Intraoperative cell salvage is associated with reduced postoperative blood loss and transfusion requirements in cardiac surgery: a cohort study

Cardiac Surgical Bleeding, Transfusion, and Quality Metrics: Joint Consensus Statement by the Enhanced Recovery After Surgery Cardiac Society and Society for the Advancement of Patient Blood Management

BACKGROUND

Excessive perioperative bleeding is associated with major complications in cardiac surgery, resulting in increased morbidity, mortality, and cost.

METHODS

An international expert panel was convened to develop consensus statements on the control of bleeding and management of transfusion and to suggest key quality metrics for cardiac surgical bleeding. The panel reviewed relevant literature from the previous 10 years and used a modified RAND Delphi methodology to achieve consensus.

RESULTS

The panel developed 30 consensus statements in 8 categories, including prioritizing control of bleeding, prechest closure checklists, and the need for additional quality indicators beyond reexploration rate, such as time to reexploration. Consensus was also reached on the need for a universal definition of excessive bleeding, the use of antifibrinolytics, optimal cessation of antithrombotic agents, and preoperative risk scoring based on patient and procedural factors to identify those at greatest risk of excessive bleeding. Furthermore, an objective bleeding scale is needed based on the volume and rapidity of blood loss accompanied by viscoelastic management algorithms and standardized, patient-centered blood management strategies reflecting an interdisciplinary approach to quality improvement.

CONCLUSIONS

Prioritizing the timely control and management of bleeding is essential to improving patient outcomes in cardiac surgery. To this end, a cardiac surgical bleeding quality metric that is more comprehensive than reexploration rate alone is needed. Similarly, interdisciplinary quality initiatives that seek to implement enhanced quality indicators will likely lead to improved patient care and outcomes.

Evaluation of Red Blood Cell Biochemical Markers and Coagulation Profiles Following Cell Salvage in Cardiac Surgery: A Systematic Review and Meta-Analysis

Background: Individuals undergoing cardiac surgery face an increased risk of bleeding, as well as alterations in biochemical and coagulation patterns. Therefore, assessing the effectiveness of systems such as Cell Salvage is necessary to prevent potential surgical complications. Objective: To evaluate the efficacy of Cell Salvage in relation to the biochemical parameters of the red blood series and coagulation, as well as the risk of hemorrhage. Methods: A systematic review, accompanied by a meta-analysis, was executed via an extensive literature exploration encompassing Medline, CINAHL, Scopus, Web of Science, and the Cochrane Library. The inclusion criteria comprised studies in English or Spanish, without year restrictions, conducted in adults and with a randomized controlled trial design. Results: Twenty-six studies were included in the systematic review, involving a total of 2850 patients (experimental group = 1415; control group = 1435). Cell Salvage did not demonstrate superior outcomes compared to allogeneic transfusions in the management of post-surgical hemorrhage, as well as in total blood loss, platelet count, fresh frozen plasma, and fibrinogen. However, Cell Salvage showed a greater effectiveness for hemoglobin (moderate evidence), hematocrit (low evidence), post intervention D-dimer (low evidence), and some coagulation-related parameters (low evidence) compared to allogeneic transfusions. Finally, better results were found in the control group for INR parameters. Conclusions: The use of the Cell Salvage system holds high potential to improve the postoperative levels of biochemical and coagulation parameters. However, the results do not provide definitive evidence regarding its effectiveness for hemorrhage control, platelet count, fresh frozen plasma, and fibrinogen. Therefore, it is recommended to increase the number of studies to assess the impact of the Cell Salvage system on improvements in the red blood cell count and patient coagulation patterns. In addition, protocols should be homogenized, and variables such as the sex of the participants should be taken into account.

The effectiveness of cell salvage in extracorporeal circulation surgeries in relation to use of health resources after use: A systematic review and meta-analysis

Background

Alternatives to allogeneic blood transfusions are sought for resource management reasons and it is necessary to investigate the efficiency and efficacy on Cell Salvage use. The objective of this study is to analyze the effectiveness of the Cell Salvage system in addressing factors related to healthcare service utilization that may lead to increased healthcare expenditure.

Methods

A systematic review with meta-analysis was conducted through literature search in Medline, CINAHL, Scopus, Web of Science, and Cochrane Library. Inclusion criteria were studies in English/Spanish, without year restriction and Randomized Controlled Trials design, conducted in adults.

Results

Twenty-six studies were included in the systematic review, involving a total of 4781 patients (nexperimental group = 2365; ncontrol group = 2416). Significant differences favored the Cell Salvage system in units of transfused Red Blood Cells, in terms of units (p = 0.04; SMD = -0.42 95 % CI = -0.83 to -0.02) and individuals (p = 0.001; RR = 0.71, 95 % CI = 0.60 to 0.84) transfused. No significant differences were found in ICU (p = 0.93) and hospital stay duration (p = 0.21), number of reoperations (p = 0.68), and number of units and individuals transfused in terms of platelets (p > 0.05).

Conclusions

Cell Salvage use holds high potential for reducing healthcare costs and indirectly contributing to improving blood and blood product reserves within blood banks. Results obtained thus far do not provide definitive evidence regarding the duration of hospital stay, ICU stay, need for reoperation, or the quantity of transfused platelets. Therefore, it is recommended to increase the number of studies to assess the impact on the economic models of the Cell Salvage system.

Association between intraoperative blood salvage and coagulation disorder after cardiopulmonary bypass

BACKGROUND

This study investigated whether intraoperative blood salvage was associated with coagulation disorder diagnosed by conventional coagulation tests and thromboelastography (TEG) after cardiopulmonary bypass (CPB).

STUDY DESIGN AND METHODS

This was a prospective, observational study. Ninety-two patients who underwent cardiovascular surgery with CPB were enrolled. We evaluated coagulation function in patients with or without cell salvage blood transfusion at the following time points: before CPB, just after protamine administration, and 1 h after protamine administration. We evaluated platelet count, fibrinogen concentration, and TEG parameters. Patients were considered to have coagulation disorder if one or more of the following criteria were present: (1) residual heparin, (2) low platelet count, (3) low fibrinogen level, (4) low clotting factor level, and (5) hyperfibrinolysis.

