Net Prime Volume Is Associated with Increased Odds of Blood Transfusion

Hemodilutional anemia has been cited as a contributing factor to red blood cell (RBC) transfusions in cardiac surgery patients. Accordingly, efforts have been made to minimize hemodilution by reducing cardiopulmonary bypass (CPB) prime volume. We sought to assess the impact of these efforts on intraoperative RBC transfusions. We evaluated 21,360 patients undergoing coronary artery bypass with or without aortic valve surgery between July 2011 through December 2016 at any of 42 centers participating in the Perfusion Measures and Outcomes registry. The primary exposure was net CPB prime volume (total prime volume minus retrograde autologous prime volume) indexed to body surface area (mL/m²), which was further divided into quartiles (Q1: <262 mL/m², Q2: 262-377 mL/m², Q3: 377-516 mL/m², and Q4: >516 mL/m²). The primary outcome was intraoperative RBC transfusion. We modeled the effect of index net prime volume on transfusion, adjusting for patient (age, gender, race, diabetes, vascular disease, previous myocardial infarction, ejection fraction, creatinine, preoperative hematocrit (HCT), total albumin, status, aspirin, and antiplatelet agents), procedural (procedure types) characteristics, surgical year, and hospital. The median net prime volume was 378 mL/m² (25th percentile: 262 mL/m², 75th percentile: 516 mL/m²). Relative to patients in Q1, patients in Q4 were more likely to be older, female, nondiabetic, have higher ejection fraction, have more ultrafiltration volume removed, and undergo more elective and aortic valve procedures (all p < .05). Patients in Q4 relative to Q1 were exposed to lower nadir HCTs on bypass, p < .05. The net prime volume was associated with an increased risk of transfusion (8.9% in Q1 vs. 22.6% in Q4, p < .001). After adjustment, patients in Q4 (relative to Q1) had a 2.9-fold increased odds (OR_adj = 2.9, 95% CI [2.4, 3.4]) of intraoperative RBC transfusion. In this large, multicenter experience, patients exposed to larger net prime volumes were associated with greater adjusted odds of receiving intraoperative transfusions. Our findings reinforce the importance of efforts to reduce the net CPB prime volume. Based on these findings and other supporting evidence, the net prime volume should be adopted as a national quality measure.

Predictive scores for major bleeding after coronary artery bypass surgery in low operative risk patients

BACKGROUND

Cardiac surgery is associated with perioperative bleeding and carries high risk of allogeneic blood transfusion. Recently new scores for prediction of severe bleeding have been developed. This study aims to compare the WILL-BLEED, CRUSADE, PAPWORTH, TRUST, TRACK and ACTION scores in predicting major bleeding after CABG in patients with low estimated operative risk.

METHODS

A multicenter observational study included 1391 patients who underwent isolated CABG from July 2015 to January 2018. We tested the hypothesis that the WILL-BLEED score, specifically designed for CABG, would perform at least as well as the CRUSADE, PAPWORTH, TRUST, TRACK and ACTION scores in predicting postoperative major bleeding in low operative risk patients. The primary endpoint was the performance of known bleeding risk scores after CABG. The secondary endpoint was the evaluation of in-hospital mortality.

RESULTS

Mean age was 68.2±9.4 years and median Euroscore II value was 1.69% (IQR 1.15-2.81%). Mean blood losses in the first 12 postoperative hours was 339.75 mL. Seventy-three (5.2%) subjects underwent administration of blood products. The rate of severe-massive bleeding according to UDPB grades 3-4 was 1.5%. WILL-BLEED, TRUST, TRACK and ACTION scores were significantly associated with severe postoperative bleeding. WILL-BLEED presented the best c-index (AUC: 0.658; 95% CI: 0.600,0.716). Reclassification analysis showed a worsening in sensitivity and significant negative reclassification of CRUSADE, PAPWORTH, TRACK and ACTION scores when compared with WILL-BEED. The combination of WILL-BLEED and TRUST scores improved the prediction ability (AUC: 0.673; 95% CI: 0.615-0.732). Overall in-hospital mortality was 1.65%. Early mortality in patients with severe versus no-severe bleeding was found to be 11.8% vs. 1.0% Severe bleeding (OR: 13.26; P value<0.001) was found to be significantly associated with early mortality.

CONCLUSIONS

Severe bleeding after CABG is a harmful event associated with adverse outcomes. WILL-BLEED Score has the better performance in predicting severe-massive bleeding after CABG. The TRUST Score, although suboptimal, represents a valuable alternative in this setting.

