ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190508.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:Platelet activation is an important factor impeding the clinical effectiveness of platelet transfusions. In this study, platelet concentrates (PCs) were prepared by a novel suspended‐bag buffy coat technique that was followed by the addition of a mixture of platelet activation inhibitors to the storage bag.Study Design and Methods:In vitro platelet function was evaluated in PCs prepared by the suspended‐bag buffy coat technique and stored at 22 degrees C for 5 days in the presence of (n = 12) or absence (n = 12) of apyrase, ascorbic acid, and aprotinin (AAA).Results:Platelets from AAA‐ incubated PCs demonstrated mean ATP levels 17 percent (p<0.004), 13 percent (p<0.02), and 22 percent (p<0.003) higher than those measured in parallel control PCs on Days 1, 3, and 5, respectively. Similarly, on Days 3 and 5 of storage, respectively, 45‐percent (p<0.001) and 50‐percent (p<0.001) greater ADP‐induced maximum aggregation was observed in AAA‐incubated PCs than was seen in control preparations. AAA‐incubated PCs demonstrated alpha‐granule membrane protein‐140 expression 92 percent (p<0.01), 133 percent (p<0.003), and 104 percent (p<0.001) below that in control PCs on Days 1, 3, and 5, respectively. At similar intervals, a significant increase in recovery from hypotonic shock also was observed in AAA‐incubated PCs. Further, Day 5 AAA‐PCs demonstrated significantly higher morphology scores and O2 consumption than did control preparations.Conclusion:Buffy coat platelets prepared in suspended bags and stored in the presence of AAA demonstrate significantly reduced activation and enhanced functional

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190509.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:The increased use of white (WBC)‐reduced blood components has prompted many institutions to develop quality assurance programs directed to such component preparation processes. For consistent preparation of WBC‐reduced blood components that meet clinical needs as well as national standards, a program of process validation and control should be instituted. This involves controlling key factors that affect WBC reduction as well as periodic monitoring of the residual cellular content of components. Practical guidelines for the implementation of such a program are provided.Study Design and Methods:A program involving three phases of monitoring was developed by individuals belonging to an international working party of the International Society of Blood Transfusion.Results:The first phase, process validation, evaluates a minimum of 20 consecutive units (a minimum of 60 units when nonparametric measurements are used) to document the successful local implementation of a new or substantially modified process. Ongoing process control employing Levey‐Jennings type control charts is used to demonstrate that the process remains stable over time. Process capability assessment and conformance with standards are evaluated once residual WBCs are counted in a sufficient number of units. This enables a facility to claim with a specified degree of confidence that a stated proportion of WBC‐reduced units will meet national standards. Two approaches to determine the number of units that should be selected for counting are presented. The first approach considers units as either acceptable or not acceptable and assumes that the distribution of failed (or nonconforming) units approximates the Poisson distribution. The second approach takes into consideration the observed WBC content of the tested units, with the assumption that the residual WBC content in WBC‐reduced components follows a lognormal distribution. A method to assess the lognormal distribution of residual WBCs is presented. Specific tables based on each of these approaches are provided to guide the reader in the design of a program that will verify conformance with any national standard at specific confidence levels. The approach can be generalized to other process control applications.Conclusion:Guidelines are presented for process validation, process control, and assessment of conformance in the production of WBC‐reduced blood components. Policy makers retain the responsibility to establish, on the basis of the expected use of WBC‐ reduced components, requirements for the frequency of testing and for the proportion of prepared units that are expected with a stated degree of confidence to meet the standards. Facilities preparing WBC‐reduced components can monitor key factors that influence the preparation of WBC‐reduced blood, can periodically assess their conformance with the standards, and can intervene to correct adverse changes in the process. This approach can be used to ensure the consistent quality of WBC‐ reduc

