Reinfusion of shed blood after orthopaedic procedures in children and adolescents

Cell salvage in trauma

PURPOSE OF REVIEW

The collection of shed blood and its reinfusion has been termed 'cell salvage' or 'autotransfusion'. This review will summarize the historical foundation of cell salvage and summarize recent literature associated with cell salvage use in trauma.

RECENT FINDINGS

There have been no publications on cell salvage in trauma during the last 2 years. This is based on a PubMed search using the key words, 'cell salvage', 'autologous blood transfusion' and 'operative blood salvage'. Although the wars in Iraq and Afghanistan were ongoing, publications focused upon autotranfusion of unwashed blood from the hemothorax and on the resuscitation of the injured in remote settings.

SUMMARY

Autotransfusion or cell salvage is markedly under utilized in trauma. Opportunities exist for significant blood savings if it is used more frequently. More research is clearly needed to assess the safety of autotransfusion in the traumatized patient.

Successful management of catastrophic peripheral vascular hemorrhage using massive autotransfusion and damage control surgery in a dog

OBJECTIVE

To describe a case of massive transfusion using unwashed, non-anticoagulated, nonsterile autologous blood in a dog with catastrophic hemorrhage from a peripheral vessel during orthopedic surgery. A damage control surgical strategy was also employed.

CASE SUMMARY

A 6-year-old, 48 kg neutered male Labrador Retriever experienced massive hemorrhage after transection of a large blood vessel while undergoing femoral head and neck osteotomy. Blood was collected from clean, but not sterile, suction canisters and clots were skimmed off. The blood was then transfused back to the dog using a standard in-line blood filter. Approximately 58% of the dog's blood volume was autotransfused in less than 2 hours, thereby meeting the criteria for massive transfusion. Surgery was aborted after hemostasis was achieved by ligation of the vessel and packing of the surgical site. Two units of fresh frozen plasma were administered postoperatively due to the development of a coagulopathy. Hemoglobinuria developed but resolved within 18 hours. Three days later, completion of the surgical procedure was performed without incident. The dog was discharged 4 days after the initial surgery. Marked swelling of the affected limb developed, but resolved after the sixth day. No other significant complications developed.

NEW OR UNIQUE INFORMATION PROVIDED

In this case report, the authors describe the successful management of catastrophic hemorrhage with autotransfusion performed in the absence of sterile collection, cell washing, or anticoagulation. Although not ideal, autotransfusion under these conditions can be lifesaving in situations of massive hemorrhage. This case also highlighted the employment of a damage control surgical strategy.

Blood salvage with a continuous autotransfusion system compared with a haemofiltration system

Background: Red blood cells may be destroyed by autotransfusion processing during intraoperative salvage. The aim of the present study was to evaluate the blood component recovery rate of techniques built on either continuous centrifugation and washing, or haemofiltration (HF).

Methods: Two different methods used in blood salvage - red cell salvage with continuous processing with centrifugation and saline washing (Continuous Auto Transfusion System, CATS) and whole blood recirculation through a 30000-Da filter, i.e., HF - were compared in a randomized laboratory study using donor whole blood activated by cobra venom factor. The recovery of red blood cells, haemoglobin, free haemoglobin, leucocytes, platelets, albumin, total protein and potassium was measured.

Results: The recovery of red cells was 86% with CATS and 76% with HF. HF had a significantly higher recovery of leucocytes (CATS 20%, HF 63%), platelets (CATS 4%, HF 37%), albumin (CATS 0.2%, HF 70%), total protein (CATS 1.3%, HF 71%) and potassium (CATS 2%, HF 17%). Less than 1% haemolysis was obtained in processed blood from both groups.

Conclusion: Both methods caused little destruction of the red blood cells during processing. There was a larger reinfusion of leucocytes, platelets, albumin, total protein and extracellular potassium when HF was used compared with the ‘CATS’ method.

Post-operative retransfusion of unwashed filtered shed blood reduces allogenic blood demand in hip hemiarthroplasty in traumatic femoral neck fractures-a prospective randomized trial

PURPOSE

Patients who undergo hip hemiarthroplasty (HHA) due to traumatic femoral neck fracture frequently require red blood cell (RBC) transfusion. Although post-operative autologous blood transfusion (ABT) is well established in elective arthroplasty, its role in trauma patients remains unclear.

METHODS

Two hundred twenty-nine patients with a traumatic femoral neck fracture that underwent HHA at our level-I trauma centre between 2005 and 2009 were prospectively randomized to a high-vacuum drainage or an ABT device. In this single-institution analysis, the number of RBC units as well as the amount of retransfused shed blood were recorded and compared according to study groups. Additionally, the significance of confounding factors for allogenic blood demand such as age, gender, pre-operative Hb level, surgical approach, type of prosthesis and amount of intra-operative RBC units were evaluated using multivariate analysis.

RESULTS

One hundred thirty-five patients were randomized in the high-vacuum group while 94 patients received an ABT device. Intention to treat analysis revealed no significant difference in post-operative RBC demand (ABT: 0.87 RBC, high-vacuum drainage: 1.01 RBC; P = 0.374). However, patients that actually received retransfusion (N = 35) had a reduced post-operative RBC demand (0.49 RBC units, P = 0.014).

CONCLUSION

While only one third of trauma patients treated with an ABT device during HHA actually receive retransfusion, retransfused patients seem to significantly benefit from this treatment as reflected by a reduced pos-toperative RBC demand.

