Units Of Fresh Whole Blood Research Articles

Comparative Analysis ofWhole Blood Infusion Effects: Assessing LifeFlow Versus Pressure Bag ina Sus scrofa Model.

To improve survival for hemorrhagic shock treatment, guidelines emphasize two patient care priorities: (1) immediate hemorrhage control and (2) early resuscitation with whole blood or blood products. The LifeFlow device is designed to rapidly infuse blood products. However, the effects of using this device compared to pressure-bag systems remain unclear. We hypothesize that there will be no laboratory-measured difference with the blood when infused through the LifeFlow versus the current standard pressure bag system. Two units of fresh whole blood were obtained from a sus scrofa model. One unit was "infused" using the LifeFlow with the other unit used as a control through a standard pressure bag system into an empty bag. The "before" measurements were obtained from blood samples from a standard fresh whole blood collection bag. The blood was "infused" into a whole blood bag devoid of storage solution from which the "after" measurements were obtained. This study utilized 22 clinically healthy sus scrofa. Blood units were primarily obtained from a left subclavian central line (50.0%). The median time to acquire and administer a unit of blood was similar for both the LifeFlow device (8.4 min and 8.1 min) and the pressure bag (8.7 min and 7.4 min). No significant differences were found in the total time to acquire or administer blood between the two devices. The median volume of blood acquired was 500 mL for both groups. While no significant differences in blood parameters were observed between the two devices, significant differences were noted when comparing pre- and post-transfusion values within each device. For the LifeFlow device, an increase in hemoglobin and chloride levels and a decrease in thromboplastin time and glucose levels were observed. With the pressure bag, only a decrease in blood urea nitrogen was observed. In comparing the LifeFlow to the pressure bag, there were no significant differences noted in the total time to acquire or administer a whole unit of blood. However, there were differences with several laboratory parameters of unclear clinical significance.

A prospective assessment of the time required to obtain one unit of fresh whole blood by civilian phlebotomists and Army laboratory technicians (68 K).

Resuscitation with blood products improves survival after major hemorrhage. Blood product administration at or near the point-of-injury (POI) amplifies this benefit. Size, weight, and cold-chain management challenges all limit the amount of blood medics can carry. Warm fresh whole blood (WFWB) transfusions from a pre-screened donor within the unit represent an alternative source of blood at the POI. We measured the time required for civilian and Army technicians performing phlebotomy frequently to obtain one unit of blood to serve as a goal metric for combat medics being trained in this skill. We gathered demographic and experience data along with proportion of first intravenous cannulation attempt success, time to blood flow initiated, and time to unit draw complete. We prospectively enrolled 12 civilian phlebotomy technicians and 10 Army laboratory technicians performing whole blood collections on 50 and 68 donors respectively. The mean time from setup to needle insertion was 3.7 min for civilians versus 4.2 min for Army technicians. The mean time from blood flowing to the bag being full was 10.7 min versus 8.4 min for civilians versus Army technicians respectively. The mean bag weights were 514 g versus 522 g. First-pass intravenous cannulation success was 96% versus 98% respectively. We found a high first intravenous cannulation attempt success among both the civilian and Army technicians. Medians times were <5 min to obtain venipuncture and <11 min to obtain one unit. These findings provide time-based benchmarks for potential use during transfusion training among military medics.

Hemostatic capacity of canine chilled whole blood over time.

To determine the hemostatic potential of canine chilled whole blood maintained at clinically relevant storage conditions. In vitro experimental study. Government blood and coagulation research laboratory and government referral veterinary hospital. Ten healthy Department of Defense military working dogs. One unit of fresh whole blood was collected from each of 10 military working dogs using aseptic technique. Blood was maintained in a medical-grade refrigerator for 28 days at 4°C (39°F) and analyzed before refrigeration (day 0) and after (days 2, 4, 7, 9, 11, 14, 21, and 28). Ten units of canine blood were analyzed with whole blood platelet aggregation, thromboelastography, CBC, biochemical analysis, blood gas, and prothrombin/activated partial thromboplastin/fibrinogen assay. Clotting strength of chilled blood was maintained up to 21 days despite significant decreases in platelet aggregation to ADP, collagen, or γ-thrombin, significant prolongation of prothrombin and activated partial thromboplastin times, and reduced speed of clot formation (K time, alpha angle). Fibrinogen concentration, WBC, RBC, and platelet counts did not change over time. Chilled canine whole blood loses a small percentage of clot strength through 21 days of refrigerated storage. Further research is needed to determine if this hemostatic potential is clinically relevant in hemorrhaging dogs who require surgical intervention or are exposed to traumatic events.

Operation Blood Rain: The Effect of Airdrop on Fresh Whole Blood.

Administration of fresh whole blood (FWB) is a life-saving treatment that prolongs life until definitive surgical intervention can be performed; however, collecting FWB is a time-consuming and resource-intensive process. Furthermore, it may be difficult to collect sufficient FWB to treat critically wounded patients or multiple-hemorrhaging casualties. This study describes the effect of airdrop on FWB and explores the possibility of using airdrop to deliver FWB to combat medics treating casualties in the prehospital setting when FDA-approved, cold-stored blood products are not readily available and timely casualty evacuation (CASEVAC) is not feasible. Four units of FWB were collected from volunteer donors and loaded into a blood cooler that was dropped from a fixed-wing aircraft under a standard airdrop training bundle (SATB) parachute. A control group of 4 units of FWB was stored in a blood cooler that was not dropped. Baseline and postintervention laboratory samples were measured in both airdropped and control units, including full blood counts, prothrombin time/partial thromboplastin time/international normalized ratio (PT/PTT/INR), pH, lactate, potassium, indirect bilirubin, glucose, fibrinogen, lactate dehydrogenase, and peripheral blood smears. The blood cooler, cooling bags, and all 4 FWB units did not sustain any damage from the airdrop. There was no evidence of hemolysis. All airdropped blood met parameters for transfusion per the Whole Blood Transfusion Clinical Practice Guideline of the Joint Trauma System (JTS). Airdrop of FWB in a blood cooler with a SATB parachute may be a viable way of delivering blood products to combat medics treating hemorrhaging patients in the prehospital setting, although further research is needed to fully validate the safety of this method of FWB delivery.

Effect of the fresh whole blood transfusion on perioperative bleeding in adult patients undergoing emergency coronary artery bypass grafting surgery: a randomized study

Objective The present study aimed to assess the hemostatic effects of fresh whole blood (FWB) transfusion on bleeding and blood product transfusion in patients on clopidogrel undergoing emergency coronary artery bypass grafting surgery (CABG). Design A randomized study was conducted. Setting The study was conducted at a cardiac center. Patients and methods The study included 124 patients undergoing CABG surgery. The patients were divided into two groups: FWB group patients received two to six units of FWB after weaning off cardiopulmonary bypass and in the cardiac surgery ICU. Control group patients received blood products (packed red blood cells, platelets, fresh frozen plasma, or cryoprecipitate) after weaning off cardiopulmonary bypass and after surgery in cardiac surgery ICU. Total number of the transfused FWB, platelets, packed red blood cell, fresh frozen plasma, and cryoprecipitate (intraoperative and postoperative transfusion), bleeding time, and platelet aggregation function were measured. Moreover, the thorax closure time and amount of blood losses, re-exploration, pulmonary edema, and postoperative mechanical ventilation were monitored. Results FWB significantly decreased the blood loss and blood product transfusion compared with the control group (P=0.001 and 0.001, respectively). The bleeding time and platelet aggregation function were better in the FWB group compared with the control group (P=0.020 and 0.034, respectively). Moreover, the thorax closure time, cardiac tamponade, re-exploration, pulmonary edema, and postoperative mechanical ventilation decreased significantly in the FWB group compared with the control group (P Conclusion FWB decreased the blood loss, blood product transfusion, cardiac tamponade, and re-exploration in patients on preoperative clopidogrel undergoing emergency CABG.

Bee sting envenomation resulting in gross haematuria in an eight-year-old Nigerian male with sickle cell anaemia: A case report.

Gross haematuria is an unusual complication of Honey bee stings. Herein, we report a rare case of gross haematuria following multiple honeybees stings in an 8-year-old Nigerian child with sickle cell anaemia. The patient had evidence of massive intravascular haemolysis and was transfused with a unit of fresh whole blood. However, he died within 36 hours on admission despite medical intervention.

An ex vivo evaluation of efficacy of refrigerated canine plasma.

To determine thawing times of fresh frozen plasma (FFP), and to evaluate the activity of hemostatic proteins (coagulation factors V, VII, VIII, IX, X, and fibrinogen), clotting times (prothrombin time and activated partial thromboplastin time), and sterility of canine plasma stored refrigerated. Prospective laboratory-based study. Veterinary teaching hospital blood bank. Phase 1: Six units of canine FFP were retrieved from the blood bank and thawed individually in a warm water bath. Time for thaw was recorded in minutes and reported as mean ± SD. Phase 2: One unit of fresh whole blood was collected from 9 dogs and processed routinely. Resulting plasma was divided into 2 aliquots, 1 stored as refrigerated plasma (RP) and 1 as frozen plasma. Samples from the RP were taken at 0, 1, 5, 7, and 14 days and from the FFP at days 0 and 14 for determination of clotting factor activity (V, VII, VIII, IX, and X and fibrinogen) and clotting times. Coagulation factors and clotting times were analyzed using a mixed effects linear model for ANOVA, comparing changes over time as well as differences between groups. For all comparisons, a P value of <0.05 was considered significant. Batch bacterial aerobic and anaerobic cultures of the RP samples were submitted on days 7 and 14 and from the frozen plasma on day 14. Time to thaw for FFP units was 34.7 ± 1.38 minutes. Refrigerated storage resulted in significant decreases in the activity of all clotting factors and a subsequent prolongation in clotting times. However, no values were outside of the reference interval. All bacterial cultures yielded no growth. Refrigerated storage results in only minor loss of coagulation factor activity in canine plasma. The use of RP, therefore, may be a viable option in high-volume veterinary hospitals for rapid correction of coagulopathy in critical care patients.

Acute bilateral leg amputation following combat injury in UK servicemen

BackgroundThis study aims to characterise the injuries and surgical management of British servicemen sustaining bilateral lower limb amputations. MethodsThe UK Military Trauma Registry was searched for all cases of primary bilateral lower limb amputation sustained between March 2004 and March 2010. Amputations were excluded if they occurred more than 7 days after injury or if they were at the ankle or more distal. ResultsThere were 1694 UK military patients injured or killed during this six-year study period. Forty-three of these (2.8%) were casualties with bilateral lower limb amputations. All casualties were men with a mean age of 25.1 years (SD 4.3): all were injured in Afghanistan by Improvised Explosive Devices (IEDs). Six casualties were in vehicles when they were injured with the remaining 37 (80%) patrolling on foot. The mean New Injury Severity Score (NISS) was 48.2 (SD 13.2): four patients had a maximum score of 75. The mean TRISS probability of survival was 60% (SD 39.4), with 18 having a survival probability of less than 50% i.e. unexpected survivors. The most common amputation pattern was bilateral trans-femoral (TF) amputations, which was seen in 25 patients (58%). Nine patients also lost an upper limb (triple amputation): no patients survived loss of all four limbs. In retained upper limbs extensive injuries to the hands and forearms were common, including loss of digits. Six patients (14%) sustained an open pelvic fracture. Perineal/genital injury was a feature in 19 (44%) patients, ranging from unilateral orchidectomy to loss of genitalia and permanent requirement for colostomy and urostomy. The mean requirement for blood products was 66 units (SD 41.7). The maximum transfusion was 12 units of platelets, 94 packed red cells, 8 cryoprecipitate, 76 units of fresh frozen plasma and 3 units of fresh whole blood, a total of 193 units of blood products. ConclusionsOur findings detail the severe nature of these injuries together with the massive surgical and resuscitative efforts required to firstly keep patients alive and secondly reconstruct and prepare them for rehabilitation.

Transfusion sanguine en opération extérieure. Expérience à l’hôpital médico-chirurgical de Kaboul

ObjectivesBlood transfusion is an aspect of medical care on the battlefield. French assets include: red blood cell units (RBCu), lyophilized plasma (PLYO), fresh whole blood (FWB) but neither fresh-frozen plasma (FFP) nor platelets. French transfusion strategy in military operations follows the evolution of knowledge and resources. We describe the characteristics of the transfusion at the military hospital in Kabul. Patients and methodsRetrospective study of records of patients transfused between October 2010 to December 2011 conducted in Kabul from transfusion register. Variables studied were: patient characteristics, biology at admission, type and amount of transfusion products, evolution. ResultsOne hundred and twenty-six patients were transfused: 49 military (39%) which 22 French soldier (17%), most of time afghan (n=97; 77%), mean age at 24 years old (3–66). Two hundred and seventy-three RBCu from France were transfused and 350 unused were destroyed. Conditions leading to a transfusion were: 76 war wounds (60%), 21 trauma (17%) and 29 other (23%). In the first 24hours, patients received in mean: two RBCu (0–12), one unit of FWB (0–18) and two PLYO (0–14). PLYO/RBCu ratio was 1/1.6. A massive transfusion (more than 10 RBCu) concerned 9% of patients. Twenty-seven percent of patients received FWB. We note 17 dead people (13.5%). ConclusionThe use of the FWB and PLYO in substitution of FFP and platelets can provide cares of high quality in a logistically constrained context while controlling costs.

Putting Evidence Into Nursing Practice: Four Traditional Practices Not Supported by the Evidence

Evidence-based nursing practice is essential to the delivery of high-quality care that optimizes patients' outcomes. Studies continue to show improved outcomes when best evidence is used in the delivery of patient care. Despite awareness of the importance of practicing by using best evidence, achieving and sustaining evidence-based practice within practice environments can be challenging, and research suggests that integration of evidence-based practice into daily clinical practice remains inconsistent. This article addresses 4 practice issues that, first, are within the realm of nursing and if changed might improve care of patients and, second, are areas in which the tradition and the evidence do not agree and practice continues to follow tradition. The topics addressed are (1) noninvasive measurement of blood pressure in children, (2) oxygen administration for patients with chronic obstructive pulmonary disease, (3) intravenous catheter size and blood administration, and (4) infection control practices to prevent infections. The related beliefs, current evidence, and recommendations for practice related to each topic are described.

Early onset pancytopenia in patient on methotrexate

A 30-years-old female presented to emergency department with a history of fever, epistaxis and bleeding gums since 3 days. She gave history of methotrexate (MTX) prescribed for joint pain (a cumulative dose of 20 mg in 3 days) prior to the presentation. Her blood counts were normal prior to MTX ingestion. But on the day of admission, all the three cell lines were low. She was given 5 units of fresh whole blood and antimicrobial and antifungal coverage during her total stay in the hospital. Her bone marrow finding was suggestive of aplastic anemia/drug induced bone marrow suppression. After 2 weeks of supportive therapy, her blood counts were normal. She was advised to repeat bone marrow examination, which she denied. Her anti-CCP levels were normal and did not meet the criteria for rheumatoid arthritis so advised to stop MTX. Although, pancytopenia associated with low-dose MTX therapy is not expected as early as 3 days after initiation of the therapy, physicians should also be aware of this life threatening adverse effect during the very first days of MTX therapy.

A Prospective Audit of Blood Transfusion Reactions in Tertiary Care Hospital for the Use of Blood and Blood Components

Aims and Background: Like any other drug, therapeutic use of blood and its components has its own side effects, adverse reactions and risks involved. Overall use of blood has been on the increase in most tertiary care hospitals. Since the guidelines for blood and its components use in a clinical setting are well defined, but not practiced in reality, the present study aims at defining the problems associated with blood transfusion in the light of its risks and benefits as a drug. Materials and Methods: We carried out prospective survey of 1453 units of blood and components for 696 patients during period of 6 months and recorded the indications for usage and transfusion reactions associated with its usage. Results: Out of 1453 units’ blood/blood component transfused, 48 (3.30%) units of blood developed transfusion reactions. Of these, 41 were produced by whole blood, (85.41%) & 5 units (10.42%) by packed cells. FFP 1 unit (2.08 %) for a patient with alcoholic liver disease produced reaction. 1 unit of fresh whole blood (2.08%) has produced reaction. Medical cases produced the more number of blood transfusion reactions (14 patients). Most of the blood transfusion reactions were allergic (50%) and most of the reactions were produced after multiple transfusions. Conclusion: There is lack of blood transfusion committee in IGGGH&PGI, Puducherry Hospital, which has produced inappropriate transfusions due to absence of strict transfusion triggers. Transfusion Trigger: Hb% < 7 gms% is an indication for blood transfusion and hematocrit < 27% is an indication. Blood transfusion should be started immediately after its issue from blood bank, if not used within ½ hour and then replaces it to blood bank for cold chain maintenance. Transfusion reactions (3.3%) more common agent is whole blood, since it contains all unnecessary components, which produces allo- immunization. Blood component usage should be increased which will reduce the incidence of transfusion reaction.

Angiodysplasia of the colon: A report of two cases and review of literature

Angiodysplasias of the colon are enlarged and fragile blood vessels in the colon result in occasional loss of blood from the lower gastrointestinal tract. It may be observed incidentally at colonoscopy or patients may present with lower gastrointestinal bleeding. The objective of this case report is to highlight two cases of colonic vascular ectasia seen using a Pentax video colonoscope at the Endoscopy unit of Crescent hospital, Ilorin. The first patient is an 85-year-old man, who presented with constipation, left-sided abdominal pain, and weight loss of two weeks duration. There was no anorexia, abdominal swelling, diarrhea, or hematochezia. Abdomino-pelvic ultrasonography showed normal findings. Colonoscopy done, reaching the ileo-cecal valve and caecum, showed an area of dilated tortuous blood vessel (vascular ectasia) in the wall of the descending colon approximately 45 cm from the anal verge, with no features of bleeding. No ulcers or mass lesion was seen. Colonoscopy showed angiodysplasia of the colon. The second patient is a 30-year-old female trader who presented with two days history of massive hematochezia of about 7 episodes prior to presentation with an estimated blood loss per episode of about 300 ml. There were clinical features of shock. Packed cell volume at presentation was 14%. She was transfused with 4 units of fresh whole blood. Post stabilization, colonoscopy was done 5 days after bleeding had stopped, which revealed an area of erosion with mucosal blood clot about 27 cm from the anal verge. An area of angiodysplasia was seen. No hemorrhoids or mass lesion was seen anywhere in the colon. Angiodysplasia is an uncommon finding in Ilorin. These are the first reported cases of angiodysplasia of the colon from Ilorin, Nigeria.

Storage of Blood Components Does Not Decrease Haemostatic Potential: In vitro Assessment of Fresh versus Stored Blood Components Using Thromboelastography

Background: Major surgery and severe trauma typically lead to massive blood loss requiring rapid transfusion of large amounts of blood products. It has been suggested that fresh, unrefrigerated whole blood provides a haemostatic advantage in this setting. The aim of the current study was to compare the clot formation parameters of fresh, unrefrigerated whole blood and whole blood reconstituted from components stored for varying periods of time, using rotational thromboelastography (ROTEM®). Methods: Fresh whole blood and reconstituted whole blood using combinations of nonleucoreduced red cell units (stored for 7, 14, 21, 28, or 35 days), platelet concentrates (stored for 1, 3 or 5 days), and fresh frozen plasma (stored for 6 months) were analysed using ROTEM. Measurements of the clotting time (CT), clot formation time (CFT), and maximal clot firmness (MCF) were compared between units of fresh whole blood and reconstituted whole blood samples. Results: There was no difference in the haemostatic parameters measured of fresh whole blood and reconstituted whole blood using red cell units stored for less than 21 days. ROTEM demonstrated that the CT and CFT were significantly shorter for reconstituted whole blood samples using red cells stored for longer than 21 days when compared to fresh whole blood and to reconstituted whole blood samples using red cell units stored for less than 21 days. The CT was inversely correlated to the duration of platelet storage. The MCF was unchanged regardless of duration of blood product storage. Conclusion: Fresh unrefrigerated whole blood and blood products stored for short duration (less than 21 days) were not superior to those stored for longer durations.

From Donor to Patient in 20 Minutes

From Donor to Patient in 20 Minutes

Risks associated with fresh whole blood and red blood cell transfusions in a combat support hospital

Fresh whole blood (FWB) and red blood cells (RBCs) are transfused to injured casualties in combat support hospitals. We evaluated the risks of FWB and RBCs transfused to combat-related casualties. Retrospective chart review. Deployed U.S. Army combat support hospitals. Donors of FWB and recipients of FWB and RBCs. The storage age of RBCs at transfusion was measured as an indicator of overall risk associated with the storage lesion of RBCs between January 2004 and December 2004 at one combat support hospital. Between April 2004 and December 2004, FWB was prescreened only at one combat support hospital for human immunodeficiency virus, hepatitis C virus, and hepatitis B surface antigen before transfusion. To estimate the general incidence of infectious agent contamination in FWB units, samples collected between May 2003 and February 2006 were tested retrospectively for human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus, and human lymphotropic virus. Results were compared between FWB samples prescreened and not prescreened for infectious agents before transfusion. At one combat support hospital in 2004, 87 patients were transfused 545 units of FWB and 685 patients were transfused 5,294 units of RBCs with a mean age at transfusion of 33 days (+/- 6 days). Retrospective testing of 2,831 samples from FWB donor units transfused in Iraq and Afghanistan between May 2003 and February 2006 indicated that three of 2,831 (0.11%) were positive for hepatitis C virus recombinant immunoblot assay, two of 2,831 (0.07%) were positive for human lymphotropic virus enzyme immunoassay, and none of 2,831 were positive for both human immunodeficiency virus 1/2 and hepatitis B surface antigen by Western blot and neutralization methods, respectively. The differences in the incidence of hepatitis C virus contamination of FWB donor units between those prescreened for hepatitis C virus (zero of 406; 0%) and not prescreened (three of 2,425; 0.12%) were not significant (p = .48). The risk of infectious disease transmission with FWB transfusion can be minimized by rapid screening tests before transfusion. Because of the potential adverse outcomes of transfusing RBCs of increased storage age to combat-related trauma patients, the risks and benefits of FWB transfusions must be balanced with those of transfusing old RBCs in patients with life-threatening traumatic injuries.

Warm storage of whole blood for 72 hours

In field emergency medicine, fresh whole-blood units are stored at room temperature up to 24 hours or occasionally longer. Few data exist on the integrity and in vitro functional properties of whole blood stored warm beyond 24 hours. Ten citrate phosphate dextrose solution whole-blood units were collected and divided into two equal volumes. One-half of each unit was stored at 19 degrees C and the other half was stored at 25 degrees C, encompassing the accepted range for room temperature storage. At 6, 24, 48, and 72 hours, aliquots were collected from each unit and whole blood analyzed for cell counts, gases, and clotting function with thromboelastography, red cells for intracellular analytes, platelet (PLT)-rich plasma for aggregometry, and the supernatant for hemoglobin, potassium, glucose, lactate, and plasma clotting studies. Whole-blood units stored at room temperature maintained cellular counts and coagulation activity for up to 72 hours. Units stored at 19 degrees C demonstrated greater RBC adenosine triphosphate and 2,3-diphosphoglycerate (DPG) content and stronger responses in PLT aggregation studies when compared with 25 degrees C storage. No significant hemolysis was observed, and no bacterial growth was detected. Storage of whole blood at room temperature for 72 hours leads to marked reductions in pH and DPG, but the observed reduction in PLT function and plasma coagulation factor activity was surprisingly modest compared to literature values. These findings should prompt additional investigation, given their potential importance for whole blood processing and field-expedient transfusion.