Sensitivity of Viscoelastic Tests to Platelet Function

Viscoelastic tests provide a dynamic assessment of coagulation, by exploring the time to clot formation and the clot strength. Using specific activators or inhibitors, additional factors can be explored, like the fibrinogen contribution to clot strength. Since the early days, various attempts have been done to measure platelet function with viscoelastic test. In general, the difference between the maximum clot strength and the fibrinogen contribution is considered an index of platelet contribution. However, this parameter does not clearly split platelet count from function; additionally, the extensive thrombin generation of standard activated viscoelastic tests activates platelet through the protease activated receptors, bypassing the other pathways. For this reason, standard viscoelastic tests cannot be used to assess platelet reactivity under the effects of aspirin or P2Y12 inhibitors. To overcome this limitation, a specific test was developed (thromboelastography platelet mapping). This test has been compared with the gold standard of light transmission aggregometry and with other point-of-care tests, with conflicting results. In general, the use of viscoelastic tests to assess the effects of antiplatelet agents is still limited. Conversely, platelet contribution to clot strength in the setting of coagulopathic bleeding is considered an important parameter to trigger platelet transfusion or desmopressin.

Preoperative atorvastatin reduces bleeding and blood transfusions in patients undergoing elective isolated aortic valve replacement

OBJECTIVES

Minimization of bleeding to reduce the use of blood products is of utmost importance in cardiac surgery. Statins are known for their pleiotropic effects beyond lipid-lowering properties, and the use of atorvastatin preoperatively is associated with reduced risk of bleeding and blood product use after coronary surgery. However, no studies have investigated if this beneficial effect also extends to aortic valve surgery.

METHODS

In this retrospective cohort study, 1145 consecutive patients undergoing elective primary isolated aortic valve replacement meeting the inclusion and exclusion criteria were selected from January 2009 to December 2017 (547 in the atorvastatin group, 598 in the control group). Postoperative bleeding, blood product use, and complications were monitored during hospitalization.

RESULTS

Postoperative bleeding was significantly lower in the atorvastatin group compared with the controls in the first 12 h after surgery (372 ± 137 vs 561 ± 219 ml; P = 0.001) and considering overall bleeding (678 ± 387 vs 981 ± 345 ml, P = 0.001). A total of 32.3% of controls and 26.3% of atorvastatin users received packed red blood cells (P = 0.027), and major surgical complications were similar between the groups. Postoperative length of stay was shorter in the atorvastatin group with an average reduction of 1 day of hospitalization (6.0 ± 1.4 vs 6.9 ± 2.1 days; P = 0.001). Postoperative bleeding among the atorvastatin-treated patients was significantly greater in those taking lower doses compared to those taking higher doses of atorvastatin with a 20% between-group difference (P = 0.001).

CONCLUSIONS

Preoperative treatment with atorvastatin might reduce postoperative bleeding and transfusion of packed red blood cells in patients undergoing elective isolated aortic valve replacement. This result might translate into faster recovery after surgery and reduced hospitalization costs.

Bleeding in critical care associated with left ventricular assist devices: pathophysiology, symptoms, and management

Chronic heart failure (HF) is a growing health problem, and it is associated with high morbidity and mortality. Left ventricular assist devices (LVADs) are nowadays an important treatment option for patients with end-stage HF not only as a bridging tool to heart transplantation but also, as a permanent therapy for end-stage HF (destination therapy). The use of LVAD is associated with a high risk for bleeding complications and thromboembolic events, including pump thrombosis and ischemic stroke. Bleeding is the most frequent complication, occurring in 30% to 60% of patients, both early and late after LVAD implantation. Although the design of LVADs has improved over time, bleeding complications are still the most common complication and occur very frequently. The introduction of an LVAD results in an altered hemostatic balance as a consequence of blood-pump interactions, changes in hemodynamics, acquired coagulation abnormalities, and the strict need for long-term anticoagulant treatment with oral anticoagulants and antiplatelet therapy. LVAD patients may experience an acquired coagulopathy, including platelet dysfunction and impaired von Willebrand factor activity, resulting in acquired von Willebrand syndrome. In this educational manuscript, the epidemiology, etiology, and pathophysiology of bleeding in patients with LVAD will be discussed. Because hematologist are frequently consulted in cases of bleeding problems in these individuals in a critical care setting, the observed type of bleeding complications and management strategies to treat bleeding are also reviewed.

Absence of perioperative excessive bleeding in on-pump coronary artery bypass grafting cases performed by residents

OBJECTIVES

On-pump coronary artery bypass grafting (CABG) is associated with elevated bleeding risk. Our aim was to evaluate the role of surgical experience in postoperative blood loss.

METHODS

A propensity score-matched analysis was employed to compare on-pump CABG patients operated on by residents and specialists. End points included drainage volume and bleeding severity, as assessed by the Universal Definition of Perioperative Bleeding in cardiac surgery and E-CABG scale.

RESULTS

A total of 212 matched pairs (c-statistics 0.693) were selected from patients operated on by residents (n = 294) and specialists (n = 4394) between October 2012 and May 2018. Patients did not differ in bleeding risk. There were no statistically significant differences in postoperative 6-, 12- and 24-h drainages between subjects operated on by residents and specialists, and there was no between-group difference in rethoracotomy or transfusion rate. There were no differences in Universal Definition of Perioperative Bleeding or E-CABG grades. In June 2018, after a median follow-up of 2.8 years (range 0.1-5.7 years), the overall survival was 94%, with no differences between the patients operated on by residents (95%) and specialists (92%) (P = 0.27).

