Evaluation of an automated system for the collection of packed RBCs, platelets, and plasma.

BACKGROUND: This study evaluated the quality of WBC-reduced platelets, RBCs, and plasma collected on a new system (Trima, Gambro BCT) designed to automate the collection of all blood components. The study also evaluated donor safety and suitability of these components for transfusion. STUDY DESIGN AND METHODS: In Phase I, the quality of the components collected on the new system was evaluated by standard in vitro and in vivo testing methods. Results were compared to those from control components collected by currently approved standard methods. In Phase II, additional collections were performed to evaluate the acceptability of the new system and the safety of platelets collected. RESULTS: In vivo 24-hour RBC recovery was 76.8 +/- 3.1 percent for the test RBC units and 77.1 +/- 4.4 percent recovery for whole-blood (control) RBCs. The differences between test and control platelet results in the in vivo and in vitro assays were not clinically significant. Plasma clotting factors and fibrinogen levels met international standards. The system was well accepted by donors, and no major adverse donor reactions were reported for the 68 procedures performed. No problems were reported with transfusing the blood components collected. CONCLUSION: Blood components collected with the Trima are equivalent to currently available components, and they meet the applicable regulatory standards. This system provides consistent, standardized components with predictable yields. It provides the option of fully automating the collection of all blood components.

Pediatric large volume peripheral blood progenitor cell collections from patients under 25 kg: a primer.

Collection of peripheral blood progenitor cells from small pediatric patients provides many social and technical challenges not faced when collecting from adult patients. This paper provides a single institutions experience with 85 collections from 14 patients less than 25 kg of weight over a 2 year period. Specific challenges include obtaining venous access, anticoagulation, volume shifts, and obtaining patient cooperation. A systematic analysis of options for access, alternative modes of anticoagulation, and the effect of large ratios of extra-corporeal volume to patient's blood volume are discussed. Access uniformly required central venous catheters (CVC) ranging from 7-10 Fr. Anticoagulation included systemic heparinization titrating dose by activated clotting time in all cases and combined with citrate at a ratio of 1:25-1:30 in most cases. Collections were performed on a COBE Spectra, after priming with leukoreduced irradiated red cells and omitting both the initial 120cc diversion and rinse back of red cells at the end. Social challenges include issues of assent and ability to distract patients for the duration of a prolonged collection. Progenitor yields from collections from 14 patients were quantitated by CD34+ assay in all cases and CFU-GM in ten of 14 patients. A median of 4.5 x 10(6)/kg CD34+ cells were obtained for each collection. Complications, including those related to catheter access, are enumerated. In summary, large volume peripheral blood progenitor collection can be safely and efficaciously performed in small pediatric patients.

Coagulation factor deficiencies during initiation of extracorporeal membrane oxygenation.

OBJECTIVE: We examined the hypothesis that critically ill patients receiving extracorporeal membrane oxygenation (ECMO) have reduced clotting factor levels, which may contribute to the risk of hemorrhagic complications. METHODS: Blood samples were collected from 19 patients before and 1 hour after initiation of ECMO. Heparin present in samples was removed by ECTEOLA (epichlorohydrin triethanolamine) cellulose resin adsorption, and coagulation factors were assayed by automated techniques. Factor deficiency was defined as levels at least 2 SD less than published age-adjusted reference values. RESULTS: Thirteen patients (68%) had deficiencies of two or more factors before ECMO. Despite inclusion of factor-containing blood products in the ECMO priming solution, 10 patients (53%) had deficiencies of two or more factors after initiation of ECMO. Four patients had intracranial hemorrhages and were found to be deficient in five or more factors at the time of cannulation. CONCLUSIONS: Severe coagulation factor deficiencies are often present in patients requiring ECMO, and coagulation factors provided through the circuit prime are insufficient to ensure correction of these deficiencies. Deficiency of multiple coagulation factors may contribute to the risk of intracranial hemorrhage during ECMO; the practice of excluding factor-containing solutions from the circuit prime should be examined prospectively.

Intensive blood and plasma exchange for treatment of coagulopathy in meningococcemia.

