Bloodless medicine: clinical care without allogeneic blood transfusion

A Global Definition of Patient Blood Management

While patient blood management (PBM) initiatives are increasingly adopted across the globe as part of standard of care, there is need for a clear and widely accepted definition of PBM. To address this, an expert group representing PBM organizations, from the International Foundation for Patient Blood Management (IFPBM), the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA), the Society for the Advancement of Patient Blood Management (SABM), the Western Australia Patient Blood Management (WAPBM) Group, and OnTrac (Ontario Nurse Transfusion Coordinators) convened and developed this definition: "Patient blood management is a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment." The definition emphasizes the critical role of informed choice. PBM involves the timely, multidisciplinary application of evidence-based medical and surgical concepts aimed at screening for, diagnosing and appropriately treating anemia, minimizing surgical, procedural, and iatrogenic blood losses, managing coagulopathic bleeding throughout the care and supporting the patient while appropriate treatment is initiated. We believe that having a common definition for PBM will assist all those involved including PBM organizations, hospital administrators, individual clinicians and policy makers to focus on the appropriate issues when discussing and implementing PBM. The proposed definition is expected to continue to evolve, making this endeavor a work in progress.

Evolution of Bloodless Surgery: A Case for Bloodless Suprapubic Prostatectomy

Allogeneic blood transfusion is commonly prescribed to patients undergoing suprapubic prostatectomy for benign prostatic hyperplasia as a treatment option to replace blood loss. Historically, suprapubic prostatectomy has been perceived as an extremely high hemorrhagic surgery, and this has led to the association of suprapubic prostatectomy with a high rate of allogeneic blood transfusion. However, the outcome of suprapubic prostatectomy has significantly improved over the years and has become less hemorrhagic in many hands - creating the opportunity to consistently avoid allogeneic blood transfusion. On the other hand, the efficacy of blood transfusion has come under more stringent scrutiny as many clinical studies have reported inconsistent effects of blood transfusion on patient outcome. In contemporary practice, a more conservative/bloodless approach in the perioperative management of anemia in surgical patients is strongly being advocated with convincing evidence that many surgical patients can be routinely and safely managed without allogeneic blood transfusion. There is no large-scale discussion on bloodless surgery in urology in the contemporary literature, especially in the area of suprapubic prostatectomy that has been historically associated with a high rate of blood transfusion. This review article will discuss the evolution of bloodless surgery including the ongoing controversies surrounding blood transfusion in general, and then the relatively small but ongoing penetration of bloodless surgical approach in the field of suprapubic prostatectomy. Furthermore, the authors' approach to bloodless suprapubic prostatectomy will be highlighted, and in doing so, it can be emphasized that suprapubic prostatectomy is no more as hemorrhagic as was historically perceived, but rather a routine bloodless suprapubic prostatectomy is now possible in many hands.

Bloodless Intensive Care: A Case Series and Review of Jehovah's Witnesses in ICU

The objective of this study was to assess the outcome of Jehovah's Witness (JW) patients admitted to a major Australasian ICU and to review the literature regarding the management of critically ill Jehovah's Witness patients.

All Jehovah's Witness patients admitted to the ICU between January 1999 and September 2003 were identified from a prospective database. Their ICU mortality, APACHE II scores, APACHE II risk of death and ICU length of stay were compared to the general ICU population. Twenty-one (0.24%) out of 8869 patients (excluding re-admissions) admitted to the ICU over this period were Jehovah's Witness patients. Their mean APACHE II score was 14.1 (±7.0), the mean APACHE II risk of death was 21.2% (±16.6), and the mean nadir haemoglobin (Hb) was 80.2 g/l (±36.4). Four out of 21 Jehovah's Witness patients died in ICU compared to 782 out of 8848 non- Jehovah's Witness patients (19.0% vs 8.8%, P=0.10, chi square). The median ICU length of stay in both groups was two days (P=0.64, Wilcoxon rank sum). The lowest Hb recorded in a survivor was 23 g/l.