CONCLUSIONS

Patients undergoing on-pump CABG, when operated on by a resident, are not exposed to an elevated bleeding risk, as compared with patients operated on by experienced surgeons.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Tranexamic acid in cardiac surgery: a systematic review and meta-analysis (protocol)

INTRODUCTION

Bleeding during cardiac surgery is associated with increased morbidity and mortality. Tranexamic acid is an antifibrinolytic with proven efficacy in major surgeries. Current clinical practice guidelines recommend intraoperative use in cardiac procedures. However, several complications have been reported with tranexamic acid including seizures. This review intends to summarise the evidence examining the efficacy and safety of tranexamic acid in patients undergoing cardiac surgery.

METHODS/DESIGN

We will search MEDLINE, Embase, PubMED, ACPJC, CINAHL and the Cochrane trial registry for eligible randomised controlled trials, the search dates for all databases will be from inception until 1 January 2019, investigating the perioperative use of topical and/or intravenous tranexamic acid as a stand-alone antifibrinolytic agent compared with placebo in patients undergoing open cardiac surgery. We categorised outcomes as patient critical or patient important. Selected patient-critical outcomes are: mortality (intensive care unit, hospital and 30-day endpoints), reoperation within 24 hours, postoperative bleeding requiring transfusion of packed red blood cells, myocardial infarction, stroke, pulmonary embolism, bowel infarction, upper or lower limb deep vein thrombosis and seizures. Those outcomes, we perceived as clinical experts to be most patient valued and patients were not involved in outcomes selection process. We will not apply publication date, language, journal or methodological quality restrictions. Two reviewers will independently screen and identify eligible studies using predefined eligibility criteria and then review full reports of all potentially relevant citations. A third reviewer will resolve disagreements if consensus cannot be achieved. We will present the results as relative risk with 95% CIs for dichotomous outcomes and as mean difference or standardised mean difference for continuous outcomes with 95% CIs. We will assess the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication TRIAL REGISTRATION NUMBER: CRD42018105904.

Point-of-care measurement of activated clotting time for cardiac surgery as measured by the Hemochron signature elite and the Abbott i-STAT: agreement, concordance, and clinical reliability

BACKGROUND

Since inadequate heparin anticoagulation and insufficient reversal can result in complications during cardiopulmonary bypass (CPB) surgery, heparin anticoagulation monitoring by point-of-care (POC) activated clotting time (ACT) measurements is essential for CPB initiation, maintainance, and anticoagulant reversal. However, concerns exist regarding reproducibility of ACT assays and comparability of devices.

METHODS

We evaluated the agreement of ACT assays using four parallel measurements performed on two commonly used devices each (i.e., two Hemochron Signature Elite (Hemochron) and two Abbott i-STAT (i-STAT) devices, respectively). Blood samples from 30 patients undergoing cardiac surgery on CPB were assayed at specified steps (baseline, after heparin administration, after protamine administration) with four parallel measurements (two of each device type) using commercial Kaolin activated assays provided by the respective manufactures. Measurements were compared between identical and different device types using linear regression, Bland-Altman analyses, and calculation of Cohen's kappa coefficient.

RESULTS

Parallel i-STAT ACTs demonstrated a good linear correlation (r = 0.985). Bias, as determined by Bland-Altman analysis, was low (- 3.8 s; 95% limits of agreement (LOA): - 77.8 -70.2 s), and Cohen's Kappa demonstrated good agreement (kappa = 0.809). Hemochron derived ACTs demonstrated worse linear correlation (r = 0.782), larger bias with considerably broader LOA (- 13.14 s; 95%LOA:-316.3-290 s), and lesser concordance between parallel assays (kappa = 0.554). Although demonstrating a fair linear correlation (r = 0.815), parallel measurements on different ACT-devices showed large bias (-20s; 95% LOA: - 290-250 s) and little concordance (kappa = 0.368). Overall, disconcordant results according to clinically predefined target values were more frequent with the Hemochron than i-STAT. Furthermore, while discrepancies in ACT between two parallel iSTAT assays showed little or no clinical relevance, deviations from parallel Hemochron assays and iSTAT versus Hemochron measurements revealed marked and sometimes clinically critical deviations.

CONCLUSION

Currently used ACT point-of-care devices cannot be used interchangeably. Furthermore, our data question the reliability of the Hemochron in assessing adequacy of heparin anticoagulation monitoring for CPB.

Cardiopulmonary bypass and dual antiplatelet therapy: a strategy to minimise transfusions and blood loss

BACKGROUND

Patients with preoperative dual antiplatelet therapy prior to coronary artery bypass surgery are at risk of bleeding and blood component transfusion. We hypothesise that an optimised cardiopulmonary bypass strategy reduces postoperative blood loss and transfusions.

