Quality of intraoperative autologous blood withdrawal used for retransfusion after cardiopulmonary bypass

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Acute normovolemic hemodilution and intraoperative autotransfusion

Autologous blood transfusion can be achieved through different techniques, including by the patient donating blood before surgery (pre-deposit), collecting blood from the patient immediately before the operation and replacing the volume with colloids or plasma expanders (acute normovolemic hemodilution) or through the salvage of lost blood, during or immediately after surgery, and its retransfusion after washing (intraoperative or postoperative recovery). We will focus on the two methods used intraoperatively that are of fundamental importance in the management and conservation of the patient's own blood.

Effect of acute normovolemic hemodilution in patients undergoing cardiac surgery with remimazolam anesthesia

PURPOSE

The reduced effects of allogeneic transfusion with acute normovolemic hemodilution (ANH) have been reported. Harvesting a large volume of blood may maximize the effect in patients with low body weight, and the prevention of hypotension is important. Remimazolam is an anesthetic with few circulatory responses. Our aim was to evaluate whether high-volume ANH reduces the need for transfusion in cardiac patients under remimazolam anesthesia.

METHODS

In this retrospective single-center study, we enrolled cardiopulmonary bypass (CPB) patients who received remimazolam anesthesia. Changes in hemodynamic parameters were assessed. The numbers of blood transfusions and chest tube outputs were also evaluated.

RESULTS

In a total of 51 patients, ANH was performed in 27 patients with a mean body mass index of 23.2 (ANH volume: 740 ± 222 mL). No significant differences were observed in mean blood pressure during blood collection. The intraoperative amount of red blood cell (RBC) transfusion was significantly lower in the ANH group than in the control group (431 ± 678 and 1260 ± 572 mL, p < 0.001). The avoidance rates of RBC were 66.7 and 4.2%, respectively. The multivariate analysis result revealed that ANH correlated with RBC, with an odds ratio of 0.067 (95% confidence interval 0.005-0.84, p < 0.05). The postoperative bleeding at 24 h was significantly lower in the ANH group (455 ± 228 and 797 ± 535 mL, p < 0.01).

CONCLUSION

In patients undergoing CPB, ANH reduced intraoperative transfusion amount and postoperative bleeding. Hemodynamic changes during blood collection were minimal under remimazolam anesthesia and high-volume ANH was feasible.

Large volume acute normovolemic hemodilution in patients undergoing cardiac surgery with intermediate-high risk of transfusion: A randomized controlled trial

STUDY OBJECTIVE

To investigate whether large volume acute normovolemic hemodilution (L-ANH), compared with moderate acute normovolemic hemodilution (M-ANH), can reduce perioperative allogeneic blood transfusion in patients with intermediate-high risk of transfusion during cardiac surgery with cardiopulmonary bypass (CPB).

DESIGN

Prospective randomized controlled trial.

SETTING

University hospital.

PATIENTS

Patients with transfusion risk understanding scoring tool ("TRUST") ≥2 points undergoing cardiac surgery with CPB in the Second Affiliated Hospital of Zhejiang University from May 2020 to January 2021 were included.

INTERVENTIONS

The patients were randomly assigned with a 1:1 ratio to M-ANH (5 to 8 mL/kg) or L-ANH (12 to 15 mL/kg).

MEASUREMENTS

The primary outcome was perioperative red blood cell (RBC) transfusion units. The composite outcome included new-onset atrial fibrillation, pulmonary infection, cardiac surgery associated acute kidney injury (CSA-AKI) class ≥2, surgical incision infection, postoperative excessive bleeding, and resternotomy.

MAIN RESULTS

Total 159 patients were screened and 110 (55 L-ANH and 55 M-ANH) were included for final analysis. Removed blood volume of L-ANH is significantly higher than M-ANH (886 ± 152 vs. 395 ± 86 mL, P < 0.001). Perioperative RBC transfusion was median 0 unit ([25th, 75th] percentiles: 0-4.4) in M-ANH group vs. 0 unit ([25th, 75th] percentiles: 0-2.0) in L-ANH group (P = 0.012) and L-ANH was associated with lower incidence of transfusion (23.6% vs. 41.8%, P = 0.042, rate difference: 0.182, 95% confidence interval [0.007-0.343]). The incidence of postoperative excessive bleeding was significantly lower in L-ANH vs. M-ANH (3.6% vs. 18.2%, P = 0.029, rate difference: 0.146, 95% confidence interval [0.027-0.270]) without significant difference for other second outcomes. The volume of ANH was inversely related to perioperative RBC transfusion units (Spearman r = -0.483, 95% confidence interval [-0.708 to -0.168], P = 0.003), and L-ANH in cardiac surgery was associated with a significantly reduced risk of perioperative RBC transfusion (odds ratio: 0.43, 95% confidence interval: 0.19-0.98, P = 0.044).

