Regional transfusion centre preoperative autologous blood donation programme: the first two years.

OBJECTIVE--To assess the efficacy of a regional autologous blood donation programme. DESIGN--Clinical and laboratory data were collected and stored prospectively. Transfusion data were collected retrospectively from hospital blood bank records. SETTING--Northern Region Blood Transfusion Service and 14 hospitals within the Northern Regional Health Authority. SUBJECTS--505 patients referred for autologous blood donation before elective surgery. MAIN OUTCOME MEASURES--Patient eligibility, adverse events from donation, autologous blood units provided, and autologous and allogeneic blood units transfused within 10 days of operation. RESULTS--Of 505 patients referred, 354 donated at least one unit. 78 of 151 referred patients who did not donate were excluded at the autologous clinic, mostly because of anaemia or ischaemic heart disease. In 73 cases the patient, general practitioner, or hospital consultant decided against donation. 363 autologous procedures were undertaken. In 213 (59%) cases all requested units were provided. The most common reasons for incomplete provision were late referral or anaemia. Adverse events accompanied 24 of 928 donations (2.6%). Transfusion data were obtained for 357 of the 363 procedures. 281 donors were transfused; autologous blood only was given to 225, autologous and allogeneic blood was given to 52, and allogeneic blood only was given to four. 648 of 902 (72%) units of autologous blood were transfused. Complete provision of requested autologous units was followed by allogeneic transfusion in 12 of 208 procedures (5.8%). Incomplete provision was followed by allogeneic transfusion in 44 of 149 procedures (30%). CONCLUSIONS--This study shows the feasibility of a regional autologous transfusion programme. Autologous donors only infrequently received allogeneic transfusion. Patients should be appropriately selected and referred early.     

The use of intraoperative autotransfusion during cranial vault remodeling for craniosynostosis.

Intraoperative autotransfusion salvages blood shed during surgery for use in immediate resuscitation of the patient. The purpose of this study was to determine whether such autotransfusion decreases the volume of homologous blood transfused in patients undergoing primary cranial vault remodeling for craniosynostosis. The Cobe-Bret 2 autologous blood recovery system (Hemo Concepts, Union, N.J.) was used in 11 cases, and an equal number of consecutive cases did not receive intraoperative autotransfusion. There were no significant differences between the groups with respect to age, sex, and weight. Mean estimated blood loss was 43.2 ml/kg (range, 20.3 to 65.0 ml/kg) in the intraoperative autotransfusion group and 40.2 ml/kg (range, 6.8 to 72.3 ml/kg) in the control group (not statistically significant; p < 0.05). There was no significant difference in volume of homologous blood transfusion between the two groups. The autotransfusion group received 34.1 ml/kg of homologous blood (range, 0 to 60.7 ml/kg), and the control group received a mean of 32.7 ml/kg (range, 14.5 to 60.2 ml/kg). The autotransfusion group received a mean of 10.4 ml/kg of recovered autologous blood (range, 0 to 21.4 ml/kg). In four of the 11 autotransfusion patients, insufficient autologous blood was recovered intraoperatively to warrant transfusion. Results of this study suggest little benefit for the use of intraoperative autotransfusion in primary cranial vault remodeling for craniosynostosis in the young patient. It was hypothesized that this finding was a result of the following: (1) intraoperative autotransfusion blood was usually available only toward the end of the procedure, after homologous blood had already been administered, and (2) the volume of recovered intraoperative autotransfusion blood is minimal, compared with the homologous transfusion volume requirements during an extensive cranial vault remodeling and fronto-orbital advancement procedure. In the context of unproven cost benefit and increasing similar evidence from other comparative studies, emphasis should be directed to other medical and surgical strategies to minimize the need for perioperative blood transfusion.     

Cost of allogeneic and autologous blood transfusion in Canada. Canadian Cost of Transfusion Study Group.

OBJECTIVE: To determine the cost, from a societal perspective, of blood transfusion in Canada. STUDY DESIGN: Cost-structure analysis. SETTING: Data were collected from eight hospitals and from six blood centres operated by the Canadian Red Cross Society in four provinces. OUTCOME MEASURES: Costs associated with four stages of transfusion-- collection, production, distribution and delivery--in 1933 were assessed. Costs were divided into the following categories; personnel, purchases, external services, overhead, donors'' time, patients'' time (for autologous transfusion), wastage and infection. RESULTS: The mean overall cost of a transfusion performed on an inpatient basis was $210 per unit of red blood cells for an allogeneic transfusion and $338 per unit of blood for an autologous transfusion. The mean cost of an allogeneic transfusion performed on an outpatient basis was $280 per unit of red blood cells. CONCLUSION: The costs determined in this study can be used in future studies comparing the cost-effectiveness of allogeneic transfusion with that of alternative methods.     