METHODS

In total, 60 patients admitted for coronary artery bypass grafting with ticagrelor and aspirin medication withdrawn <96 hours before surgery were prospectively randomised into two equal sized groups. Cardiopulmonary bypass combined a closed Cortiva^® heparin-coated circuit with low systemic heparinisation (activated clotting time < 250 seconds) and intraoperative cell salvage in the study group, whereas the control group used a Balance^® coated open circuit, full systemic heparinisation (activated clotting time > 480 seconds) and conventional cardiotomy suction. This perfusion strategy was evaluated by the chest drain volume after 24 hours, perioperative haemoglobin and platelet loss accompanied by global coagulation assessments.

RESULTS

Patients in the study group demonstrated significantly better outcomes signified by lower blood loss 554 ± 224 versus 1,100 ± 989 mL (p < 0.001), reduced packed red cell transfusion 7% versus 53% (p < 0.001), reduced haemoglobin -28 ± 15 versus -40 ± 14 g/L (p = 0.004) and platelet loss -35 ± 36 versus -82 ± 67 × 10⁹/L (p = 0.001). Indices of rotational thromboelastometry indicated shorter clotting times within the internal and external pathways. Adenosine diphosphate activated platelet function was within normal range based on Multiplate^® aggregometry, while ROTEM^® platelet analyses indicated inhibited function both preoperatively and post-bypass. Platelet inhibition by aspirin was verified throughout the perioperative period. Platelet function showed no intergroup differences.

CONCLUSION

A stringent perfusion strategy reduced blood loss and transfusions in dual antiplatelet therapy patients requiring urgent surgery.

Minimal invasive extracorporeal circulation preserves platelet function after cardiac surgery: a prospective observational study

Introduction:

Cardiac surgery on conventional cardiopulmonary bypass induces a combination of thrombocytopenia and platelet dysfunction which is strongly related to postoperative bleeding. Minimal invasive extracorporeal circulation has been shown to preserve coagulation integrity, though effect on platelet function remains unclear. We aimed to prospectively investigate perioperative platelet function in a series of patients undergoing cardiac surgery on minimal invasive extracorporeal circulation using point-of-care testing.

Methods:

A total of 57 patients undergoing elective cardiac surgery on minimal invasive extracorporeal circulation were prospectively recruited. Anticoagulation strategy was based on individualized heparin management and heparin level–guided protamine titration performed in all patients with a specialized point-of-care device (Hemostasis Management System – HMS Plus; Medtronic, Minneapolis, MN, USA). Platelet function was evaluated with impedance aggregometry using the ROTEM platelet (TEM International GmbH, Munich, Germany). ADPtest and TRAPtest values were assessed before surgery and after cardiopulmonary bypass.

Results:

ADPtest value was preserved during surgery on minimal invasive extracorporeal circulation (58.2 ± 20 U vs. 53.6 ± 21 U; p = 0.1), while TRAPtest was found significantly increased (90 ± 27 U vs. 103 ± 38 U; p = 0.03). Postoperative ADPtest and TRAPtest values were inversely related to postoperative bleeding (correlation coefficient: −0.29; p = 0.03 for ADPtest and correlation coefficient: −0.28; p = 0.04 for TRAPtest). The preoperative use of P2Y12 inhibitors was identified as the only independent predictor of a low postoperative ADPtest value (OR = 15.3; p = 0.02).

Conclusion:

Cardiac surgery on minimal invasive extracorporeal circulation is a platelet preservation strategy, which contributes to the beneficial effect of minimal invasive extracorporeal circulation in coagulation integrity.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Association among Clopidogrel Cessation, Platelet Function, and Bleeding in Coronary Bypass Surgery: An Observational Trial

OBJECTIVES

 This study sought to determine (1) the association between the length of preoperative clopidogrel discontinuation, blood loss, and transfusion requirements and (2) whether preoperative platelet function testing predicts excessive postoperative bleeding in patients undergoing coronary artery bypass grafting (CABG) surgery.

METHODS

 In this retrospective analysis, patients undergoing CABG were divided into three groups with regard to the period between preoperative clopidogrel cessation and surgery: group 1 (n = 94, ≤3 days), group 2 (n = 100, 4-5 days), and group 3 (n = 83, 6-7 days), respectively. Impedance aggregometry (Multiplate) with arachidonic acid (ASPI) test assay (used for platelets stimulation) and adenosine diphosphate (ADP) test (used for platelets stimulation) was performed before the surgery. Primary outcome was 24 hours chest tube output (CTO) and transfusion requirements (red blood cell concentrate [RBCC], platelet concentrate [PC], fibrinogen concentrate [FC], and fresh-frozen plasma [FFP]) were considered as secondary outcomes.