Jehovah's Witness patients appear to be an uncommon patient population in a major Australasian ICU but are not over-represented when compared with their prevalence in the community. Despite similar severity of illness scores and predicted mortality to those in the general ICU population, there was a trend towards higher mortality in Jehovah's Witness patients.

Management of anemia in patients who decline blood transfusion

Declining a treatment modality should not be considered the same as refusal of medical care as illustrated by the management of Jehovah's Witness patients who do not accept transfusions. Over the years, a comprehensive set of strategies have been developed to meet the specific needs of these patients and these strategies are collectively called "Bloodless Medicine and Surgery" (BMS). The focus in BMS is to optimize the patients' hematopoietic capacity to increase hemoglobin (Hgb) level, minimize blood loss, improve hemostasis, and provide supportive strategies to minimize oxygen consumption and maximize oxygen utilization. We present 3 case reports that illustrate some of the challenges faced and measures available to effectively treat these patients. Under BMS programs, patients with extremely low hemoglobin levels, not conducive to survival under ordinary conditions, have survived and recovered without receiving allogeneic transfusions. Additionally, the valuable experience gained from caring for these patients has paved the way to develop the concept of Patient Blood Management as a standard care to benefit all patients, and not only those for whom blood is not an option.

Blood Product Administration in the Critical Care and Perioperative Settings

The critical care and perioperative settings are high consumers of blood products, with multiple units and different products often given to an individual patient. The recommendation of this review is always to consider the risks and benefits for a specific blood product for a specific patient in a specific clinical setting. Optimize patient status by treating anemia and preventing the need for red blood cell transfusion. Consider other options for correction of anemia and coagulation disorders and use an imperative non-overtransfusion policy for all blood products.

Beneficial effects of novel cross-linked hemoglobin YQ23 on hemorrhagic shock in rats and pigs

BACKGROUND

To overcome the problems of previously reported hemoglobin-based oxygen carriers, we developed a stabilized nonpolymeric cross-linked tetrameric hemoglobin solution (YQ23). The aims of this study were to investigate the oxygen carrying and releasing properties of this novel hemoglobin-based oxygen carrier and to determine whether it has beneficial effects for hemorrhagic shock.

METHODS

Using a hemorrhagic shock model in Sprague-Dawley rats and mini-pigs, we tested the effects of infusing 0.1, 0.3, and 0.5 g/kg YQ23 on animal survival, tissue oxygen delivery (DO₂) and consumption (VO₂), hemodynamics parameters, and liver, renal, and cardiac function.

RESULTS

YQ23 infusion increased the survival rate of rats and pigs with severe hemorrhagic shock in a dose-dependent manner. Moreover, it improved the hemodynamic parameters, cardiac output, DO₂ and VO₂, and the mitochondrial respiratory function of vital organs. Among the three doses of YQ23, 0.5 gHb/kg YQ23 achieved a similar beneficial effect as whole blood.

CONCLUSIONS

This study indicated that the novel cross-linked tetrameric hemoglobin YQ23 has good oxygen carrying and releasing properties and exhibits beneficial effects on hemorrhagic shock in rats and pigs by improving the oxygen carrying and delivery function of blood, which maintains organ function.

Clinical and Surgical Strategies for Avoiding or Reducing Allogeneic Blood Transfusions

Blood transfusions have still been used as a standard therapy to treat severe anemia. Current evidences point to both excessive allogeneic blood consumption and decreased donations, which result in reduced stocks in blood banks. Several studies have increasingly suggested a more restrictive transfusion practice for blood products. Currently, a number of autologous blood conservation protocols in surgeries have been noted. We report a case of severe anemia with 2.9 g/dL hemoglobin, which was successfully handled without using the standard therapy to treat anemia with hemotransfusions. Such a case of severe anemia condition resulted after the patient was submitted to ascending aortic aneurism repair, valvar aortic replacement, reimplantation of right coronary ostium, followed by a coronary artery bypass grafting and several postoperative complications. The main clinical and surgical strategies used in this case to avoid blood transfusions were acute normovolemic hemodilution, intraoperative blood cell salvage, and meticulous hemostasis, beyond epsilon-aminocaproic acid, desmopressin, prothrombin complex concentrate, human fibrinogen concentrate, factor VIIa recombinant, erythropoietin and hyperoxic ventilation.

