospital). Mild frequent PPCs (eg, atelectasis and prolonged oxygen therapy need) deserve increased attention and intervention for improving perioperative outcomes.