RESULTS

 CTO during 24 hours was significantly higher in group 1 as compared with groups 2 and 3, respectively (p = 0.003). Considering secondary outcomes, RBCC (p = 0.043), PC (p = 0.001), FC (p = 0.003), and FFP (p = 0.010) were more frequently transfused in group 1 as compared with groups 2 and 3, respectively. Multiple electrode aggregometry ASPI and ADP tests were significantly correlated with the 24-hour CTO (ASPI test-rho = -0.258, p < 0.001; ADP test-rho = -0.164, p = 0.007). A significant correlation was observed between clopidogrel-free interval and 24-hour CTO (rho = -0.200, p < 0.001). Receiver-operating characteristics (ROC) curve analysis revealed cutoff values to delineate bleeding tendency (ASPI test ≤ 25 area under the aggregation curve [AUC], ADP test ≤63 AUC, and clopidogrel-free interval ≤3 days).

CONCLUSION

 Excessive postoperative bleeding occurred less frequently if the period between clopidogrel discontinuation and surgery was longer than 3 days, as compared with shorter waiting time. Inadequate recovery of the platelets function following clopidogrel cessation in preoperative period was associated with increased bleeding risk. Platelet function testing was found to be a useful tool for postoperative bleeding management in our hands.

Adjusted calculation model of heparin management during cardiopulmonary bypass in obese patients: A randomised controlled trial

BACKGROUND

Anticoagulation during cardiopulmonary bypass (CPB) is usually adapted to total body weight (TBW). This may be inaccurate in obese patients and lead to heparin overdose with a risk of bleeding.

OBJECTIVES

To validate the efficacy and safety of an adjusted calculation model of heparin dosing based on ideal body weight (IBW) rather than TBW in obese CPB patients, with an expected target mean plasma heparin concentration of 4.5 IU ml after onset of CPB in the experimental group.

DESIGN

Randomised controlled study.

SETTING

University hospital.

PATIENTS

Sixty obese patients (BMI ≥ 30 kg m) scheduled for CPB were included from January to June 2016.

INTERVENTIONS

Patients received a bolus dose of unfractionated heparin of either 300 IU kg of TBW or 340 IU kg of IBW before onset of CPB. Additional adjusted boluses were injected to maintain an activated clotting time (ACT) of at least 400 s.

MAIN OUTCOME MEASURES

Plasma heparin concentration and ACT were measured at different time points. Total heparin doses and transfusion requirements were recorded.

RESULTS

The target heparin concentration of 4.5 IU ml was reached in the IBW group at the onset of CPB and maintained at all time points during CPB. Heparin concentrations were significantly higher in the TBW group after the bolus (6.52 ± 0.97 vs. 4.54 ± 1.13 IU ml, P < 0.001) and after cardioplegia (5.10 ± 1.03 vs. 4.31 ± 1.00 IU ml, P = 0.02). Total heparin doses were significantly higher in the TBW group. Mean ACT was significantly lower in the IBW group but remained over 400 s during CPB. The correlation between heparin and ACT was poor. Peri-operative bleeding and transfusion requirements were comparable. No thrombotic event occurred in the CPB circuit.

CONCLUSION

The current IBW-adjusted regimen of heparin administration may be used efficiently in obese CPB patients, thereby avoiding overdose which cannot be accurately assessed by ACT monitoring alone.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02675647.

The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic method and enables to assess viscoelastic profiles of whole blood in various clinical settings. ROTEM-guided bleeding management has become an essential part of patient blood management (PBM) which is an important concept in improving patient safety. Here, ROTEM testing and hemostatic interventions should be linked by evidence-based, setting-specific algorithms adapted to the specific patient population of the hospitals and the local availability of hemostatic interventions. Accordingly, ROTEM-guided algorithms implement the concept of personalized or precision medicine in perioperative bleeding management (‘theranostic’ approach). ROTEM-guided PBM has been shown to be effective in reducing bleeding, transfusion requirements, complication rates, and health care costs. Accordingly, several randomized-controlled trials, meta-analyses, and health technology assessments provided evidence that using ROTEM-guided algorithms in bleeding patients resulted in improved patient’s safety and outcomes including perioperative morbidity and mortality. However, the implementation of ROTEM in the PBM concept requires adequate technical and interpretation training, education and logistics, as well as interdisciplinary communication and collaboration.

The Use of Umbilical Cord Blood for Autologous Transfusion in Neonatal Open Heart Surgery

In the last few decades, the use of umbilical cord blood (UCB) has received increasing attention, not only as a source of stem cells, but also as a transfusion product for the treatment of anemia in the neonatal and even the adult population. This review focuses on data reports and collection efforts related to the autologous transfusion of UCB in full-term neonates with prenatally diagnosed critical congenital heart defects. This review summarizes different aspects of UCB transfusion, including indications and contraindications; the collection procedure; storage timing; and special properties of one of its constituents, fetal hemoglobin, in the setting of hypothermic cardiopulmonary bypass.