CONCLUSIONS

Compared with M-ANH, L-ANH during cardiac surgery inclined to be associated with reduced perioperative RBC transfusion and the volume of RBC transfusion was inversely proportional to the volume of ANH. In addition, LANH during cardiac surgery was associated with a lower incidence of postoperative excessive bleeding.

Intraoperative blood collection without fluid replacement for cardiac surgery - A retrospective analysis

BACKGROUND

Transfusion rates in cardiac surgery are high.

AIM

To determine if intraoperative autologous blood removal without volume replacement is associated with fewer homologous blood transfusions without increasing acute kidney injury.

SETTING AND DESIGN

Retrospective, comparative study.

MATERIALS AND METHODS

Adult patients undergoing cardiac surgery, excluding those who underwent ventricular assist device surgery, heart transplants, or cardiac surgery without cardiopulmonary bypass were excluded, who had 1-3 units of intraoperative autologous blood removal were compared to patients without blood removal for determination of volume replacement, vasopressor support, acute kidney injury, and transfusions.

RESULTS

Autologous blood removal was associated with fewer patients receiving homologous transfusions: intraoperative red cell transfusions fell from 75% (Control) to 48% (1 unit removed), 40% (2 units), and 30% (3 units), P &lt; 0.001. Total intraoperative and postoperative homologous RBC units transfused were lower in the blood removal groups: median (interquartile range) 3 (1, 6) in Control patients and 0 (0, 2), 0 (0, 2) and 0 (0, 1) in the 1, 2, and 3 units removed groups, P &lt; 0.001. Similarly, plasma, platelet, and cryoprecipitate transfusions decreased. After adjustment for confounders, increased amounts of autologous blood removal were associated with increased intravenous fluids, only when 2 units were removed, and trivially increased vasopressor use. However, it was not associated with acidosis or acute kidney injury.

CONCLUSIONS

Intraoperative autologous blood removal without volume replacement of 1-3 units for later autologous transfusion is associated with decreased homologous transfusions without acidosis or acute kidney injury.

Challenges in Patient Blood Management for Cardiac Surgery: A Narrative Review

About 15 years ago, Patient Blood Management (PBM) emerged as a new paradigm in perioperative medicine and rapidly found support of all major medical societies and government bodies. Blood products are precious, scarce and expensive and their use is frequently associated with adverse short- and long-term outcomes. Recommendations and guidelines on the topic are published in an increasing rate. The concept aims at using an evidence-based approach to rationalize transfusion practices by optimizing the patient's red blood cell mass in the pre-, intra- and postoperative periods. However, elegant as a concept, the implementation of a PBM program on an institutional level or even in a single surgical discipline like cardiac surgery, can be easier said than done. Many barriers, such as dogmatic ideas, logistics and lack of support from the medical and administrative departments need to be overcome and each center must find solutions to their specific problems. In this paper we present a narrative overview of the challenges and updated recommendations for the implementation of a PBM program in cardiac surgery.

Intra-operative autologous blood donation for cardiovascular surgeries in Japan: A retrospective cohort study

Intra-operative autologous blood donation is a blood conservation technique with limited evidence. We evaluated the association between intra-operative autologous blood donation and decrease in peri-operative transfusion in cardiovascular surgery based on evidence from a Japanese administrative database. We extracted the data of patients who had undergone cardiovascular surgery from the Diagnosis Procedure Combination database in Japan (2016–2019). Based on the surgery type, we examined the association of intra-operative autologous blood donation with the transfusion rate and amount of blood used in cardiac and aortic surgeries using multilevel propensity score matching. We enrolled 32,433 and 4,267 patients who underwent cardiac and aortic surgeries and received 5.0% and 6.7% intra-operative autologous blood donation with mean volumes of 557.68 mL and 616.96 mL, respectively. The red blood cell transfusion rates of the control and intra-operative autologous blood donation groups were 60.6% and 38.4%, respectively, in the cardiac surgery cohort (p < .001) and 91.4%, and 83.8%, respectively, in the aortic surgery cohort (p = .037). The transfusion amounts for the control and intra-operative autologous blood donation groups were 5.9 and 3.5 units of red blood cells, respectively, for cardiac surgery patients (p < .001) and 11.9 and 7.9 units, respectively, for aortic surgery patients (p < .001). Intra-operative autologous blood donation could reduce the transfusion rate or amount of red blood cells and fresh frozen plasma for patients undergoing index cardiovascular surgery and could be an effective blood transfusion strategy in cardiovascular surgery for Japanese patients.