Perioperative blood conservation strategies for major spine surgery

BACKGROUND

Orthopedic surgery, especially spine and spinal deformity surgery, may be associated with high perioperative blood loss. In order to reduce the risk of excessive blood loss and unnecessary blood transfusions, strategies such as Patient Blood Management including goal-directed coagulation management have been developed.

RECENT FINDINGS

Adverse effects of allogeneic blood transfusions have been shown for most surgical fields including orthopedic surgery. Several efforts have been made to increase the preoperative red blood cell (RBC) mass, to reduce the intraoperative blood loss, and to use restrictive transfusion triggers in order to minimize or avoid RBC transfusions. Measures to reduce intraoperative blood loss include new surgical techniques, use of cell salvage where possible, bedside coagulation management with point-of-care devices, substitution of coagulation factors, antifibrinolytic agents, and desmopressin, induced hypotension, and avoidance of hypothermia.

SUMMARY

Blood conservation in spinal surgery is a multidisciplinary approach and the efficacy of most single measures has been shown. Cost-effectiveness and the benefits of long-term patient outcomes are the subjects of current and future research.

Efficacy and safety using autotransfusion system with postoperative shed blood following total knee arthroplasty in haemophilia

The purpose of this study was to evaluate the efficacy and safety of postoperative wound drain salvage and autotransfusion system in haemophilic patients undergoing elective total knee arthroplasty (TKA). No literature exists on reinfusing drained blood in patient with haemophilia undergoing TKA. Eighty-eight knees of 66 patients received cemented TKA due to end-stage haemophilic arthropathy (group I; with autotransfusion in 59 knees, group II; without autotransfusion in 29 knees). In group I, the postoperative shed blood was transfused within 6 h after surgery. The amount of blood drainage and reinfused blood, rate and amount of allogenic transfusion, postoperative change of haemoglobin level, prothrombin time (PT) and activated partial thromboplastin time were analysed. The mean postoperative blood drainage was 932 ± 479 mL in group I and 830 ± 492 mL in group II (P > 0.05). The mean volume of blood reinfused was 530 ± 265 mL in group I. Allogenic transfusion was needed in six knees (10.2%) of group I and eight knees (27.6%) of group II (P = 0.036). The mean volume of allogenic transfusion was 480 ± 49 mL in group I and 1041 ± 691 mL in group II (P > 0.05). Changes of all the laboratory results before and after TKA showed no statistically significant difference except PT was prolonged in group I (P = 0.008) at postoperative day 1. Moreover, there was no significant complication related to either reinfusion or allogenic transfusion in both groups. This study showed that reinfusion of drained blood is a simple, safe and efficacious method in patients with haemophilia undergoing TKA.

The effect of salvaged blood on coagulation function as measured by thromboelastography

BACKGROUND

There is concern that salvaged blood has the potential to activate the coagulation system, which might place patients at risk of thrombotic complications. The aim of this study was to determine whether transfusion of salvaged blood after total knee arthroplasty (TKA) would lead to procoagulopathic changes as measured by thromboelastography (TEG) and furthermore if washing would reduce this risk.

STUDY DESIGN AND METHODS

Twenty-two patients undergoing TKA were enrolled. Control samples were venous blood samples taken before surgery. Test samples were created by mixing the control samples with postoperatively salvaged blood, either washed or unwashed. TEG profiles were measured, noting the time to initiate clotting (R), the time of clot formation (K), the angle of clot formation (α-angle), and the maximum amplitude (clot strength [MA]).

RESULTS

The changes in the coagulation profile from control samples to test samples were consistent for both the washed and the unwashed groups: R time decreased, MA decreased, and K and α-angle remained the same. However, the changes were more pronounced in the unwashed group than the washed group, with a 61% decrease in R time compared with 14%, and a 26% decrease in MA compared with 6%.

CONCLUSION

The addition of salvaged blood to the patient's preoperative blood resulted in decreased MA as well as decreased R time. This suggests that the reinfusion of postoperatively salvaged washed or unwashed blood after TKA favors a change toward a more hypocoagulable state, and washing appears to reduce this effect.

Is routine chemoprophylaxis necessary for prevention of venous thromboembolism following knee arthroplasty in a low incidence population?

BACKGROUND

Standard thromboprophylaxis guidelines have not been applied universally in regions with low incidence of deep-vein thrombosis (DVT) considering risks of chemoprophylaxis and low incidence itself. We evaluated the prevalence of DVT, efficacy and safety of chemoprophylaxis, and necessity of pharmacological prevention in a low DVT incidence population.

METHODS

One hundred and forty-eight patients undergoing unilateral total knee arthroplasty (TKA) were prospectively randomized to receive either a placebo or 2.5 mg of fondaparinux once daily for 5 days. Doppler ultrasonography was performed preoperatively and 7 days after surgery. The primary efficacy outcome was prevalence of DVT up to day 7. Secondary efficacy outcome was prevalence of symptomatic venous thromboembolism (VTE) up to day 90. Primary and secondary safety outcomes were incidence of major and minor bleeding, respectively.

RESULTS

The prevalence of total DVT was 25.7 % in placebo group and 6.8 % in fondaparinux group (p = 0.002) and the prevalence of proximal DVT was lower in both groups with no statistical difference. There was no symptomatic VTE in either group up to day 90. Although no major bleeding was developed, fondaparinux group had a significant increase of minor bleeding events (p < 0.001).

CONCLUSIONS

There remains low incidence of VTE following TKA in East Asians even without chemoprophylaxis. Although short-term fondaparinux protocol could reduce the incidence of overall DVT, its routine use seems debatable due to extremely rare proximal DVT and symptomatic PE and drug-related bleeding complication. However, modified and selective use of chemoprophylaxis would be considerable in high risk patients.

