Acute intravascular hemolysis secondaryto out-of-group platelet transfusion

BACKGROUND: Acute intravascular hemolysis is rarely associated with platelet transfusion. Out-of-group single-donor platelets may cause hemolysis if the donor has high-titer ABO hemagglutinins. CASE REPORT: A 44-year-old woman, blood group A, was recently diagnosed with acute myeloid leukemia and was receiving chemotherapy. After the transfusion of apheresis platelets from a group O donor, back pain, hemoglobinuria, and hemoglobinemia developed, and her Hb dropped by 2.3 g per dL, despite the transfusion of 2 units of RBCs. RESULTS: Investigation revealed acute intravascular hemolysis with a positive DAT due to anti-A(1) on her RBCs. The donor's titer of anti-A(1) was greater than 16,000. CONCLUSION: Review of published cases raises the possibility that hemolytic reactions to out-of-group platelets may be more frequent since the use of apheresis platelets has increased.     

Transfusion-transmitted bacterial infectionin the United States, 1998 through 2000

BACKGROUND: Bacterial contamination of blood components can result in transfusion-transmitted infection, but the risk is not established. STUDY DESIGN AND METHODS: Suspected cases of transfusion-transmitted bacteremia were reported to the CDC by participating blood collection facilities and transfusion services affiliated with the American Red Cross, AABB, or Department of Defense blood programs from 1998 through 2000. A case was defined as any transfusion reaction meeting clinical criteria in which the same organism species was cultured from a blood component and from recipient blood, with the organism pair confirmed as identical by molecular typing. RESULTS: There were 34 cases and 9 deaths. The rate of transfusion-transmitted bacteremia (in events/million units) was 9.98 for single-donor platelets, 10.64 for pooled platelets, and 0.21 for RBC units; for fatal reactions, the rates were 1.94, 2.22, and 0.13, respectively. Patients at greatest risk for death received components containing gram-negative organisms (OR, 7.5; 95% CI, 1.3-64.2; p = 0.009). CONCLUSION: Bacterial contamination of blood is an important cause of transfusion-transmitted infection; infection risk from platelet transfusion is higher compared with that from RBCs, and, overall, the risk of infection from bacterial contamination now may exceed that from viral agents. Recipients of components containing gram-negative organisms are at highest risk for transfusion-related death. The results of this study may help direct efforts to improve transfusion-related patient safety.     

A feasibility evaluation of an automated bloodcomponent collection system platelets and red cells

BACKGROUND: The purpose of these studies was to evaluate the functional properties of blood components collected with an automated collection system. STUDY DESIGN AND METHODS: Single-donor platelets (n = 44) and packed red cell (RBC) units (n = 10) were collected. In vitro and in vivo assays were used to assess the function of single-donor platelet components stored for 5 days and of packed RBC units after storage for 42 days at 4 degrees C. RESULTS: Adverse events observed in the 44 study subjects were minor. The mean 24-hour recovery value for the packed RBC units stored for 42 days was 83.6 +/- 5.4 percent, with a mean percentage of hemolysis on Day 42 at 0.46 +/- 0.19 percent. The 25 patients receiving platelet components achieved a mean corrected count increment of 15.1 +/- 10.4 x 10(3). All platelet concentrates had less than 1 x 10(6) total white cells. CONCLUSION: Both in vitro and in vivo testing for the packed RBCs collected and stored for 42 days met the standards for both hemolysis and percentage of 51Cr 24-hour RBC recovery. The in vitro results and transfusion data on white cell-reduced platelet components transfused to thrombocytopenic patients were comparable to those on available platelet components.     