RESULTS

Fifty-three of 92 patients (57.6%) received intraoperative cell salvage. Coagulation disorder was observed in 56 of 92 patients (60.9%) after CPB. There was no significant difference between patients with or without intraoperative blood salvage in terms of the incidence of coagulation disorder (p = 0.542) or the total volume of blood from the drain after CPB (p = 0.437). Intraoperative blood salvage was not associated with coagulation disorder diagnosed by either TEG or conventional coagulation tests (odds ratio 1.329, 95% confidence interval: 0.549-3.213, p = 0.547). There were no significant interactions between patients with or without intraoperative blood salvage regarding coagulation parameters derived from TEG.

CONCLUSIONS

The incidence of coagulation disorder and the total blood volume from the drain after CPB did not differ significantly between patients with or without intraoperative blood salvage.

Clinical efficacy of intraoperative Cell Saver autologous blood salvage in emergency surgery for massive hemothorax

The objective of this study was to investigate the efficacy of intraoperative Cell Saver blood salvage during emergency surgery for massive hemothorax on minimizing perioperative allogeneic red blood cell (RBC) transfusion. Fourteen consecutive patients of massive hemothorax with more than 800 cc of intrathoracic bleeding estimated by chest X-ray and/or chest computed tomography (CT) scan at presentation between 2009 and 2021 were retrospectively reviewed. Intraoperative Cell Saver blood salvage was performed in 11 patients (Cell Saver group) with a median volume of 820 cc (range, 421-1700 cc). The amount of perioperative allogeneic RBC transfusion in the Cell Saver group (median, 4 units) was significantly smaller than that in the non-Cell Saver group (median, 10 units) (P = 0.009). The volume of Cell Saver autologous transfusion in 6 patients without preoperative chest tube drainage (median, 1114 cc) was significantly larger than that in 5 patients who had preoperative drainage (median, 660 cc) (P = 0.0173). In conclusion, the utilization of intraoperative blood salvage in emergency surgery for massive hemothorax along with limiting the amount of preoperative chest tube drainage is an efficient strategy to minimize perioperative allogeneic RBC transfusion.

Intraoperative use of cell saver devices decreases the rate of hyperlactatemia in patients undergoing cardiac surgery

Objective

This study was aimed to elucidate the effect of the intraoperative cell saver (CS) on hyperlactatemia of patients who underwent cardiac surgery.

Design

A sub-analysis of the CS was performed, which is a historial control trial of patients undergoing cardiac surgery.

Setting

This was a retrospective single-center and not blinded study.

Participants

We examined the occurrence of hyperlactatemia retrospectively in patients of CS group (n = 78) who were included in prospective trial and received valvular surgery, where CS was used during the procedure. Patients subjected to valvular surgery before February 2021 were adopted in control group (n = 79).

Interventions

Arterial blood was sampled (1) before cardiopulmonary bypass, (2) during bypass (3) immediately after bypass, (4) on ICU admission and (5) every 4 h up to 24 h postoperatively.

Measurements and main results

A lower incidence of hyperlactatemia (32.1% vs. 57.0%; P = 0.001) was observed in patients from the CS group. Furthermore, the blood lactate concentration was higher in control group than in CS group during CPB, post CPB, on ICU admission and lasted until 20 h after the operation. Multivariable analysis revealed that intraoperative use of CS was expected to be a protective factor against hyperlactatemia in this study (OR = 0.31, 95% CI 0.15-0.63, P = 0.001).

Conclusion

Intraoperative use of a CS device was associated with a lower incidence of hyperlactatemia. Whether such device use is valuable to limiting hyperlactatemia in cardiac patients after surgery requires further evaluation in larger prospective studies.

Patient Blood Management in adults and children: what have we achieved, and what still needs to be addressed?

An overview of Patient Blood Management (PBM), with its main scope to preserve the patient's own blood to improve the patient's outcome, is presented here, including the research gaps that needs to be addressed, particularly in the pediatric age group. Next, novel techniques to analyse PBM data and the challenges and strategies of PBM implementation will also be discussed.

Perioperative Tracking of Intravenous Iron in Patients Undergoing On-Pump Cardiac Surgery: A Prospective, Single-Center Pilot Trial

BACKGROUND

Preoperative intravenous iron administration is a frequently used patient blood management procedure. If the timeframe of intravenous iron administration before surgery is short, (1) the concentration of the intravenous iron compound might still be high in patients' plasma when undergoing surgery and (2) this iron in patients' plasma is at risk to be lost due to blood loss. The aim of the current study was, therefore, to track the iron compound ferric carboxymaltose (FCM) before, during, and after cardiac surgery requiring cardiopulmonary bypass, with an emphasis on intraoperative iron losses in shed blood and potential recovery through autologous cell salvage.

METHODS

Concentrations of FCM were analyzed in patients' blood using a hyphenation of liquid chromatography and inductively coupled plasma-mass spectrometry to distinguish between pharmaceutical compound FCM and serum iron. In this prospective, single-center pilot trial, 13 anemic and 10 control patients were included. Anemic patients with hemoglobin levels ≤12/13 g/dL in women and men were treated with 500 milligrams (mg) intravenous FCM 12 to 96 hours before elective on-pump cardiac surgery. Patients' blood samples were collected before surgery and at days 0, 1, 3, and 7 after surgery. One sample each was taken of the cardiopulmonary bypass, the autologous red blood cell concentrate generated by cell salvage, and the cell salvage disposal bag.