Mechanical methods of reducing blood transfusion in cardiac surgery: randomised controlled trial

ObjectiveTo assess the effectiveness of two mechanical methods of blood conservation in reducing the need for allogeneic red blood cells or coagulation products during cardiac surgery.DesignRandomised controlled trial.SettingRegional cardiac centre in a teaching hospital in Southampton.Participants263 adults aged 18-80 years undergoing elective coronary artery bypass surgery entered the study, of whom 252 completed the trial. All patients received routine perioperative care. Patients were allocated to one of three treatment groups: intraoperative cell salvage, intraoperative cell salvage with acute perioperative normovolaemic haemodilution, or no mechanical blood conservation. There were 84 patients in each group.ResultsOf the patients in the intraoperative cell salvage group, 26 were given a transfusion of allogeneic blood, compared with 43 in the control group (odds ratio 0.43 (95% confidence interval 0.23 to 0.80)). The mean number of units of allogeneic blood transfused per patient in the intraoperative cell salvage group was 0.68 units (SD=1.55), compared with 1.07 (1.56) units in the control group. 32 of the patients in the intraoperative cell salvage group were given any blood product, compared with 47 in the control group (odds ratio 0.47 (0.25 to 0.89); P=0.019). Combining acute perioperative normovolaemic haemodilution with intraoperative cell salvage conferred no additional benefits.ConclusionsAn intraoperative cell salvage device should be used in elective coronary artery bypass grafting. Pharmacological strategies may achieve further reductions in blood transfusions. Yet further reductions in blood transfusions could be achieved if the lower safe limit of haemoglobin concentration in patients undergoing cardiac surgery were known.

What is already known on this topic

Patients undergoing elective coronary artery bypass surgery often need a blood transfusionRecent meta-analyses have shown that the mechanical blood conservation techniques of intraoperative cell salvage and acute perioperative normovolaemic haemodilution may reduce the need for transfusion, but flawed methods in trials mean that clear evidence in cardiac surgery is lacking

What this study adds

Intraoperative cell salvage significantly reduces the number of patients needing an allogeneic blood transfusionCombining acute perioperative normovolaemic haemodilution with intraoperative cell salvage does not confer any additional benefit     

The effect of partial removal of yolk on the chilling sensitivity of zebrafish (Danio rerio) embryos

In a group of 39 patients with ischemic heart and valvular disease (January 1997 to May 1998), three platelet collection methods were compared in terms of safety and effectiveness. The methods were: (i) collection of autologous platelets over several weeks and freezing them for storage until surgery (frozen group, 12 patients); (ii) collection of autologous platelets on the day before surgery and preserving them without freezing (fresh group, 8 patients); and (iii) collection of autologous platelets intraoperatively (intraoperative group, 9 patients). Ten patients served as controls (control group). Blood pressure was not significantly affected by platelet collection in the frozen and fresh groups, but both systolic (P < 0.01) and diastolic blood pressure (P < 0.05) decreased significantly after collecting platelets in the intraoperative group. Similarly, heart rate was unaffected by platelet collection in the frozen and fresh groups, while it increased significantly in the intraoperative group (P < 0.05). Blood loss after 24 h was significantly smaller in the fresh group than in the frozen group (P < 0.05). Total blood transfusion volume was significantly smaller in the frozen and fresh groups than in the intraoperative and control groups (P < 0.05). Bleeding time 2 h postoperatively, when administration of autologous platelets had been completed, was reduced compared with immediately postoperative values in all three groups receiving autologous platelets (P < 0.05). However, only the frozen and fresh groups showed a significantly shorter bleeding time than the control group (P < 0.05). In all three groups receiving autologous platelets, the platelet count was significantly increased after administration of autologous platelets, but only the fresh group had a platelet count that was significantly greater than the control group (P < 0.05). From these results we conclude that the frozen and fresh groups received safer treatment than the intraoperative group. Although hemostasis improved after all three regimes of autologous platelet transfusion, only the frozen and fresh groups had a reduced need for allogeneic blood transfusion compared with the control group. For this reason we conclude that the frozen and fresh groups were also superior to the intraoperative group in terms of effectiveness. However, the recovery of platelets after frozen storage was low, and to obtain a good effect with the freezing method it is necessary to collect and store large volumes of platelets. In terms of simplicity, safety, and efficacy, the fresh method seems to be the preferred technique.     