Predictors of transfusion for spinal surgery in Maryland, 1997 to 2000

BACKGROUND: The purpose of this study was to identify preoperative patient, hospital, and surgeon characteristics associated with transfusion for spinal surgery. STUDY DESIGN AND METHODS: Discharge data were obtained from 39 Maryland hospitals for adult patients (n = 3988) who had a primary procedure code for spinal surgery between July 1997 through June 2000, and with these codes, surgeons and hospitals were characterized by annual patient volume. Outcome variables included any allogeneic transfusion, any transfusion, RBCs, autologous blood, FFP, or platelet transfusion. Logistic regression was used for univariate and multivariate analyses. RESULTS: Characteristics independently associated with an increased risk of receiving any allogeneic transfusion (n = 786) included age >54 (OR, 1.6; 95% CI, 1.3-2.1), age >66 (OR, 2.7; 95% CI, 2.0-3.5), female sex (OR, 1.6; 95% CI, 1.2-2.0), diabetes with chronic complications (OR, 2.5; 95% CI, 1.3-4.9), and metastatic tumor (OR, 4.9; 95% CI, 2.3-10.5), emergency room admission (OR, 2.3; 95% CI, 1.4-3.8), and greater hospital volume (OR, 4.0; 95% CI, 1.8-8.6). Characteristics independently associated with increased autologous transfusions (n = 574) included white race (OR, 1.7; 95% CI, 1.2-2.4), female sex (OR, 1.4; 95% CI, 1.1-1.8), and greater surgeon volume (OR, 3.5; 95% CI, 1.4-9.1). DISCUSSION: This information can be used to provide informed risk-benefit discussions with patients regarding the risk for blood transfusion as well as to target high-risk patients and institutions for interventions to reduce the risk of exposure to blood components.     

Effects of nitric oxide on platelet activation during plateletpheresis and in vivo tracking of biotinylated platelets in humans

BACKGROUND: The use of platelet transfusions has risen considerably over the last few years, which leads to the collection and transfusion of a greater number of donor plateletpheresis units. Plateletpheresis activates platelets in platelet concentrates, which determines the degree of the storage lesion subsequently observed. STUDY DESIGN AND METHODS: As nitric oxide (NO) is a potent inhibitor of platelet aggregation and activation, a placebo-controlled crossover trial was performed in healthy young male volunteers to determine whether the NO-donating compound, sodium nitroprusside (SNP), decreases platelet activation during apheresis and whether activated (p-selectin+) platelets circulate in vivo after transfusion. The study also investigated whether nonradioactive biotin labeling of apheresis platelets is feasible for the study of platelet recovery after transfusion in humans. RESULTS: Platelet activation increased after plateletpheresis in the platelet components, but SNP did not inhibit platelet activation during apheresis, as measured by the percentage of p-selectin expression and the secretion of soluble p-selectin and RANTES. Only a minor increase in p-selectin+ platelets was seen in peripheral blood at 60 minutes after transfusion of the platelets, a rise that was considerably less than that calculated in p-selectin+ platelets if they all were recovered as activated platelets after transfusion. Biotin-labeled platelets averaged 1.5 percent at 10 minutes after transfusion and increased slowly to 2.6 and 3.4 percent after 60 minutes and 24 hours, respectively (p<0.05). CONCLUSION: SNP does not decrease platelet activation during apheresis and subsequent storage, and only a minor proportion of activated (p-selectin+) platelets circulate after transfusion in men. Moreover, biotin labeling of PCs can safely be used in humans for the study of platelet recovery after transfusion, and measuring recovery at 1 hour may lead to an underestimation of the true recovery when activated platelets are transfused.     

Evaluation of a whole-blood WBC-reduction filter that saves platelets: in vitro studies

BACKGROUND: In this study, a new WBC-reduction in-line filter that removes WBCs but not platelets was evaluated. Three WBC-reduced blood components were prepared: RBCs, plasma, and platelet concentrates (PCs). STUDY DESIGN AND METHODS: Whole-blood components (n = 30) were filtered within 2 to 4 hours after collection and then were centrifuged and separated into RBCs, plasma, and WBC-reduced buffy coat. Saline-adenine-glucose-mannitol solution was added to the RBCS: The WBC-reduced buffy coats were stored overnight; on the following day, PCs were prepared from pooled WBC-reduced buffy coats and stored in a medium composed of approximately 35 percent CPD plasma and 65 percent platelet additive solution (T-Sol, Baxter). The WBC-reduction capacity of the filter, the recovery of cells after filtration, and the in vitro storage of RBCs (n = 10) and platelets (n = 6) were evaluated. RESULTS: Mean and maximum WBC counts after filtration were 0.08 x 10(6) and 0.3 x 10(6), respectively, per filtered whole-blood unit. Recovery of RBCs (mean values) after filtration was 90 percent in whole-blood components and 73 percent in RBCS: Recovery of platelets (mean values) was 81 percent after filtration and 66 percent in PCS: The in vitro storage study of RBCs showed results comparable with previously published data, except for a lower degree of hemolysis. In the in vitro platelet storage study, results were compared with those of standard preparations. In all essentials, similar results were found. CONCLUSION: The results of the present study suggest that effective WBC reduction meets current standards and satisfactory recovery after filtration. The storage characteristics for RBCs and PCs are similar to those of standard preparations. Use of a whole-blood in-line filter to save platelets is a new option for whole-blood processing, which may simplify WBC reduction and blood component preparation, as well as reduce costs in the future.     