Effect of acute normovolemic hemodilution on coronary artery bypass grafting: A systematic review and meta-analysis of 22 randomized trials

BACKGROUND

Efficacy of minimal acute normovolemic hemodilution (ANH) in avoiding homologous blood transfusion during cardiovascular surgery remains controversial. Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations. To better understand the role of acute normovolemic hemodilution (ANH) in coronary artery bypass grafting (CABG), we compared ANH with standard intraoperative care in a systematic review including a standard pairwise meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched the Cochrane Library, PubMed, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) up to April 1, 2020. The primary outcome was to assess the incidence of ANH-related number of allogeneic red blood cell units (ARBCu) transfused. Secondary outcomes included the rate of allogeneic blood transfusion and estimated total blood loss.

RESULTS

A total of 22 RCTs including 1688 patients were identified for the present meta-analysis. Of these studies, 19 were about CABG with on-pump and three with off-pump. Our pooled result indicated that patients received ANH experienced fewer ARBCu transfusions, with a standardized mean difference (SMD) of -0.60 (95%CI -0.96 to -0.24; P = 0.001). The rate of allogeneic blood transfusion in ANH group was significant reduced when compared with controls, with a relative risk (RR) of 0.65 (95%CI 0.52 to 0.82; P = 0.0002). In addition, less postoperative estimated total blood loss was present, with a SMD of -0.53 (95%CI -0.88 to -0.17; P = 0.004).

CONCLUSIONS

The present meta-analysis indicated that ANH could reduce the number of ARBCu transfused in the CABG surgery setting. In addition, ANH could also reduce the rate of ARBCu transfusion and estimated total blood loss for CABG patients.

Effect of Autotransfusion Using Intraoperative Predonated Autologous Blood on Coagulopathy during Thoracic Aortic Surgery: A Randomized Controlled Trial

Background: Intraoperative predonated autologous blood transfusion is thought to replenish platelets and coagulation factors and ameliorate coagulopathy. This study aimed to evaluate whether intraoperative predonated autotransfusion improves coagulopathy during thoracic aortic surgery.

Methods: Patients who underwent thoracic aortic surgery were randomized into two groups as follows: those who received intraoperative predonated blood (group A: n = 31) and those who did not receive (group N: n = 22). In group A, autologous blood was retransfused immediately after cessation of cardiopulmonary bypass (c-CPB).

Results: The mean intraoperative allogenic blood or blood product transfusion requirements were significantly lesser in group A than in group N (packed red blood cells [RBCs]: 6.3 ± 5.1 vs. 9.1 ± 4.3 units, p = 0.04; fresh frozen plasma [FFP]: 3.0 ± 4.1 vs. 6.1 ± 5.7 units, p = 0.03). After c-CPB, hemoglobin (Hb) level, platelet count, and coagulopathy became significantly worse than those at the start of surgery in both the groups. However, the values significantly improved 30 min after c-CPB only in group A. Renal function was significantly worse in group N.

Conclusions: Intraoperative predonated autotransfusion significantly improved coagulopathy, with reduced allogeneic blood transfusion volume during thoracic aortic surgery. Furthermore, reduction of allogeneic blood transfusion may reduce the adverse effects on renal function.

Platelet function, but not thrombin generation, is impaired in acute normovolemic hemodilution (ANH) blood

STUDY OBJECTIVE

We investigated the coagulation changes that might occur in acute normovolemic hemodilution (ANH) blood over several hours during cardiac surgery requiring cardiopulmonary bypass.

DESIGN

This study was a prospective observational study.

SETTING

This study took place at a university teaching hospital.

PATIENTS

This study included 26 patients, either ASA 3 or 4 and without known coagulation disorders, undergoing cardiac surgery. Patients were included if the use of cardiopulmonary bypass was expected to reach 2.5 h.

INTERVENTIONS

ANH blood was collected into CPDA-1 collection bags before systemic heparinization. Samples were taken directly from the bags at time of collection and reinfusion to assess changes in platelet and thrombin generation parameters.

MEASUREMENTS

Whole blood from citrated tubes was used immediately for rotational thromboelastometry and platelet aggregometry analyses. Thrombin generation was assessed using calibrated automated thrombography with platelet poor plasma.

MAIN RESULTS

Despite no significant change in platelet count over the ANH storage period, there was significant degradation in platelet function as measured by thrombin receptor activating peptide stimulation on Mulltiplate™ analysis and maximum clot formation on ROTEM™ EXTEM. Notably, there was no change in the ability to generate thrombin.

CONCLUSIONS

Little data exists regarding the quality of coagulation factors in autologous blood. Our study confirms ANH collection results in decreased platelet aggregation with TRAP stimulation; however, this is not appreciated with ADP stimulation. Thrombin generation capacity remains preserved.

Feasibility of autologous intraoperative blood collection and retransfusion in small children with complex congenital heart defects undergoing cardiopulmonary bypass

INTRODUCTION

Allogeneic blood product transfusion is common in pediatric patients undergoing cardiopulmonary bypass although it is associated with an increased risk for adverse events. Furthermore, numerous donor exposures may affect future blood transfusion needs and human leukocyte antigen matching for patients who may ultimately require cardiac transplantation. Autologous intraoperative blood collection and retransfusion is a known method of blood preservation, but has not been extensively practiced in pediatric patients. In this study we assess the feasibility of this blood conservation technique in small children with complex congenital heart defects undergoing cardiopulmonary bypass.

METHODS

After Institutional Review Board approval, we retrospectively reviewed the medical records of children weighing <10 kg who underwent cardiopulmonary bypass over a 2-year period. Eighteen patients underwent autologous intraoperative blood collection and retransfusion and comprised the study group. Eighteen control patients were chosen by a 1:1 matched design using preoperative hematocrit, surgical procedure, and body weight. Multiple corresponding demographic and surgical variables, transfusion data, and clinical outcomes were compared.

RESULTS

Patient demographics, operative parameters and preoperative laboratory, and coagulation values were similar between the two groups. Despite the removal of autologous blood, study patients did not require more inotropic support prior to cardiopulmonary bypass. They also did not experience a significant increase in bleeding as measured by 24-hour postoperative chest tube output. Study patients were exposed to significantly fewer donor units intraoperatively and within the first 24 hours postoperatively.

DISCUSSION

The use of autologous intraoperative blood collection and retransfusion is a feasible option for small children with complex congenital heart defects undergoing cardiopulmonary bypass. Study patients received significantly fewer donor exposures without an increase in postoperative bleeding. Children who require multiple cardiac surgeries or eventually transplantation could benefit from this blood conservation technique.

Major Factors of Homologous Blood Transfusion in Valvular Heart Operation with Intraoperative Autologous Blood Predonation in Cases with Difficulty in Preoperative Predonation

Intraoperative autologous blood predonation is reported to be useful for the prevention of homologous blood transfusion in cardiac operations, especially in on-pump coronary artery bypass grafting (CABG). However, CABG is now performed more often off-pump than on-pump. We analyzed the major factors of homologous blood transfusion in 25 consecutive cases of valvular heart operation with intraoperative autologous blood predonation except those with preoperative autologous blood donation. Homologous blood was not transfused in 18 cases, but was in 7 cases only after cardiopulmonary bypass (CPB). The homologous transfusion was not correlated with body weight, CPB dilution or duration, or preoperative hematocrit level, but was found to correlate with age (R2=0.289, p=0.0413), bleeding output (R2=0.197, p=0.0485), and predonation blood volume (R2=0.436, p=0.0152). In conclusion, suitable intraoperative predonation may reduce the necessity for homologous blood transfusion in valvular heart operations.

The effectiveness of acute normolvolemic hemodilution and autologous prime on intraoperative blood management during cardiac surgery

Objective:

Intraoperative blood management during cardiac surgery is a multifaceted process incorporating various interventions directed at optimizing oxygen delivery and enhancing hemostasis. The purpose of this study was to evaluate the effects of acute normovolemic hemodilution (ANH) and autologous priming (AP) on preserving the hematocrit during cardiopulmonary bypass (CPB).

Method:

Case records from a national registry of adult patients who underwent cardiac surgery between January and October 2016 were reviewed. Groups were determined as follows: ANH, AP, ANH+AP or Neither. Primary endpoint was first the hematocrit on CPB with secondary endpoints of hematocrit drift and red blood cell (RBC) transfusion rate.

Results:

Eighteen thousand and twenty-four (18,024) consecutive patients were reviewed. The first CPB hematocrit was lowest in the ANH group (26.5%±4.4%) and highest in ANH+AP patients (27.5%±4.8%) (p<0.001). The change in hematocrit was greatest in the ANH group (8.3%±3.9%) compared to both the AP (6.4%±3.8%) and ANH+AP (6.9%±4.1%) groups (p<0.001). Intraoperative RBC transfusions were as follows: ANH 26 (7.8%), AP 2,531 (20.0%), ANH+AP 287 (10.3%) and Neither 592 (26.7%) (p<0.001).

Conclusions:

Regression results show that the use of ANH will result in the greatest decline in hematocrit values. When combined with AP, higher hematocrits and lower transfusions were seen.

Platelet function in stored heparinised autologous blood is not superior to in patient platelet function during routine cardiopulmonary bypass

Background

In cardiac surgery, cardiopulmonary bypass (CPB) and unfractionated heparin have negative effects on blood platelet function. In acute normovolemic haemodilution autologous unfractionated heparinised blood is stored ex-vivo and retransfused at the end of the procedure to reduce (allogeneic) transfusion requirements. In this observational study we assessed whether platelet function is better preserved in ex vivo stored autologous blood compared to platelet function in the patient during CPB.

Methodology/Principal Finding

We measured platelet aggregation responses pre-CPB, 5 min after the start of CPB, at the end of CPB, and after unfractionated heparin reversal, using multiple electrode aggregometry (Multiplate®) with adenosine diphosphate (ADP), thrombin receptor activating peptide (TRAP) and ristocetin activated test cells. We compared blood samples taken from the patient with samples taken from 100 ml ex-vivo stored blood, which we took to mimick blood storage during normovolemic haemodilution. Platelet function declined both in ex-vivo stored blood as well as in blood taken from the patient. At the end of CPB there were no differences in platelet aggregation responses between samples from the ex vivo stored blood and the patient.

Conclusion/Significance

Ex vivo preservation of autologous blood in unfractionated heparin does not seem to be profitable to preserve platelet function.

Anesthetic management for ascending aorta replacement in a patient who refused autologous transfusion for religious reasons

We report on the anesthetic management of a 69-year-old female Jehovah's Witness undergoing cardiopulmonary bypass to replace the ascending aorta; the patient refused transfusion of stored autologous or allogeneic blood products for religious reasons. The strategy involved preoperative hematopoiesis with recombinant human erythropoietin and iron, intraoperative acute normovolemic hemodilution, the use of a cell-saver system, administration of high-dose tranexamic acid, controlled hypotension, avoidance of low body temperature, simplification of the surgery, and lower blood dilution during cardiopulmonary bypass.

A reduced priming system

Cardiopulmonary bypass (CPB), an integral part of valve surgery, is known to cause hemodilution, which can lead to a need for blood transfusion as well as a systemic inflammatory reaction. Our aim was to evaluate a reduced priming (RP) system for CPB with regard to clinical outcomes in patients undergoing valve surgery. Eleven patients were assigned to the new system with an RP volume. The RP system allowed for reduced hemodilution and a possible reduction in the necessity for blood transfusions.

Hemodynamic effects of cardiotomy suction blood

OBJECTIVE

Cardiac surgery induces a systemic inflammatory activation, which in severe cases is associated with peripheral vasodilation and hypotension. Cardiotomy suction blood contains high levels of inflammatory mediators, but the effect of cardiotomy suction blood on the vasculture is unknown. We investigated the effect of cardiotomy suction blood on systemic vascular resistance in vivo and whether cell-saver processing of suction blood affects the vascular response.

METHODS

Twenty-five patients undergoing coronary surgery (mean age, 68 +/- 2 years; 80% men) were included in a prospective randomized study. The patients were randomized to retransfusion of cell-saver processed (n = 13) or cell-saver unprocessed (n = 12) suction blood during full cardiopulmonary bypass. Mean arterial blood pressure was continuously registered during retransfusion, and systemic vascular resistance was calculated. Plasma concentrations of tumor necrosis factor alpha, interleukin 6, and complement factor C3a were measured in suction blood.

RESULTS

Retransfusion of cardiotomy suction blood induced a transient reduction in systemic vascular resistance in all patients. The peak reduction was significantly less pronounced in the group receiving cell-saver processed blood (-12% +/- 2% vs -28% +/- 3%, P = .001). There was a significant correlation between tumor necrosis factor alpha concentration in retransfused cardiotomy suction blood and peak reduction of systemic vascular resistance (r = 0.60, P = .002).

CONCLUSIONS

The results suggest cardiotomy suction blood is vasoactive and might influence vascular resistance and blood pressure during cardiac surgery. The observed vasodilation is proportional to the inflammatory activation of suction blood and can be reduced by processing suction blood with a cell-saving device before retransfusion.