Collection, storage and transfusion of blood stem cells for the treatment of hemopoietic failure.

Migration of hemopoietic stem cells via the blood to sites of stem cell need is a principle that becomes established during the embryonic development of hemopoiesis and can be observed in the adult whenever bone marrow transplantations are being performed. The regular presence of stem cells in the peripheral blood lends itself to the study of their collection, storage, and use for transfusion purposes in cases of bone marrow failure. Both in dog and in man, granulocyte-macrophage progenitor cells (CFU-C) can be collected by leukapheresis from the blood in large quantities, particularly if the yield is increased by the administration of mobilizing agents such as dextran sulfate, and appear to be an indicator for the presence of stem cells. For collection and storage, a closed plastic bag system has been developed that allows the safe handling of the cells. The loss of CFU-C from freezing and thawing with DMSO as a cryoprotective agent is only 10%-20%. If frozen and thawed mononuclear leukocytes are transfused into 1200 rad whole-body X-irradiated autologous or allogeneic recipient dogs, a hemopoietic take is observed when 0.2 X 10(5) CFU-C are present among the mononuclear leukocytes (MNC). Graft-versus-host disease can be avoided in the allogeneic situation when a purified CFU-C rich cell fraction is being transfused. In man collection and storage of MNC including CFU-C is feasible and may eventually become a therapeutic tool.     

Where does blood go? Prospective observational study of red cell transfusion in north England

ObjectiveTo collect population based information on transfusion of red blood cells.DesignProspective observational study over 28 days.SettingHospital blood banks in the north of England (population 2.9 million).ParticipantsAll patients who received a red cell transfusion during the study period. Data completed by hospital blood bank staff.ResultsThe destination of 9848 units was recorded (97% of expected blood use). In total 9774 units were transfused: 5047 (51.6%) units were given to medical patients, 3982 (40.7%) to surgical patients, and 612 (6.3%) to obstetric and gynaecology patients. Nearly half (49.3%) of all blood is given to female recipients, and the mean age of recipients of individual units was 62.7 years. The most common surgical indications for transfusion were total hip replacement (4.6% of all blood transfused) and coronary artery bypass grafting (4.1%). Haematological disorders accounted for 15.5% of use. Overall use was 4274 units per 100 000 population per year.ConclusionIn the north east of England more than half of red cell units are transfused for medical indications. Demand for red cell transfusion increases with age. With anticipated changes in the age structure of the population the demand for blood will increase by 4.9% by 2008.

What is already known on this topic

There have been no systematic population based surveys on use of red cells in the United KingdomStudies in France and the United States have shown that more than half of transfused red cells go to surgical patients

What this study adds

In the north of England over half of red cells are given for medical indicationsRates of red cell transfusion rise steeply with advancing ageSmall increases in the number of elderly people will have large effects on demand     

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

Background

The 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.

Methods

In 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.

Results

Hematocrit 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%].

Conclusion

The new autotransfusion device enables sufficient red cell separation and washout quality.

     

三种自体输血方法在剖宫产手术中应用的适宜性分析

目的:分析三种自体输血方法在剖宫产手术中的可行性与易行性。方法:根据孕产妇的生理特点,分别对三种自体输血方法在应用中可能出现的问题及优缺点进行针对性的研究分析。结果:贮存式自体输血在操作时间上较灵活,贮血量较大,但环节较多,相对繁琐;稀释式自体输血极为契合产妇的生理特点,可提供血液贮备,也能促进机体组织细胞对氧的摄取和利用,但一次性采血量会有局限;回收式自体输血无需对产妇本身进行直接操作,患者相对容易接受,但由于回收血液可能会受到羊水和胎儿血液污染,在实际工作中应用很少。结论:三种自体输血方式各有利弊,但稀释式自体输血由于其简单易行且适合于产妇的生理特点,在剖宫产手术的应用中可行性更高。对于预计出血量极大的情况,可考虑两种或三种自体输血方式的联合应用。     

自体输血与异体输血对创伤性颅脑损伤开颅手术患者凝血功能、细胞免疫功能和神经损伤标志物的影响

摘要 目的：探讨自体输血与异体输血对创伤性颅脑损伤（TBI）开颅手术患者凝血功能、细胞免疫功能和神经损伤标志物的影响。方法：回顾性分析2019年4月~2022年5月期间在本院行开颅手术的120例TBI患者的临床资料。根据输血方式的不同将患者分为异体输血组（n=58,异体输血）和自体输血组（n=62,自体输血）,观察两组临床指标、细胞免疫功能、凝血功能、神经损伤标志物和不良反应发生率情况。结果：两组患者手术出血量、输血量、输注含凝血成分血制品比例对比,差异无统计学意义（P>0.05）。自体输血组出院时CD3⁺、CD4⁺、CD4⁺/CD8⁺高于异体输血组,CD8⁺低于异体输血组（P<0.05）。两组出院时凝血酶原时间（PT）、凝血酶时间（TT）、纤维蛋白原（FIB）、活化部分凝血活酶时间（APTT）组间对比无统计学差异（P>0.05）。自体输血组出院时S100钙结合蛋白B（S100B）、神经胶质原纤维酸性蛋白（GFAP）、神经元特异性烯醇化酶（NSE）低于异体输血组（P<0.05）。两组不良反应发生率组间比较无差异（P>0.05）。结论：自体输血用于TBI开颅手术患者,对患者的凝血功能影响较小,同时还可改善机体细胞免疫功能,降低神经损伤标志物水平。     

Homologous blood use and conservation techniques for cardiac surgery in the United Kingdom.

The transfusion laboratories of 32 cardiothoracic surgical centres for adults were surveyed to determine the donor blood requirement for open heart surgery in the United Kingdom. Details of the transfusion practice and the use of blood conservation techniques were sought from a representative senior cardiac anaesthetist at each centre. Suitable data were received from 24 transfusion laboratories (75%) and 29 anaesthetists (90%). The mean (SD) blood use was 5.07 (1.53) units per operation. Seven centres routinely transfused fresh frozen plasma to all patients postoperatively. Experience with autologous deposit (three centres), "cell separators" (four centres), and the reinfusion of shed mediastinal blood (four centres) was limited. Prebypass phlebotomy for postbypass reinfusion (14 centres) and the infusion of residual oxygenator blood (27 centres) were the conservation techniques most commonly applied. In only nine centres was a postoperative normovolaemic anaemia to a haemoglobin concentration of less than 100 g/l accepted. Applying blood conservation techniques more widely would help to maintain blood supplies and reduce morbidity and mortality related to transfusion.     

Analysis of the shelf life and transfusion life of whole blood and erythrocyte concentrates

The shelf life of 60,000 units of whole blood and red cell concentrates in the blood center were analysed before delivering to hospitals as well as the transfusion age of 18,000 units in relation to the stock-size and the outdated units. The mean transfusion age of whole blood units and red blood cell concentrates amounted to 11 to 12 days and 16 to 17 days, respectively. The shelf life of blood transfused within 24 hours after collection was 1.6% and 3.8% transfused within 48 hours according to the total number of whole blood and red blood cell concentrates. Washed red cell concentrates were prepared from buffy coat-free resuspended red cell concentrates on an average at the 7th day of storage. A high stock-size of about 1,000 units rather than of 600 units in the blood center increased the shelf life and also the number of outdated units from less than 0.5% up to more than 3%.     

Preoperative Acute Normovolaemic Hemodilution (ANH) in combination with Hypotensive Epidural Anaesthesia (HEA) during knee arthroplasty surgery. No effect on transfusion rate. A randomized controlled trial [ISRCTN87597684]

BACKGROUND: Hypotensive epidural anaesthesia (HEA) combines a high epidural anaesthesia, performing a sympathetic blockade, with low-dose iv-infusion of epinephrine to stabilize circulation in the conscious patient. Mean artery blood pressure is reduced to 45-50 mmHg and hereby a reduced blood loss. In this study we have combined HEA with preoperative acute normovolaemic hemodilution (ANH) in attempt to further reduce the blood loss and need for blood transfusion in total knee arthroplasty surgery (TKR). METHODS: Twenty-eight patients scheduled for TKR are randomised to ANH or no hemodilution (non-ANH). Both groups are anaesthetized with HEA. ANH is established with predonation of 20 % of the total blood volume, and replacement with equal volume of HAES 6 %. Blood re-transfusion is completed within 6 h. RESULTS: A mean of 877 ml blood was predonated (19.7 % of the total blood volume). Blood loss was, except from the intraoperative loss, significantly higher in ANH group. The total loss was 1306 mL (ANH) vs. 1026 mL (non-ANH), p < 0.05. Except from the first hour postoperatively, hematocrit was identical in between groups postoperatively. The amount of blood transfusion was identical 386 ml (ANH) vs. 343 ml (non-ANH) (ns). 50 % went through surgery without receiving blood (ANH) vs. 58 % (non-ANH). No renal, neurological or cardiopulmonary complications were registered. CONCLUSIONS: These data suggest no benefits in combining HEA and ANH in TKR surgery. Probably because of the reduced viscosity of the blood after ANH, there is an increased postoperative blood loss. The need for homologous blood transfusion was identical.     