RESULTS

Patients who had received FCM <48 hours before surgery had higher FCM serum levels (median [Q1-Q3], 52.9 [13.0-91.6]) compared to ≥48 hours (2.1 [0.7-5.1] µg/mL, P = .008). Of 500-mg FCM administered <48 hours, 327.37 (257.96-402.48) mg were incorporated compared to administration ≥48 hours with 493.60 (487.78-496.70) mg. After surgery, patients' plasma FCM concentration in the FCM <48 hours group was decreased (-27.1 [-30 to -5.9] µg/mL). Little FCM was found in the cell salvage disposal bag (<48 hours, 4.2 [3.0-25.8] µg/mL, equivalent to 29.0 [19.0-40.7] mg total; equivalent to 5.8% or 1/17th of the 500 mg FCM initially administered), almost none in the autologous red blood cell concentrate (<48 hours, 0.1 [0.0-0.43] µg/mL).

CONCLUSIONS

The data generate the hypotheses that nearly all FCM is incorporated into iron stores with administration ≥48 hours before surgery. When FCM is given <48 hours of surgery, the majority is incorporated into iron stores by the time of surgery, although a small amount may be lost during surgical bleeding with limited recovery by cell salvage.

Risk factors associated with positive bacterial culture in salvaged red blood cells during cardiac surgery and postoperative infection incidence: A prospective cohort study

Background

This study was designed to explore factors associated with the incidence of positive bacterial culture of salvaged red blood cells (sRBCs) recovered with a Cell Saver instrument during cardiac surgery and the impact of such positive outcomes on postoperative infection-related morbidity.

Methods

The cohort study enrolled 204 patients scheduled for cardiac surgery with intraoperative blood cell salvage and retransfusion from July 2021 to July 2022. These patients were stratified into two groups based on intraoperative sRBCs bacterial culture results: culture (+) and culture (-) groups. Preoperative and intraoperative variables were compared between these groups aim to detect possible predictors of positive culture in sRBCs. In addition, differences in postoperative infection-related morbidity and other clinical outcomes were compared between these groups.

Results

Of these patients, 49% were sRBCs culture (+), with Staphylococcus epidermidis as the most commonly identified pathogen. Risk factors independently associated with the risk of positive culture in sRBCs included BMI ≥25 kg/m², a history of smoking, an operative duration ≥277.5 min, the higher number of staff in the operating room and higher surgical case order. Patients in the sRBCs culture (+) group exhibited a longer average ICU stay [3.5 days (2.0-6.0) vs. 2 days (1.0-4.0), P < 0.01], a longer duration of ventilation [20.45 h (12.0-17.8) vs. 13 h (11.0-17.0, P = 0.02)], underwent more allogeneic blood transfusions, exhibited higher transfusion-related costs [2,962 (1,683.0-5,608.8) vs. 2,525 (1,532.3-3,595.0), P = 0.01], and had higher rates of postoperative infections (22 vs. 9.6%, P = 0.02) as compared to patients in the sRBCs culture (-) group. In addition, culture (+) in sRBCs was an independent risk factor for postoperative infection (OR 2.62, 95% CI 1.16-5.90, P = 0.02).

Conclusion

Staphylococcus epidermidis was the most common pathogen detected in sRBCs in the culture (+) group in this study, identifying it as a potential driver of postoperative infection. Positive sRBCs culture may contribute to postoperative infection and its incidence was significantly associated with patient BMI, history of smoking, operative duration, the number of staff in the operating room and surgical case order.

Plasma rocuronium concentration in cell salvage blood following cardiac surgery: a case series

PURPOSE

The aim of the study was to evaluate the plasma rocuronium concentration in autologous blood transfusion obtained from the cell salvage (CS) system following cardiac surgery with cardiopulmonary bypass (CPB).

METHODS

This prospective observational study was conducted in a university teaching hospital from July to November 2020. Patients undergoing general anesthesia for cardiac surgery with CPB were enrolled in the study. After separation from CPB, residual blood remaining in the extracorporeal system was collected as the control sample. The second sample (CS blood) was collected from the autologous blood transfusion obtained after completion of the CS system with Cell Saver® Elite®. Hematocrit values of both samples were also examined.

RESULTS

Ten subjects (aged 57-86 years) were enrolled in this study. Plasma rocuronium concentrations (ng/ml) were significantly lower in the CS blood (94.0 ± 77.5) compared to the control (2950 ± 812.2) (p = 0.002). Hematocrit values (%) were significantly higher in the CS blood (75.2 ± 11.3) compared to the control (40.2 ± 10.2) (p = 0.002).

CONCLUSION

Autologous blood transfusion obtained from CS system following cardiac surgery with CPB, only retained a small amount of plasma rocuronium concentration, therefore, the risk of autologous blood transfusion contributing to clinically relevant residual neuromuscular blockade postoperatively should be considered to be low.

TRIAL REGISTRATION

This trial was registered in the University Hospital Medical Information Network under registration number UMIN000040877 (registration date; June 24, 2020).

Quality Management of a Comprehensive Blood Conservation Program During Cardiopulmonary Bypass

BACKGROUND

Red blood cell transfusion is common and associated with adverse outcomes for cardiac surgery, while present blood conservation guidelines have not been fully implemented until now. This study aims to evaluate our comprehensive blood conservation program after quality management, exploring its impact on blood transfusion and outcomes in patients undergoing cardiopulmonary bypass (CPB).

METHODS

We retrospectively compared blood transfusions and outcomes of patients from two different time periods, before and after the quality management of the comprehensive blood conservation program. The comprehensive program included restrictive transfusion protocols, conventional ultrafiltration, cell salvage, residual pump blood ultrafiltration and a modified mini-extracorporeal circulation system. A 1:1 propensity score matching and subgroup analysis were conducted.

RESULTS

3977 pairs were created, a significant decrease of red cell transfusion was observed during CPB (28.4% vs 18.6%, p＜.001), in the operation (40.7% vs 34.3%, p＜.001 ) and after the operation (6.2% vs 4.3%, p＜.001). 30-day mortality and some major complications also reduced. Subgroup analysis showed that the comprehensive blood conservation program was more beneficial for the following patients: above 60, male and the medium-risk European System for Cardiac Operative Risk Evaluation (EuroSCORE) of score 3-5.