Eight pediatric patients with fulminant meningococcemia, purpura, and disseminated intravascular cogulation who by multiple prognostic scoring systems were anticipated to have a poor outcome underwent intensive plasma exchange (IPE) or whole blood exchange (WBE) in addition to standard medical therapy. IPE/WBE was initiated shortly after admission with a mixture of both fresh frozen plasma and cryoprecipitate as the replacement solution. All IPE procedures were performed using a continuous flow system and a red cell prime. The mean fibrinogen level increased from 62 to 192 mg/dl, the prothrombin time (PT) decreased from a mean of 32.4 seconds to 15.1 seconds, and the mean activated partial thromboplastin time (APTT) decreased from 89.5 seconds to 40.1 seconds following completion of the initial IPE/WBE. There was a corresponding improvement in all coagulation factor levels but only slight improvement in antithrombin III (ATIII) and protein C levels. Seven of eight patients survived (87.5%) their initial presentation with the sole early death attributed to meningitis with cerebral edema. Mean fluid balance after the procedure was +10.8 +/- 5.87 cc/kg. There were no significant bleeding or cardiovascular complications during the procedure. There was no clinical or radiographic evidence of fluid overload after the procedure. This experience demonstrates that IPE/WBE may be conducted safely in critically ill, unstable pediatric patients and is effective in rapidly improving coagulopathy without fluid overload.

Survival and half-life of red cells salvaged after hip and knee replacement surgery.

The survival of autologous red cells collected intraoperatively has been reported previously. This study measures the survival and half-life of red cells collected 3 hours after hip and knee arthroplasty. For six patients, four having knee replacements and two having hip replacements, the salvaged red cells were labeled with radioactive 51Cr. Peripheral blood was simultaneously labeled with nonradioactive 52Cr. There was no significant difference in the survival or half-life of the salvaged and the venous blood.

Aminocaproic acid decreases the incidence of intracranial hemorrhage and other hemorrhagic complications of ECMO.

Since the inception of extracorporeal membrane oxygenation (ECMO), hemorrhage has been a major complication often limiting its usefulness. This study was undertaken to evaluate the effect of aminocaproic acid (AMICAR), an inhibitor of fibrinolysis, on all hemorrhagic complications of ECMO including intracranial hemorrhage (ICH). In 1990, 49 neonates and 5 older children received ECMO therapy. None of these patients received AMICAR. In 1991, 51 neonates and 5 older children received ECMO. Forty-two of these patients who were considered to be at high risk for bleeding complications (preexisting or anticipated surgical procedures, preexisting ICH, or profound hypoxia, acidosis, coagulopathy, or prematurity) were given AMICAR. The remaining 14 low-risk neonates did not receive AMICAR, and for purposes of analysis were combined with the 1990 group. AMICAR was administered just prior to or after cannulation (100 mg/kg, intravenously) and was infused continuously at 30 mg/kg/h until decannulation. Except for the addition of AMICAR, the ECMO protocol was identical for these two patient groups. Patients who received AMICAR had significantly less bleeding while on ECMO (P = .03) and required fewer blood transfusions (P = .01) than patients not receiving AMICAR. This difference was most significant in the congenital diaphragmatic hernia and cardiac subgroups (P = .0001) and was not significant in the meconium aspiration subgroup (P = .1). The incidence of ICH in the neonatal subgroup was also significantly reduced with no patient on AMICAR developing a new or extending a preexisting ICH (P = .007). Reexploration of the cannulation site for bleeding was also reduced in the AMICAR-treated group but the difference failed to reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative management for cholecystectomy in sickle cell disease.