Single-donor platelets reduce the risk of septic platelet transfusion reactions

BACKGROUND: Septic platelet transfusion reactions (SPTRs) are the most common, serious risk of transfusion. Because SPTRs result from donor skin flora or asymptomatic bacteremia, the use of single-donor platelets (SDPs) has been proposed to reduce the risk of SPTRs from the risks with pools of platelet concentrates (PCs). STUDY DESIGN AND METHODS: Beginning in 1986, all febrile transfusion reactions were evaluated by culture of the platelet bag. Confirmed SPTRs were identified by isolation of the same bacteria from the bag and the patient's blood or by positive Gram's stain of the bag that confirmed a positive platelet culture. In 1987, a program to minimize PC use in favor of SDP use was initiated as a means of reducing SPTRs. RESULTS: In 12 years, the use of SDPs increased from 51.7 percent to 99.4 percent of all platelet transfusions at one institution. SPTRs fell from three events in 1 year to the current rate of one event per year. The incidence of SPTRs decreased from 1 in 4,818 transfusions to 1 in 15,098 transfusions. The rate of SPTRs due to PCs was 5.39 times higher than that of SPTRs due to SDPs (95% CI, 1.89,12.9). CONCLUSION: The use of SDPs is a simple means of reducing SPTRs. Other measures such as sterilization will be required to eliminate all SPTRs.     

Reactions and platelet increments after transfusion of platelet concentrates in plasma or an additive solution: a prospective, randomized study

BACKGROUND: Reactions after platelet transfusions are rather common and frequently are caused by plasma constituents. In recent developments, the preparation and storage of platelet concentrates (PCs) in a platelet additive solution (PAS-2) have been shown to result in acceptable storage conditions. A major drawback of the use of these PCs is the progressive increase of P-selectin-positive platelets during storage. The clinical benefit of transfusions of PCs in PAS-2 was studied. STUDY DESIGN AND METHODS: PCs prepared from buffy coats were suspended in either plasma or PAS-2 and stored for up to 5 days. Clinical responses were evaluated in a prospective study in 21 patients treated with intensive chemotherapy for hematologic malignancies. Eligible patients were randomly assigned to receive prophylactic transfusions of PCs prepared in either plasma or PAS-2. Reactions and CCIs were recorded after each transfusion. RESULTS: The incidence of reactions in 12 patients given PCs in plasma (n = 192) was 12 percent. Transfusions to 9 patients of PCs in PAS-2 (n = 132) showed a reduction in the incidence of reactions to 5.3 percent (p<0.05). The average 1-hour and 20-hour CCIs after transfusion of PCs in plasma were 20.7 +/- 8. 5 and 11.5 +/- 8.0, respectively. CCIs after transfusion of PCs in PAS-2 were significantly lower: the average 1-hour CCI was 17.1 +/- 6.6 (p<0.001) and the average 20-hour CCI was 9.5 +/- 7.0 (p<0.05). Storage conditions of PCs were optimal: in each group, average 1-hour CCIs of both fresh and stored PCs were similar. The 20-hour CCIs after the transfusion of fresh and stored PCs in PAS-2 also were similar. CONCLUSION: Transfusion of PCs in PAS-2 significantly reduces the incidence of reactions. The 1-hour and 20-hour CCIs after transfusion of PCs in PAS-2 were significantly lower than the CCIs after transfusion of PCs in plasma. Because storage conditions of both PCs were found to be optimal, the decrease in CCIs after transfusion of PCs prepared in PAS-2 may be caused by rapid elimination of a subpopulation of P-selectin-positive platelets from the circulation.     