CONCLUSIONS

The comprehensive blood conservation program during CPB is safe and effective in adult cardiac surgery, reducing blood utilization with no adverse outcomes. For the patients who are older, male and EuroSCORE 3-5, blood transfusion should be more cautious.

Efficacy and cost-effectiveness of cell saver usage in the repair of thoracic aortic aneurysms and dissections

INTRODUCTION

A substantial amount of blood loss occurs during the open repair of aortic aneurysms or dissections. The aim of the present study is to determine the efficacy and cost-effectiveness of cell saver devices in blood conservation during the open repair of thoracic aortic pathologies.

METHODS

The present study prospectively collected the data pertaining to 25 patients who underwent surgical management of thoracic aortic aneurysms or dissections using a cell saver (Group 1, n = 25). The volume and cost of transfusion and postoperative outcomes were compared with the second group of patients who underwent surgery without the use of cell savers in the previous year (Group 2, n = 25); the data pertaining to the same were retrospectively collected from the hospital records. The patient characteristics and categorical variables were compared using the x² test and Fisher's exact test. Transfusion volume and costs were compared using the independent samples t-test and Mann-Whitney U test.

RESULTS

The patients in both the groups displayed similar characteristics and risk factors. The total volume of allogenic red blood cell (p < 0.001) and total blood product (p = 0.01) transfusions were significantly lower in Group 1. The cost of red blood cell (p < 0.001) and total transfusions (p = 0.03) were lower in Group 1. The two groups displayed similar in-hospital morbidity and mortality rates.

CONCLUSIONS

There was a significant association between the use of cell savers and the decreased need for red blood cell and total blood product transfusions. Considering the cost of the cell saver set, transfusion costs in the two groups were comparable.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

An In Vitro Pilot Study Comparing the Novel HemoClear Gravity-Driven Microfiltration Cell Salvage System with the Conventional Centrifugal XTRA™ Autotransfusion Device

BACKGROUND

In 2013, the World Health Organization reported a shortage of 17 million red blood cell units, a number that remains growing. Acts to relieve this shortage have primarily focused on allogeneic blood collection. Nevertheless, autologous transfusion can partially alleviate the current pressure and dependence on blood banking systems. To achieve this, current gold standard autotransfusion devices should be complemented with widely available, cost-efficient, and time-efficient devices. The novel HemoClear cell salvage device (HemoClear BV, Zwolle, Netherlands), a gravity-driven microfilter, potentially is widely employable. We evaluated its performance in the cardiac postoperative setting compared to the centrifugal XTRA™ autotransfusion device.

METHODS

In a split-unit study (n = 18), shed blood collected 18 hours after cardiothoracic surgery was divided into two equal volumes. One-half was processed by the XTRA™ device and the other with the HemoClear blood separation system. In this paired set-up, equal washing volumes were used for both methods. Washing effectivity and cellular recovery were determined by measuring of complete blood count, free hemoglobin, complement C3, complement C4, and D-dimer in both concentrate as filtrate. Also, processing times and volumes were evaluated.

RESULTS

The HemoClear and XTRA™ devices showed equal effectiveness in concentrating erythrocytes and leucocytes. Both methods reduced complement C3, complement C4, and D-dimer by ≥90%. The centrifugal device reduced solutes more significantly by up to 99%. Free hemoglobin load was reduced to 12.9% and 15.5% by the XTRA™ and HemoClear, respectively.

CONCLUSION

The HemoClear device effectively produced washed concentrated red blood cells comparably to the conventional centrifugal XTRA™ autotransfusion device. Although the centrifugal XTRA™ device achieved a significantly higher reduction in contaminants, the HemoClear device achieved acceptable blood quality and seems promising in settings where gold standard cell savers are unaffordable or unpractical.

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams.

Optimizing surgical management of patients who decline blood transfusion

PURPOSE OF REVIEW

This review highlights the complexity of caring for gynecologic patients who refuse blood transfusion and discusses the importance of early, targeted perioperative and intraoperative medical optimization. We review alternative interventions and the importance of medical management to minimize blood loss and maximize hematopoiesis, particularly in gynecologic patients who may have significant uterine bleeding. The review also focuses on intraoperative interventions and surgical techniques to prevent and control surgical blood loss.

RECENT FINDINGS

With improvements in surgical technique, greater availability of minimally invasive surgery, and increased use of preop UAE and cell salvage, definitive surgical management can be safely performed. New technologies have been developed that allow for safer surgeries or alternatives to traditional surgical procedures. Many medical therapies have been shown to decrease blood loss and improve surgical outcomes. Nonsurgical interventions have also been developed for use as adjuncts or alternatives to surgery.

SUMMARY

The care of a patient who declines blood transfusion may be complex, but gynecologic surgeons can safely and successfully offer a wide variety of therapies depending on the patient's goals and needs. Medical management should be implemented early. A multidisciplinary team should be mobilized to provide comprehensive and patient-centered care.

Microcirculatory perfusion disturbances following cardiac surgery with cardiopulmonary bypass are associated with in vitro endothelial hyperpermeability and increased angiopoietin-2 levels

Background

Endothelial hyperpermeability following cardiopulmonary bypass (CPB) contributes to microcirculatory perfusion disturbances and postoperative complications after cardiac surgery. We investigated the postoperative course of renal and pulmonary endothelial barrier function and the association with microcirculatory perfusion and angiopoietin-2 levels in patients after CPB.

Methods

Clinical data, sublingual microcirculatory data, and plasma samples were collected from patients undergoing coronary artery bypass graft surgery with CPB (n = 17) before and at several time points up to 72 h after CPB. Renal and pulmonary microvascular endothelial cells were incubated with patient plasma, and in vitro endothelial barrier function was assessed using electric cell–substrate impedance sensing. Plasma levels of angiopoietin-1,-2, and soluble Tie2 were measured, and the association with in vitro endothelial barrier function and in vivo microcirculatory perfusion was determined.