Washing and filtering of cell-salvaged blood - does it make autotransfusion safer?

Autologous transfusion was first performed in the late 1800s, but it was not until the 1970s that devices were developed that enabled widespread adoption of the practice. Unwashed salvaged blood contains thrombogenic products, cell breakdown products and plasma proteins, and gross chemical, cellular and physical contaminants. Washing and filtering of salvaged blood is routinely performed to remove or reduce these elements. In this paper we review the clinical data supporting the need for washing and filtering of salvaged blood.

A cost study of postoperative cell salvage in the setting of elective primary hip and knee arthroplasty

BACKGROUND

The increasing costs, limited supply, and clinical risks associated with allogeneic blood transfusion have prompted investigation into autologous blood management strategies, such as postoperative red blood cell (RBC) salvage. This study provides a cost comparison of transfusing washed postoperatively salvaged RBCs using an orthopedic perioperative autotransfusion device (OrthoPat, Haemonetics Corporation) versus unwashed shed blood and banked allogeneic blood.

STUDY DESIGN AND METHODS

Cell salvage data were retrospectively reviewed for a sample of 392 patients who underwent primary hip or knee arthroplasty. Mean unit costs were calculated for washed salvaged RBCs, equivalent units of unwashed shed blood, and therapeutically equivalent volumes of allogeneic RBCs.

RESULTS

No initial capital investment was required for the establishment of the postoperative cell salvage program. For patients undergoing total knee arthroplasty (TKA), the mean unit costs for washed postoperatively salvaged cells, unwashed shed blood, and allogeneic banked blood were $758.80, $474.95, and $765.49, respectively. In patients undergoing total hip arthroplasty (THA), the mean unit costs for washed postoperatively salvaged cells, unwashed shed blood, and allogeneic banked blood were $1827.41, $1167.41, and $2609.44, respectively.

CONCLUSION

This analysis suggests that transfusing washed postoperatively salvaged cells using the OrthoPat device is more costly than using unwashed shed blood in both THA and TKA. When compared to allogeneic transfusion, washed postoperatively salvaged cells carry a comparable cost in TKA, but potentially represent a significant savings in patients undergoing THA. Sensitivity analysis suggests that in the case of TKA, however, cost comparability exists within a narrow range of units collected and infused.

Impact of shed blood products on stimulated cytokine release in an in vitro model of transfusion

BACKGROUND

Blood transfusion is reported to suppress the recipient's immune system. To avoid allogenic transfusion, post-operative shed blood retransfusion is a commonly used method. The aim of this study was to investigate the dose-related impact of post-operatively collected shed blood products on the stimulated cytokine release in an in vitro model of transfusion.

METHODS

Venous blood samples obtained from 20 patients undergoing hip arthroplasty were mixed with post-operatively collected unprocessed, processed, and irradiated shed blood as well as normal saline as a control. Shed blood was processed by centrifugation and separating the cellular fraction from the soluble fraction and washing the cellular fraction with phosphate buffered saline to eliminate any cell fragments and other substances. Mixing ratios were 1:3, 1:1, and 3:1. Endotoxin-stimulated release of Tumor Necrosis Factor-alpha (TNF-α) was measured after 24 h of culture by enzyme-linked immunosorbent assay.

RESULTS

Unprocessed, irradiated shed blood and the soluble fraction caused a significant suppression of stimulated TNF-α release compared to control. The addition of the cellular shed blood fraction had no significant influence on the TNF-α release compared to control.

CONCLUSION

Shed blood and its components caused a dose-independent immunomodulation as indicated by a suppressed stimulated TNF-α release. Leukocytes seem to play a minor role, as we observed a sustained suppression after transfusion of γ-irradiated shed blood. Only the elimination of soluble factors by centrifugation and followed by an additional washing step prevented the observed suppression of TNF-α. Thus, we assume that washing of shed blood can prevent potential detrimental effects.

Reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery

At present, individual techniques, including intraoperative acute normovolemic hemodilution, use of tranexamic acid, use of intrathecal morphine, proper positioning, and modification of operative techniques, seem most promising for reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery. Other techniques including preoperative autologous predonation; mandatory discontinuation of use of antiplatelet agents; intraoperative and postoperative red-blood-cell salvage; use of aprotinin, epsilon-aminocaproic acid, recombinant factor VIIa, or desmopressin; induced hypotension; avoidance of hypothermia; and minimally invasive operative techniques require additional studies to either establish their effectiveness or address safety considerations.

The future of blood management

An evolving understanding of the consequences of allogeneic blood transfusion and escalating costs of providing allogeneic blood have resulted in an interest in blood management. Understanding the consequences of allogeneic transfusion includes a recognition of the immunosuppressive effects of allogeneic transfusion, a growing awareness of transfusion-related acute lung injury, and a rediscovery of transfusion-associated circulatory overload. More recently, interest has focused on the effect of stored blood on patient outcome. Although this discussion is not all-inclusive, it is intended to show that many techniques can be applied to decrease the exposure to allogeneic blood.

Red blood cell hemolysis during blood bank storage: using national quality management data to answer basic scientific questions

BACKGROUND

Hemolysis of red blood cells (RBCs) during blood bank storage is the most obvious manifestation of RBC storage system failure. However, its analysis is made difficult because the largest source of interunit difference is donor specific. Availability of data from national blood systems on large numbers of RBC units used for internal quality control (QC) purposes and stored and processed in uniform ways permits statistical analysis.

STUDY DESIGN AND METHODS

Measures of hemolysis during and at the end of storage on randomly selected donor units observed for QC purposes were obtained from four national blood systems. Groups of these measures from units that had undergone similar processing and storage were sorted to create histograms and the histograms were compared statistically.

RESULTS

A total of 14,087 measures were obtained under seven storage conditions, including more than 12,000 measures made in a single country under four closely related conditions. Distributions of percent hemolysis are skewed normal and outliers are random. Additive solutions appear to be equivalent, except that the 42 mmol/L mannitol in AS-1 reduces hemolysis compared to conventional 30 mmol/L mannitol in saline, adenine, glucose, and mannitol. Increasing storage from 35 to 42 days increased measured hemolysis by 30% and leukoreduction decreased it by 53%.

CONCLUSIONS

Large national data sets provide useful information about the distribution of hemolysis at the end of RBC storage. This information can aid blood storage system development and regulatory science.

Reinfusion of unwashed salvaged blood after total knee arthroplasty in patients with rheumatoid arthritis

Autotransfusion with unwashed salvaged blood (USB) is effective for avoiding allogeneic blood transfusion (ABT) in patients undergoing total knee arthroplasty (TKA). We performed a retrospective study to determine the percentage of patients receiving ABT and the volume of postoperative blood drainage after introduction of autotransfusion with USB for patients with rheumatoid arthritis (RA) undergoing TKA. In 100 patients without autotransfusion (group 1) and 100 patients receiving autotransfusion of USB (group 2), we compared the number of patients who required ABT, as well as the postoperative drainage volume, ABT volume, and autotransfusion volume. In group 1, 83% of the patients received ABT, while only 47% received ABT in group 2, and there was a significant decrease (p < 0.001). However, the postoperative drainage volume was significantly increased in group 2 (p < 0.001).

Research on coagulation of unwashed shed blood after total knee replacement in Chinese patients

To evaluate quality of unwashed but filtered wound shed blood through ConstaVac blood conservation system (Stryker Company) after total knee replacement, we selected 30 patients who underwent total knee replacement consecutively from July 2003 to July 2004 and received retransfusion of wound shed blood. Pre- and postoperative coagulative factors of peripheral vein blood and wound shed blood were measured, such as fibrinogen, AT-III, D-dimer, plasminogen, and PT, APTT were also measured. No clinical evidence of coagulation and DIC appeared in these patients. There is significant change of coagulative factors in unwashed but filtered wound shed blood and it may cause a potential risk of coagulopathy to retransfuse wound shed blood, but retransfusion of unwashed but filtered shed blood appeared to be relative safe clinically.

Efficacy and economics of postoperative blood salvage in patients undergoing elective total hip replacement

INTRODUCTION

Patients undergoing total hip replacement (THR) regularly receive allogenic blood transfusions. The infusion of allogenic blood exposes the recipient to significant risks including the transmission of infection, anaphylactic and haemolytic reactions. The purpose of this study was to determine the effect of introducing a system to retransfuse salvaged drainage blood in patients undergoing primary THR.

PATIENTS AND METHODS

We reviewed records of 109 consecutive patients who underwent THR following the introduction of the ABTrans autologous retransfusion system at our institution in January 2000. For comparison, we reviewed the medical records of 109 patients who underwent the same procedure immediately before the introduction of the retransfusion system.

RESULTS

Overall, 9% of patients treated with blood salvage and 30% treated without blood salvage required allogenic blood transfusions. Patients treated with the salvage system had significantly smaller haemoglobin drops in the peri-operative period (difference 0.56 g/dl; P = 0.001). The overall cost of using the retransfusion system was similar to that of routine vacuum drainage when the savings of reduced allogenic blood transfusion were taken into account.

CONCLUSIONS

The retransfusion of postoperative drainage blood is a simple, effective and safe way of providing autologous blood for patients undergoing primary THR.

Decreasing the blood transfusion rate in elective hip replacement surgery using an autologous drainage system

INTRODUCTION

This is a prospective study looking at the effectiveness of autologous postoperative drains in primary uncemented total hip replacement (THR) surgery.

PATIENTS AND METHODS

A total of 86 patients were studied, with 43 using standard suction drains (normal drain group) and 43 using autologous drains (autologous drain group).

RESULTS

Thirty-seven units of homologous blood were transfused in the normal drain group and 5 units in the autologous drain group. The mean number of units of homologous blood transfused per patient was reduced from 0.86 to 0.12 (P < 0.01) with the use of autologous drains and the transfusion rate was reduced from 23% to 6% (P < 0.02). The mean length of hospital stay was also reduced by two nights (P < 0.05). There were no adverse effects from using the autologous system and it does reduce the need for a homologous blood transfusion.

CONCLUSIONS

The system is simple and easy to use and we have also found it to be cost effective. Previously, it has not been reported as being effective in hip arthroplasty surgery, unlike knee arthroplasty surgery. We would recommend using autologous postoperative drains in primary THR surgery.

Blood loss minimization and blood salvage techniques for complex spinal surgery

Several techniques to limit blood loss and salvage lost blood are available to surgeons, physicians, and personnel who treat complex spinal disorders. These techniques include red blood cell augmentation, intraoperative antifibrinolytic administration, use of topical hemostatic agents, and intraoperative blood salvage and postoperative blood salvage. A substantial amount of research has been directed toward reducing perioperative blood loss in spinal surgery. More efforts need to be directed toward effective perioperative blood management in complex spinal surgery.

Effect of shed blood retransfusion on pulmonary perfusion after total knee arthroplasty: a prospective controlled study

Postoperative shed blood retransfusion (autotransfusion) is a commonly used salvage method following major surgical operations, such as total knee arthroplasty (TKA). The systemic effects of shed blood are still unclear. We studied the effect of residual substances in the retransfused shed blood, on lung perfusion after TKA. Fifteen unilateral and one bilateral TKAs were performed with autotransfusion (the study group) and 15 unilateral and three bilateral TKAs were performed in a control group. Lung X-rays, arterial blood gases (ABG), D-dimer values, and lung perfusion scintigraphies were performed preoperatively and postoperatively. A mean of 300.0 +/- 335.6 ml of bank blood was needed in the autotransfusion group and a mean of 685.7 +/- 365.5 ml of bank blood was needed in the control group (p=0.001). There was a postoperative segmental perfusion defect at the lateral segment of the superior lobe of the left lung in one patient of the control group and he also had risk factors for thrombosis. Although both groups had a decrease in lung perfusion postoperatively, there were no significant differences among the groups regarding the lung perfusion scintigraphy, chest X-rays, ABG, and D-dimer values. In conclusion, although pulmonary perfusion diminishes following TKA, shed blood retransfusion does not add any risk to pulmonary perfusion.

Hemostatic defect in baboons autotransfused treated plasma to simulate shed blood

BACKGROUND

Nonwashed shed blood may contain products of clotting and fibrinolytic, and antifibrinolytic substances. This study was done to determine how autotransfusion of nontreated plasma and plasma treated with urokinase with and without aprotinin affected hemostasis in healthy baboons.

METHODS

A 500-mL volume of blood was collected from the baboon, a 250-mL volume of plasma was isolated, and the RBCs were reinfused. Three baboons were autotransfused untreated plasma. Four baboons received plasma that had been treated with 3000 IU/mL urokinase at +37 degrees C for 30 minutes. Eight baboons received plasma that had been treated first with urokinase 3000 IU/mL at +37 degrees C for 30 minutes and then with aprotinin (1000 KIU/mL). Bleeding time, fibrinogen degradation products (FDP), D-dimer, and alpha-2 antiplasmin levels were measured.

RESULTS

During the 4-hour period following autotransfusion of the urokinase-aprotinin-treated plasma, the levels of D-dimer and FDP were significantly higher and fibrinogen and alpha-2 antiplasmin levels were significantly lower than those levels seen after the autotransfusion of nontreated plasma. FDP and D-dimer levels showed significant positive correlations with prothrombin time (PT) and activated partial thromboplastin time (aPTT). A significant negative correlation was observed between thrombin time (TT) and fibrinogen level. A significant positive correlation was observed between bleeding time and D-dimer level and a significant negative correlation between the bleeding time and the fibrinogen level.

CONCLUSIONS

The infusion of a volume of urokinase or urokinase-aprotinin treated autologous plasma equivalent to 15% of the blood volume was not associated with a bleeding diathesis in healthy baboons.

The survival and function of baboon red blood cells, platelets, and plasma proteins: a review of the experience from 1972 to 2002 at the Naval Blood Research Laboratory, Boston, Massachusetts

The studies reported in this monograph were performed between 1972 and 2002 when it was possible to study healthy male and female baboons. A colony of baboons was maintained for 30 years without any adverse events observed in these baboons in the numerous studies that were performed. These protocols were reviewed and approved by the institutional animal care and use committees (IACUC) at the sites where the studies were performed and by the veterinarian services of the U.S. Navy's Bureau of Medicine and Surgery, the Office of Naval Research, and the Department of Defense. The physiology of red blood cells (RBCs), platelets (PLTs), and plasma proteins in the baboon was investigated together with the viability and function of preserved RBCs, PLTs, and plasma proteins. These studies in the baboon could not have been performed in normal volunteers and patients. The data obtained have provided critical information to explain the clinical observations reported in normal volunteers and patients after transfusion of fresh and preserved blood products. These studies were supported by the U.S. Navy's Bureau of Medicine and Surgery and the Office of Naval Research. In addition, the support of the late Congressman J. Joseph Moakley from Massachusetts is acknowledged because without his support many of these studies could not have been performed. The authors acknowledge the contributions of the numerous research collaborators identified in the 52 peer-reviewed publications that cite other funding agencies that supported the research that is reported, the editorial assistance of Ms Cynthia Ann Valeri, and the assistance of Ms Deborah Tattersall who prepared the figures and tables reported in this publication.

Fatal pulmonary fat embolism following spinal fusion surgery

OBJECTIVE

To report the case of a fatal pulmonary fat embolism as a complication of spinal fusion surgery.

DESIGN

Case report.

SETTING

Pediatric intensive care unit at a freestanding tertiary care children's hospital.

PATIENT

An adolescent female with neuromuscular scoliosis who underwent spinal fusion surgery with instrumentation and suffered a fatal pulmonary fat embolism.

CONCLUSION

Spinal fusion surgery for neuromuscular scoliosis is a common operative procedure. Pulmonary fat embolism as a complication of this procedure is rare. This case emphasizes the need to be aware of this potentially fatal postoperative complication. Specifically evaluating for this rare complication may lead to understanding cases of unexplained deterioration and death.

Impact of postoperative shed blood transfusion, with or without leucocyte reduction, on acute-phase response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR) most blood loss occurs postoperatively and return of unwashed filtered shed blood (USB) from postoperative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return, with or without leucocytes, on the acute-phase response (APR) after TKR.

PATIENTS AND METHODS

Forty-eight TKR patients, intended to receive postoperative USB, entered the study. Blood samples were obtained before and 6, 24, 72 h and 7 days after surgery, and from the USB before and after it passed through a 40-microm filter (Group F40) or a leucocyte-reduction filter (Group LRF). Haematimetric parameters, APR proteins (albumin, prealbumin, ceruloplasmin, haptoglobin, C-reactive protein), complement C3 and C4, and cytokines (IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha) were measured in all samples.

RESULTS

Twenty-eight patients (Group F40=14, Group LRF=14) received a mean of 1.2 USB units, without any clinically relevant incident, and did not need additional ABT. Sixteen out of the 20 remaining patients who received neither USB nor ABT served as a control group for the postoperative APR study. All patients showed the typical postoperative APR profile and there were no significant differences between groups for APR parameters, postoperative complications, or hospital stay.

CONCLUSIONS

Postoperative blood salvage and return, with or without a LRF, after TKR does not present any clinically relevant side-effects and does not modify APR induced by surgery. These findings seem to confirm the clinical experience that postoperative USB return is safe and questions the beneficial effect of using LRF.

Blood Conservation in Pediatric Anesthesia

This review focuses on perioperative blood conservation techniques and the role of transfusion triggers and algorithms, preoperative autologous donation, acute normovolemic hemodilution, intraoperative blood salvage, deliberate hypotension, and preoperative recombinant human erythropoietin in avoiding allogeneic blood transfusion in pediatric patients.

Composition of the blood sampled from surgical drainage after joint arthroplasty: quality of return

BACKGROUND

The quality of blood obtained with a device for postoperative blood drainage and autotransfusion (Bellovac-ABT, Astra Tech AB) was investigated in 50 patients who underwent total hip replacement (THR) or total knee replacement (TKR) surgeries.

STUDY DESIGN AND METHODS

The Bellovac-ABT drainage set was inserted and blood collection began after skin closure (THR) or 15 minutes after tourniquet deflation (TKR). A collecting bag stayed in place for less than 6 hours. The product was then returned after sedimentation and discard of supernatant, without anticoagulants.

RESULTS

Blood returned with the Bellovac-ABT had optimal hemoglobin levels and red blood cell (RBC) counts; the low platelet count reduced the risk of disseminated intravascular coagulation. Inertia of materials maintained acceptable values of C-reactive protein, whereas cytokines and complement split products rose rapidly. Higher concentrations of adenosine triphosphate and 2,3-diphosphoglycerate than in circulating blood suggested a normal RBC metabolism. No adverse reactions were observed in any participants.

CONCLUSION

Because of its simplicity and safety, the Bellovac-ABT autologous blood transfusion system is recommended in THR or TKR without joint infection or malignancy.

Severe blood loss during spinal reconstructive procedures: The potential usefulness of topical hemostatic agents

Complex spinal reconstructive procedures are invariably associated with excessive intraoperative blood loss that significantly increases the risk of severe perioperative complications. In some cases, excessive hemorrhage is equivalent to estimated total blood volume. Unfortunately, widely exposed bony surfaces are not amenable to standard hemostatic maneuvers utilized during soft tissue surgery. This article evaluates the clinical effectiveness of several approaches to blood management in this setting, and hypothesizes that underappreciated topical hemostatic agents may provide benefit by reducing the need for autologous predonation, banked donor blood or antifibrinolytic agents. Topical agents combining collagen, thrombin and fibrin have demonstrated initial promise by inducing platelet aggregation and initiating the clotting cascade when applied directly to bleeding bony sites. Clinical studies are clearly warranted.

Transfusion of post-operative shed blood: laboratory characteristics and clinical utility

Increased awareness of the potential hazards of allogenic blood transfusion, such as incompatibility reactions, metabolic and immunologic disorders, or transmission of viral diseases, has led to an emphasis on allogeneic blood alternatives. For orthopaedic surgery, several autologous transfusion modalities have emerged as alternatives to allogeneic blood transfusion, avoiding its immunomodulatory effects. Among them, transfusion or return of post-operative salvaged shed blood has become popular in major orthopaedic procedures. However, although the effectiveness of this blood-saving method is well documented, several authors have questioned its safety and recommended the use of washed blood. Therefore, this review analyses the haematologic characteristics of unwashed filtered shed blood, including metabolic status and survival of red blood cells, the components of the haemostatic system, the content of fat particles, bacterial and tumour cells and the possibility of their removal, the content of inflammatory mediators, and the effects on the patient's immune system. From data reviewed in this paper, it can be concluded that post-operative salvage of blood seems to be an excellent source of functional and viable red cells without many of the transfusion-related risks and with some immuno-stimulatory effects. In addition, from our experience, post-operative re-infusion of unwashed shed blood after major spine procedures has proved to reduce post-operative homologous transfusion requirements and to complement pre-operative autologous blood donation, without any clinically relevant complication.

Comparison of perioperative blood salvage and postoperative reinfusion of drained blood during surgical correction of craniosynostosis in infants

BACKGROUND

The surgical correction of craniosynostosis may be associated with extensive blood loss and transfusion. The aim of this study was to compare the efficacy of the perioperative use of the continuous autotransfusion system (CATS group) and of the postoperative use of the CBCII ConstaVac(R) system (CV group) to reduce homologous transfusion in infants during repair of craniosynostosis.

METHODS

Two groups of consecutive infants, weighing <10 kg, and scheduled for the surgical correction of craniosynostosis, were compared retrospectively according to the blood salvaging system used: CATS group and CV group. The primary endpoint was the comparison of the total volume of homologous blood transfused.

RESULTS

There was no significant difference between the CV (n = 69) and the CATS (n = 135) groups with regard to physical, preoperative and postoperative data, except for the type of craniosysnostosis with more scaphocephaly in the CV group (P = 0.03). No significant difference in blood loss and homologous transfusion was observed between the two groups during the perioperative period. Two subgroups of patients were also compared: a subgroup including patients operated on with a linear craniectomy for scaphocephaly, and a subgroup including all other patients. There was also no significant difference in blood loss and homologous transfusion between the CV and the CATS groups for these two subgroups of patients.

CONCLUSION

Our results suggest that the postoperative use of the CBCII ConstaVac(R) system is as efficient as the perioperative use of the CATS(R) system for reducing homologous blood transfusion during repair of craniosynostosis in infants weighing <10 kg.

Perioperative blood and blood product management for spinal deformity surgery

BACKGROUND CONTEXT

Spinal deformity surgery, like many other orthopedic procedures, involves significant operative blood loss. In order to avoid the necessity of bank blood transfusions, many blood management strategies have been devised.

PURPOSE

The goal of this review is to analyze the utility of current blood management strategies.

STUDY DESIGN/SETTING

Review paper.

METHODS

Using Medline reviews, pertinent data on blood management agents and strategies were assembled.

RESULTS

Techniques can be organized into preoperative, intraoperative and postoperative categories. Preoperative techniques include autologous blood donation and red cell augmentation. In addition to some established surgical and anesthesia techniques, recent pharmacologic agents have become available to include thrombotic agents and antifibrinolytics, which surgeons may add to their intraoperative armamentarium. A brief mention of postoperative blood salvage drains is also included.

CONCLUSIONS

The judicious use of the agents and techniques can significantly reduce the need for blood transfusions in the setting of spinal deformity surgery.

Inflammatory mediators in autotransfusion drain blood after knee arthroplasty, with and without leucocyte reduction

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate whether leucocyte-reducing filters influenced complement activation and the formation of pro-inflammatory cytokines in autotransfusion drain blood after knee arthroplasty.

MATERIALS AND METHODS

Twenty-three patients undergoing knee arthroplasty were divided into two groups. All patients were given salvage blood postoperatively. In Group A, a leucocyte filter was connected between the wound and the drain blood container. In Group B the drain blood was not leucocyte filtered. Complement split products and cytokines were analysed in circulating blood and in drain blood, together with blood-cellular differential counts.

RESULTS

Drain blood showed activation vs. venous blood, with elevated concentrations of C3a, SC5b-9, interleukin (IL)-6, IL-8, polymorphonuclear (PMN) elastase and tumour necrosis factor-alpha (TNF-alpha) (P<0.05 to P<0.001). The leucocyte filter reduced TNF-alpha (P<0.01), but triggered complement activation (P<0.05). Room-temperature incubation increased the concentration of IL-8 (P<0.01), which was seen in both venous and drain blood. The leucocyte filter prevented formation of IL-8 (P<0.01). In drain blood at 24 h the inflammatory reactions accelerated (P<0.05-0.001), although the filter reduced the leucocyte counts and TNF-alpha concentrations.

CONCLUSIONS

The leucocyte filter reduced IL-8 and TNF-alpha in drain blood, but at the same time triggered complement activation. Incubation affected the inflammatory spectrum of both drain blood and control venous blood, and the filtering reduced this activation.

Rapid sequence quadruple joint replacement in a rheumatoid Jehovah's Witness

We report the case of a wheelchair-bound rheumatoid Jehovah's Witness who underwent rapid sequence, staged, simultaneous ipsilateral hip and knee replacements. Using perioperative erythropoietin and postoperative blood salvage, all four joints were reconstructed without homologous blood transfusion. One year following surgery, the patient has achieved an independent functional status, and all four replaced joints remain painless.

Predictors of red cell transfusion in children and adolescents undergoing spinal fusion surgery

STUDY DESIGN

A retrospective review was performed.

OBJECTIVE

To determine clinical predictors of allogeneic and autologous red cell transfusion in children and adolescents undergoing spinal fusion surgery.

SUMMARY OF BACKGROUND DATA

Blood loss during spinal fusion surgery often results in the need for transfusion therapy. Preoperative identification of patients at increased risk for red cell transfusion would allow more specific use of interventions designed to control excessive bleeding.

METHODS

The medical records of all patients undergoing posterior spinal fusion surgery at a single institution between July 1, 1999 and June 30, 2001 were reviewed. Logistic and stepwise multiple regression analyses were used to identify predictors of allogeneic and autologous red cell transfusion during the operative and postoperative periods.

RESULTS

Posterior spinal fusion surgery was performed in 107 patients (males, 42%) with a median age of 13.7 years (range, 1-20 years). The median intraoperative blood loss was 22 mL/kg (range, 4.4-72 mL/kg). Blood transfusion involved 63 patients (59%) who received 17 mL/kg (range, 3-65 mL/kg) of allogeneic packed red blood cells and 14 patients (13%) who received 7 mL/kg (range, 4-19 mL/kg) of autologous red cells donated before surgery. Underlying neuromuscular disease, lower body weight, and a higher number of vertebrae fused independently predicted a greater number of allogeneic red cells transfused (R2 = 0.53). The amount of autologous blood donated before surgery predicted the number of autologous red cells transfused (R2 = 0.56).

CONCLUSIONS

Allogeneic red cell transfusion often is required for small patients with underlying neuromuscular disease who undergo extensive spinal fusion surgery. These patients may be less able to donate autologous blood before surgery. Newer therapies to reduce blood loss and transfusion requirement are needed most for this population.