Electron micrographic study of the removal of Trypanosoma cruzi from blood products by leukodepletion filters

Leukodepletion filters have been used to reduce the number of Trypanosoma cruzi in blood products in spite of the fact that while circulating in blood, these organisms are not contained within WBCs. We recently demonstrated by electron microscopy that leukodepletion filters remove the free extracellular form of the Leishmania promastigote, which has a similar structure and surface charge to that of the T. cruzi trypomastigote. The mechanism of removal in the case of the Leishmania promastigote is via direct adherence of the promastigotes to filter fibers. In the case of Leishmania, the amasitgote form of the organism is contained within monocytes and is removed as WBCs are trapped within filters; however, we demonstrated that free amastigotes and promastigotes adhere to filter fibers and are also removed. To investigate the mechanism of removal of T. cruzi, trypomastigotes were added to plasma separated from a unit of fresh whole blood collected into CPD and then passed through whole-blood leukodepletion filters (WBF2, Pall, East Hills, NY). Immediately after filtration, fixation was accomplished by adding 4 percent formaldehyde-1 percent glutaraldehyde to the filters. Filters were opened, and intact sheets of fibers were removed for examination by transmission and scanning electron microscopy. Figure A shows multiple trypomastigotes adhering to filter fibers. (Scanning electron micrograph of flagellated T. cruzi trypomastigotes adherent to leukodepletion filter fibers after filtration. Organisms can be seen to adhere via both body and flagella [magnification 3000x].) Figures B and C demonstrate adherence of individual organisms to fibers. (Fig. B-Transmission electron micrograph showing a T. cruzi trypomastigote adhering to a leukodepletion filter fiber [magnification 4000x]; Fig. C-Scanning electron micrograph showing a T. cruzi trypomastigote adhering to a leukodepletion filter fiber. The undulating membrane of the trypomastigote can be seen clearly in this EM. The undulating membrane is an organelle present in trypanosome and trichomonad parasites. It is a fin-like extension of the cell membrane with the flagellar sheath and contains microtubules. The membrane undulates producing movement of the organism [magnification 25,000x].) This work demonstrates that the T. cruzi trypomastigote adheres to leukodepletion filter fibers in a similar way to that of the Leishmania promastigote. In contrast to a prior report of removal by predominantly mechanical means, we found that the predominant mechanism appears to be via adherence of trypomastigotes to filter fibers.

Mathematical considerations in the practice of acute normovolemic hemodilution.

Acute normovolemic hemodilution (ANH) is recommended as a simple and cost-effective method of autologous transfusion. The present mathematical model, based on the current clinical practice of removing 2 to 3 units of fresh whole blood, defines the indications for ANH. A mathematical model and subsequent nomograms were developed to define patients for whom removal of 2 to 3 units (450 mL each) would allow a theoretical red cell savings equivalent to 1 unit of packed red cells (volume, 250 mL; hematocrit, 60%), that is, a successful application of the technique. Minimal safe target hematocrits were defined as 30, 26, and 22 percent. The minimal initial hematocrits required for given patient weights are displayed on nomograms derived from the mathematical model. The nomograms also indicate the surgical blood loss allowed without ANH: for example, a 75-kg man, (2-unit ANH, minimal safe hematocrit 22%) requires a minimal initial hematocrit of 42 percent (surgical blood loss of 0.64 x estimated blood volume = 3100 mL). ANH involving the removal of 2 to 3 units (450 mL each) may be useful in patients with anticipated blood loss exceeding 50 percent of estimated blood volume, high initial hematocrit, and a capacity to tolerate dilution-induced anemia.

当院における血液製剤の使用状況，特に廃棄血液の現状について

This study evaluated the usage and discard of all the blood products (124533 units) supplied from the Japan Red Cross blood center from April in 1989 to Marchin 1993.The units of fresh whole blood and stored whole blood purchased and used significantly decreased during 4 years. The units of fresh whole blood purchased was 22% in 1992 compared with those in 1989. The purchase and use of platelet concentrate significantly increased, especially in recent 2 years.The percentage of discarded blood was extremely lowered to 0.78% in 1992. Discards of whole blood and red cell concentrate due to inadequate management at the ward were especially decreased. The units of red cell concentrate discarded due to the expiration of stored period were also decreased because of the introduction of concentrated red cells stored in MAP solution (RC-MAP) in April 1992.Frequent communication between our division and the doctors in charge was necessary to reduce the discard of platelet concentrate which were over ordered for patients. In addition, the blood management system should be clearly understood among the doctors to reduce the discards of whole blood and red cell concentrate.