Results

A plasma-induced reduction of renal and pulmonary endothelial barrier function was observed in all samples taken within the first three postoperative days (P < 0.001 for all time points vs. pre-CPB). Angiopoietin-2 and soluble Tie2 levels increased within 72 h after CPB (5.7 ± 4.4 vs. 1.7 ± 0.4 ng/ml, P < 0.0001; 16.3 ± 4.7 vs. 11.9 ± 1.9 ng/ml, P = 0.018, vs. pre-CPB), whereas angiopoietin-1 remained stable. Interestingly, reduced in vitro renal and pulmonary endothelial barrier moderately correlated with reduced in vivo microcirculatory perfusion after CPB (r = 0.47, P = 0.005; r = 0.79, P < 0.001). In addition, increased angiopoietin-2 levels moderately correlated with reduced in vitro renal and pulmonary endothelial barrier (r = − 0.46, P < 0.001; r = − 0.40, P = 0.005) and reduced in vivo microcirculatory perfusion (r = − 0.43, P = 0.01; r = − 0.41, P = 0.03).

Conclusions

CPB is associated with an impairment of in vitro endothelial barrier function that continues in the first postoperative days and correlates with reduced postoperative microcirculatory perfusion and increased circulating angiopoietin-2 levels. These results suggest that angiopoietin-2 is a biomarker for postoperative endothelial hyperpermeability, which may contribute to delayed recovery of microcirculatory perfusion after CPB.

Trial registration

NTR4212.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2418-5) contains supplementary material, which is available to authorized users.

[Cell salvage : Scientific evidence, clinical practice and legal framework]

Cell salvage is an efficient method to reduce the transfusion of homologous banked blood, as documented by several meta-analyses detected in a systematic literature search. Cell salvage is widely used in orthopedics, trauma surgery, cardiovascular and abdominal transplantation surgery. The retransfusion of unwashed shed blood from wounds or drainage is not permitted according to German regulations. Following irradiation of wound blood, salvaged blood can also be used in tumor surgery. Cell salvage makes a valuable contribution to providing sufficient compatible blood for transfusions in cases of massive blood loss. Certain surgical procedures for Jehovah's Witnesses are only possible with the use of cell salvage. Another possible use is the washing of homologous banked blood, e. g. to prevent potassium-induced arrhythmia or sequestration of autologous platelets. Other advantages besides a good compatibility are the high vitality and functionality of the unstored autologous red blood cells. These have been declared a pharmaceutical product by the German transfusion task force in 2014, so that the autologous red blood cells are now under the control of the Pharmaceutical Products Act (AMG). The new hemotherapy guidelines, however, tolerate cell salvage only under strict rules, whereby the production of autologous blood during or after surgery is still possible without additional special permits. The new guidelines now require the introduction of a quality management system for cell salvage and regular quality controls. These quality controls include a control of the product hematocrit for every application, monthly controls of the protein and albumin elimination rates and the erythrocyte recovery rate for each cell salvage device. Testing for infection markers is not required. The application of cell salvage has to be reported to the appropriate authorities.

Postoperative microcirculatory perfusion and endothelial glycocalyx shedding following cardiac surgery with cardiopulmonary bypass

We investigated microcirculatory perfusion disturbances following cardiopulmonary bypass in the early postoperative period and whether the course of these disturbances mirrored restoration of endothelial glycocalyx integrity. We performed sublingual sidestream dark field imaging of the microcirculation during the first three postoperative days in patients who had undergone on‐pump coronary artery bypass graft surgery. We calculated the perfused vessel density, proportion of perfused vessels and perfused boundary region. Plasma was obtained to measure heparan sulphate and syndecan‐1 levels as glycocalyx shedding markers. We recruited 17 patients; the mean (SD) duration of non‐pulsatile cardiopulmonary bypass was 103 (18) min, following which 491 (29) ml autologous blood was transfused through cell salvage. Cardiopulmonary bypass immediately decreased both microcirculatory perfused vessel density; 11 (3) vs. 16 (4) mm.mm⁻², p = 0.052 and the proportion of perfused vessels; 92 (5) vs. 69 (9) %, p < 0.0001. The proportion of perfused vessels did not increase after transfusion of autologous salvaged blood following cardiopulmonary bypass; 72 (7) %, p = 0.19 or during the first three postoperative days; 71 (5) %, p < 0.0001. The perfused boundary region increased after cardiopulmonary bypass; 2.2 (0.3) vs. 1.9 (0.3) μm, p = 0.037 and during the first three postoperative days; 2.4 (0.3) vs. 1.9 (0.3) μm, p = 0.003. Increased plasma heparan sulphate levels were inversely associated with the proportion of perfused vessels during cardiopulmonary bypass; R = −0.49, p = 0.02. Plasma syndecan‐1 levels were inversely associated with the proportion of perfused vessels during the entire study period; R = −0.51, p < 0.0001. Our study shows that cardiopulmonary bypass‐induced acute microcirculatory perfusion disturbances persist in the first three postoperative days, and are associated with prolonged endothelial glycocalyx shedding. This suggests prolonged impairment and delayed recovery of both microcirculatory perfusion and function after on‐pump cardiac surgery.

Additional filtering of blood from a cell salvage device is not likely to show important additional benefits in outcome in cardiac surgery

BACKGROUND

Several authors and manufacturers of cell salvage devices recommend additional filtering of processed blood before transfusion. There is no evidence to support this practice. Therefore, we compared the clinical outcome and biochemical effects of cell salvage with or without additional filtering.