Responses of advanced directives by Jehovah's Witnesses on a gynecologic oncology service

Objectives

To review the responses of advance directives signed by Jehovah’s Witness patients prior to undergoing surgery at a gynecologic oncology service.

Study design

A retrospective chart review of gynecologic oncology patients undergoing surgery at a bloodless surgery center from 1998–2007 was conducted. Demographic, pathologic, and clinical data were recorded. The proportion of patients who accepted and refused various blood-derived products was determined and was compared to previously published results from a similar study of labor and delivery unit patients.

Results

No gynecologic oncology patients agreed to accept transfusions of whole blood, red cells, white cells, platelets, or plasma under any circumstance, whereas 9.8% of pregnant patients accepted transfusion (P=0.0385). However, 98% of gynecologic oncology patients agreed to accept some blood products, including fractions such as albumin, immunoglobulins, and clotting factors, while only 39% of pregnant patients agreed (P<0.0001). In addition, all gynecologic oncology patients (100%) accepted intraoperative hemodilution, compared to 55% of pregnant patients (P<0.0001).

Conclusion

Our results confirm the commonly held belief that the majority of Jehovah’s Witness patients refuse to accept major blood components. However, Jehovah’s Witness patients at a gynecologic oncology service will accept a variety of blood-derived products (minor fractions) and interventions designed to optimize outcomes when undergoing transfusion-free surgery. Patients presenting to a gynecologic oncology service respond differently to advanced directives related to bloodless surgery, as compared to patients from an obstetrical service.

Alternatives to blood transfusion

The use of alternatives to allogeneic blood continues to rest on the principles that blood transfusions have inherent risks, associated costs, and affect the blood inventory available for health-care delivery. Increasing evidence exists of a fall in the use of blood because of associated costs and adverse outcomes, and suggests that the challenge for the use of alternatives to blood components will similarly be driven by costs and patient outcomes. Additionally, the risk-benefit profiles of alternatives to blood transfusion such as autologous blood procurement, erythropoiesis-stimulating agents, and haemostatic agents are under investigation. Nevertheless, the inherent risks of blood, along with the continued rise in blood costs are likely to favour the continued development and use of alternatives to blood transfusion. We summarise the current roles of alternatives to blood in the management of medical and surgical anaemias.

Can maximum surgical blood order schedule be used as a predictor of successful completion of bloodless surgery?

Background

The Soonchunhyang University Hospital Bloodless Center was established in 2000, and more than 2,000 bloodless surgeries have been performed there since. In this study, the lowest postoperative Hb/preoperative Hb (Hb_low/pre) ratio and mortality rates of patients who underwent bloodless surgery were analyzed for each maximum surgical blood order schedule (MSBOS) category to assess whether MSBOS can be used as a predictor of successful completion of bloodless surgery.

Methods

A total of 971 patients were included. MSBOS was defined as the average number of units of RBCs transfused during each elective surgery. We used the Hb_low/pre ratio as an alternative to intraoperative blood loss. Frequency of Hb_low/pre ratios ≤0.5, use of transfusion alternatives, and mortality rates were compared across MSBOS categories.

Results

Out of the 971 patients, 701 (72.2%) were categorized as type and screen (T&S), 184 (18.9%) as MSBOS 1, 64 (6.6%) as MSBOS 2, and 22 (2.3%) as MSBOS 4. Transfusion alternatives were used by 397 (40.9%) patients. The frequency of the use of simultaneous erythropoietin and iron, hemostatics, acute normovolemic hemodilution, and Cell Saver (Haemonetics corp., USA) was higher in patients in the higher MSBOS categories. Six (0.6%) patients died within 30 days of surgery. Hb_low/pre ratios tended to be lower as the level of MSBOS category increased.

Conclusions

Surgeries in the higher MSBOS categories tended to be associated with high blood loss and mortality. Active use of transfusion alternatives is recommended in patients in high MSBOS categories who are scheduled to undergo bloodless surgery.

Blood utilization: fostering an effective hospital transfusion culture

An effective hospital transfusion culture should encourage clinicians to consider the possibility of transfusion in their patients well before the need actually arises, and to plan ahead in an attempt to use blood products most efficiently. Strategies for improved blood utilization include timely and adequate preoperative assessment of risk, optimization of baseline hemoglobin, anticipation of potential transfusion problems, intraoperative techniques to minimize blood loss, blood conservation technologies, transfusion guidelines and targeted therapy, point of care testing, and massive transfusion protocols. Attention to these elements promotes a safe and cost-effective transfusion culture.

Ferric carboxymaltose with or without erythropoietin for the prevention of red-cell transfusions in the perioperative period of osteoporotic hip fractures: a randomized contolled trial. The PAHFRAC-01 project

Background

Around one third to one half of patients with hip fractures require red-cell pack transfusion. The increasing incidence of hip fracture has also raised the need for this scarce resource. Additionally, red-cell pack transfusions are not without complications which may involve excessive morbidity and mortality. This makes it necessary to develop blood-saving strategies. Our objective was to assess safety, efficacy, and cost-effictveness of combined treatment of i.v. ferric carboxymaltose and erythropoietin (EPOFE arm) versus i.v. ferric carboxymaltose (FE arm) versus a placebo (PLACEBO arm) in reducing the percentage of patients who receive blood transfusions, as well as mortality in the perioperative period of hip fracture intervention.

Methods/Design

Multicentric, phase III, randomized, controlled, double blinded, parallel groups clinical trial. Patients > 65 years admitted to hospital with a hip fracture will be eligible to participate. Patients will be treated with either a single dosage of i.v. ferric carboxymaltose of 1 g and subcutaneous erythropoietin (40.000 IU), or i.v. ferric carboxymaltose and subcutaneous placebo, or i.v. placebo and subcutaneous placebo. Follow-up will be performed until 60 days after discharge, assessing transfusion needs, morbidity, mortality, safety, costs, and health-related quality of life. Intention to treat, as well as per protocol, and incremental cost-effectiveness analysis will be performed. The number of recruited patients per arm is set at 102, a total of 306 patients.

Discussion

We think that this trial will contribute to the knowledge about the safety and efficacy of ferric carboxymaltose with/without erythropoietin in preventing red-cell pack transfusions in patients with hip fracture. ClinicalTrials.gov identifier: NCT01154491.

Bleeding in a Jehovah's Witness patient undergoing a redo aortic valve replacement controlled with cryoprecipitate and a prothrombin complex concentrate

PURPOSE

This is a case report involving a middle-aged Jehovah's Witness patient who underwent a redo aortic valve replacement, coronary artery bypass graft, and Maze procedure facilitated by cardiopulmonary bypass. The consent process included a discussion of the management of bleeding and hemostasis in the perioperative period in the context of the patients' religious choice and the possible consequences of avoiding transfusion in massive bleeding. The medical team agreed to abide by the patient's wishes with respect to the blood and blood products deemed unacceptable by the patient irrespective of the consequences. The consent included a discussion of manufactured hemostatic agents that are designated by the Hospital Liaison Committee Network for Jehovah's Witnesses as subject to personal decision. There was also a discussion of recombinant agents available, all of which are acceptable to Jehovah's Witness patients. The patient accepted the use of cryoprecipitate, prothrombin complex concentrate, and recombinant factor VIIa.

CLINICAL FEATURES

After separation from cardiopulmonary bypass and protamine administration, blood loss was 350 mL over a ten-minute period. The international normalized ratio (INR) was 3.5 at that time. Cryoprecipitate 15 U, 1-deamino-8-D-arginine vasopressin 16 U, and a prothrombin complex concentrate, Octaplex®, 60 mL were administered. Blood loss improved significantly. The INR in the cardiac surgical intensive care unit was 1.3. The sample was taken approximately one hour following the administration of the hemostatic agents. The patient's chest was closed, and chest tube drainage was 310 mL over the next 12 hr.

CONCLUSION

This is a novel case involving the use of prothrombin complex concentrate in the setting of a Jehovah's Witness patient undergoing a complex operative procedure.

Non-blood medical care in gynecologic oncology: a review and update of blood conservation management schemes

This review attempts to outline the alternative measures and interventions used in bloodless surgery in the field of gynecologic oncology and demonstrate their effectiveness. Nowadays, as increasingly more patients are expressing their fears concerning the potential risks accompanying allogenic transfusion of blood products, putting the theory of bloodless surgery into practice seems to gaining greater acceptance. An increasing number of institutions appear to be successfully adopting approaches that minimize blood usage for all patients treated for gynecologic malignancies. Preoperative, intraoperative and postoperative measures are required, such as optimization of red blood cell mass, adequate preoperative plan and invasive hemostatic procedures, assisting anesthetic techniques, individualization of anemia tolerance, autologous blood donation, normovolemic hemodilution, intraoperative cell salvage and pharmacologic agents for controlling blood loss. An individualised management plan of experienced personnel adopting a multidisciplinary team approach should be available to establish non-blood management strategies, and not only on demand of the patient, in the field of gynecologic oncology with the use of drugs, devices and surgical-medical techniques.

Blood transfusion safety in Africa: a literature review of infectious disease and organizational challenges

Blood safety remains an important public health concern in Africa where lack of availability or provision of unsafe blood adversely impacts morbidity and mortality in the region. In recognition of this shortfall, the World Health Organization (WHO) established a goal of regional blood safety by 2012 through improved "organization and management, blood donor recruitment and collection, testing of donor blood as well as appropriate clinical use of blood" (Tagny et al: Transfusion. 2008;48:1256-1261; Tapko et al: Status of Blood Safety in the WHO African Region: Report of the 2006 Survey http://www.afro.who.int/en/divisions-a-programmes/dsd/health-technologies-a-laboratories.html. Brazzaville, Republic of Congo: WHO Regional Office for Africa; 2006). Although there has been substantial progress toward meeting these objectives, there are continued obstacles to both development and sustainability. In a setting where transfusion oversight is still being improved, transfusion-transmitted infections are of real concern. The high prevalence of some transfusion-transmissible agents such as hepatitis B virus and HIV in the general population means that some infected blood units escape detection by even well-performed laboratory testing, resulting in potential downstream transmission to patients. The spectrum of transfusion-transmitted infection include conventional as well as exotic pathogens, many of which are endemic to the region, thereby imparting ongoing challenges to recruitment and testing strategies.

Blood conservation in surgery: current concepts and practice

Blood conservation is based on the principle of avoiding allogeneic blood transfusion with the aim of improving outcome and protecting patients' rights. Surgical patients receive a significant proportion of the allogeneic blood transfused in the hospital. Blood conservation in surgery greatly reduces overall allogeneic blood use, thereby reducing costs, hazards, and adverse outcomes. Blood conservation techniques aim to lower the "transfusion trigger," optimize the hematocrit, minimize blood loss, and optimize tissue oxygenation. Successful blood conservation involves a combination of techniques tailored to the individual patient. It requires planning and a multidisciplinary team approach but usually little technology. Bloodless medicine and surgery programs represent the gold standard in blood conservation. Blood conservation is evidence based, and it results in faster recovery, lower morbidity, lower mortality, shorter hospital stay, lower cost, and better patient (and physician) satisfaction while avoiding the hazards of allogeneic blood transfusion. Blood conservation is thus the current standard of care.