WBC-reduced platelet concentrates from pooled buffy coats in additive solution: an evaluation of in vitro and in vivo measures

BACKGROUND: The use of a platelet additive solution (PAS-II, Baxter) may have benefits over plasma for storage of platelets. It was the aim of this study to develop a method to produce WBC-reduced platelet concentrates (PCs) in PAS-II with >240 x 10(9) platelets and <1 x 10(6) WBCs per unit, which can be stored for 5 days at pH >6.8 and that will give sufficient platelet increments after transfusion: a 1-hour CCI of >7.5 and a 20-hour CCI of >2.5. STUDY DESIGN AND METHODS: PCs were made from five pooled buffy coats and 250 g of PAS-II. After centrifugation the PCs were WBC-reduced with a filter (Autostop BC, Pall Biomedical) and stored in a 1000-mL polyolefin container. CCIs were assessed in stable hemato-oncologic patients after 5-day old PCs were transfused. RESULTS: Routinely produced PCs contained a median of 310 x 10(9) platelets (n = 5,363) with 3.5 percent containing <240 x 10(9) platelets, in a median volume of 320 mL (n = 11,834). The median number of WBCs was <0.03 x 10(6) (n = 694). The WBC count exceeded 1 x 10(6) in three PCs, but it was always <5 x 10(6), giving 99-percent confidence that more than 99.5 percent of the units will contain <1 x 10(6) WBCs. The pH remained >6.8 on Day 8, provided the concentration was below 1.1 x 10(9) platelets per mL (n = 32). After 28 transfusions in 28 patients, the 1-hour CCI was 12.6 +/- 4.3 (mean +/- SD, with 2/28 CCIs <7.5) and the 20-hour CCI was 8.9 +/- 5.6 (with 4/28 CCIs <2.5). Limitations of this study include the absence of a control group of patients receiving platelets stored in plasma and of in vivo radiolabeled survival studies, but a comparison of these data with previously published data suggested that the in vivo survival of platelets stored in PAS-II is less than that of platelets stored in plasma. CONCLUSION: The WBC-reduced PCs conformed to specifications. These WBC-reduced PCs could be stored at least 5 days with maintenance of pH, and they gave sufficient increments after transfusion to patients.     

Analysis of the kinetics of TPO uptake during platelet transfusion

BACKGROUND: It has been shown in several studies that platelets play a role in the removal of TPO from the circulation. For instance, in vitro studies have shown that platelets can bind and internalize TPO, and transfusion studies have shown that the concentration of circulating TPO decreased after platelet transfusion. In the current study, the in vivo kinetics of plasma TPO levels and TPO uptake by transfused platelets is analyzed in more detail. STUDY DESIGN AND METHODS: Serial blood samples from patients who received a platelet transfusion were analyzed with respect to platelet count, plasma TPO concentration, and TPO content per platelet. In addition, the capacity of transfused platelets to bind TPO in vitro was assessed. RESULTS: Platelet counts increased immediately after transfusion, but subsequently started to decrease. Conversely, TPO levels decreased significantly but then returned to baseline level by 44 hours after transfusion. Platelet count and plasma TPO concentration were inversely correlated (r(p) = -0.9; p<0.05). The decrease in TPO concentration upon transfusion was accompanied by a significant increase in the platelet-associated TPO concentration. After transfusion, platelets isolated from the patient still displayed functional TPO receptors, as indicated by their intact capacity to bind TPO in vitro. CONCLUSION: The decrease in plasma TPO followed by the increase in platelet TPO provides evidence that platelets are responsible for the clearance of TPO in circulation. In vivo, platelets can bind and may degrade TPO upon platelet transfusion.     

