Reinfusate Heparin Concentrations Produced by Two Autotransfusion Systems

Quality comparison of autotransfusion devices in cardiac surgery: a prospective observational cohort study

PURPOSE

We sought to conduct a quality improvement initiative to compare the wash quality and speed of autologous red blood cell (RBC) processing of four autotransfusion devices during cardiac surgery.

METHODS

Using a prospective observational cohort study approach, we prospectively evaluated four commercially available autologous cell savage devices (autoLog IQ™, Medtronic plc, Minneapolis, MN, USA [135 mL]; Xtra™, LivaNova, plc, Houston, TX, USA [125 mL, 225 mL]; Cell Saver® Elite®+, Haemonetics Corp., Boston, MA, USA [125 mL, 225 mL]; and CATSmart®, Fresenius Kabi AG, Bad Homburg vor der Höhe, Germany) in adult patients undergoing cardiac surgery. Device settings were determined by manufacturer recommendations for optimal wash quality. We collected pre- and postprocessing samples, volumes, and processing times from each device to calculate removal ratios of heparin, potassium, plasma free hemoglobin (PfHb), white blood cells (WBCs), platelets, reinfusion concentrations of heparin and potassium, and red blood cell (RBC) recovery rates.

RESULTS

A total of 130 consecutive patients underwent autologous cell salvage, but 15 cases were excluded because of incomplete data. All devices removed > 99% heparin, > 95% potassium, > 94% platelets, and > 85% PfHb from collected shed blood. Comparison of processing sets showed significant differences in median [interquartile range] WBC removal ratios, ranging from 26 [19-33]% to 59 [42-68]%, and median heparin reinfusion concentrations, which ranged from 0.09 [0.08-0.11] to 0.63 [0.55-0.70] U·mL-1 processed red cells. Median RBC recovery rates also showed significant differences between processing sets, ranging from 8 [8-10] mL RBC·min-1 to 24 [22-25] mL RBC·min-1.

CONCLUSION

Wash quality and processing speed differed between autotransfusion devices and processing sets. These findings may have clinical implications when large volumes of shed blood are processed and reinfused.

Clues of incomplete reversal of heparin in cardiac surgery

OBJECTIVES

In our center, an unusual rate of patients had abnormalities of hemostasis in immediate postoperative period of cardiac surgery. Our objectives were to identify the cause of these sudden hemostasis abnormalities and to evaluate the performances of point of care coagulation testing.

METHODS

In this prospective and descriptive study, we included 33 consecutive patients undergoing elective cardiac surgery for 1 month. Heparin-induced anticoagulation and calculation of the protamine dose were tested by the Hemostasis Management System Plus device (Medtronic, Minneapolis, MN, USA). Fifteen minutes after the end of the protamine infusion, activated clotting time (ACT), activated partial thromboplastin time and anti Xa activity were measured. In case of unusual clinical bleeding, a Quantra analysis (Stago, HemoSonics LLC, Charlottesville, VA) was added.

RESULTS

Residual antiXa activity >0.2 IU/mL after neutralization was present in 44% of patients. Our investigation concluded incomplete heparin reversal. There was no association between cellular reinfusate and the presence of heparin. The unusual rate of hemostasis abnormalities was explained by a less efficient protamine reversal of heparin. ACT and Clot Time Ratio (CTR, Quantra system) correlated with AntiXa with Spearman's coefficients of 0.85 (p < .0001) and 0.95 (p = .0012), respectively. About ACT, a threshold of 150 seconds had a sensitivity of 85% [58-97] and a specificity of 85% [58-97%] for detection of AntiXa>0.2. For CTR, a threshold of 1.4 had a sensitivity of 67% [30-94] and a specificity of 100% [18-100].

CONCLUSION

The use of point of care coagulation testing is effective in detecting incomplete reversal of heparin.