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190510.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:During the storage of cellular components before transfusion, cytokines that may mediate transfusion reactions are released from white cells (WBCs). Adverse effects of transfused cellular blood components therefore depend not only on the number of residual WBCs in blood components, but also on the timing of WBC reduction.Study Design and Methods:Febrile nonhemolytic transfusion reactions (FNHTRs), allergic reactions, and other reactions were characterized in recipients of 4728 units of red cells (RBCs) and 3405 bags of single‐donor apheresis platelets (SDAPs), all of which underwent prestorage WBC reduction. To delineate the impact of prestorage versus poststorage WBC reduction of RBCs on transfusion reactions, these results were compared with reactions occurring after the transfusion to similar recipients of 6447 bags of RBCs that underwent poststorage WBC reduction by bedside filtration and 5197 units of SDAPs that underwent prestorage WBC reduction. The levels of interleukin (IL) 1 beta, IL‐6, IL‐8, and tumor necrosis factor‐alpha (TNF‐alpha) were measured in a subset of 20 implicated cellular blood components at the time of transfusion reactions and correlated with the duration of storage before transfusion.Results:The incidence of reactions was greater after transfusions of SDAPs (5.49%) than of RBCs (1.63%). The incidence of FNHTRs after transfusion of RBCs that were WBC reduced before storage (1.1%) was significantly lower (p = 0.0045) than that after transfusion of RBCs that were WBC reduced after storage (2.15%). Although allergic reactions to RBCs that were WBC reduced before storage were also less common (0.41%) than those to RBCs that were WBC reduced after storage (0.51%), the difference was not significant (p = 0.067). At the time of reactions to RBCs and SDAPs that were reduced before storage, the level of IL‐6 was negatively correlated (r = ‐0.54, p = 0.014) with the duration of storage before transfusion, and there was no correlation between the level of either IL‐1 beta or IL‐8 and the interval before transfusion. TNF‐alpha was not detectable in any implicated component.Conclusion:FNHTRs, but not allergic reactions, were less common after transfusion of RBCs that were WBC reduced before storage than after the transfusion of those WBC reduced after storage at the bedside by filtration. The level of IL‐6 in implicated cellular blood components that were WBC reduced before storage was inversely correlated with the length of storage before transfusion. Further studies are needed to determine whether the transfusion of cellular blood components that were WBC reduced before storage can both diminish the incidence of adverse reaction

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190511.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:This randomized controlled study was undertaken to determine the effect of recombinant human erythropoietin (rHuEPO) on erythropoiesis, autologous blood collection, and allogeneic transfusion risk in elective surgery patients with low baseline hematocrits.Study Design and Methods:Patients (n = 204) with low baseline hematocrits (or = 33 percent, and rHuEPO (600 U/kg) or placebo was administered intravenously.Results:One hundred seventy‐three patients were evaluable. The number of autologous units collected from the rHuEPO and control groups, respectively, was 4.5 ± 1.0 and 3.0 ± 1.1 (p<0.001), and marrow production of red cells increased by 668 ± 222 and 353 ± 155 mL over and above baseline production (p6 units, 29 percent of control and 14 percent of rHuEPO patients required allogeneic blood (p = 0.015). Logistic regression modeling determined that the risk of allogeneic transfusion was reduced by rHuEPO (p = 0.025).Conclusion:The use of rHuEPO stimulates erythropoiesis, permits the storage of more autologous blood, and reduces allogeneic transfusion risk in patients with low hematocrits who are undergoing elective orthopedic surgery. Additional studies are necessary to determine the optimal schedules of rHuEPO administration and autologous blood collection as well as the cost‐effectiveness of this s