Impact of minimal invasive extracorporeal circulation on the need of red blood cell transfusion

OBJECTIVE

Minimal invasive extracorporeal circulation may decrease the need of packed red blood cell transfusions and reduce hemodilution during cardiopulmonary bypass. However, more data are needed on the effects of minimal invasive extracorporeal circulation in more complex cardiac procedures. We compared minimal invasive extracorporeal circulation and conventional extracorporeal circulation methods of cardiopulmonary bypass.

METHODS

A total of 424 patients in the minimal invasive extracorporeal circulation group and 844 patients in the conventional extracorporeal circulation group undergoing coronary artery bypass grafting and more complex cardiac surgery were evaluated. Age, sex, type of surgery, and duration of perfusion were used as matching criteria. Hemoglobin <80 g/L was used as red blood cell transfusion trigger. The primary endpoint was the use of red blood cells during the day of operation and the five postoperative days. Secondary endpoints were hemodilution (hemoglobin drop after the onset of perfusion) and postoperative bleeding from the chest tubes during the first 12 hours after the operation.

RESULTS

Red blood cell transfusions were needed less often in the minimal invasive extracorporeal circulation group compared to the conventional extracorporeal circulation group (26.4% vs. 33.4%, p = 0.011, odds ratio 0.72, 95% confidence interval 0.55-0.93), especially in coronary artery bypass grafting subgroup (21.3% vs. 35.1%, p < 0.001, odds ratio 0.50, 95% confidence interval 0.35-0.73). Hemoglobin drop after onset of perfusion was also lower in the minimal invasive extracorporeal circulation group than in the conventional extracorporeal circulation group (24.2 ± 8.5% vs. 32.6 ± 12.6%, p < 0.001). Postoperative bleeding from the chest tube did not differ between the groups (p = 0.808).

CONCLUSION

Minimal invasive extracorporeal circulation reduced the need of red blood cell transfusions and hemoglobin drop when compared to the conventional extracorporeal circulation group. This may have implications when choosing the perfusion method in cardiac surgery.

Why does a point of care guided transfusion algorithm not improve blood loss and transfusion practice in patients undergoing high-risk cardiac surgery? A prospective randomized controlled pilot study

Background

Adult cardiac surgery is often complicated by elevated blood losses that account for elevated transfusion requirements. Perioperative bleeding and transfusion of blood products are major risk factors for morbidity and mortality. Timely diagnostic and goal-directed therapies aim at the reduction of bleeding and need for allogeneic transfusions.

Methods

Single-centre, prospective, randomized trial assessing blood loss and transfusion requirements of 26 adult patients undergoing elective cardiac surgery at high risk for perioperative bleeding. Primary endpoint was blood loss at 24 h postoperatively. Random assignment to intra- and postoperative haemostatic management following either an algorithm based on conventional coagulation assays (conventional group: platelet count, aPTT, PT, fibrinogen) or based on point-of-care (PoC-group) monitoring, i.e. activated rotational thromboelastometry (ROTEM®) combined with multiple aggregometry (Multiplate®). Differences between groups were analysed using nonparametric tests for independent samples.

Results

The study was terminated after interim analysis (n = 26). Chest tube drainage volume was 360 ml (IQR 229-599 ml) in the conventional group, and 380 ml (IQR 310-590 ml) in the PoC-group (p = 0.767) after 24 h. Basic patient characteristics, results of PoC coagulation assays, and transfusion requirements of red blood cells and fresh frozen plasma did not differ between groups. Coagulation results were comparable. Platelets were transfused in the PoC group only.

Conclusion

Blood loss via chest tube drainage and transfusion amounts were not different comparing PoC- and central lab-driven transfusion algorithms in subjects that underwent high-risk cardiac surgery. Routine PoC coagulation diagnostics do not seem to be beneficial when actual blood loss is low. High risk procedures might not suffice as a sole risk factor for increased blood loss.

Trial registration

NCT01402739, Date of registration July 26, 2011.

Patient blood management in cardiac surgery: The "Granducato algorithm"

BACKGROUND

Patients undergoing cardiac surgery are subject to severe alterations of the coagulation system. The four cardiac surgery centers in Tuscany (Italy) structured and shared an algorithm (Granducato Patient Blood Management algorithm, G-PBMa) with predefined interventions for patient blood management. The aim of the study is to analyze the impact of that algorithm on the transfusion needs and bleeding-related outcomes in a large patient population.

METHODS

Multicenter retrospective observational study on 3839 patients undergoing cardiac surgery at the four cardiac centers in Tuscany. The G-PBMa was released at the end of 2015 and it was structured in three parts: pre-, intra-, and post-operative. The year 2014, before the G-PBMa (1955 patients) and the year 2016 (1884 patients) after the G-PBMa in place were compared. Logistic regression analyses were used.