Combined Platelet and Red Blood Cell Recovery during On-pump Cardiac Surgery Using same™ by i-SEP Autotransfusion Device: A First-in-human Noncomparative Study (i-TRANSEP Study)

BACKGROUND

Centrifugation-based autotransfusion devices only salvage red blood cells while platelets are removed. The same™ device (Smart Autotransfusion for ME; i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage both red blood cells and platelets. The authors tested the hypothesis that this new device could allow a red blood cell recovery exceeding 80% with a posttreatment hematocrit exceeding 40%, and would remove more than 90% of heparin and 75% of free hemoglobin.

METHODS

Adults undergoing on-pump elective cardiac surgery were included in a noncomparative multicenter trial. The device was used intraoperatively to treat shed and residual cardiopulmonary bypass blood. The primary outcome was a composite of cell recovery performance, assessed in the device by red blood cell recovery and posttreatment hematocrit, and of biologic safety assessed in the device by the washout of heparin and free hemoglobin expressed as removal ratios. Secondary outcomes included platelet recovery and function and adverse events (clinical and device-related adverse events) up to 30 days after surgery.

RESULTS

The study included 50 patients, of whom 18 (35%) underwent isolated coronary artery bypass graft, 26 (52%) valve surgery, and 6 (12%) aortic root surgery. The median red blood cell recovery per cycle was 86.1% (25th percentile to 75th percentile interquartile range, 80.8 to 91.6) with posttreatment hematocrit of 41.8% (39.7 to 44.2). Removal ratios for heparin and free hemoglobin were 98.9% (98.2 to 99.7) and 94.6% (92.7 to 96.6), respectively. No adverse device effect was reported. Median platelet recovery was 52.4% (44.2 to 60.1), with a posttreatment concentration of 116 (93 to 146) · 109/l. Platelet activation state and function, evaluated by flow cytometry, were found to be unaltered by the device.

CONCLUSIONS

In this first-in-human study, the same™ device was able to simultaneously recover and wash both platelets and red blood cells. Compared with preclinical evaluations, the device achieved a higher platelet recovery of 52% with minimal platelet activation while maintaining platelet ability to be activated in vitro.

EDITOR’S PERSPECTIVE

Combined Platelet and Erythrocyte Salvage: Evaluation of a New Filtration-based Autotransfusion Device

BACKGROUND

The SAME device (i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage and wash both red blood cells and platelets. This study evaluated the device performances using human whole blood with the hypothesis that the device will be able to salvage platelets while achieving a erythrocyte yield of 80% and removal ratios of 90% for heparin and 80% for major plasma proteins without inducing signification activation of salvaged cells.

METHODS

Thirty healthy human whole blood units (median volume, 478 ml) were diluted, heparinized, and processed by the device in two consecutive treatment cycles. Samples from the collection reservoir and the concentrated blood were analyzed. Complete blood count was performed to measure blood cell recovery rates. Flow cytometry evaluated the activation state and function of platelets and leukocytes. Heparin and plasma proteins were measured to assess washing performance.

RESULTS

The global erythrocyte yield was 88.1% (84.1 to 91.1%; median [25th to 75th]) with posttreatment hematocrits of 48.9% (44.8 to 51.4%) and 51.4% (48.4 to 53.2%) for the first and second cycles, respectively. Ektacytometry did not show evidence of erythrocyte alteration. Platelet recovery was 36.8% (26.3 to 43.4%), with posttreatment counts of 88 × 109/l (73 to 101 × 109/l) and 115 × 109/l (95 to 135 × 109/l) for the first and second cycles, respectively. Recovered platelets showed a low basal P-selectin expression at 10.8% (8.1 to 15.2%) and a strong response to thrombin-activating peptide. Leukocyte yield was 93.0% (90.1 to 95.7%) with no activation or cell death. Global removal ratios were 98.3% (97.8 to 98.9%), 98.2% (96.9 to 98.8%), and 88.3% (86.6 to 90.7%) for heparin, albumin, and fibrinogen, respectively. The processing times were 4.4 min (4.2 to 4.6 min) and 4.4 min (4.2 to 4.7 min) for the first and second cycles, respectively.