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190512.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:Follow‐up studies from the mid‐1980s showed that 1 to 5 percent of blood donors testing reactive in anti‐human immunodeficiency virus type 1 (HIV‐1) enzyme immunoassay (EIA) and testing indeterminate in Western blot were infected with HIV‐1 and were in the process of seroconverting. The present study was conducted to establish the rate of HIV infection among contemporary anti‐HIV‐1/HIV type 2 (HIV‐2) EIA‐ reactive, Western blot‐indeterminate donors.Study Design and Methods:Donations (n = 607) with indeterminate HIV supplemental test results were identified by screening 3,021,342 donations given from November 1990 through August 1993 at five participating blood centers. Consenting donors were enrolled and samples taken 4 to 8 weeks after donation. Follow‐up sera were tested by EIA and Western blot for anti‐ HIV‐1 seroconversion and by type‐specific peptide assays for antibodies to HIV‐2 and HIV‐1 subtype O. Peripheral blood mononuclear cells and/or plasma from the follow‐up samples were tested for HIV‐1 DNA and/or RNA by polymerase chain reaction. The rate of HIV‐1 infection among Western blot‐indeterminate donors was also estimated by multiplying the incidence rate of HIV‐1 seroconversion in this donor population by the estimated duration of the EIA‐reactive and Western blot‐indeterminate window during seroconversion (8.5 days).Results:Supplemental test‐ indeterminate donors (n = 355) enrolled a median of 38 days after donation; 265 (75%) of these donors were identified as indeterminate after an anti‐HIV‐1/2 EIA‐reactive donation. Enrolled and non‐enrolled donors had similar distributions of demographic characteristics and band patterns. Follow‐up samples from all 355 donors tested negative for HIV‐1 in polymerase chain reaction. Follow‐up sera tested Western blot‐negative in 54 cases (15%) and Western blot‐indeterminate in 299 (84%). Two follow‐up sera (0.6%) were interpreted, according to manufacturer's package insert criteria, as Western blot positive with p24 and gp41 bands and/or gp120/160 bands; however, paired testing of index and follow‐up sera from these two cases showed identical Western blot and EIA reactivity, and polymerase chain reaction was negative for HIV RNA and DNA, which ruled out HIV infection. The absence of HIV infection in 355 Western blot‐indeterminate donors was consistent with our incidence‐based model analysis, which yielded an estimate of one HIV‐1 infection for every 215 Western blot‐indeterminate donations (95% CI, 1/39‐1/8333).Conclusion:Contemporary blood donors classified as indeterminate in supplemental HIV testing are infrequently infected with HIV. Donors whose follow‐up samples test negative in anti‐HIV‐1/2 EIAs and negative or persis

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190513.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:The manufacturers' criteria for a positive human immunodeficiency virus type 1 (HIV‐1) Western blot (WB) test were recently revised to require reactivity to only two of the following bands: p24, gp41, and gp120/160. In a recent report, low‐risk blood donors were identified in whom nonspecific reactivity to multiple env antigens in WB testing resulted in apparently false‐positive WBs by these criteria. The present study was conducted to verify the existence of false‐positive WBs among noninfected donors and to assess the extent of this problem.Study Design and Methods:Four donors classified as WB‐ positive on the basis of env‐only (3 cases) or p24/env‐only (1 case) patterns were investigated. Index and/or follow‐up specimens were tested by polymerase chain reaction (PCR), by overlapping recombinant env antigens and synthetic peptides in enzyme immunoassays, and by deglycosylated and denatured antigen WBs. WB records from American Red Cross blood centers were reviewed to determine the frequency of env‐ only and p24/env‐only patterns, relative to all positive WBs, from 1988 through 1993.Results:The four index‐case donors denied risk and had stable WB reactivity during follow‐up. HIV PCR was negative in all. Env reactivity was restricted to nonglycosylated gp41 epitopes; no gp120‐ specific reactivity was detected. For three of the four donors, env reactivity was mapped to a 20‐amino acid N‐terminal epitope of gp41. The rate of detecting WBs with these false‐positive patterns increased from 0.6 percent of all positive WBs from 1988 to 1990 (4/776) to 8 percent in 1991 and 1992 (52/683), and then it declined to 6 percent in 1992 and 1993 (47/783). Env‐only patterns predominated in 1991 and 1992, whereas p24/env‐only patterns were more frequent following implementation of combined anti‐HIV‐1/HIV type 2 enzyme immunoassays in 1992.Conclusion:Low‐risk blood donors can have false‐positive results on WB tests. Increased detection of env‐only and p24/env‐only WBs appears related to the enhanced sensitivity of newer enzyme immunoassays to gp41 and p24 antibodies. Donors with these patterns should undergo follow‐up testing to