Red blood cell transfusion following burn

A severe burn will significantly alter haematologic parameters, and manifest as anaemia, which is commonly found in patients with greater than 10% total body surface area (TBSA) involvement. Maintaining haemoglobin and haematocrit levels with blood transfusion has been the gold standard for the treatment of anaemia for many years. While there is no consensus on when to transfuse, an increasing number of authors have expressed that less blood products should be transfused. Current transfusion protocols use a specific level of haemoglobin or haematocrit, which dictates when to transfuse packed red blood cells (PRBCs). This level is known as the trigger. There is no one 'common trigger' as values range from 6 g dl(-1) to 8 g dl(-1) of haemoglobin. The aim of this study was to analyse the current status of red blood cell (RBC) transfusions in the treatment of burn patients, and address new information regarding burn and blood transfusion management. Analysis of existing transfusion literature confirms that individual burn centres transfuse at a lower trigger than in previous years. The quest for a universal transfusion trigger should be abandoned. All RBC transfusions should be tailored to the patient's blood volume status, acuity of blood loss and ongoing perfusion requirements. We also focus on the prevention of unnecessary transfusion as well as techniques to minimise blood loss, optimise red cell production and determine when transfusion is appropriate.

Patient blood management - a new paradigm for transfusion medicine?

The saving of many lives in history has been duly credited to blood transfusions. What is frequently overlooked is the fact that, in light of a wealth of evidence as well as other management options, a therapy deemed suitable yesterday may no longer be the first choice today. Use of blood has not been based upon scientific evaluation of benefits, but mostly on anecdotal experience and a variety of factors are challenging current practice. Blood is a precious resource with an ever limiting supply due to the aging population. Costs have also continually increased due to advances (and complexities) in collection, testing, processing and administration of transfusion, which could make up 5% of the total health service budget. Risks of transfusions remain a major concern, with advances in blood screening and processing shifting the profile from infectious to non‐infectious risks. Most worrying though, is the accumulating literature demonstrating a strong (often dose‐dependent) association between transfusion and adverse outcomes. These include increased length of stay, postoperative infection, morbidity and mortality. To this end, a recent international consensus conference on transfusion outcomes (ICCTO) concluded that there was little evidence to corroborate that blood would improve patients’ outcomes in the vast majority of clinical scenarios in which transfusions are currently routinely considered; more appropriate clinical management options should be adopted and transfusion avoided wherever possible. On the other hand, there are patients for whom the perceived benefits of transfusion are likely to outweigh the potential risks. Consensus guidelines for blood component therapy have been developed to assist clinicians in identifying these patients and most of these guidelines have long advocated more conservative ‘triggers’ for transfusion. However, significant variation in practice and inappropriate transfusions are still prevalent. The ‘blood must always be good philosophy’ continues to permeate clinical practice. An alternative approach, however, is being adopted in an increasing number of centres. Experience in managing Jehovah’s Witness patients has shown that complex care without transfusion is possible and results are comparable with, if not better than those of transfused patients. These experiences and rising awareness of downsides of transfusion helped create what has become known as ‘patient blood management’. Principles of this approach include optimizing erythropoiesis, reducing surgical blood loss and harnessing the patient’s physiological tolerance of anaemia. Treatment is tailored to the individual patient, using a multidisciplinary team approach and employing a combination of modalities. Results have demonstrated reduction of transfusion, improved patient outcomes and patient satisfaction. Significant healthcare cost savings have also followed. Despite the success of patient blood management programmes and calls for practice change, the potential and actual harm to patients caused through inappropriate transfusion is still not sufficiently tangible for the public and many clinicians. This has to change. The medical, ethical, legal and economic evidence cannot be ignored. Patient blood management needs to be implemented as the standard of care for all patients.

Blood loss in surgical oncology: neglected quality indicator?

Quality indicators can be defined as "specific and measurable elements of practice that can be used to assess the quality of care". Surgical blood loss is one of the most significant perioperative predictors of patient outcome. Blood loss is a modifiable quality indicator for oncologic cancer surgery. Surgical oncologists need to alter their surgical technique to promote bloodless surgery and decrease the variability in reported blood loss and rates of blood transfusion.

Blood conservation in practice: an overview

Allogeneic blood transfusions are associated with risks and unfavourable outcomes. Blood conservation provides an alternative, with potential to improve patient care with limited or no blood transfusion. Many approaches are available, but the most essential ones are simple and cost free.