CONCLUSIONS

This study demonstrated the performance of the SAME device. Platelets and red blood cells were salvaged without significant impact on cell integrity and function. In the meantime, leukocytes were not activated, and the washing quality of the device prevented reinfusion of high concentrations of heparin and plasma proteins.

EDITOR’S PERSPECTIVE

The Year in Coagulation: Selected Highlights from 2020

This is the second annual review in the Journal of Cardiothoracic and Vascular Anesthesia to cover highlights in coagulation for cardiac surgery. The goal of this article is to provide readers with a focused summary from the literature of the prior year's most important coagulation topics. In 2020, this included a discussion covering allogeneic transfusion, antiplatelet and anticoagulant therapy, factor concentrates, coagulation testing, mechanical circulatory support, and the effects of coronavirus disease 2019.

Exploration on the effect of predeposit autotransfusion on bone marrow hematopoiesis after femoral shaft fracture

OBJECTIVE

By observing the changes in the number and activity of CD34+ cells in bone marrow after predeposit autotransfusion (PAT) to patients with femoral shaft fracture (FSF), to evaluate the effects of PAT on hematopoietic function and hematopoietic stem cells in bone marrow.

METHODS

Selected FSF patients were randomly divided into 2 groups: the control group (patients did not receive blood transfusion after surgery) and PAT group (patients received PAT after surgery). The content of RBC and Plt in blood samples were counted by blood routine. The cell cycle and proportion of CD34+ myelinated cells in blood samples was analyzed by flow cytometry. The telomere DNA length of hematopoietic stem cells (HSCs) in the control groups and PAT group at postoperation 24 was analyzed by southern blot.

RESULTS

The content of RBC and Plt in postoperation 6h and 24h in the control group was evidently higher compared to that in PAT group, while Hb content in control group was significantly lower compared to that in PAT group. The proportion of CD34+ myelinated cells in post-transfusion 6h and postoperation 24h in PAT group was evidently higher compared to that in the control group. In PAT group, S phase at postoperation 24h was significantly larger compared to that at post-transfusion 6h. The telomere DNA length of HSCs in PAT group was longer than that in the control group.

CONCLUSION

PAT can increase the number of HSC, while does not cause the abnormal aging of HSCs. PAT is suitable for postoperative blood transfusion of patients with FSF.

Controversies in the Clinical Practice of Patient Blood Management

Patient blood management (PBM) has been proposed as a standard of care in modern perioperative medicine. PBM-related interventions usually are implemented as bundles, but randomized controlled trials on the implementation of PBM as a bundle are missing. This special article focuses on the current evidence and controversies in the clinical practice of PBM and on emerging data related to specific PBM-related interventions in patients undergoing cardiac surgery. Strong evidence for many PBM-related interventions is limited because of missing studies or the poor quality of published findings and study endpoints. Restrictive blood transfusion and timely interventions to maintain hemoglobin concentration and to reduce blood loss potentially might result in improved patient outcome, although the latter has yet to be proven.

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.

Haematological alterations in the cardiac patient after use of an autotransfusion system

OBJECTIVE

There are studies that declare blood recovered with the autotransfusion system that is potentially heparinised and mixed with other drugs, can cause haematological alterations in the patient, according to existing evidence. The proposal was to compare the haematological values of the patients before reinfusing red blood cells from the cell saver and 12h after reinfusion.

MATERIAL AND METHODS

Observational analytical study of 479 patients who underwent cardiac surgery where the cell saver was used. Haematological variables were collected before reinfusion and 12h after reinfusion.

RESULTS

Statistically significant haematological values before reinfusion and 12h after reinfusion were: haemoglobin (9.5 to 12.5g/dL), haematocrit (26 to 38%), platelets (214.2 to 164.210^3/μL), total proteins (7.6 to 5.1g/dL), PCR (8.5 to 22.1mg/L) and D-dimer (493.3 to 875.5μg/L) with P<.05.

CONCLUSIONS

With the use of the cell saver an increase was observed of haemoglobin, haematocrit, PCR and D-dimer values together with a decrease in platelet and total protein numbers.