Perioperative complications of surgical procedures are frequently encountered in patients with sickle cell disease. We have reviewed our series of patients with hemoglobinopathies who underwent cholecystectomy from 1978 to 1991 to evaluate their perioperative management and clinical outcome. Twenty-two children with major sickle hemoglobinopathy underwent cholecystectomy for symptomatic cholelithiasis. All 22 were transfused to achieve a hemoglobin (Hgb) level greater than 9 g/dL and hemoglobin S (HbS) less than 37%. Fourteen underwent immediate preoperative automated red cell exchange (ARCE). The median preexchange Hgb of these patients was 8.1 g/dL (range, 6.8 to 10.5). Their median HbS was 84% (range, 53% to 97%). These patients underwent placement of an apheresis catheter under local anesthesia followed by red cell exchange. The median volume of packed red blood cells (PRBC) exchanged was 28.1 mL/kg (range, 13.8 to 58.7). The median HbS after exchange was 21% (range, 16% to 37%) and the median Hgb was 10.6 g/dL (range, 6.5 to 16.7). Eight other patients underwent sequential transfusion (3 after an exchange for an acute pulmonary vasoocclusive crisis). These patients had been prepared over an interval of 2 to 8 weeks preoperatively and had received a median of 26.9 mL PRBC/kg (range, 12.8 to 95). Following sequential transfusion the median Hgb was 11.8 g/dL (range, 9 to 15.7) and the median HbS was 19% (range, 5% to 32%) at the time of surgery. All patients received extended antigen matched blood. Complications of preoperative transfusion were minor and included two febrile-/allergic reactions and one mild superficial catheter-induced phlebitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Suitable survival and half-life of red cells after frozen storage in excess of 10 years.

To examine the appropriateness of the Food and Drug Administration's 10-year storage time for previously frozen red cells, 24-hour posttransfusion survival studies were performed, and the half-life of 3 units of autologous red cells that had been stored for 13.5, 14, and 17 years, respectively, was measured. The units had acceptable freeze-thaw-wash recovery (83.3-91.4%). When a 51Cr label was used for the previously frozen red cells and a simultaneous 52Cr label for freshly drawn autologous red cells was used as a comparison, it was seen that the previously frozen cells had normal 24-hour posttransfusion survival (75.1-88.4%) as well as normal half-life (23-33.7 days). These findings support further extension of the maximum allowable storage time for previously frozen red cells.

[A new approach for transfusion of neocytes: the Neocel system]. / Une nouvelle approche pour la transfusion de néocytes: le système Néocel.

Young red cells (neocytes) were prepared in a double transfer pack having a long, narrow separation bag that allows for a density gradient column to be established during centrifugation. The lighter fraction of red cells (neocyte fraction) was then expressed into a second delivery bag. Phthalate ester density distribution curves showed that 87.1% of the neocyte units had greater than 85% enrichment, i.e. more than 85% of the cells had densities lower than the midpoint density of the original red cell unit, thalassemic patients receiving neocytes had an average decrease of 21.1% in red cells per kg/yr as compared to their frozen red cell requirement, and an average of 6.9% fewer transfusions.

Human blood cells at microgravity: the NASA Initial Blood Storage Experiment.

The Initial Blood Storage Experiment (IBSE) probed the behavior of human red cells, white cells, and platelets during exposure to microgravity for 6 days and 2 hours on a National Aeronautics and Space Administration (NASA) shuttle mission, named STS 61-C, which was launched on January 12, 1986. IBSE involved carefully controlled comparisons between two identical sets of blood cells, one exposed to microgravity and the other held on the ground. Specially designed and fabricated, electrically powered environmental chambers provided appropriate environmental temperatures and air flow to support cell metabolism throughout the experiment. To circumvent the need for constant agitation of platelets during storage, a new thin-layer compression method for platelet preservation was developed. Blood cell samples were allocated to the two arms of the experiment, microgravity and earth gravity, by blind assignment. Moreover, to ensure unbiased assessment of the experiment's findings, postexperiment samples for measurement were identified by code. To optimize the chances of detecting possible gravitational effects, a wide array of measurements of cellular function, morphology, metabolism, and immunology were made. Analysis of variance was used in analyzing the data. The most striking finding was that platelets displayed markedly superior structural and functional integrity at microgravity. Granulocytes held on the ground were preserved slightly better than those that orbited in the shuttle, whereas red cells displayed few effects that were attributable to the gravitational variable. Polyvinylchloride-di-(2-ethylhexyl)phthalate (PVC-DEHP) was the plastic of choice for storage of red cells, while PVC-trioctyltrimellitate (TOTM) was superior to PVC-DEHP and polyolefin (PO) for platelets.

Blood component therapy during the neonatal period: a national survey of red cell transfusion practice, 1985.