Immunologic changes after transfusion of autologous or allogeneic buffy coat-poor versus white cell-reduced blood to patients undergoing arthroplasty. I. Proliferative T-cell responses and the balance of helper and suppressor T cells

BACKGROUND: Donor white cells (WBCs) contained in red cell (RBC) transfusions are thought to provoke down-regulation of T-cell-mediated immunity. This study investigated this topic in otherwise healthy patients receiving buffy coat-depleted or WBC-filtered RBCs and undergoing standardized perioperative management. STUDY DESIGN AND METHODS: Patients undergoing elective orthopedic surgery (primary hip and knee replacement surgery) were enrolled in a prospective study. Perioperative changes in T-cell proliferation (stimulation with phytohemagglutinin and mixed lymphocyte culture) and T-cell balance (T-lymphocytes, helper T cells, and suppressor T cells) were compared after random assignment to allogeneic buffy coat-depleted (Group 2, n = 8) or WBC-reduced RBC (Group 3, n = 11) transfusion regimens. Recipients of autologous buffy coat-depleted RBC transfusions (n = 15) served as controls (Group 1). RESULTS: Compared to that in autologous transfusion recipients, alloantigen-induced T-cell proliferation was significantly reduced in recipients of allogeneic WBC-reduced RBCs (Day 3, p = 0.0274). After the transfusion of allogeneic buffy coat-depleted RBCs, a weak trend toward decreased T-cell proliferation was observed (p = 0.0933) and the numbers of CD4+ T cells were also significantly lower (Day 7, p = 0.0389). On Day 10, alloantigen-induced T-cell proliferation remained significantly below baseline after transfusion of WBC-reduced RBCs (p = 0.05), the numbers of CD3+ cells decreased in allogeneic RBC recipients (Group 2, p = 0.078; Group 3, p = 0.05), and those of CD8+ cells decreased significantly after the transfusion of allogeneic buffy coat-depleted RBCs (p = 0.0234) concomitant with an increased CD4:CD8 ratio (p = 0.0391). CONCLUSION: Results of the present study confirm the hypothesis of impaired T-cell-mediated immunity after allogeneic transfusion.     

Validating billing data for RBC transfusions: a brief report

BACKGROUND: Administrative data are used often for research, but without validation of their accuracy. The validity of the billing for blood transfusion was assessed in one tertiary-care hospital. MATERIALS AND METHODS: Patient discharge data were retrieved from a database containing demographics, diagnoses, and charges. There was random selection of 358 patients who were billed for RBC transfusion and 358 who were not, within a 2-month period. The blood bank's transfusion records were reviewed. Sensitivity was defined as the proportion of transfused patients who were billed, and specificity as the proportion of nontransfused patients who were not billed. Patient characteristics were compared by using Wilcoxon's rank sum test and the chi-square test. RESULTS: Sixty-one transfused patients were not billed for the transfusion. No patient was billed without transfusion. Thus, the sensitivity and specificity were 83 percent (95% CI, 79-87%) and 100 percent, respectively. Nine patients who were not issued RBCs were appropriately not billed for RBCs, although the billing record suggests they had a procedure involving transfusion. These patients were called true-negative. The patients not billed were older (58 years vs. 55 years; p = 0.046) and less likely to have commercial insurance (5% vs. 15%; p = 0.035) than billed patients. CONCLUSIONS: The billing for RBC transfusion in one large institution is reassuringly valid. The specificity is excellent, and the sensitivity is higher than that seen in other studies of coding validity.     

Transfusion and postoperative pneumonia in coronary artery bypass graft surgery: effect of the length of storage of transfused red cells