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190514.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:The performance of cultures to assess possible bacterial contamination of bone marrow and peripheral blood progenitor cell preparations is required by the standards of the American Association of Blood Banks.Study Design and Methods:Consecutive (n = 893) bone marrow and peripheral blood progenitor cell preparations were cultured for assessment of possible contamination by microorganisms.Results:Consecutive bone marrow and peripheral blood progenitor cell preparations (n = 893) were cultured; the overall positive rate detected was 2.5 percent (22/893). The isolates predominantly were skin contaminants (gram‐positive cocci) and so‐called water‐borne organisms (gram‐negative rods). The 6.0‐percent rate of positivity in 317 bone marrow preparations was higher than the 0.5‐percent rate in 576 peripheral blood progenitor cell preparations (p<10(‐6)). Culture‐ positive preparations were transfused to 16 patients at this institution; however, none of these transfusions led to documented sepsis with the contaminating organism.Conclusion:The culture method described here complies with the standards of the American Association of Blood Banks. Contamination can be detected in both bone marrow and peripheral blood progenitor cell preparations. When contaminated preparations are transfused, there are few complications that can be attributed to th

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190515.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:Suction vacuum pressure (VP) not exceeding 150 torr is recommended during intraoperative blood salvage to minimize hemolysis. When the suction provided by this VP becomes inadequate because of brisk bleeding, an alternative high‐VP suction should be used and the blood discarded. This approach often results in the salvage of only a small fraction of the blood shed during surgery complicated by large hemorrhage.Study Design and Methods:This laboratory study was designed to quantitate the hemolysis caused by various VPs in a suction system commonly used for intraoperative blood salvage. For each experiment, a batch of blood with a hematocrit of 30 to 35 percent was prepared by mixing of outdated units of red cells, fresh‐frozen plasma, and saline solution. Aliquots of this blood were suctioned at VPs of 150, 200, 250, and 300 torr, either without (6 experiments) or with (4 experiments) maximal air entrainment. Total hemoglobin, hematocrit, red cell count, plasma‐free hemoglobin, and serum potassium were measured in the blood before suction and in each aliquot after suction.Results:Suction of blood mixed with air caused much greater hemolysis than suction of blood alone (p<0.01 at each VP tested). Raising the VP from 150 to 300 torr increased hemolysis from 0.14 +/− 0.20 percent (mean +/− SD) to 0.32 +/− 0.21 percent (p<0.05) when blood alone was aspirated and from 1.45 +/− 0.50 percent to 2.85 +/− 0.22 percent (p<0.05) when blood was suctioned with air. With either type of suction, red cell count, hematocrit, and serum potassium did not change significantly throughout the range of VPs tested.Conclusion:Hemolysis was found to depend on the VP applied and, to a much greater extent, on the amount of blood and air mixing. Increasing the VP above the recommended limit of 150 torr was not associated with inordinate hemolysis. Even when a VP as high as 300 torr was used, hemolysis ranged between 0.3 and 3.0 percent, depending on whether air was suctioned with the blood or not. The data support the idea that the lowest VP compatible with a clear surgical field should be used during intraoperative blood salvage and that the suctioning of air should be avoided as much as possible. These data also suggest that, in contrast to current recommendations, suction VP during intraoperative blood salvage can be increased up to 300 torr if required by the rate of bleeding, without causing exce

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190516.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Background:The impact of extracorporeal membrane oxygenation (ECMO), performed on adult patients, on the blood transfusion service of a tertiary‐care hospital was assessed. The quantity and pattern of blood component utilization by these patients were compared to those in a previous evaluation of neonatal patients receiving similar treatment.Study Design and Methods:The records of blood component transfusion to 74 adult patients, treated with ECMO within a 6‐year period, were reviewed. This information was correlated with the clinical indication for ECMO and duration of ECMO treatment. In addition, daily use of components for these patients was studied to ascertain whether the blood requirements were predictable and uniform.Results:Over 15,000 units of blood components, with platelet concentrates making up the largest portion, were transfused to these patients while they were undergoing ECMO. The duration of ECMO varied from less than 1 day to 53 days. However, the length of treatment could not uniformly be correlated with blood utilization or with survival. Daily blood transfusion needs often could not be anticipated, which meant that the transfusion service frequently had to respond to urgent requests for transfusion support. The provision of platelet concentrates proved to be the most difficult part of the maintenance of this program.Conclusion:Whereas ECMO treatment of neonatal patients has a relatively minor impact on a transfusion service, the same is not true for a program that uses this form of treatment for adults as w

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36196190517.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY