bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep and Academic Performance in U.S. Military Training and Education Programs
Authors: Miller Nita Lewis , Shattuck Lawrence G. , Matsangas Panagiotis , Dyche Jeff
Published: February 2008

ABSTRACT— This review examines the effects of military training regimes, which might include some degree of sleep deprivation, on sleep–wake schedules. We report a 4‐year longitudinal study of sleep patterns of cadets at the United States Military Academy and the consequences of an extension of sleep from 6 to 8 hr per night at the United States Navy’s Recruit Training Command. These studies provide an opportunity to observe sleep in a college‐age population and also to record sleep patterns over an entire 4‐year college experience, adding to our understanding of the changes in sleep patterns over the life span.
Teaching Chronobiology and Sleep Habits in School and University
Authors: Azevedo Carolina V. M. , Sousa Ivanise , Paul Ketema , MacLeish Marlene Y. , Mondéjar Ma Teresa , Sarabia Juan Antonio , Ángeles Rol M. , Madrid Juan Antonio
Published: February 2008

ABSTRACT— Early morning school schedules are in the opposite direction to the sleep–wake cycle in adolescence and early adulthood. This conflict leads to sleep deprivation and irregular patterns whose consequences are scarcely explored. This article discusses the effects of three educational experiences with high school students, parents, teachers, and medical students. The first experience was developed with high school students in Natal, Brazil, to determine whether sleep habits would improve with increased awareness. Positive effects were observed in some aspects of sleep knowledge and practices. In the second experience in Atlanta, GA, sleep education activities were presented to middle and high school teachers, parents, and students to emphasize the importance of sleep. In the third program in Murcia, Spain, undergraduate medical students were introduced to chronobiology of sleep by a practical exercise that pointed out to what extent they shared most of adolescent sleep characteristics. Educational chronobiological experiences about sleep are essential to develop healthy sleep habits in the general population, particularly in students.
Benefits of Red Blood Cell Transfusion: Where is the Evidence ?
Authors: Spahn Donat R.
Published: February 2008

The aim of the present article is to summarize existing evidence of benefits of red blood cell transfusion and to dicuss studies that failed to document such effects. In specific situations with organ dysfunction caused by extreme acute anemia, transfusion of red blood cells has been shown to be an efficacious treatment. In most of these studies, this was achieved by transfusion of fresh, mostly autologous, red blood cells. Large studies have failed to demonstrate an outcome benefit in liberally transfused patients; in contrast, there is strong evidence that liberal transfusion of red blood cells adversely affects morbidity and mortality in surgical and critically ill patients. Judicious and restrictive use of red blood cell transfusion is thus indicated.
Utilization of Autologous Transfusion Technologies for Allogeneic‐blood‐free Cardiac Transplantation in Pediatric Patients
Authors: Potter Paul S.
Published: February 2008

The use of blood products has diminished over the last several years. The avoidance of allogeneic blood not only has the benefit of reduced disease transmission but also reduces other complications such as immunosuppression. While this is a goal for all patients, in the pediatric population this is not a simple matter. In cardiac surgery, red cell volume must be maintained, but platelet function and clotting factors are also of concern. In the pediatric Jehovah's Witness patient for cardiac transplant all concerns take on increased importance. The maximization of perioperative blood management will allow the preservation of all blood components and can be done in such a way as to honor the beliefs and requirements of this religious group. This article will discuss the methodology for the accomplishment of major cardiac surgery in the pediatric patient using no blood products.
Erythropoietin and Iron in the Anemia of Prematurity
Authors: Messer Jean , Escande Benoît , Matis Jacqueline
Published: February 2008

Premature infants are frequently anemic during the first weeks of life, especially if they are born before 30 weeks of gestational age. This so‐called “anemia of prematurity” has several causes; one is a transitory inadequate production of erythropoietin relative to the degree of anemia. Since 1990, several trials of erythropoietin therapy in the anemia of prematurity have been conducted. They showed a reduction of transfusion requirements in treated infants. The enhancement of erythropoiesis requires the administration of substantial quantities of iron; oral administration is sometimes difficult due to poor gastrointestinal tolerance. It is probable that in the future, the use of intravenous iron may be the solution.
Volume Therapy in Patients with Acute Stroke
Authors: MT Grauer , Woessner R , Haass A , Treib J
Published: February 2008

In acute ischemic stroke, because of impaired autoregulation, the perfusion of the ischemic brain region and its neighboring region, the penumbra, depends on blood pressure, cardiac output and rheological characteristics.

Improvement of rheological parameters and hemodynamics is therefore a promising therapeutic strategy for ischemic stroke. Volume therapy in acute ischemic stroke attempts to increase cardiac output and blood pressure by increasing cardiac preload through the infusion of colloid and crystalloid solutions. Another important therapeutic avenue is the improvement of rheology through a decrease in hematocrit, plasma viscosity and erythrocyte aggregation. The adequate choice of plasma substitutes allows for a more differentiated volume therapy in acute stroke. With newer, medium‐ or low‐molecular weight hydroxyethyl starches, it is possible to safely use a high‐dose, hemodynamic volume therapy in acute ischemic stroke and improve hemodynamic and rheological parameters without increased risk of hemorrhages.
Alternative Strategies in Platelet Therapy
Authors: Goodnough Lawrence Tim
Published: February 2008

Recent developments in transfusion practices are prompting re‐evaluation of platelet therapy. For example, the use of single‐donor apheresis products has increased substantially, from 365,000 units in 1989 to 607,000 in 1992 and to 714,000 in 1994, as shown in Table 11; in some regions, apheresis platelets account for 70% of transfusions 2.The use of these components has been driven in part by the need for adequate platelet inventory in order to support cardiac surgery and hematopoietic stem cell transplantation programs, but also in part by commercial interests, in which promotion of the use of leucodepleted platelet products targets surgeons directly3.

However, emerging issues related to the handling of the apheresis donor4, 5, the higher costs of apheresis platelets compared to pooled platelet concentrates6 8, and the results of the TRAP (Transfusion‐Related Alloimmunization to Platelets9,10) study have caused renewed debate regarding the role of apheresis platelets compared to platelet concentrates.

Furthermore, recent studies have suggested alternative strategies in platelet therapy. These strategies include the platelet threshold for prophylactic platelet transfusion, platelet transfusion dose, and the emerging role of thrombopoietin therapy; these developments will be reviewed in this article.
Erythropoietin in Cancer Surgery
Authors: Gentilini Oreste D. , Gianotti Luca , Vignali Andrea , Braga Marco
Published: February 2008

Patients with gastrointestinal cancer usually have a sideropenic anemia unresponsive to iron supplementation which is characterized by low levels of endogenous erythropoietin. Anemic patients are not suitable for preoperative autologous blood donation programs and are at high risk for perioperative homologous blood transfusions. Preoperative treatment with recombinant human erythropoietin (r‐HuEPO) has allowed anemic patients to donate autologous blood and reduced homologous blood transfusion after surgery. A dose‐response study showed that 400 U/kg of r‐HuEPO, divided in four doses administered every four days, is the minimum effective dose which increases hemoglobin levels about 10 g/L/week. The red blood cell (RBC) gain was 268 ± 79 mL, which is grossly equivalent to the RBC content of two units of predonated autologous blood. The total charge for this treatment ($280) was substantially lower than in other experiences in which higher doses of r‐HuEPO were given. To maximize erythropoietic response, it is necessary to provide supplementary IV iron (125 mg daily). This results in a normalization of circulating and stored iron, suggesting that the amount was adequate both to sustain the production of new RBCs and to replace tissue stores during r‐HuEPO treatment.
Colloids/Crystalloids J Does Albumin Influence the Mortality Risk?
Authors: Bold Joachim
Published: February 2008

Effective fluid therapy is a main stay in the ma nagement of the critically ill patient. The ideal kind of volume replacement in this situation still remains achallenge. To treat hypovolemia, colloids are widely used, and the natural colloid h u man albumin is still preferred for volume therapy in several centers. H oweve r, most studies do not show any bene fits of using albumin with regard to hemodyna mics, organ function or side effects (e. g. hemostasis, renalfunction). Alternative plasma substitutes such as synthetic colloids are associated with some beneficial effects compared to albumin administration (e. g. improved splanchnic perfusion). Given albumin's costs, its use does not appear to be justified, and other solutions (e. g. synthetic colloids) are attractive alternatives. Inspite of some theoretical adva n tages based on our current knowledge, use of albumin cannot be recommended and should be completely avoided.
Efficacy and Safety of Crystalloids and Colloids
Authors: Spahn Donat
Published: February 2008

Crystalloids and colloids may be used to maintain normovolemia. Crystalloids are generally well tolerated. To increase blood volume by 0.5 L, 2‐2.5 L of crystalloidshave to be administered. In addition, the duration of intravascular persistence is short and thus significant quantities have to be re‐administered following the initial infusion. The administration of large quantities of cry stalloids results in tissue edema. In contrast, 0.5 L of isotonic colloids such as hydroxyethyl starch (HES) and gelatin increase blood volume by approximately 0.5 L and their intravascular persistence is longer than that of crystalloids. However, colloids are associated with some side effects such as anaphylactoid reactions (gelatin > H E S), compromised blood coagulation (HES > gelatin), tissue storage and pruritus (HES > gelatin) and impairment of renal function in kidne y transplantation (HES > gelatin). In clinical ane sthesia, both cry s talloids and colloids need to be combine d. During rapid blood loss, colloids are particularly effective in main taining normovolemia. Using cry s talloids during periods of less severe blood loss may help to avoid side effects.
Hemorrhagic Shock and Early Resuscitation: the Pros
Authors: Carli P. , Incagnoli P.
Published: February 2008

Management of trauma patients with hemorrhagic shock in the prehospital setting remains a particularly controversial issue, with opposing approaches used in North America and Europe. The United States, served by emergency medical technicians and paramedics, is based on the “scoop and run‘ approach. The opposite is the case in European countries, where the prehospital teams usually include qualified physicians who can provide sophisticated prehospital care adapted to each patient (the “stay and play” approach). Even if there is controversy about prehospital volume loading in patients with penetrating injuries to the torso, in most cases of trauma patients with hemorrhagic shock, efficient airway control, early mechanical ventilation, prehospital chest tube thoracostomy (in the case of tension pneumothorax) and prehospital volume loading performed by a specialized team with prehospital and in‐hospital experience have been clearly demonstrated to improve patient prognosis. Moreover, physicians on the scene provide not only advanced life support but also analgesia, anesthesia, first diagnosis of injuries and orders for appropriate hospital admissions.
Transfusion Mortality and Morbidity in Orthopedic Surgery
Authors: Carson Jeffrey L. , Reynolds Richard C
Published: February 2008

Red blood cell transfusions are commonly used in orthopedic surgery and cost billions of dollars annually. The goals of transfusion are to reduce mortality, morbidity and functional impairment that result from anemia and inadequate oxygen delivery. Risks of infections from transfusion are low and continue to decline, but evidence is growing that red cell transfusions are immunosuppressive and predispose patients to postoperative infections. However, there actually are very little data on when transfusion is indicated. Observational data suggest that transfusion does not reduce mortality in patients with pre‐ or postoperative hemoglobin levels >8 g/dL, although no conclusions could be drawn about the effect of transfusion in patients with hemoglobin >8 g/dL. Large well‐performed randomized clinical trials are needed to establish the efficacy of transfusion. Until better data are available, orthopedic surgeons will have to rely on clinical judgement in transfusion decisions. The author recommends using a higher transfusion threshold in patients with cardiovascular disease.
Hyperchloremic Metabolic Acidosis: Is It Clinically Relevant?
Authors: Mythen Michael G. , Hamilton Mark A.
Published: February 2008

“First, do no harm. ‘These words have been the doctrine of medicine since its inception. The era of evidence‐based medicine now compels us to provide scientific evidence that we indeed do no harm and that the treatments we prescribe have a beneficial effect. The colloid/crystalloid debate continues to evolve and is as hotly contested now as it was a decade ago. There may be some international differences in the use of colloids or crystalloids, but most of us continue to use both. Whatever our preferred choice of intravenous fluid for the treatment of hypovolemia, clinical outcome studies suggest that “when?” and “how much?” are probably more important questions than “what?”. There are now a wide variety of fluids available to the clinician and most differ markedly in their composition. Aside from the gross classification of IV fluids into colloids and crystalloids, they may be subclassified into balanced or unbalanced categories, i.e., those that contain concentrations of electrolytes similar to those in the plasma and those that do not (see Table 1).The very fact that “normal” saline is unphysiological was recognized many years ago. This fact led Alexis Hartmann to develop Hartmann's solution in an attempt to produce an isotonic alkalizing solution. He recognized the need for proportionately more sodium than chloride1, which led to a solution very similar to Ringer's original2. The existence of hyperchloremic acidosis has been recognized in many areas for some time, e.g., diabetic ketoacidosis and ammonium chloride poisoning, and is generally termed a low‐anion gap acidosis. There is now mounting evidence that the administration of intravenous saline and saline‐based fluids is the commonest avoidable cause of clinically relevant hyperchloremic acidosis.
HES: Is There a Maximal Dose?
Authors: Boldt Joachim
Published: February 2008

The pharmacokinetics and pharmacodynamics of the various solutions available for volume replacement therapy differ widely. The natural colloid albumin and the synthetic colloid gelatin can be used in an unlimited manner according to manufacturer instructions. By contrast, dextran and the various hydroxyethyl starch (HES) preparations have manufacturer‐recommended dose limitations. The physical and chemical characteristics of HES are defined by concentration, degree of substitution (DS), mean molecular weight (Mw), and the C2/C6 ratio of substitution. Currently specified dose limitations to minimize unwanted side effects on hemostasis, accumulation and storage are 20 mL/kg for 10% HES 200/0.5 and 33 mL/kg for 6% HES 200/0.5. Other possible HES‐associated side effects are not dose‐dependent (e.g., anaphylaxis) or are similar to those produced by other substances used for volume replacement (e.g., dilution of clotting factors). A new HES, 6% HES 130/0.4, with a lower Mw and a lower DS is a promising substance endowed with improved pharmaco‐chemical properties. It shows significantly less accumulation even after repeated dosing over several days. Thus, there may be no dose limitations at the current level with this new HES preparation.
Capillary Leak and Starches
Authors: Gosling Peter
Published: February 2008

One of the earliest features of an acute inflammatory response is an increase in vascular permeability, which allows plasma proteins, including albumin, to move into the interstitial space and cause edema. Systemic capillary permeability is amplified by the kidney and can be monitored by measurement of low‐level urine albumin excretion in the 20 to 200 mg/L range (microalbuminuria). Microalbuminuria reflects rapid changes in systemic capillary permeability, which increases dramatically within a few minutes of injury and usually returns to normal within 6 to 12 hours. Failure of capillary permeability to return to normal is an early predictor of later pulmonary dysfunction and organ failure. Recent studies suggest that, following trauma or surgery, medium‐molecular weight hydroxyethyl starches as opposed to human albumin or gelatine solutions markedly reduce capillary leak, improve pulmonary gas exchange and organ function, and downregulate the acute inflammatory response. It is not clear which mechanisms underlie this microvascular protective effect although blocking of endothelial cell activation may be involved.
Transfusion‐Transmitted Infections
Authors: Barbara John A. J.
Published: February 2008

Although the risks of transfusion‐transmitted infection are currently very small compared with other medical interventions, the perception remains that these risks are significant. Infection risks from recognized agents for which we select appropriate candidate donors and/or perform systematic laboratory testing include inadequacy of donor selection, errors in laboratory testing or inventory control, insensitivity of screening tests, and donations in the “window period” prior to seroconversion. Potential threats from emerging (or newly recognized) microbial agents remain a continuing reality. To date, however, GB‐virus C and TT‐virus, though transfusion‐transmissible, appear to be non‐pathogenic. Human herpes virus 8 (HHV‐8), the causative agent of Kaposi's sarcoma, has not been demonstrated to be transfusion‐transmissible and the potential threat from variant Creutzfeldt‐Jakob disease (vCJD) has also not yet been demonstrated. However, the risk from bacteria is demonstrable and, as viral risk is reduced, becomes proportionately more significant.

Interventions to reduce risk include leukodepletion, extension of nucleic acid testing and/or testing for hepatitis C virus antigen, use of combined human immunodeficiency antigen plus antibody tests, and extended interventions to reduce bacterial risks. The safety yields and cost/benefit ratio of these interventions (often very low) need careful consideration, especially in the context of commercial pathogen inactivation systems soon to become available.
Transfusion‐Related Immunomodulation:
Authors: Vamvakas Eleftherios C.
Published: February 2008

Allogeneic blood transfusion (ABT) has been claimed to cause deleterious clinical effects, including the recurrence of resected malignancies, postoperative bacterial infection, and virus activation. These purported adverse effects of ABT have been attributed to transfusion‐related immunomodulation (TRIM). However, the mechanism(s) of the TRIM effect(s) remains or remain to be defined, and the blood constituent(s) that might mediate TRIM effect(s) is or are unknown. Randomized, controlled trials (RCTs) have been conducted to investigate the TRIM effect(s), based on the assumption that the transfusion of autologous or leukoreduced allogeneic red blood cells is immunologically neutral. The findings of these RCTs have been highly contradictory, and the long‐standing hypothesis of a deleterious TRIM effect of ABT remains unresolved. This review examines the clinical evidence as to whether a deleterious TRIM effect exists and can be abrogated by leukoreducing transfused cellular blood components.
Anemia in Critically Ill Patients: How Much Can They Tolerate?
Authors: Linden Philippe Vander
Published: February 2008

Anemia is a common occurrence in intensive care unit (ICU) patients and frequently results in allogeneic blood transfusion. In critical illness, patient tolerance to a reduction in the blood's oxygen‐carrying capacity may be reduced because of a blunting of the physiologic compensatory response mechanisms to – anemia and/or to an increase in tissue metabolic needs. Anemia has indeed been associated with an increased risk of mortality in critically ill patients, particularly in those with pre‐existing cardiovascular disease or in those with significant blood loss. Clinical trials comparing a liberal versus restrictive transfusion strategy defined by a specified hemoglobin (or hematocrit) concentration showed that mortality, morbidity and length of hospital stay seem unaffected by the transfusion strategy, even in hemodynamically stable cardiovascular disease patients. The absence of outcome improvement associated with a more liberal transfusion strategy remains largely to be elucidated. There is, however, some experimental evidence that blood transfusion may have adverse effects on tissue oxygen delivery because of erythrocyte storage‐related changes. The decision to transfuse a given patient must also take into account the risks associated with allogeneic blood, in particular those related to its potential immunosuppressive effects. There is no one “optimal” hemoglobin value for ICU patients, and the decision to transfuse should be made on a case‐by‐case basis, with each patient being assessed according to his or her clinical status, the underlying cause of anemia and the risk of potential complications. In any case, preventive measures should be taken whenever possible to limit the development of anemia in the ICU.
Decision Analysis in Transfusion Medicine – Practical Considerations
Authors: Adeyi Oyedele , AuBuchon James P.
Published: February 2008

Cost and cost‐effectiveness analyses have sometimes been regarded as inappropriate endeavors for a physician dedicated to the welfare of patients. While cost considerations alone should not be used as the decision‐making criterion in managing individual patients, the transfusion medicine physician nevertheless needs to appreciate the value of these analyses when making policy decisions for his or her laboratory and hospital. This article highlights the practical applications of decision analyses as decision‐making tools and recommends that they be regarded as useful adjuncts in the practice of transfusion medicine.
Impact of a Centralized Transfusion Service on Transfusion Costs: The Hospital Transfusion Service Versus the Blood Center Perspective
Authors: Triulzi Darrell J. , Hahn Linda
Published: February 2008

A Centralized Transfusion Service (CTS) utilizes an integrated laboratory‐based approach to the delivery of transfusion medicine services within a region. The CTS model has emerged as probably the most cost‐efficient method for the delivery of these services. Its positive impact on both operational and component costs exceeds the level of hospital savings typically achieved by merely negotiating a “cheaper” red cell with the blood provider. Even the regional blood provider benefits from the superior management of the community's blood supply. Hospitals and hospital networks seeking to reduce transfusion‐associated costs should consider a CTS model.
Mechanism of Action of Recombinant Activated Factor VII
Authors: Lisman Ton , Groot Philip G. de
Published: February 2008

Recombinant activated coagulation factor VII (rFVIIa, NovoSeven®) is indicated for the treatment of bleeding episodes or as a prophylactic hemostatic agent during surgery in patients with inhibitor‐complicated hemophilia. Currently, the use of rFVIIa for indications other than hemophilia is being investigated in clinical trials. The original idea behind the development of rFVIIa was that it would function via enhancement of tissue factor‐dependent coagulation. However, the effects of rFVIIa on hemostasis proved to be more complex than initially anticipated. This paper summarizes current data and hypotheses on the mechanism of action of rFVIIa, providing a general model for the molecular basis for the efficacy of rFVIIa in its different applications.
The Use of Recombinant Factor VIIa in Surgical Bleeding in Nonhemophiliac Patients
Authors: O'Connell Niamh M. , Perry David J.
Published: February 2008

Hemorrhage due to elective or emergency surgery results in significant patient morbidity and mortality and consumption of scarce transfusion resources. Recombinant factor VIIa (rFVIIa) has been proposed as a universal hemostatic agent which may be beneficial in reducing blood loss and in treating unexpected massive hemorrhage in surgical patients. In elective surgery, a small number of randomized studies have shown a limited benefit for rFVIIa in the reduction of transfusion requirements. In massive hemorrhage associated with surgery, two case series and a growing number of case reports suggest that rFVIIa is successful as salvage therapy. However, a number of questions remain regarding the optimal dose, the true rate of thromboembolic complications and the overall survival and cost benefit when rFVIIa is used for this indication. In this review, the role of rFVIIa in managing blood loss in surgical patients is assessed in the light of current evidence.
The Use of Recombinant Factor VIIa for Hemorrhage Control in Trauma Patients
Authors: Kenet Gili
Published: February 2008

Uncontrolled hemorrhage is the second leading cause of death from trauma. Most critically ill trauma patients suffer profound bleeding accompanied by systemic coagulopathy. The compassionate use of rFVIIa for uncontrolled hemorrhage was approved by the ethical committee of the Israeli Ministry of Health in late 1999. This manuscript reviews the published results of the first 19 Israeli trauma patients and the recent case series by Dutton and colleagues analyzing the early experience in critically ill trauma patients treated in Baltimore, MD, USA. Patients'survival was affected by severity of injury, the degree of coagulopathy prior to the drug's administration, and by coexistence of acidosis. In conclusion, the use of rFVIIa is currently recommended in massively bleeding patients, along with conventional surgical and hemostatic techniques. For optimal results, maximal correction of acidosis and coagulation parameters is advised prior to the drug's administration. Prospective, randomized placebo‐controlled trials of rFVIIa in traumatic injury are warranted.
Hemovigilance: Definition and Overview of Current Hemovigilance Systems
Authors: FABER Jean‐Claude
Published: February 2008

SUMMARy

Hemovigilance, as a safety concept, appeared in the beginning of the 1990s. Its primary aim is to assure the surveillance of blood transfusion, to collect data on (serious) sequelae of blood transfusions, to inform health policy to improve transfusion standards, to assist in the formulation of guidelines in the field of transfusion and to increase the safety and quality of the entire transfusion process.

Two different “poles” of systems exist. In France, where hemovigilance was rendered mandatory by law in 1994, the system is centralized and nationwide, with a legal obligation to notify in written form each and every side effect related to blood transfusion. In the UK, hemovigilance is a national voluntary scheme between professionals (SHOT, Serious Hazards of Transfusion). Learning from the lessons generated by the British and French systems enables the introduction, in other countries, of models representing “hybrids” of the two systems.

Within the European Union, the recent European Blood Directive requires hemovigilance in each Member State; its provisions have to be transposed into national legislations within two years. In order to ally efforts at the Community level it would make sense to appeal to existing initiatives in this field that have proven that efficient cooperation is possible: the European Haemovigilance Network (EHN) has played a major role in bringing this important matter forward and in developing it into an efficient tool intended to increase safety and quality in European blood transfusion.
SHOT–A Voluntary System for the Reporting of Serious Hazards of Transfusion in the UK
Authors: Love Elizabeth M. , Jones Hilary , Williamson Lorna M. , Cohen Hannah , Todd Audrey , Soldan Kate , Revill John , Norfolk Derek R. , Barbara John , Atterbury Claire L.J. , Asher Deborah , Chapman Catherine
Published: February 2008

SUMMARy

Background: From 1996–2001 the SHOT scheme has collected a powerful body of data on serious transfusion complications in the UK from which to make firm recommendations for improvements in transfusion safety. The UK Blood Services issue approximately 3.5 million blood components annually.

Results: With 413 eligible hospitals on the scheme, by year five, participation was running at 92%. Of 1,148 fully analyzed reports there were 699 (61%) “wrong blood” incidents. Of these, 161 were ABO incompatible transfusions leading to 11 deaths and 60 cases of major morbidity and 73 were RhD incompatible leading to potential RhD sensitization in 17 young females. Multiple errors occurred in 49% of cases. 55% of errors involved mis‐identification at the point of collection from the hospital storage site and/or bedside administration, whilst laboratories and prescription/sampling/request errors contributed 28% and <13% respectively. Immune complications comprised 35.7% of reports. 70 cases of possible TRALI over 5 years resulted in 49 cases of major morbidity and up to 20 deaths possibly related to transfusion. Transfusion‐transmitted infection (TTI) comprised < 3% of reports but of 39 confirmed TTIs 25 were bacterial contamination incidents (21 platelets, 4 red cells) resulting in 6 deaths (5 platelets; one red cells).

Recommendations:“Wrong blood” incidents are avoidable errors. Efforts should be directed at developing computerized bedside identification systems to reduce human error. These can be linked to secure systems to reduce errors at the point of collection from storage and are also applicable in the drugs administration setting. Options to reduce the incidence of TRALI should be explored. Possible strategies to reduce bacterial contamination should be given appropriate priority.
Is the Clinical Significance of Blood Storage Lesions Underestimated?
Authors: Isbister James P.
Published: February 2008

SUMMARy

There is a general agreement that blood and blood components all deteriorate from the moment they are removed from the donor's vein. Clinicians have expressed their concern for decades about the potential of the storage lesions having adverse effects on patients. However, this has been difficult to prove in clinical studies due to the multifactorial nature and complexity of many transfusion settings, especially hemorrhagic shock and trauma. The role of transfusion as a contributor to adverse consequences that are only possible and multifactorial such as those potentially due to storage lesions can only be identified by large, well‐conducted and controlled trials. If transfusion can be identified as a significant contributory factor to a specific complication its role is considered more as a risk factor rather than a direct 1:1 causal factor. Nevertheless, it is of interest to underline that many of the changes occurring during storage are related to the presence of leukocytes (especially granulocytes) and can be minimized by pre‐storage leukoreduction. Pre‐storage leukoreduction is now standard practice in many countries. Although its introduction has been for reasons other than the minimization of storage lesions, it is of interest to note hat it is probably the most effective intervention to improve the survival and the quality of red cell and platelet concentrates.
Should Albumin Be Used to Correct Hypoalbuminemia in the Critically Ill? No
Authors: AL‐Khafaji Ali , Webb Andrew R.
Published: February 2008

Hypoalbuminemia is the consequence of a disease process and successful treatment of the underlying disease should result in a gradual return to normal serum albumin values. There are many theoretical useful properties of albumin that make achieving normal serum values an attractive proposition. The available literature does not support the use of albumin to correct hypoalbuminemia. In fact we might do more harm than good by infusing albumin.
Cell Salvage – State of the Art and Cost‐Effectiveness
Authors: Haynes Sarah L. , Torella Francesco , McCollum Charles N.
Published: February 2008

Cell salvage is an autologous blood transfusion technique, which has been in common use for over twenty years. It has the obvious potential to reduce allogeneic blood usage as fresh red cells that would otherwise be lost are reinfused. Properly used, there is no risk of clerical error and no need to screen for transmissible disease. Although used extensively in the USA and Europe, the adoption of cell salvage, and indeed all autologous blood transfusion techniques, has been very slow in the UK. This may be partly due to the paucity of adequately powered randomized clinical trials demonstrating the efficacy and cost‐effectiveness of cell salvage. This article will review these aspects of cell salvage with particular emphasis on its routine use in vascular surgery.
Criteria for Clinical Transfusion Practice:Teaching of Transfusion Medicine
Authors: Maniatis Alice , Müller Norbert
Published: February 2008

Developments in blood transfusion over the last two decades have been wide reaching. The variety of blood components available allows for a much more specific approach to each patient's needs. Safety parameters have to be taken into consideration in making choices, therefore knowledge of the risks of transfusion as well as of the availability of transfusion alternatives, is necessary. In addition, considerations of blood sufficiency or lack thereof, demand the use of transfusion, only in cases with proven efficacy. All these issues, well known to transfusion medicine specialists, are not necessarily registered by clinicians, many of whom, even today, consider blood transfusion a routine, simple and safe therapeutic maneuver. The European Union has emphasized in recent years the need for adoption by the EU states of similar criteria in the various areas of blood collection and transfusion, it was therefore of interest to inquire into transfusion practices in EU states and this was undertaken by the network of transfusion societies, EuroNet‐TMS, with the help of a questionnaire. Analysis of the responses reveals persistent heterogeneity in some areas, although there is a tendency for convergence.
The Use of Aprotinin in Pediatric Cardiac Surgery
Authors: Miller Bruce E.
Published: February 2008

The use of aprotinin in children undergoing cardiopulmonary bypass (CPB) attenuates activation of the coagulation and fibrinolytic systems, preserves platelet function, and reduces some inflammatory processes. The clinical outcomes in children as a result of these effects have varied among studies and patient populations, however, this is probably in large part due to variations in dosing regimens. Nevertheless, improved clinical outcomes have been consistently demonstrated in neonates undergoing primary sternotomies and in children undergoing repeat sternotomies or lung transplantation with the use of aprotinin. Such clinical outcomes create a strong argument for the routine administration of aprotinin to these subsets of children. The magnitude of beneficial clinical outcomes after aprotinin administration is dose‐dependent so, while a definitive dosing regimen has not been established for children, higher dose regimens should be employed. Indeed, the use of some very high dose regimens have indicated that aprotinin may even be beneficial in children, other than neonates, undergoing primary sternotomies. The occurrence of adverse effects from the use of aprotinin in children is low but allergic reactions from repeat exposures, especially within six months of the prior use of aprotinin, must be anticipated and guidelines followed to minimize their occurrence and effects. Aprotinin is a potent part of a clinician's arsenal when dealing with children undergoing CPB and its cost‐effective improvement of clinical outcomes justifies its consideration when planning the management strategy of these children.
High-Speed End Milling Using a Feedforward Control Architecture
Authors: Tung E. D. , Tomizuka M. , Urushisaki Y.
Published: February 2008

Experiments are performed for end milling aluminum at 15,000 RPM spindle speed (1,508 m/min cutting speed) and up to 3 m/min table feedrate using an experimental machine tool control system. A digital feedforward controller for feed drive control incorporates the Zero Phase Error Tracking Controller (ZPETC) and feedforward friction compensation. The controller achieves near-perfect (±3 μm) tracking over a 26 mm trajectory with a maximum speed of 2 m/min. The maximum contouring error for a 26 mm diameter circle at this speed is less than 4 μm. Tracking and contouring experiments are conducted for table feedrates as high as 10 m/min. Frequency domain analysis demonstrates that the feedforward controller achieves a bandwidth of 10 Hz without phase distortion. In a direct comparison of accuracy, the machining errors in specimens produced by the experimental controller were up to 20 times smaller than the errors in specimens machined by an industrial CNC.
Modeling and Analysis of Acoustic Emission in Diamond Turning
Authors: Liu J. J. , Dornfeld D. A.
Published: February 2008

To estimate the acoustic emission (AE) energy released in diamond turning, a quantitative model, which contains the energy from primary, secondary, tertiary cutting zones and the rubbing zones, is proposed and compared with experimental data. The purpose of this model is to assist in process characterization and monitoring. As part of the model developed here the plowing energy, that is, the energy released in the tertiary zone, is approximated by the forming load in the rolling process where the roller is stationary. This load is theoretically calculated by the upper bound method and used in the estimation. A series of diamond turning tests were conducted to check the validity of the model. It was found that the energy content of the AE signal is close to the theoretical predictions. The spectral analysis of the AE signal in these tests is also carried out. It was noticed that when the diamond tool first touches the workpiece without producing any chip, more high frequency components were observed and this stage was recognized as the rubbing stage. The results further support the previous findings, that is, that abnormal rubbing always increases the mean frequency of the raw AE signal.
A Dynamic Model for End Milling Using Single Point Cutting Theory
Authors: Kulkarni N. M. , Chandra A. , Jagdale S. S.
Published: February 2008

The dynamics of a milling process can significantly influence the surface quality and integrity of the finished part. Accordingly, various researchers have investigated the dynamics of milling processes using a hierarchy of models. Tlusty and Smith (1991) provides a review of these models. In recent years, several other researchers (e.g., Armarego and Deshpande, 1989; Montgomery and Altintas, 1991; Nallakatla and Smith, 1992) have also continued to enhance various aspects of such dynamic models. While these dynamic models provide significant insights into the cutting characteristics of a milling process, their utilization in process design has proven to be elusive. The accuracy of these models, however, depends significantly on the prediction of cutting force characteristics. Under the current state-of-the-art, detailed experimentations using actual set-up are necessary to make such predictions accurately. Experimentally obtained constants can vary widely from one milling situation to another, which in turn, significantly restricts their usefulness as predictive tools for process design.
3-Dimensional Circular Interpolation for CNC Machines
Authors: Papaioannou S. G. , Omirou S. L.
Published: February 2008

An efficient and accurate algorithm for generating circular arcs on arbitrary planes is presented and its implementation in the context of CNC is discussed. Besides having significant application potential as a CNC feature, it exemplifies a class of precise interpolation algorithms which can be developed on the basis of an integer programming formulation of Danielson’s step selection criteria.
Machining Accuracy Analysis for Computer-aided Fixture Design Verification
Authors: Rong Y. , Bai Y.
Published: February 2008

This paper presents a machining accuracy analysis for computer-aided fixture design verification. While discussing the utilization of CNC machine tools and machining centers, machining errors are described in terms of deterministic and random components and analyzed on the bases of their sources, where high machining accuracy and multi-operation under a single setup become major characteristics of manufacturing systems. In machining processes, a resultant dimension may be generated in terms of several relevant dimensions. The dependency of variation among these dimensions is examined and the relationships of locating datum and machining surfaces are analyzed. Variation among linear and angular dimensions are considered. Five basic models of dimension variation relationships are proposed to estimate the machining error, where different formulas of resultant dimension variation are given for different combinations of variation among relevant dimensions. A datum-machining surface relationship graph (DMG) is developed to represent the dependent relationships. A matrix-based reasoning algorithm is designed to search for the shortest path in the DMG. Once the relationship between a specified pair of surfaces is identified, different models of corresponding relationships may be utilized to estimate the possible machining errors which can be used to compare the fixturing accuracy requirement.
A Variational Upper-Bound Method for Plane Strain Problems
Authors: Yeh Wei-Ching , Yang Yeon-Sheng
Published: February 2008

In this paper, a variational upper-bound (VUB) method is proposed. It is the method that determines an upper-bound solution using variational calculus. By using the method, a set of so called “naturally boundary conditions,” which were all ignored in past investigations, can be theoretically derived for the rigid/plastic interface assumed to be arbitrary function in prior. This method is shown to be applicable to the cup ironing problem. From the result we can clearly indicate the role of these natural boundary conditions which reasonably account for the effect of friction on the pattern of metal flow. The VUB method not only presents an improvement on the traditional upper-bound method, but also favorably agrees with experimental result of Nielsen et al. (1963) in calculating upper-bound energy.
The Application of Meta Functions to the Quasi-Static Analysis of Workpiece Displacement Within a Machining Fixture
Authors: Hockenberger M. J. , De Meter E. C.
Published: February 2008

Spherical-tipped locators and clamps are often used for the restraint of workpieces during machining. For structurally rigid fixtures and workpieces, contact region deformation, slip, and lift-off are the predominant modes of workpiece displacement during clamp actuation and machining. This paper presents a general model for the quasi-static analysis of workpiece displacement. It also shows how meta functions can be applied to simplify the modeling of contact forces. Through the use of meta functions, the general model can be formulated and solved quickly. This paper concludes with a description of an experimental study used to validate this model.
Control of Cutting Force for End Milling Processes Using an Extended Model Reference Adaptive Control Scheme
Authors: Rober S. J. , Shin Y. C.
Published: February 2008

In this work an extended Model Reference Adaptive Control (MRAC) technique is used to control the cutting force of an end milling process. The technique incorporates Zero Phase Error Tracking Control (ZPETC) into the MRAC system. The extended MRAC controller remains stable even in the presence of marginally stable and nonminimum phase process zeros. A modified recursive least-squares estimation algorithm is used for on-line parameter identification. Simulation results are presente to compare the extended MRAC controller to the standard MRAC controller. A microprocessor system is used to implement adaptive force control of a single-input single-output milling process where the microprocessor monitors the system cutting forces and controls the desired feedrate. A constant cutting force is maintained in the presence of time-varying plant gains and a high random component of the output force. Experimental results are presented for standard MRAC and extended MRAC controllers for comparison.
Optical Sensor for Detecting a Position and an Inclination
Authors: Aoyama H. , Yamazaki K. , Sawabe M.
Published: February 2008

This paper deals with an optical sensor designed to automatically measure a sculptured surface geometry. The sensor can continuously and simultaneously detect a position vector (a gap distance) and a unit normal vector (an inclination angle) of a point to be measured without touching. In this paper, the principle of detecting a gap distance and an inclination angle is clarified, and the feasibility of the principle is tested by simulation and by a physical prototype. Developing a primitive prototype, the detectable range of a gap distance and surface inclination are evaluated by experiments. While performing the simulations and the experiments, it became clear that the sensor has a measured range of 20 mm for detecting a gap distance and a measured range from −70 to 70 degrees for detecting an inclination angle with regard to a diffuse surface.
Modeling and Dynamics of Epitrochoid Generated Orbital Rotary Piston LSHT Hydraulic Motor: A Bondgraph Approach
Authors: Dasgupta K. , Mukherjee A. , Maiti R.
Published: February 2008

In this paper the dynamics of epitrochoid generated Orbital ‘rotary piston machine’ (ROPIMA) type ‘low speed high torque’ (LSHT) hydrostatic unit are studied. The complex variation of the volume of a chamber of such a machine with shaft rotation along with dynamic characteristics of the rotary flow distributor valve, interchamber leakages, fluid compressibility, inertia of orbiting rotor, etc. demand a structured approach to arrive at its mathematical model. In conventional approaches the system morphology gets obscured as the mathematical model is arrived at. Owing to the lack of modularity the errors in deduction of equations may remain eclipsed. Bondgraphs provide a structured approach to model engineering systems. The bondgraph model of the LSHT orbital motor is presented in this work. Relevant simulation results are discussed. The mathematical model was found to be stiff and its integrations were costly and time consuming. A tractable approach to estimate its steady state behavior is suggested and validated. The authors believe that such an approach would be suitable in the initial stages of design of such machines and in the development of control systems where these machines are used as actuators.