BACKGROUND: Various bioactive substances are released from white cell (WBC) granules into red cell (RBC) components in a time-dependent manner during blood storage. Some of these substances may have immunosuppressive effects and may contribute to transfusion-induced immunomodulation. RBCs transfused after prolonged storage may be associated with a higher incidence of postoperative infections than fresh RBCs. This hypothesis does not seem to have been investigated in a clinical study. STUDY DESIGN AND METHODS: The records of 416 consecutive patients undergoing coronary artery bypass graft operations at the Massachusetts General Hospital were reviewed. The association between the length of storage of the transfused RBCs, as well as the number of units of non-WBC-reduced allogeneic RBCs and/or platelets transfused, and the occurrence of postoperative pneumonia was calculated by logistic regression analyses adjusting for the effects of confounding factors. Among these were the numbers of days of intubation, days of impaired consciousness, and units of RBCs transfused. RESULTS: By Centers for Disease Control and Prevention criteria, pneumonia developed in 54 patients (13.0%). Among 269 patients given RBCs, the risk of pneumonia increased by 1 percent per day of increase in the mean storage time of the transfused RBCs (p<0.005). In an analysis of all patients, the risk of pneumonia increased by 5 percent per unit of non-WBC-reduced allogeneic RBCs and/or platelets received (p = 0.0584). CONCLUSION: After adjustment for the effects of the risk factors for pneumonia and the number of transfused RBCs, an association was observed between the length of storage of transfused RBCs and the development of postoperative pneumonia. This association should be investigated further in future studies of the outcomes of blood transfusion.     

Clinical consequences of alterations in platelet transfusion dose: a prospective, randomized, double-blind trial

BACKGROUND: The dose-response relationship for platelet transfusion has become increasingly important as the use of platelet transfusion has grown. STUDY DESIGN AND METHODS: One hundred fifty-eight prophylactic apheresis platelet transfusions were administered to 46 patients undergoing high-dose therapy followed by hematopoietic progenitor cell transplantation in a prospective, randomized, double-blind, multiple-crossover study. Transfusions were administered in pairs, differing only in platelet content. Each pair consisted of a lower-dose platelet component (LDP) and a higher-dose platelet component (HDP) administered in random order to the same patient. LDPs contained a mean of 3.1 x 10(11) platelets (range, 2.3-3.5 x 10(11)), and HDPs contained a mean of 5.0 x 10(11) platelets (range, 4.5-6.1 x 10(11)). Patients with active bleeding and those who were refractory to platelet transfusions were excluded. RESULTS: The mean posttransfusion platelet count increment with LDP was 17,010 per microL, and that with HDP was 31,057 per microL (p<0.0001). Only 37 percent of LDPs resulted in platelet count increments of at least 20,000 per microL, whereas 81 percent of HDPs resulted in increments above this level (p<0.0001). The mean transfusion-free interval with LDP was 2.16 days, whereas that with HDP was 3.03 days (p<0.01). Administration of LDPs was associated with a 39 to 82 percent increase in the relative risk (per day) of requiring subsequent platelet transfusions (p<0.0001). CONCLUSION: As compared to the administration of HDPs, the administration of LDPs for prophylactic transfusion in hematopoietic progenitor cell transplant patients results in a lower platelet count increment, a lower likelihood of obtaining a posttransfusion platelet increment >20,000 per microL, a shorter transfusion-free interval, and a greater relative risk per day of requiring additional transfusions.     

Emergency department blood transfusion predicts early massive transfusion and early blood component requirement

BACKGROUND: The purpose of this study was to evaluate the ability of uncrossmatched transfusions in the emergency department (ED) to predict early (<6 hr) massive transfusion (MT) of red blood cells (RBCs) and blood components. STUDY DESIGN AND METHODS: All patients admitted to a Level 1 trauma center between July 2005 and June 2007 who received any transfusions and were transported directly from the scene of injury were included. Early MT was defined as the need for 10 U or more or RBCs in the first 6 hours. Early MT plasma was defined as 6 U or more of plasma in the first 6 hours. Early MT platelets (PLTs) were defined as two or more apheresis transfusions in the first 6 hours. Univariate and multivariate analyses were performed. RESULTS: A total of 485 patients (34%) received ED transfusions (ED RBC+) and 956 (66%) did not receive ED transfusions (ED RBC–). ED RBC+ patients were younger, were more likely to be male, and arrived with more severe injuries. Multivariate regression identified ED transfusion of uncrossmatched RBC as an independent predictor of requiring early MT of RBCs (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.36‐7.59; p = 0.001), plasma (OR, 2.7; 95% CI, 1.66‐4.39; p < 0.001), and PLTs (OR, 1.9; 95% CI, 1.08‐3.41; p = 0.025). CONCLUSION: Patients receiving uncrossmatched RBCs in the ED are more than three times more likely to receive early MT of RBCs. Additionally, patients transfused with ED RBCs are more likely to receive 6 units or more of plasma and two or more apheresis PLT transfusions. Given these findings, ED transfusion of uncrossmatched RBCs should be considered a potential trigger for activation of an institution's MT protocol.     