STUDY DESIGN AND METHODS

The patients, scheduled for coronary artery bypass grafting, valve replacement, or combined procedures were part of our randomized multicenter factorial study of cell salvage and filter use on transfusion requirements (ISRCTN 58333401). They were randomized to intraoperative cell salvage or cell salvage plus additional WBC depletion filter. We compared the occurrence of major adverse events (combined death/stroke/myocardial infarction) as primary outcome and minor adverse events (renal function disturbances, infections, delirium), ventilation time, and length of stay in the intensive care unit and hospital. We also measured biochemical markers of organ injury and inflammation.

RESULTS

One hundred eighty-nine patients had cell salvage, and 175 patients had cell salvage plus filter and completed the study. Demographic data, surgical procedures, and amount of salvaged blood were not different between the groups. There was no difference in the primary outcome with a risk of 6.3% (95% confidence interval [CI], 3.34-11.25) in the cell salvage plus filter group versus 5.8% (95% CI, 3.09-10.45) in the cell salvage group, a relative risk of 1.08 (95% CI, 0.48- 2.43]. There were no differences in minor adverse events and biochemical markers between the groups.

CONCLUSION

The routine use of an additional filter for transfusion of salvaged blood is unlikely to show important additional benefits.

Safety, efficacy, and cost-effectiveness of intraoperative blood salvage in OPCABG with different amount of bleeding: a single-center, retrospective study

Background

We sought to evaluate the safety, efficacy, and cost-effectiveness of intraoperative blood salvage (IBS) in off-pump coronary artery bypass grafting (OPCABG) surgery with different amount of bleeding.

Methods

We retrospectively reviewed the medical records of 321 patients who underwent OPCABG between December 2012 and December 2016 at our hospital. Patients treated with IBS or allogeneic blood (AB) transfusions were divided into three groups depending on the amount of bleeding respectively: IBS1 or AB1 group (400–600 ml); IBS2 or AB2 group (600–1000 ml); IBS3 or AB3 group (1000–1500 ml). The intraoperative and postoperative conditions, blood transfusion volume, clinical and hematological outcomes, and total blood transfusion cost were examined.

Results

The amount of allogeneic red blood cell (RBC) transfusion in the IBSs groups were significantly lower than that in the ABs groups (P < 0.01). Furthermore, drainage volume 24 h post-surgery (P < 0.05) and white blood cell count (WBC) 2 day post-surgery (P < 0.01) in IBS3 group were significantly higher compared with the AB3 group. Additionally, when IBS cost was 230 USD per set, the total blood transfusion cost in the IBSs groups was significantly higher than that in the ABs groups (P < 0.01); however, when 199 or 184 USD, only the IBS1 group, rather than IBS2 or IBS3, showed significantly higher cost of the total blood transfusion compared with the AB1 group (P < 0.05).

Conclusions

When the amount of bleeding was 600–1000 ml, IBS can significantly reduce the demand for allogeneic blood, and has no direct adverse effects on coagulation function and recuperation, and is cost-effective in OPCABG.

A red cell preservation strategy reduces postoperative transfusions in pediatric heart surgery patients

BACKGROUND

Blood transfusion has well-documented adverse effects. As part of a blood conservation initiative at our center, we began routine use of cell saver for all congenital heart surgery performed on cardiopulmonary bypass since 2014.

AIMS

This study aimed to compare transfusion rates prior to, and in the first and second year after this initiative. We hypothesized that cell saver use would decrease transfusion requirements in second year after use of the cell saver compared to the pre cell saver group.

METHODS

Consecutive patients under 18 years undergoing congenital heart surgery on cardiopulmonary bypass were retrospectively analyzed as 3 one-year cohorts defined above. We excluded patients who required mechanical support or reoperation at index admission. Baseline characteristics, and use of blood intraoperatively and postoperatively were compared between groups.

RESULTS

The 3 groups had similar baseline characteristics. Blood use was significantly lower in year 2 after cell saver initiation as compared to the pre cell saver group both intra- and postoperatively. The median difference in volume of intraoperative blood transfusion was lower by 138 mL/m² (-266, -10 mL/m² ) in year 2 when compared to the pre cell saver group. Similarly, the proportion of subjects requiring red blood cell transfusion postoperatively on day of surgery was lower by 10% (-15%, -6%).

CONCLUSION

Standardized use of cell saver significantly decreased perioperative blood use in children undergoing cardiac surgery at our center. A risk-adjusted transfusion threshold for children undergoing heart surgery needs to be developed to further decrease exposure to blood products and associated costs.

Prediction of severe bleeding after coronary surgery: the WILL-BLEED Risk Score

Severe perioperative bleeding after coronary artery bypass grafting (CABG) is associated with poor outcome. An additive score for prediction of severe bleeding was derived (n=2494) and validated (n=1250) in patients from the E-CABG registry. Severe bleeding was defined as E-CABG bleeding grades 2–3 (transfusion of >4 units of red blood cells or reoperation for bleeding). The overall incidence of severe bleeding was 6.4 %. Preoperative anaemia (3 points), female gender (2 points), eGFR <45 ml/min/1.73 m2 (3 points), potent antiplatelet drugs discontinued less than five days (2 points), critical preoperative state (5 points), acute coronary syndrome (2 points), use of low-molecular-weight heparin/fondaparinux/unfractionated heparin (1 point) were independent predictors of severe bleeding. The WILL-BLEED score was associated with increasing rates of severe bleeding in both the derivation and validation cohorts (scores 0–3: 2.9 % vs 3.4 %; scores 4–6: 6.8 % vs 7.5 %; scores>6: 24.6 % vs 24.2 %, both p<0.0001). The WILL-BLEED score had a better discriminatory ability (AUC 0.725) for prediction of severe bleeding compared to the ACTION (AUC 0.671), CRUSADE (AUC 0.642), Papworth (AUC 0.605), TRUST (AUC 0.660) and TRACK (AUC 0.640) bleeding scores. The net reclassification index and integrated discrimination improvement using the WILL-BLEED score as opposed to the other bleeding scores were significant (p<0.0001). The decision curve analysis demonstrated a net benefit with the WILL-BLEED score compared to the other bleeding scores. In conclusion, the WILL-BLEED risk score is a simple risk stratification method which allows the identification of patients at high risk of severe bleeding after CABG.

Clinical Trial Registration: NCT02319083 (https://clinicaltrials.gov/ct2/show/NCT02319083)

Efficacy of intraoperative cell salvage in decreasing perioperative blood transfusion rates in first-time cardiac surgery patients: a retrospective study

BACKGROUND

Evidence regarding the safety and efficacy of intraoperative cell salvage (ICS) in transfusion reduction during cardiac surgery remains conflicting. We sought to evaluate the impact of routine ICS on outcomes following cardiac surgery.

METHODS

We conducted a retrospective analysis of patients who underwent nonemergent, first-time cardiac surgery 18 months before and 18 months after the implementation of routine ICS. Perioperative transfusion rates, postoperative bleeding, clinical and hematological outcomes, and overall cost were examined. We used multivariable logistic regression modelling to determine the risk-adjusted effect of ICS on likelihood of perioperative transfusion.

RESULTS

A total of 389 patients formed the final study population (186 undergoing ICS and 203 controls). Patients undergoing ICS had significantly lower perioperative transfusion rates of packed red blood cells (pRBCs; 33.9% v. 45.3% p = 0.021), coagulation products (16.7% v. 32.5% p < 0.001) and any blood product (38.2% v. 52.7%, p = 0.004). Patients receiving ICS had decreased mediastinal drainage at 12 h (mean 320 [range 230-550] mL v. mean 400 [range 260-690] mL, p = 0.011) and increased postoperative hemoglobin (mean 104.7 ± 13.2 g/L v. 95.0 ± 11.9 g/L, p < 0.001). Following adjustment for other baseline and intraoperative covariates, ICS emerged as an independent predictor of lower perioperative transfusion rates of pRBCs (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.31-0.87), coagulation products (OR 0.41, 95% CI 0.24-0.71) and any blood product (OR 0.47, 95% CI 0.29-0.77). Additionally, ICS was associated with a cost benefit of $116 per patient.

CONCLUSION

Intraoperative cell salvage could represent a clinically cost-effective way of reducing transfusion rates in patients undergoing cardiac surgery. Further research on systematic ICS is required before recommending it for routine use.

Indications and Outcomes of Cell Saver in Adolescent Scoliosis Correction Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

The aim of this study was to determine the indications and outcomes for intraoperative cell salvage during adolescent scoliosis correction surgery by systematically reviewing all available evidence.

SUMMARY OF BACKGROUND DATA

Several blood conservation strategies exist to minimize the consequences of blood loss because of scoliosis correction surgery. The utility of intraoperative cell salvage has been contested in the literature with respect to benefits and cost. High-quality randomized control trials are needed to help surgeons make an informed decision about including Cell Saver into their practice.

METHODS

The databases Medline, Embase, Ovid Healthstar, and PubMed were searched for English language literature investigating Cell Saver use during adolescent scoliosis correction surgery, mean ages 10 to 19 years inclusively. Qualitative and quantitative findings from relevant studies are presented.

RESULTS

There were seven eligible studies that directly compared the use of Cell Saver (349 patients) against a Control (non-Cell Saver) group (244 patients). The majority of the demographic and hematologic data were consistent between both groups. The average volume of blood that was re-infused into patients in the Cell Saver group was 453.8 mL. Patients in the Cell Saver group received significantly fewer allogenic blood transfusions than the Control group, with 32.6% less intraoperatively, 45.9% less postoperatively, and 47.3% less perioperatively. On average, Cell Saver patients received 1.0 fewer unit of allogenic blood compared to the Control group patients.

CONCLUSION

Cell Saver reduces the demand for allogenic transfusion. This review supports the use of Cell Saver if the associated monetary costs are expected to be less than the cost of transfusing one unit of allogenic blood.

LEVEL OF EVIDENCE

4.

Oxygen carrying capacity of salvaged blood in patients undergoing off-pump coronary artery bypass grafting surgery: a prospective observational study

BACKGROUND

Intraoperative cell salvage (ICS), hereby referred to 'mechanical red cell salvage', has been widely used and proven to be an effective way to reduce or avoid the need for allogeneic red blood cells (RBCs)transfusion and its associated complications in surgeries involving major blood loss. However, little is known about the influence of this technique on the functional state of salvaged RBCs. Furthermore, there are no articles that describe the change of free hemoglobin (fHb) in salvage blood during storage, which is a key index of the quality control of salvaged blood. Therefore, in this study, the influence of ICS on the function of salvaged RBCs and the changes of salvaged RBCs during storage were studied with respect to the presence of oxyhemoglobin affinity (recorded as a P50 value) and the level of 2, 3-diphosphoglycerate (2, 3-DPG) and fHb by comparing salvaged RBCs with self-venous RBCs and 2-week-old packed RBCs.

METHODS

Fifteen patients undergoing off-pump coronary artery bypass grafting (OPCAB) surgery were enrolled. Blood was collected and processed using a Dideco Electa device. The level of P50, 2, 3-DPG and fHB from salvaged RBCs, venous RBCs and 2-week-old packed RBCs was measured. We also measured the changes of these indicators among salvaged RBCs at 4 h (storage at 21-24 °C) and at 24 h (storage at 1-6 °C).

RESULTS

The P50 value of salvaged RBCs at 0 h (28.77 ± 0.27 mmHg) was significantly higher than the value of venous RBCs (27.07 ± 0.23 mmHg, p=0.000) and the value of the 2-week-old packed RBCs (16.26 ± 0.62 mmHg, p=0.000). P50 value did not change obviously at 4 h (p=0.121) and 24 h (p=0.384) compared with the value at 0 h. The 2, 3-DPG value of salvaged RBCs at 0 h (17.94 ± 6.91 μmol/g Hb) was significantly higher than the value of venous RBCs (12.73 ± 6.52 mmHg, p = 0.007) and the value of the 2-week-old packed RBCs (2.62 ± 3.13 mmHg, p=0.000). The level of 2, 3-DPG slightly decreased at 4 h (p=0.380) and 24 h (p=0.425) compared with the value at 0 h. Percentage of hemolysis of the salvaged blood at 0 h(0.51 ± 0.27 %) was significantly higher than the level of venous blood (0.07 ± 0.05 %, p=0.000) and the value of 2-week-old packed RBCs (0.07 ± 0.05 %, p=0.000), and reached 1.11 ± 0.42 % at 4 h (p=0.002) and 1.83 ± 0.77 % at 24 h (p=0.000).

CONCLUSIONS

The oxygen transport function of salvaged RBCs at 0 h was not influenced by the cell salvage process and was better than that of the venous RBCs and 2-week-old packed RBCs. At the end of storage, the oxygen transport function of salvaged RBCs did not change obviously, but percentage of hemolysis significantly increased.

The efficacy, safety and cost-effectiveness of intra-operative cell salvage in high-bleeding-risk cardiac surgery with cardiopulmonary bypass: a prospective randomized and controlled trial

OBJECTIVE

Intra-operative cell salvage (CS) was reported to be ineffective, safe and not cost-effective in low-bleeding-risk cardiac surgery with cardiopulmonary bypass (CPB), but studies in high-bleeding-risk cardiac surgery are limited. The objective of this study is to evaluate the efficacy, safety and cost-effectiveness of intra-operative CS in high-bleeding-risk cardiac surgery with CPB.

METHODS

One hundred and fifty patients were randomly assigned to either with intra-operative CS group (Group CS) or without intra-operative CS group (Group C). Study endpoints were defined as perioperative allogeneic red blood cell (RBC) transfusion, perioperative impairment of blood coagulative function, postoperative adverse events and costs of transfusion-related.

RESULTS

Both the proportion and quantity of perioperative allogeneic RBC transfusion were significantly lower in Group CS than that in Group C (p=0.0002, <0.0001, respectively). The incidence of residual heparin and total impairment of blood coagulative function in the 24 hours after surgery, the incidence of postoperative excessive bleeding, were significantly higher in Group CS than that in Group C (p=0.018, 0.042, 0.034, respectively). Cost of both allogeneic RBC transfusion and total allogeneic blood transfusion were significantly lower in Group CS than that in Group C (p<0.001, =0.002, respectively). Cost of total blood transfusion was significantly higher in Group CS than that in Group C (p =0.001).

CONCLUSION

Intra-operative CS in high-bleeding-risk cardiac surgery with CPB is effective, generally safe, and cost-effective in developed countries but not in China.

Blood transfusion practices in cardiac anaesthesia

The primary reasons for blood transfusion in cardiac surgery are to correct anaemia and to improve tissue oxygen delivery. However, there is a considerable debate regarding the actual transfusion trigger at which the benefits of transfusion overweight the risk. The association between extreme haemodilution, transfusion and adverse outcome after cardio pulmonary bypass (CPB) is not clear and the current available literature is not sufficient to provide a strong recommendation regarding the safe haematocrit range during CPB. There is no quality evidence to support use of fresh red blood cell except during massive transfusion or exchange transfusion in neonate. Overall concern regarding the safety of allogeneic blood transfusion resulted in the search for autologous blood transfusion and perioperative blood salvage. The aim of this review is to provide cardiac surgery specific clinically useful guidelines pertaining to transfusion triggers, optimal haemodilution during CPB, autologous blood transfusion and role of perioperative blood salvage based on available evidence.

Utility of cell salvage in women undergoing abdominal myomectomy

OBJECTIVE

We examined the use and cost of autologous blood cell salvage in women who undergo abdominal myomectomy.

STUDY DESIGN

Patients who underwent abdominal myomectomy from 2007-2011 were identified. Use of the cell salvage system and reinfusion of autologous blood in women who had the system set-up were analyzed. Cost was examined by directly reported data.

RESULTS

We identified 607 patients who underwent abdominal myomectomy. Four hundred twenty-five women (70%) had the set-up of the cell salvage system. Cell-salvaged blood was processed and reinfused into 85 of these subjects (20%). In a multivariable model, performance of myomectomy by a gynecologic-specific surgeon (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.28-3.59), >5 myomas (OR, 2.49; 95% CI, 1.27-4.89), and larger uterine size statistically were associated significantly with cell-salvage device set-up. Conversely, having a reproductive-endocrinology-infertility specialist as the surgeon was associated with a significant reduction in cell-salvage system set-up (OR, 0.37; 95% CI, 0.21-0.66). For the women who had cell-salvage system set-up, uterine size of >15-19 weeks of gestation (OR, 3.22; 95% CI, 1.56-8.95) or ≥20 weeks of gestation (OR, 4.62; 95% CI, 1.45-14.73), operating time of >120 minutes (OR, 3.98; 95% CI, 1.70-9.29), and intraoperative blood loss of >1000 mL (OR, 26.31; 95% CI, 10.49-65.99) were associated significantly with a higher incidence of reinfusion of cell-salvaged blood.

CONCLUSION

The routine use of cell salvage in women who undergo abdominal myomectomy does not appear to be warranted. Cell-salvage set-up appears to be cost-effective only when reinfused, but clinical characteristics cannot predict accurately which women will require reinfusion of cell-salvaged blood.

How we manage the haematological aspects of major obstetric haemorrhage

Major obstetric haemorrhage (MOH) remains an important medical challenge worldwide, contributing to significant maternal morbidity and mortality. Prompt and appropriate management is essential if we are to improve outcomes and reduce substandard care that may result in adverse consequences. This review describes the current understanding of the pathophysiological aspects of MOH together with the principles of transfusion and haemostatic therapy, with emphasis on a coordinated multidisciplinary approach. We also highlight the current lack of evidence available from randomized controlled trials to inform best practice and the need to prioritize research in this key clinical area.