Retransfusion of unwashed drainage blood after total hip and knee arthroplasty]

The method of retransfusion of drainage blood as known from the literature was investigated in a prospectiv study regarding effectivness and rate of side effects. 200 patients who underwent total hip and knee arthroplasty were investigated concerning hemoglobin, hematocrit, amount and quality of the retransfused drainage blood, the amount of autologous and homologous transfusions as well as complications and costs. 100 of these patients were selected as the control group. The amount of the retransfused drainage blood after hip arthroplasty amounted an average of 387 +/- 194 ml and after knee arthroplasty 595 +/- 250 ml. The retransfused blood had an average hemoglobin of 5,2 +/- 0,9mmol/l with a hematocrit of 0,24 0,05. No complications directly associated to the retransfusion were found. The need of transfusion was reduced for patients with knee arthroplasty about 30% and for hip arthroplasty about 25%. The retransfusion of unwashed drainage blood is a sufficient method to reduce perioperative homologous blood transfusion in patients with arthroplasty of hip and knee. Substantial complications were not observed, so that this method seems to be save enough for clinical usage. The method is easy to handle and usable without special technical devices. The autologous retransfusion of drainage blood can contribute to lower costs in patients treatement.     

Autologous versus allogeneic transfusion: patients' perceptions and experiences

BACKGROUND: Preoperative autologous donation is one way to decrease a patient''s exposure to allogeneic blood transfusion. This study was designed to determine patients'' perceptions about the autologous blood donation process and their experiences with transfusion. METHODS: To assess patient perception, a questionnaire was administered a few days before surgery to patients undergoing elective cardiac and orthopedic surgery in a Canadian teaching hospital. All patients attending the preoperative autologous donation clinic during a 10-month period were eligible. A convenience sample of patients undergoing the same types of surgery who had not predonated blood were selected from preadmission clinics. Patient charts were reviewed retrospectively to assess actual transfusion practice in all cases. RESULTS: A total of 80 patients underwent cardiac surgery (40 autologous donors, 40 nondonors) and 73 underwent orthopedic surgery (38 autologous donors, 35 nondonors). Of the autologous donors, 75 (96%) attended all scheduled donation appointments, 73 (93%) said that they were "very likely" or "likely" to predonate again, and 75 (96%) said that they would recommend autologous donation to others. There was little difference in preoperative symptoms between the autologous donors and the nondonors, although the former were more likely than the latter to report that their overall health had remained the same during the month before surgery (30 [75%] v. 21 [52%] for the cardiac surgery patients and 30 [79%] v. 18 [51%] for the orthopedic surgery patients). When the autologous donors were asked what they felt their chances would have been of receiving at least one allogeneic blood transfusion had they not predonated, the median response was 80%. When they were asked what their chances were after predonating their own blood, the median response was 0%. The autologous donors were significantly less likely to receive allogeneic blood transfusions (6 [15%] for cardiac surgery and 3 [8%] for orthopedic surgery) than were the nondonors (14 [35%] for cardiac surgery and 16 [46%] for orthopaedic surgery). They were, however, more likely to receive any transfusion (autologous or allogeneic) than were the nondonors (25 [63%] v. 14 [35%] for cardiac surgery and 31 [81%] v. 16 [46%] for orthopedic surgery). INTERPRETATION: Patients who underwent preoperative autologous blood donation were positive about the experience and did not report more symptoms than patients who did not donate blood preoperatively. Autologous donors overestimated their chances of receiving allogeneic blood transfusions had they not predonated and underestimated their chances after they had predonated. They were less likely to receive allogeneic transfusions, but more likely to receive any type of transfusion, than were patients who did not predonate.     

Blood salvage, proper choice for tumor patients?

Blood transfusion is frequently used in tumor patients, However, allogeneic blood transfusion have been claimed to be associated with an increased risk of negative outcomes, including transfusion reactions, fever, virus transmission, and alloimmunization. Other risks of homologous transfusion specific to the tumor patients are the potential deleterious effects on the recurrence of tumor and indefinite overall survival. On the contrary, autologous blood transfusion offers survival advantages to tumor patients and has been shown to minimize the occurrence of many detrimental allogeneic blood associated effects and complications. It also reduces the volume of banked blood needed and improves the prognosis of patients. However, the quality of salvaged blood is still a matter of debate, because it may contain tumor cells which are associated with potential detrimental effects such as metastasis. So, an advanced technology is needed to remove such contaminants to make autologous blood transfusion safer.     

Human red blood cells with normal or improved oxygen transport function prepared and frozen in the primary polyvinyl chloride plastic blood collection container.

This is a report a a new system for freezing human red blood cells in the same polyvinyl chloride plastic container in which the blood is collected and separated into components. This polyvinyl chloride plastic collection bag with integrally attached transfer packs for blood collection, component separation, red blood cell biochemical modification, freezing, storage, and post-thaw dilution before washing, represents a major advancement in the freeze-preservation process. The label with the donor's blood type and identification number affixed to the bag at the time of collection remains in place throughout the freezing and thawing process. The transfused red blood cells are of superior quality, and the processing cost is less than with other methods of freeze-preservation. There is a lower risk of contamination with these red blood cells because manipulation of the product is kept at a minimum. "Rejuvenation", a bioengineering process by which outdated red blood cells can be salvaged, can be incorporated into the preservation process using one of the attached transfer packs of the primary collection bag. This process has been introduced as a possible means of alleviating the dramatic blood shortages which occur periodically. Red blood cells may also be "rejuvenated" after storage in the liquid state to increase their 2,3 DPG and ATP levels to 150 to 200% of normal, and these red blood cells with improved oxygen transport function have been administered to anemic patients with and without cardiopulmonary insufficiency, patients undergoing cardiopulmonary bypass and treatment with hypothermia during cardiac surgery, and in instances where nonhemolytic transfusion reactions might be expected.     

Polymer-mediated immunocamouflage of red blood cells: Effects of polymer size on antigenic and immunogenic recognition of allogeneic donor blood cells

Developing a practical means of reducing alloimmunization in chronically transfused patients would be of significant clinical benefit. Immunocamouflaging red blood cells (RBCs) by membrane grafting of methoxypoly(ethylene glycol) (mPEG) may reduce the risk of allo-immunization. The results of this study showed that antibody recognition of non-ABO antigens was significantly reduced in an mPEG-dose- and polymer size-dependent manner, with higher molecular weight mPEGs providing better immunoprotection. Furthermore, in vivo immunogenicity was significantly reduced in mice serially transfused with mPEG-modified xenogeneic (sheep; sRBCs), allogeneic (C57Bl/6), or syngeneic (Balb/c) RBCs. Following a primary transfusion of sRBCs, mice receiving mPEG-sRBCs showed a >90% reduction in anti-sRBC IgG antibody levels. After two transfusions, mice receiving mPEG-sRBCs showed reductions of >80% in anti-sRBC IgG levels. Importantly, mPEG-modified autologous cells did not induce neoantigens or an immune (IgG or IgM) response. These data suggest that the global immunocamouflage of RBCs by polymer grafting may provide a safe and cost-effective means of reducing the risk of alloimmunization.     

血凝酶对髋关节置换术低分子肝素抗凝患者出血量及凝血功能的影响

目的:观察注射用血凝酶对髋关节置换术低分子肝素抗凝患者术中出血量及凝血功能的影响。方法:选取收治的髋关节置换术的患者共161例,采用双盲、随机的方法分为实验组83例和对照组78例,所有患者均为我院收治的行髋关节置换术的病例。对照组采用术前给予低分子肝素处理,观察组患者术前给予注射用血凝酶及低分子肝素处理。术后对两组患者术中出血量、术后24 h引流量、术后24 h红细胞(RBC)、血红蛋白(Hb)、纤维蛋白原(Fib)、术后24 h部分凝血活酶时间(APTT)、凝血酶原时间(PT)等情况进行分析。结果:实验组患者术中出血量、术后24 h引流量值均低于对照组,且差异有显著性(P0.05)。两组患者术后24 h红细胞RBC、血红蛋白Hb均下降,但是组间比较差异无统计学意义(P0.05)。术后纤维蛋白原Fib值均上升,组间比较差异无统计学意义(P0.05)。实验患者术后24 h部分凝血活酶时间APTT、凝血酶原时间PT均较术前有所降低,但是于术前及组间比较差异无统计学意义(P0.05)。结论:全髋置换术中使用注射用血凝酶不受低分子肝素的抑制,且安全有效,值得临床进一步研究和应用。