Autotransfusion Device Research Articles

A Comparison of Postprocedural Hemoglobin in Catheter-Directed Thrombolysis versus Large-Bore Aspiration Thrombectomy for Acute Pulmonary Embolism

PurposeTo compare changes in hemoglobin (HB) following catheter-directed thrombolysis (CDL) versus large-bore aspiration thrombectomy (LBAT) of acute pulmonary embolism (PE). Materials and MethodsA single-center retrospective review of patients with acute high- and intermediate-risk PE treated with CDL or LBAT between December 2009 and September 2023 was performed. The LBAT group was divided according to usage of an autotransfusion device (ATD). There were 166 patients in the CDL group (56 years ± 15). LBAT patients were treated without (LBAT, n = 58, 61 years ± 16) or with (LBATw, n = 47, 62 years ± 15) an ATD. Endpoints included change in HB between preprocedural and postprocedural measurements, the 7-day postprocedural nadir (low point), and adverse events (AEs). ResultsThe mean HB changes between preprocedural and postprocedural measurements in the CDL, LBAT, and LBATw groups were −1.3 g/dL ± 1.3, −1.6 g/dL ± 0.98, and −1.1 g/dL ± 0.9, respectively (P = .098). The mean HB changes to the 7-day postprocedural nadir in the CDL, LBAT, and LBATw groups were −1.7 g/dL (SD ± 1.4), −2.4 g/dL (SD ± 1.3), and −1.8 g/dL (SD ± 1.3), respectively (P = .008). The minor hemorrhagic AE rates were 3.6% in the CDL group, 12.1% in the LBAT group, and 14.9% in the LBATw group (P = .010). There was no significant difference in moderate (P = .079) and major (P = .529) hemorrhagic AEs between the groups. There were no procedure-related mortalities. ConclusionsThe use of LBAT without ATD resulted in a significant decrease in HB to the 7-day postprocedural nadir compared with CDL or LBAT with ATD. This did not translate into significantly higher transfusion rates or moderate or major hemorrhagic events. Findings suggest that the decision between CDL and LBAT should not be based solely on the expected blood loss consideration.

Cell Salvage Using the Autotransfusion Device CATSmart®: A Randomized Controlled Bicentric Trial Evaluating the Quality of Two New Flex Wash Programs

Background: The use of cell salvage and autologous blood transfusion is an important and widespread method of blood conservation during surgeries with expected high blood loss. The continuous autotransfusion device CATSmart^® (Fresenius Kabi, Germany) contains two new washing programs on the device called Flex wash 3 and Flex wash 5. To the best of our knowledge, there are no published clinical data regarding the performance of the two new washing programs. Methods: In total, 69 patients undergoing cardiac or orthopedic surgery were included in this randomized, controlled, bicentric trial to validate the red cell separation process and washout quality of Flex wash 3 compared to Flex wash 5. After washing, the primary quality target was to determine hematocrit value, recovery rate, albumin, and total protein elimination rate in the packed red cells (PRCs). The secondary objective was to assess the elimination of heparin by measuring the factor anti-Xa activity by a 1- and 2-stage assay in PRC after washing. Results: In the whole cohort of patients, hematocrit was 16.00% [9.15%; 21.30%] (median [Q1; Q3]) in the wound blood and 69.90% [51.10%; 80.90%] in the PRC resulting in a recovery rate of 63.92% [47.06%; 88.13%]. The albumin elimination rate was 98.77% [97.94%; 99.27%], and the total protein elimination rate was 98.85% [97.76%; 99.42%]. The heparin elimination rate was 99.95% [99.90%; 99.97%] in the 1-stage assay and 99.70% [99.41%; 99.87%] in the 2-stage assay. There was no difference between Flex wash 3 and Flex wash 5 washing procedure regarding the recovery rate 63.75% [46.64%; 78.65%] versus 67.89% [47.20%; 92.69%] (p = 0.85), albumin elimination rate 98.74% [97.67%; 99.27%] versus 98.78% [98.10%; 99.28%] (p = 0.97), protein elimination rate 98.79% [97.94%; 99.47%] versus 98.92% [97.58%; 99.42%] (p = 0.88), and anti-Xa elimination rate in the 1-stage assay 99.94% [99.79%; 99.97%] versus 99.95% [99.92%; 99.97%] (p = 0.24) and in 2-stage assay 99.66% [99.20%; 99.86%] versus 99.77% [99.47%; 99.90%] (p = 0.23). Conclusions: The two new washing procedures, Flex wash 3 and Flex wash 5, enable sufficient and comparable red cell separation and washout quality of albumin, total protein, as well as heparin.