A questionnaire to determine patterns of neonatal red cell transfusion practice during 1985 was mailed to 2200 blood banks of American Association of Blood Banks (AABB) institutional members and children's hospitals. There were 915 responses (41.6%); 785 responses (86%) contained sufficient data for analysis. The majority (70.6%) of 785 responding hospitals were community/urban institutions. However, more highly specialized, pediatric hospitals were also represented by 92 university/tertiary-care hospitals (11.7% of respondents) and 29 children's hospitals (3.7% of respondents). Two-thirds of hospitals performed a major antiglobulin crossmatch (rather than an abbreviated one) before all neonatal red cell transfusions. The red cell preparation most frequently selected for small-volume transfusions was ABO and Rh group-specific red cell concentrates. When performing only large-volume exchange transfusions, 19.2 percent of hospitals used whole blood; all others prepared reconstituted units of red cells plus fresh-frozen plasma, a practice that frequently causes exposure to two donors per unit. Another practice likely leading to multiple donor exposure is the use of fresh-frozen plasma to adjust the hematocrit of red cell preparations to a predetermined value prior to a small-volume transfusion. Over one-half of hospitals adjusting hematocrits used plasma, presumably from one donor, to dilute packed red cells from another donor, a practice that has no apparent medical benefit. Most hospitals (63.4%) provided red cells with a reduced risk of transmitting cytomegalovirus; blood from seronegative donors was selected by 65 percent of hospitals. The majority of hospitals, including most of the community/urban hospitals, did not irradiate blood products before transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial challenge of a blood cell separator outside-seal bowl system.

The ability to store platelets beyond 24 hours requires a functionally closed system. This study tested the ability of a cell separator bowl seal system to resist penetration of microbial contamination under normal running conditions and under extreme environmental stress. Three test organisms, Micrococcus luteus, Serratia marcescens, and Staphylococcus epidermidis, were applied directly to the bowl at the edge of the seal or aerosolized and passed through the centrifuge chamber while the cell separator was run through a simulated platelet collection. A sterile, bacteriologic nutrient medium was perfused through the tubing set, thus simulating the flow of blood fractions. Following the procedure, the medium was examined for microbial growth. The concentration of aerosolized bacteria ranged from 5.2 x 10(1) to 3.9 x 10(3) colony-forming units (CFU) per mL, and the concentration of bacteria applied to the edge of the seal ranged from 1.9 x 10(5) to 2.8 x 10(9) CFU per mL. The positive control, direct inoculation of S. marcescens into the circulating medium (50 CFU/500 mL), resulted in recovery of the identical organism after 24 hours' incubation. No contamination of the system was detected in 40 experiments with aerosolized bacteria or in 32 experiments in which bacteria were applied directly to the seal. This study demonstrates that this sealed-bowl system resists microbial contamination.

Nonradioactive chromium technique for red cell labeling.

Following transfusion, red cells labeled with nonradioactive chromium (52Cr) can be detected in the circulation using atomic absorption spectrophotometry. Both in rhesus monkeys and in human subjects, the survival of red cells labeled with 52Cr was found to be insignificantly different from that of cells labeled with 51Cr. Nonradioactive chromium can be used to label a second population of red cells, when 51Cr is used for the first population, or can be used on its own when the use of radioactivity is contraindicated.

Therapeutic apheresis in childhood.

The procedures for intensive plasma exchange (IPE) and cytopheresis (CY) require modification for use in children. During the past 11 years we have performed more than 2,000 procedures on children for 11 months to 18 years of age. Heparinization has been our primary method of anticoagulation. Those who were acutely ill anemic or small required a red cell-saline prime. Morbidity was virtually nonexistent. If apheresis is otherwise indicated it should not be withheld because of patient size or concurrent medical problem.

A new approach to neocyte transfusion: preliminary report.

A method has been developed using phthalate oils to quality control units of young red cells (neocytes). Neocytes prepared by the NEOCEL system have a mean young red cell enrichment of 90% with only 3.4% less than 80%. Neocytes prepared in a blood cell processor have an average enrichment of 81% with 27% less than 75%. Based on a 12 month period, the patients as a group have received an average of 14% fewer transfusions and an 18% decrease in red cells per kg/yr as compared to frozen red cells.