The role of erythropoietin in the acute phase of trauma management: evidence today

Trauma patients often present in a state of haemorrhagic shock. Blood products remain the gold standard of resuscitation, but allogeneic blood transfusions (ABTs) are associated with several risks. The stimulating effect of recombinant-erythropoietin (EPO-A) on erythropoiesis has raised interest in its administration as an alternative. The existing evidence on the early use of EPO-A in the acute phase of trauma patients management consists of only 14 publications. The level of evidence of these studies and the number of treated patients was not found to be adequate to support its generalised use, despite their favourable results. Its safety profile, the preliminary proofs of its efficacy, and the additional cyto-protective properties of EPO-A strongly encourage further controlled studies assessing its use in the acute setting of initial trauma management.

The promise of next generation colloids

The aim of perioperative haemodilution is to reduce loss of red blood cells during elective surgery. The oncotic and molecular characteristics of the various plasma substitutes employed determine how effectively normovolaemia is maintained, and their non-oncotic effects include alterations in microvascular perfusion. In the previous issue of Critical Care, Martini and colleagues assessed the effects of haemodilution with either polyethylene glycol (PEG)ylated albumin or a commercially available hydroxyethyl starch-based colloid in a hamster haemorrhage model. PEGylated albumin was superior to hydroxyethyl starch, as reflected by survival, haemodynamic parameters and assessment of the microcirculation using intravital microscopy.

Alternatives to blood transfusion

Blood transfusion therapy in the 21st century continues to present limitations regarding efficacy and risks. Blood management partners optimal blood transfusion therapy with anemia management that incorporates nonblood strategies and techniques. A planned approach to anemia prevention, identification, and treatment can reduce the need for blood transfusion and improve patient outcomes. The use of pharmaceutical agents and tools to minimize blood loss also leads to blood transfusion reduction. Nurses play an integral role in affecting the use of alternatives to blood transfusion. Through assessment, communication, and an understanding of blood management strategies, nurses are patients' front-line innovators in promoting best practices.

Survival time in severe hemorrhagic shock after perioperative hemodilution is longer with PEG-conjugated human serum albumin than with HES 130/0.4: a microvascular perspective

Introduction

Preoperative hemodilution is an established practice that is applied to reduce surgical blood loss. It has been proposed that polyethylene glycol (PEG) surface decorated proteins such as PEG-conjugated human serum albumin may be used as non-oxygen-carrying plasma expanders. The purpose of this study was to determine whether there is any difference in survival time after severe hemorrhagic shock following extreme hemodilution using a conventional hydroxyethyl starch (HES)-based plasma expander or PEG-albumin.

Methods

Experiments were performed using the hamster skinfold window preparation. Human serum albumin that was surface decorated with PEG was compared with Voluven 6% (Fresenius Kabi, Austria; a starch solution that is of low molecular weight and has a low degree of substitution; HES). These plasma expanders were used for a 50% (blood volume) exchange transfusion to simulate preoperative hemodilution. Exchange transfusion was followed by a 60% (blood volume) hemorrhage to reproduce a severe surgical bleed over a 1 hour period. Observation of the animal was continued for another hour during the shock phase.

Results

The PEG-albumin group exhibited significantly greater survival rate than did the HES group, in which none of the animals survived the hemorrhage phase of the experiment. Among the treatment groups there were no changes in mean arterial pressure and heart rate from baseline after hemodilution. Both groups experienced gradual increases in arterial oxygen tension and disturbance in acid-base balance, but this response was more pronounced in the HES group during the shock period. Mean arterial pressure remained elevated after the initial hemorrhage period in the PEG-albumin group but not in the HES group. Maintenance of a greater mean arterial pressure during the initial stages of hemorrhage is proposed to be in part due to the improved volume expansion with PEG-albumin, as indicated by the significant decrease in systemic hematocrit compared with the HES group. PEG-albumin treatment yielded higher functional capillary density during the initial stages of hemorrhage as compared with HES treatment.

Conclusion

The ability of PEG-albumin to prolong maintenance of microvascular function better than HES is a finding that would be significant in a clinical setting involving preoperative blood management and extreme blood loss.