A novel autotransfusion device saving erythrocytes and platelets used in a 72 h survival swine model of surgically induced controlled blood loss.

The purpose of this study was to develop a swine model of surgically induced blood loss to evaluate the performances of a new autotransfusion system allowing red blood cells and platelets preservation while collecting, washing and concentrating hemorrhagic blood intraoperatively. Two types of surgically induced blood loss were used in 12 minipigs to assess system performance and potential animal complications following autotransfusion: a cardiac model (cardiopulmonary bypass) and a visceral model (induced splenic bleeding). Animal clinical and hematological parameters were evaluated at different time-points from before bleeding to the end of a 72-hour post-transfusion period and followed by a post-mortem examination. System performances were evaluated by qualitative and quantitative parameters. All animals that received the autotransfusion survived. Minimal variations were seen on the red blood cell count, hemoglobin, hematocrit at the different sampling times. Coagulation tests failed to show any hypo or hypercoagulable state. Gross and histologic examination didn't reveal any thrombotic lesions. Performance parameters exceeded set objectives in both models: heparin clearance (≥ 90%), final heparin concentration (≤ 0.5 IU/mL), free hemoglobin washout (≥ 90%) and hematocrit (between 45% and 65%). The device treatment rate of diluted blood was over 80 mL/min. In the present study, both animal models succeeded in reproducing clinical conditions of perioperative cardiac and non-cardiac blood loss. Sufficient blood was collected to allow evaluation of autotransfusion effects on animals and to demonstrate the system performance by evaluating its capacity to collect, wash and concentrate red blood cells and platelets. Reinfusion of the treated blood, containing not only concentrated red blood cells but also platelets, did not lead to any postoperative adverse nor thrombogenic events. Clinical and comparative studies need to be conducted to confirm the clinical benefit of platelet reinfusion.

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

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. 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. 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. 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.

Radiologic Intervention of Internal Iliac Artery Occlusion During Cesarean Section for Dangerous Placenta Previa

Objective: The cesarean section of dangerous placenta previa always faces the problem of massive hemorrhage. The aim of this study was to analyze the clinical effect of internal iliac artery occlusion combined with obstetric autotransfusion in cesarean section of dangerous placenta previa. Method: From November 2017 to November 2019, 20 patients with placenta previa undergoing cesarean section in our hospital were selected. According to the preoperative MRI and ultrasound diagnosis, the amount of bleeding was evaluated and divided into observation group (n = 6) and control group (n = 14). All patients underwent routine cesarean section and prepared the obstetric autotransfusion device. In the observation group, the internal iliac artery balloon was placed under DSA before operation. After the fetus was taken out, the internal iliac artery was blocked. The internal iliac artery occlusion was not needed in the control group. The total length of stay, Apgar score, the incidence of disseminated intravascular coagulation (DIC), hemorrhagic shock, postoperative infection and renal dysfunction were compared between the two groups. Result: Compared with the relative data in control group, the operation time and postoperative hospital stay of the observation group were significantly shorter, the intraoperative blood loss and blood transfusion were significantly lesser, and the hemoglobin difference before and after operation was significantly lesser. There was no significant difference in the incidence of DIC, hemorrhagic shock, postoperative infection and renal dysfunction between two groups; There was no significant difference in neonatal body mass, Apgar score at 1 min and 5 min. Conclusion: The internal iliac artery occlusion can effectively reduce the amount of bleeding in delivery, promote the recovery of negligence, and have no adverse effect on complications and neonatal outcome.

Radiologic Intervention of Internal Iliac Artery Occlusion During Cesarean Section for Dangerous Placenta Previa

Objective: The cesarean section of dangerous placenta previa always faces the problem of massive hemorrhage. The aim of this study was to analyze the clinical effect of internal iliac artery occlusion combined with obstetric autotransfusion in cesarean section of dangerous placenta previa. Method: From November 2017 to November 2019, 20 patients with placenta previa undergoing cesarean section in our hospital were selected. According to the preoperative MRI and ultrasound diagnosis, the amount of bleeding was evaluated and divided into observation group (n = 6) and control group (n = 14). All patients underwent routine cesarean section and prepared the obstetric autotransfusion device. In the observation group, the internal iliac artery balloon was placed under DSA before operation. After the fetus was taken out, the internal iliac artery was blocked. The internal iliac artery occlusion was not needed in the control group. The total length of stay, Apgar score, the incidence of disseminated intravascular coagulation (DIC), hemorrhagic shock, postoperative infection and renal dysfunction were compared between the two groups. Result: Compared with the relative data in control group, the operation time and postoperative hospital stay of the observation group were significantly shorter, the intraoperative blood loss and blood transfusion were significantly lesser, and the hemoglobin difference before and after operation was significantly lesser. There was no significant difference in the incidence of DIC, hemorrhagic shock, postoperative infection and renal dysfunction between two groups; There was no significant difference in neonatal body mass, Apgar score at 1 min and 5 min. Conclusion: The internal iliac artery occlusion can effectively reduce the amount of bleeding in delivery, promote the recovery of negligence, and have no adverse effect on complications and neonatal outcome.

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.

Comparison of three autotransfusion devices for utilization in the pediatric population.

A device that may help attenuate the amount of homologous blood product given to pediatric cardiac surgical patients is the autotransfusion device. Three separate autotransfusion devices were selected for evaluation. The Sorin Xtra, Fresenius Continuous Autotransfusion System Plus (CATS*plus), and the Fresenius Continuous Autotransfusion System Smart (CATSmart) were evaluated based on the mechanical processes of each device, hematocrit value of the salvaged packed red cell product, time of processing, and the advantageous accessories with each device. Each of the autotransfusion devices were used to collect salvageable blood from the surgical field as well as to process residual blood from the cardiopulmonary bypass circuit after decannulation. The cell salvage process was performed in accordance with the manufacturer's instructions for use and the recommended settings for processing and washing. The Sorin Xtra device had the 55 mL bowl set up for all cases, while the Fresenius continuous autotransfusion systems utilized the standard disposable for each device. Each cell salvage device was employed during 30 pediatric cardiac surgery procedures, and data for each device, was broken down into four groups based on patient weight (0-10, 10-20, 20-40, and >40 kg). For all patient sizes, the Sorin Xtra tended to produce the greatest volume of cell saver product (55-825 mL) as compared to the CATS*plus and CATSmart devices (7-550 mL and 0-860 mL, respectively). The Continuous Autotransfusion System Smart tended to produce the highest hematocrit product, ranging from 44 to 81%. Through this evaluation, it was determined the continuous autotransfusion systems provided the highest hematocrit with the lowest recovered packed red cell volume, while the Sorin Xtra packed red cell product showed to have a lower hematocrit with a larger packed red cell volume. Each device proved effective within our pediatric population.

Interval analysis of blood filtration efficacy in novel device for autotransfusion in postpartum hemorrhage

Postpartum haemorrhage (PPH), the leading cause of maternal mortality, is particularly problematic in low resource settings where access to safe blood supplies and definitive medical treatment is limited. We describe the continued development of an autotransfusion device designed to treat PPH by collection, filtration and infusion of maternal blood. Previous study has demonstrated that the device effectively moves blood through a filtration apparatus and removes up to 97% of aerobic bacteria but had poor anaerobic bacteria reduction. In this study, we investigate the filtration efficacy of the device using configurations comprised of three different leukocyte depletion filter designs: the Pall Leukoguard RS leukocyte reduction filter (PLRF), the Haemonetics BPF4™ (BPF4) leukocyte reduction filter, and the Haemonetics SCRC Leukotrap® (SCRC) filter. All configurations performed well with reductions ranging from 49 to 98%. Configurations containing 2 Haemonetics SCRC Leukotrap®filters (configuration 5 and 6) consistently reduced anaerobic bacteria by at least 73%. These results indicate that utilising a combination of SCRC and PLRF filters confers a high level of microbial filtration with improved removal of anaerobic organisms.

Cell salvage using the continuous autotransfusion device CATSmart \u2013 an observational bicenter technical evaluation

BackgroundThe use of cell salvage and autologous blood transfusion has become an important method of blood conservation. So far, there are no clinical data about the performance of the continuous autotransfusion device CATSmart.MethodsIn total, 74 patients undergoing either cardiac or orthopedic surgery were included in this prospective, bicenter and observational technical evaluation to validate red cell separation process and washout quality of CATSmart. The target of red cell separation process was defined as a hematocrit value in the packed red cell unit of 55–75% and of washout quality of 80–100% removal ratio.ResultsHematocrit values measured by CATSmart and laboratory analysis were 78.5% [71.3%; 84.0%] and 73.7% [67.5%; 75.5%], respectively. Removal ratios for platelets 94.7% [88.2%; 96.7%], free hemoglobin 89.3% [85.2%; 94.9%], albumin 97.9% [96.6%; 98.5%], heparin 99.9% [99.9%; 100.0%], and potassium 92.5% [90.8%; 95.0%] were within the target range while removal of white blood cells was slightly worse 72.4% [57.9%; 87.3%].ConclusionThe new autotransfusion device enables sufficient red cell separation and washout quality.