Coagulase-negative staphylococcal contamination of whole blood and its components: the effects of WBC reduction

BACKGROUND: Most bacteria present in blood components are normal skin flora, particularly Staphylococcus epidermidis and other coagulase-negative staphylococci. Growth patterns of these bacteria and the effects of different methods of component preparation may depend on variations in behavior between different isolates of the same species. STUDY DESIGN AND METHODS: Whole-blood units were inoculated with 19 different coagulase-negative staphylococcus (CNS) isolates at 1 to 10 and 10 to 100 CFUs per mL. After overnight holding at 22 degrees C, the units were processed into components. The components were cultured before inoculation and during processing, including before and after WBC reduction. RESULTS: At low inoculum levels, CNS was detected in 15 (79%) of 19 whole-blood units and in 12 (63%) of 19 RBCs after separation; after filtration, bacteria were detected in 3 (16%) of 19 (p = 0.0069). For platelet concentrates, 6 (32%) of 19 grew bacteria before filtration and 1 of 18 after filtration (difference not statistically significant). Three (16%) of 19 plasmas were positive before and after freezing. At high inoculum levels, 16 (89%) of 18 whole-blood samples and RBCs were positive before filtration; 6 (33%) of 18 RBCs were positive after filtration (p = 0.0002); 8 (44%) of 18 platelets were positive before filtration; 3 (17%) of 18 were positive after filtration (difference not statistically significant), and 7 (37%) of 18 plasma samples were positive before and after freezing. CONCLUSION: The growth characteristics of CNS in blood components vary with differences either in the subtype of bacteria or in the donor blood. Filtration reduces but does not eradicate contamination of RBCs and platelets by CNS. Plasma may act as a reservoir for CNS infection.     

Transfusion-related risk of secondary bacterial infections in sepsis patients: a retrospective cohort study

There is a need for insight into factors that contribute to late mortality of sepsis patients. Immunomodulatory effects have been ascribed to blood transfusion. This retrospective cohort study investigates the association between the development of nosocomial bacterial infection and transfusion of leukodepleted red blood cells (RBCs) or platelets (PLTs) in survivors of the initial phase of sepsis. Patients diagnosed with sepsis after admission to the intensive care unit of a tertiary referral hospital were included. Of 134 patients with sepsis, 67 received a blood transfusion (50%). A secondary infection developed in 19 patients (14%). A multiple logistic regression model revealed that the use of immunosuppressive medication with an odds ratio (OR) of 1.17 (95% confidence interval [CI], 1.04-1.31), but not Acute Physiology and Chronic Health Evaluation II score, malignancy, HIV infection, alcohol abuse, or diabetes mellitus, was a risk factor for nosocomial infection. In an adjusted model, the amount of transfused RBCs was associated with secondary infection with an OR of 1.18 (95% CI, 1.01-1.37). Storage time of RBCs was a relevant confounder of the effect of the amount of RBCs on infection, with an adjusted OR of 1.25 (95% CI, 1.04-1.51), P = 0.02. Also, the amount of transfused PLTs was associated with secondary infection, with an OR of 1.36 (95% CI, 1.05-1.78). In conclusion, transfusion of RBCs and PLTs is associated with the onset of secondary bacterial infection in sepsis patients. Storage time of RBCs influences this increased risk. These findings suggest that immunomodulatory effects of blood transfusion contribute to adverse outcome in the convalescent phase of sepsis.     