RESULTS

The main changes introduced were the routine application of viscoelastic tests in bleeding patients (+72%) and the use of fibrinogen and prothrombin complex concentrate (+67%). The G-PBMa resulted in a significant reduction in the overall transfusion rate and in the transfusion rate of the separate blood products (relative risk for transfusions: 0.75, 95% confidence interval 0.65-0.85, P = 0.001). For preoperative hemoglobin values of between 8 and 10 g/dL, the absolute difference in RBC transfusion rate before and after the G-PBMa introduction ranged around 15%-17%. The G-PBMa introduction determined lower (P = 0.02) chest drain blood loss, lower (P = 0.001) postoperative acute kidney injury and shorter (P = 0.001) hospital stay.

CONCLUSIONS

The G-PBMa was effective in reducing blood loss, transfusion requirements, and resulted in a better outcome.

Prothrombin Complex Concentrate in Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Prothrombin complex concentrate (PCC) has recently emerged as an effective alternative to fresh frozen plasma (FFP) in treating excessive perioperative bleeding. This systematic review and meta-analysis evaluated the safety and efficacy of PCC administration as first-line treatment for coagulopathy after adult cardiac surgery.

METHODS

PubMed/MEDLINE, EMBASE, and the Cochrane Library were searched from inception to the end of March 2018 to identify eligible articles. Adult patients undergoing cardiac surgery and receiving perioperative PCC were compared with patients receiving FFP.

RESULTS

A total of 861 adult patients from four studies were retrieved. No randomized studies were identified. Pooled odds ratios (ORs) showed that the PCC cohort was associated with a significant reduction in the risk of RBC transfusion (OR, 2.22; 95% confidence interval [CI], 1.45 to 3.40) and units of RBC received (OR, 1.34; 95% CI, 0.78 to 1.90). No differences were observed between the groups for reexploration for bleeding (OR, 1.09; 95% CI, 0.66 to 1.82), chest drain output at 24 hours (OR, 66.36; 95% CI, -82.40 to 216.11), hospital mortality (OR, 0.94; 95% CI, 0.59 to 1.49), stroke (OR, 0.80; 95% CI, 0.41 to 1.56), and occurrence of acute kidney injury (OR, 0.80; 95% CI, 0.58 to 1.12). A trend toward increased risk of renal replacement therapy was observed in the PCC group (OR, 0.41; 95% CI, 0.16 to 1.02).

CONCLUSIONS

In patients with significant bleeding after cardiac surgery, PCC administration seems to be more effective than FFP in reducing perioperative blood transfusions. No additional risks of thromboembolic events or other adverse reactions were observed. Randomized controlled trials are needed to establish the safety of PCC in cardiac surgery definitively.

Perioperative point of care platelet function testing and postoperative blood loss in high-risk cardiac surgery patients

Postoperative coagulopathic bleeding is common in cardiac surgery and associated with increased morbidity and mortality. Platelet function is affected by multiple factors, including patient and procedural characteristics. Point-of-care (POC) multiple electrode aggregometry (MEA) can rapidly detect and quantify platelet dysfunction and could contribute to optimal patient blood management. In patients undergoing CABG and heart valve surgery platelet function was assessed using POC MEA at four different perioperative timepoints in response to stimulation with four specific receptor agonists (ADP, AA, COL, TRAP). Postoperative bleeding was recorded during 24 h after surgery. Regression analyses were performed to establish associations between perioperative platelet function and postoperative blood loss. Ninety-nine patients were included in the study. Fifty-nine patients (60%) were on antiplatelet therapy (APT) at time of surgery. ADP- and AA-induced platelet aggregation declined during CPB and after decannulation from CPB, with a maximum decrease of 55% for ADP (35 vs. 77 AU at baseline; P < 0.001) and 78% for ASPI (14 vs. 64 AU at baseline; P < 0.001). A linear relationship was present between ADP-induced platelet aggregometry at baseline and postoperative blood loss (r = -0.249; P = 0.015). In aspirin users, the maximum decline in platelet function between baseline and CPB decannulation was related to postoperative blood loss (r = 0.308; P = 0.037). In multivariate analysis, a reduced ADP platelet function prior to surgery remained associated with postoperative blood loss (r = -0.239; P = 0.012). Reduced ADP-induced platelet aggregation at baseline is associated with increased postoperative blood loss in high-risk cardiac surgery patients.