Platelet sequestration with a new-generation autotransfusion device.

Autologous platelet-rich plasma (PRP) can be used either to prevent platelets (PLTs) from lesions during extracorporeal circulation or for wound therapy, when processed into PLT gel. The aim of this study was to evaluate the PLT sequestration abilities of a new-generation autotransfusion device. In this experimental study the discontinuous, new-generation autotransfusion device XTRA was evaluated using fresh donor blood. The blood was processed in four different size bowls (X55, X125, X175, X225 [bowls' size in mL]) using the device's built-in "PLT sequestration program." PLT functionality was tested using aggregometry; for PLT activation, β-thromboglobulin (β-TG) and soluble P-selectin levels were determined. Cell damage was assessed by a morphology score and hypotonic shock response. Additionally, PLTs were tested after 6 hours to identify storage lesions. Platelet recovery in the PRP ranged from 39% to 64% and averaged 6.2-fold PLT enrichment as defined by the increase in PLT concentration. The preparation caused minimal cell damage and a decrease in cell function by only 10%, but a slight activation was observed amounting to 9% of the maximal β-TG release. The efficiency of the preparation, represented by the PLT recovery rate, increased in a linear fashion with the increasing bowl sizes being tested. After 6 hours of storage the prepared PLTs showed an additional 9% loss in function, but only 4% decrease in viability. The autotransfusion device XTRA was capable of high-quality perioperative PRP preparation, and the bowl size was found to have an influence on the efficiency of the preparation.

Comparison of stored red blood cell washing techniques for priming extracorporeal circuits.

The aim of this study was to compare three different blood washing techniques and describe the differences for the composition of the washed red blood cells (RBC). Stored RBCs less than 5 days old were washed using three different techniques. 1) Washing with normal saline with the COBE Model 2991 blood processor in the blood bank (BB-S). 2) Washing with normal saline with the Continuous AutoTransfusion System (C.A.T.S) in the operating room (OR-S). 3) Washing with Plasma-Lyte with the C.A.T.S in the operating room (OR-PL). Then, we compared the values for hemoglobin (Hb), hematocrit (Hct), blood volume, RBC volume, lactate, glucose, sodium and potassium of the three different groups. Forty-five units of RBCs were washed and analyzed (15 for each technique). The OR-S RBCs, when compared to the BB-S RBCs, had lower hemoglobin (g/dL) (22.8 vs 24.1, p=0.006), lower hematocrit (%) (67 vs 71, p=0.006), higher RBC volume (ml) (161 vs 130, p<0.001), higher glucose (mg/dL) (185 vs 46, p<0.001) and lower sodium (mmol/L) (153 vs 158, p<0.001). When compared to the OR-S RBCs, the OR-PL RBCs showed higher potassium (mmol/L) (5.3 vs 2, p<0.001) and lower sodium (mmol/L) (129 vs 153, p<0.001). RBCs washed with an autotransfusion device had a higher RBC volume and more physiological levels of glucose and sodium when compared with the blood processor in the blood bank. It can be an alternative option to use RBCs washed with an autotransfusion device for priming the extracorporeal circuits utilized in patients undergoing cardiac surgery.

Performance of a new-generation continuous autotransfusion device including fat removal and consequences for quality controls.

Cell salvage plays a key role in blood conservation. To maintain high performance, quality management is recommended. Accordingly, a new-generation autotransfusion device was tested for its performance and compared with its predecessor. Two different calculations of quality parameters were applied. In an experimental study, the continuous autotransfusion devices CATSmart and Continuous Autotransfusion System (C.A.T.S) plus were tested using banked blood adjusted to a haematocrit of 20% and anticoagulated with heparin 5 U/L. Test blood was processed using an emergency programme, a high-quality programme/smart wash programme and a low-volume wash programme. Samples were taken after the production of 200 mL of red blood cells (RBC) and after the final emptying of the separation chamber. In an additional set of tests, blood containing 1·25% fat was processed with both devices to examine fat removal. Both devices demonstrated an equally high performance with regards to product hematocrit (Hct); RBC recovery; and elimination rates of protein, heparin and fat. The high fat elimination rate (>99·8%) reported for C.A.T.S plus was confirmed for CATSmart, regardless of the used programme. Samples taken during the ongoing process show a higher haematocrit and RBC recovery rate than samples taken after the final emptying of the separation chamber. Interface sensors were not affected by fat in the blood. The new-generation autotransfusion device CATSmart is not inferior to its predecessor and shows high performance with regards to RBC recovery, plasma and fat elimination in all programme modes. Samples for quality controls should be taken during blood processing.

Blood Conservation in Orthopedic Trauma

In the setting of acute orthopedic trauma, blood management strategies are reactive rather than anticipatory, and patients may not receive the same options offered in elective surgery. There are several strategies for conserving blood, but it is not feasible for the orthopedic traumatologist to be familiar with the complexities of each method. Instead, practical options and those routinely offered at trauma centers should be considered. Evidence supports tolerable transfusion thresholds of hemoglobin concentrations of 7 and 8 g/dL for patients with and without history of cardiac disease, respectively. Cell salvage reduces the need for transfusions and produces modest cost savings in cases with blood loss exceeding 500 mL. Although researchers are still investigating the efficacy of tranexamic acid in orthopedic trauma, other large randomized controlled trials in the setting of general trauma, as well as in arthroplasty and spine surgery, have shown significant reductions in blood loss without increased risk of venous thromboembolism. Currently, little evidence supports the use of autotransfusion devices and biological adhesives in orthopedic trauma. Erythropoietin aids in blood conservation, but at an unacceptably high cost. Intravenously administered iron may help patients recover from postoperative anemia. There are few large, rigorous studies of blood management in orthopedic trauma; therefore, expert opinion, logical deduction, and practical reasoning are necessary to determine appropriate strategies on a case-by-case basis.

Flow Sensor in Devices for Autotransfusion

This article describes an original multi-channel flow sensor in the TRANSFEL autotransfusion device. The flow sensor in the TRANSFEL device is based on digital processing of multiple CRGB channels. The article presents the position of the sensor in the TRANSFEL device and its principle of operation and structure. Experimental results demonstrate the advantage of this sensor over its analogues since it more precisely defines the composition of the fluid going into the waste line.

Reliability of different parameters for rapid bedside evaluation of clearance rates of salvaged blood

Objective To evaluate the reliability of the clearance rates of free hemoglobin (fHb), K+ and Ca2+ for rapid bedside evaluation of the clearance rates of the salvaged blood. Methods Twenty-six patients of both sexes, aged 18-80 yr, with body mass index<32 kg/m2, of American Society of Anesthesiologists physical statusⅠ-Ⅲ, scheduled for elective surgery requiring autologous blood withdrawal-reinfusion, were involved in this study. An autotransfusion device (continuous autotransfusion system, Fresenius) was used to collect the blood shed from the surgical field and to process the salvaged blood during the surgery. The clearance rates of albumin (Alb), fHb, K+ and Ca2+ were detected in three washing modes (big flux, standard, high quality). Results Compared with the clearance rate of Alb, the clearance rates of K+ ( 0.05). There was no significant difference in the clearance rates of each parameter between the three washing modes(P>0.05). Conclusion When the autotransfusion device continuous autotransfusion system is used to collect the blood, the clearance rates of fHb and Ca2+ can be used as parameters for rapid bedside evaluation of the clearance rates of the salvaged blood, while Ca2 + detection is more convenient, and therefore it is superior to fHb. Key words: Blood transfusion, autologous; Point-of-care systems; Elimination rate

Blood Level Sensor Based on Digital Video Analyzer for Autotransfusion Devices

Results of studies of an original blood level sensor designed for use in an apparatus for intraoperative blood autotransfusion and tested in conjunction with a classical (photoelectric) sensor in the Transfel device from the Scientific Technical Center ELINS are described. The principle of operation of the sensor is based on the definition of red blood cell boundaries in a separating bell, which allows the highest possible hematocrit level in the final product. Internal sensor circuitry, algorithm, and the results of its tests (obtained HTC > 60%) are presented. Disposable sets with 125- and 225-ml Latham-type bells were used. In the Appendix, the main characteristics of the Transfel autotransfusion device are presented.

Influence of the washing program on the blood processing performance of a continuous autotransfusion device

The continuous autotransfusion system has been widely used in surgical operations. It is known that if oil is added to blood, and this mixture is then processed by an autotransfusion device, the added oil is removed and reinfusion of fat is prevented by the device. However, there is no detailed report on the influence of the particular washing program selected on the levels of blood components including blood fat after continuous autotransfusion using such a system. Fresh bovine blood samples were processed by a commercial continuous autotransfusion device using the "emergency," "quality," and "high-quality" programs, applied in random order. Complete blood count (CBC) and serum chemistry were analyzed to determine how the blood processing performance of the device changes with the washing program applied. There was no significant difference in the CBC results obtained with the three washing programs. Although all of the blood lipids in the processed blood were decreased compared to those in the blood before processing, the levels of triglyceride, phospholipid, and total cholesterol after processing via the emergency program were significantly higher than those present after processing via the quality and high-quality programs. Although the continuous autotransfusion device provided consistent hematocrit quality, the levels of some blood lipid components showed significant differences among the washing programs.

Blood loss, predictors of bleeding, transfusion practice and strategies of blood cell salvaging during liver transplantation

Blood loss during liver transplantation (OLTx) is a common consequence of pre-existing abnormalities of the hemostatic system, portal hypertension with multiple collateral vessels, portal vein thrombosis, previous abdominal surgery, splenomegaly, and poor "functional" recovery of the new liver. The intrinsic coagulopathic features of end stage cirrhosis along with surgical technical difficulties make transfusion-free liver transplantation a major challenge, and, despite the improvements in understanding of intraoperative coagulation profiles and strategies to control blood loss, the requirements for blood or blood products remains high. The impact of blood transfusion has been shown to be significant and independent of other well-known predictors of posttransplant-outcome. Negative effects on immunomodulation and an increased risk of postoperative complications and mortality have been repeatedly demonstrated. Isovolemic hemodilution, the extensive utilization of thromboelastogram and the use of autotransfusion devices are among the commonly adopted procedures to limit the amount of blood transfusion. The use of intraoperative blood salvage and autologous blood transfusion should still be considered an important method to reduce the need for allogenic blood and the associated complications. In this article we report on the common preoperative and intraoperative factors contributing to blood loss, intraoperative transfusion practices, anesthesiologic and surgical strategies to prevent blood loss, and on intraoperative blood salvaging techniques and autologous blood transfusion. Even though the advances in surgical technique and anesthetic management, as well as a better understanding of the risk factors, have resulted in a steady decrease in intraoperative bleeding, most patients still bleed extensively. Blood transfusion therapy is still a critical feature during OLTx and various studies have shown a large variability in the use of blood products among different centers and even among individual anesthesiologists within the same center. Unfortunately, despite the large number of OLTx performed each year, there is still paucity of large randomized, multicentre, and controlled studies which indicate how to prevent bleeding, the transfusion needs and thresholds, and the "evidence based" perioperative strategies to reduce the amount of transfusion.

In vitro comparison of two different methods of cell washing

The storage of red blood cells (RBC) results in increased concentrations of plasma free hemoglobin, potassium, glucose, and lactate, among other undesirable substances. These concentrations continue to increase as RBC products age and can cause deleterious effects to the patient. In the setting of cardiac surgery, the autotransfusion devices are routinely used to wash blood that is shed from the surgical site. These devices could also be used to wash stored RBC units obtained from the blood bank. The objective of this study was to compare the product created by washing a unit of RBCs with the AutoLog autotransfusion device in the operating room to the washed products from a standard cell washer in the blood bank. Eleven outdated RBC units (stored for >42 days at 4 °C) were split in half. One half was washed using the Medtronic AutoLog device; the other half was washed using the blood bank's Cobe 2991 Cell Processor. Analytes were measured on samples from the unwashed parent unit and from the washed daughter units. The parameters measured included hematocrit, free hemoglobin, lactate, lactate dehydrogenase (LDH), potassium, glucose, and pH. When compared to the original untreated RBCs, the glucose, lactate, and potassium levels were decreased when washed in an autotranfusion device. Additionally, the free hemoglobin and LDH levels were significantly lower with the Medtronic Autolog cell saver than in the COBE 2991 Cell Processor. Washing the RBC donor units in an autotransfusion device prior to transfusion can effectively attenuate the increases seen in glucose, potassium, free hemoglobin, and LDH associated with RBC storage lesion.