Corrected count increment and percent platelet recovery as measures of posttransfusion platelet response: problems and a solution

BACKGROUND: Corrected count increment (CCI) and percent platelet recovery (PPR) are measures of response to platelet transfusion that "correct" the count increment for blood volume and number of platelets transfused. Their potential for data distortion is described, and a regression analysis is suggested that is more informative and avoids the inherent problems associated with using ratios as outcome measures. STUDY DESIGN AND METHODS: Data from the first platelet transfusion for 585 patients from the Trial to Reduce Alloimmunization to Platelets (TRAP) were used to model methods of analyzing posttransfusion platelet response. RESULTS: By linear regression analysis, unfiltered platelet components gave a greater posttransfusion increment on average (p = 0.001), but filtered platelets gave a greater increment per platelet transfused (p = 0.003). In contrast, CCI and PPR showed no difference between filtered and unfiltered platelets (p = 0.36 and p = 0.29, respectively) because they combined the effects of dose, filtration, and patient size. Slightly fewer patients are required for a study analyzed by regression analysis. CONCLUSION: Regression analysis of posttransfusion platelet increments should be used instead of CCI or PPR to compare the efficacy of platelet components. CCI and PPR should not be used to define platelet refractoriness as a study outcome, because these measures are biased in favor of platelet preparation techniques that provide fewer platelets.     

Autologous blood transfusion in the United States: clinical and nonclinical determinants of use

BACKGROUND: Preoperative donation of blood lowers the risk of allogeneic RBC transfusion. The use of autologous blood is not well quantified. This study aimed at identifying the frequency and determinants of use of autologous transfusion in the United States. STUDY DESIGN AND METHODS: This national cross-sectional study, using the Nationwide Inpatient Sample, included all patients admitted to 900 hospitals in 19 states in 1996. Logistic regression with weighting yielded nationally representative results for the independent effects of clinical and nonclinical patient characteristics on autologous blood use. RESULTS: Autologous transfusion was used in 19 of 1000 hospitalizations. The procedures using autologous blood most frequently were knee arthroplasty, hip replacement, prostatectomy, spinal fusion, and hysterectomy. Blacks and Hispanics were less likely to receive autologous transfusion than were whites (OR, 0. 64; 95% CI, 0.45-0.83); patients with Medicaid were less likely than the privately insured to receive autologous transfusions (OR, 0.29; 95% CI, 0.20-0.43), with racial differences greatest among the privately insured. Women received autologous blood for cardiovascular surgeries much less often than men (OR, 0.32; 95% CI, 0.20-0.49). CONCLUSION: Ethnic minorities, women, and patients with Medicaid appear to receive fewer autologous blood transfusions than the rest of the population. Although this could reflect either better or worse quality of care, nonclinical determinants of transfusion practice warrant attention and further investigation.     

Febrile and allergic transfusion reactions after the transfusion of white cell-poor platelet preparations

BACKGROUND: Nonhemolytic transfusion reactions (NHTRs) frequently occur after platelet transfusions. White cell (WBC)-derived inflammatory cytokines can cause these reactions, but they are rarely found in WBC-poor platelet preparations. Transfusion reactions were investigated with regard to the residual WBC content in the stored platelet concentrate in two consecutive study periods.
STUDY DESIGN AND METHODS: In the first study period, platelet concentrates were WBC-reduced by bedside filtration. In the second period, all platelet concentrates were filtered before storage. Recipients who experienced transfusion reactions were examined with regard to their main clinical symptoms during and after transfusion. In the supernatant of the involved platelet concentrates, concentrations of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)α, macrophage inflammatory protein 1α, and RANTES were analyzed.
RESULTS: The incidence of transfusion reactions remained steady when the transfusion regimen was changed from bedside filtration to prestorage WBC filtration (1.63% and 1.56%; p = 0.84). In both periods, NHTRs were predominantly of allergic origin. Inflammatory mediators IL-1β, IL-6, IL-8, and TNFα were detectable in only a minority of platelet components involved in NHTRs. Platelet concentrates involved in allergic reactions contained high concentrations of RANTES (668 ± 223 ng/mL).
CONCLUSIONS: Prestorage WBC filtration did not reduce the incidence of these reactions, and inflammatory cytokines were of minor relevance. The proinflammatory platelet-derived chemokine RANTES, which accumulates even in WBC-reduced platelet concentrates, was associated with allergic transfusion reactions. Platelet-derived mediators may be a key to understanding NHTRs.