An Audit of the Diagnostic Accuracy of Rotational Thromboelastometry for the Identification of Hypofibrinogenaemia and Thrombocytopenia during Cardiopulmonary Bypass

We audited the diagnostic accuracy of ROTEM® (TEM Innovations, GmbH, Munich, Germany) measurements of hypofibrinogenaemia (fibrinogen <1.5 g/l) and thrombocytopenia (platelet count <100 × 109/l) in 200 adult non-transplant patients during cardiopulmonary bypass (CPB). Blood samples were obtained for FIBTEM (assay for the fibrin part of the clot), PLTEM (calculated platelet-specific component), and laboratory measurements simultaneously. Our thresholds for FIBTEM and PLTEM were A10 (clot firmness 10 minutes after clotting time) ≤8 mm, and <35 mm respectively. We also calculated the accuracy of smaller thresholds and earlier indices. We found that FIBTEM A10 ≤8 mm had low sensitivity (0.62) for hypofibrinogenaemia. With the 13% hypofibrinogenaemia prevalence in our sample, the positive predictive value (PPV) was 0.47. In contrast, FIBTEM A10 ≤8 mm had higher specificity (0.90) (negative predictive value [NPV] 0.94). Of the other FIBTEM values analysed, only A5 ≤6 mm had similar or superior accuracy. The PLTEM results were less encouraging (sensitivity 0.81, specificity 0.62). With our prevalence of thrombocytopenia (also 13%), the PPV was only 0.24. However, the NPV was high (0.96). Of the other PLTEM values analysed, only A5 <25 mm had similar or superior accuracy. These findings indicate that during CPB FIBTEM A10 ≤8 mm and PLTEM A10 <35 mm have greater accuracy in identifying the absence of hypofibrinogenaemia and thrombocytopenia respectively than their presence. On the basis of these results we would be reassured by FIBTEM A10 values >8 mm and PLTEM A10 values ≥35 mm, but would continue to use laboratory measurements for confirmation. We would not use FIBTEM A10 ≤8 mm or PLTEM A10 <35 mm values alone to guide replacement therapy unless clinical conditions warranted an immediate decision before laboratory measurements were available.

Platelet function after cardiac surgery and its association with severe postoperative bleeding: the PLATFORM study

Platelet dysfunction after cardiac surgery is a determinant of postoperative bleeding. The existing guidelines suggest the use of desmopressin and/or platelet concentrate transfusions in case of platelet dysfunction in bleeding patients, but no cut-off values for platelet activity exist in the literature. The Platelet Function in the Operating Room (PLATFORM) study aims to identify the relationship between platelet function after cardiopulmonary bypass and severe bleeding, finding adequate predictive values of platelet function for severe bleeding. The PLATFORM is a prospective cohort study on 490 adult patients receiving cardiac surgery with cardiopulmonary bypass. Patients received platelet function tests (multiple electrode aggregometry ADPtest and TRAPtest) before surgery and after cardiopulmonary bypass, and routine coagulation tests before surgery and at the arrival in the intensive care unit. The post-cardiopulmonary bypass ADPtest and TRAPtest were significantly (P = 0.001) associated with severe bleeding, as well as the post-cardiopulmonary bypass activated partial thromboplastin time, the international normalized ratio, and the fibrinogen concentration. At a multivariable analysis, the ADPtest (odds ratio 0.962, 95% confidence interval 0.936-0.989, P = 0.005) and the activated partial thromboplastin time (odds ratio 1.097, 95% confidence interval 1.016-1.185, P = 0.017) remained independently associated with severe bleeding. The post-cardiopulmonary bypass ADPtest had the best discrimination, with an area under the curve of 0.712. The best positive predictive value (42%) was found at a cut-off ≤8 U. In conclusion, platelet function tests after cardiopulmonary bypass are significantly associated with postoperative bleeding. However, postoperative bleeding has a multifactorial nature, and the measure of platelet function alone does not provide a high positive predictive value for severe bleeding.

Heparin dose calculated according to lean body weight during on-pump heart surgery

Background

The aim of this study is to compare heparin dose regimen calculated based on the lean body weight with traditional heparin regimen in terms of ensuring adequate anticoagulation and complications associated with perioperative bleeding.

Methods

This prospective, single-blind, randomized study included a total of 100 adult patients (42 males, 58 females; mean age 52.7 years; range, 22 to 84 years) undergoing elective valve surgery with cardiopulmonary bypass between June 2016 and January 2017. Prior to cardiopulmonary bypass, heparin dose was adjusted as 4 mg/kg, according to the actual body weight (n=50) and lean body weight (n=50). The minimal activated clotting time target value was accepted as 480 sec for cardiopulmonary bypass initiation. Demographic and hemodynamic data, post-heparin activated clotting time, additional heparin and perioperative transfusion, postoperative drainage volumes, reoperations, and mortality were recorded.

Results

Demographic data, cross-clamp and cardiopulmonary bypass times, and intraoperative transfusion requirement were not significantly different between the groups. The initial and total doses of heparin, as well as the total dose of protamine, were significantly higher in the actual body weight group. Postoperative transfusion rates were also higher in this group. None of the patients in the lean body weight group required reoperation, while three patients in the actual body weight group underwent reoperation.

Conclusion

Our study results showed that adequate anticoagulation was achieved with the titration of heparin dose calculated according to the lean body weight during cardiopulmonary bypass and reduced total heparin and protamine doses decreased postoperative bleeding and blood product transfusion requirement.