Bleeding and coagulation changes during spinal fusion surgery: a comparison of neuromuscular and idiopathic scoliosis patients

OBJECTIVE

Major blood loss is common during spinal fusion surgery. We have previously demonstrated that patients with neuromuscular scoliosis have more blood loss and greater transfusion requirement than those with idiopathic scoliosis. Our objective is to study the relationships between etiology of scoliosis, blood loss, and coagulation changes in children and adolescents undergoing spinal fusion surgery.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

PATIENTS

A total of 25 patients, 11 with neuromuscular and 14 with idiopathic scoliosis, undergoing spinal fusion surgery.

INTERVENTIONS

Blood was obtained preoperatively, 2 and 4 hrs intraoperatively, and 2 and 24 hrs postoperatively for prothrombin time, partial thromboplastin time, thrombin time, platelet count, D-dimer, factor VII and VIII activity, thrombin-antithrombin III complex, and protein induced by vitamin K absence. Changes in coagulation over time were analyzed by repeated-measures analysis of variance. Comparisons between groups were made using independent t-tests.

RESULTS

Neuromuscular scoliosis patients had significantly greater blood loss than idiopathic scoliosis patients (median blood loss, 78% of total blood volume; range, 25-127% vs. 20%, 2-82%; p < .001). Prothrombin time increased over time in both groups and was higher in the neuromuscular than the idiopathic group both preoperatively and postoperatively (p < .05). Factor VII activity decreased over time in both groups (p < .001) and was lower in the neuromuscular than the idiopathic group during surgery (p < .05). No changes in partial thromboplastin time, thrombin time, or factor VIII activity were observed. D-dimers were present in both groups by 4 hrs intraoperatively. Protein induced by vitamin K absence was not detected in any patient.

CONCLUSIONS

Neuromuscular scoliosis patients have more blood loss during spinal fusion surgery than idiopathic scoliosis patients. The prolongation of prothrombin time and decrease in Factor VII activity suggest activation of the extrinsic coagulation pathway. Depletion of clotting factors during scoliosis surgery occurs to a greater extent in patients with underlying neuromuscular disease.

Detection and removal of fat particles from postoperative salvaged blood in orthopedic surgery

BACKGROUND

Although transfusion or return of salvaged shed blood has become popular in major orthopedic procedures, this blood-saving method is still controversial because shed blood may be contaminated with chemical and tissular debris, such as fat particles, which may increase the risk of fat embolism after bone surgery.

STUDY DESIGN AND METHODS

In an effort to find an easy, reliable method for determination of both fat particle content and removal from shed blood, analyses of perioperative blood samples were performed with a cell counter (Technicon H3 [H3]) in orthopedic patients undergoing spinal fusion in which postoperative shed blood was collected and returned with a blood collection canister. A screen or surface filter was intercalated in the return line to eliminate microaggregates, fat particles, and/or WBCs.

RESULTS

Fat particles in shed blood are clearly detected as a condensed, sigmoidal-shaped area at the right-hand side of the PMN zone in the channel in which the H3 measures particles according to their degree of lobularity. This signal can be reproduced by the addition of animal or vegetable fat to venous blood, but not by the addition of activated platelets or RBC membranes. Fat particles, together with WBCs and microaggregates, in shed blood were effectively removed by surface filters, whereas screen filters were not effective.

CONCLUSION

The use of the TH3 seems to be an easy, reliable, and low-cost approach for monitoring fat particle content and removal from postoperative salvaged shed blood in orthopedic procedures.

Re-transfusion of autologous blood from wound drains: the means for reducing transfusion requirements in total knee arthroplasty

The requirements for homologous blood transfusion in patients undergoing total knee replacements under tourniquet, before and after the introduction of autologous transfusion of blood collected from wound drains, are compared. In a control population of 93 patients undergoing total knee replacement, 67 required homologous transfusions of two units or more. In 160 patients who were re-transfused with blood from wound drains, only 30 required additional homologous transfusions. Re-transfusion of filtered drained blood reduces the need for homologous bank blood. This avoids the risks associated with donated blood and affords significant cost savings.

Activation of plasma coagulation by retransfusion of unwashed drainage blood after hip joint arthroplasty: a prospective study

Twelve patients undergoing cementless hip joint arthroplasty were retransfused with unwashed drainage blood collected postoperatively. Global coagulation parameters, coagulation factors (factor V:C, factor VIII:C, activated factor XII, and factor XIII) and markers of thrombin generation (F1+2 Fibrin split products, thrombin-antithrombin complexes), fibrin generation (fibrinogen and fibrin degradation products), and fibrinolysis (D-dimers, thrombin degradation products, plasminogen) were determined. High levels of factor XIIa, thrombin and fibrin generation markers, and markers of fibrinolysis were present in the shed blood. After retransfusion (mean, 433 mL), increased levels of these markers together with decreased values for factor XIII and plasminogen were indicative of renewed clot formation and fibrinolysis in the circulation. These changes were highly significant compared with preretransfusion values. The unwashed drainage blood contained high levels of procoagulation material and induced an activation of the plasma coagulation pathway with renewed clot formation and fibrinolysis in the patients.

Fibrinolytic activity and postoperative salvaged untreated blood for autologous transfusion in major orthopaedic surgery

OBJECTIVE

To evaluate the fibrinolytic activity in a closed surgical wound, in postoperatively drained blood, and during autologous transfusion.

DESIGN

Prospective study.

SETTING

National hospital, Norway.

PATIENTS

9 patients operated on for thoracic scoliosis.

MAIN OUTCOME MEASURE

Concentrations of plasmin/antiplasmin (PAP), alpha2-antiplasmin, and D-dimers in drained, arterial, and mixed venous blood before, during, and after infusion of 10 ml/kg body weight of postoperatively drained, untreated blood.

RESULTS

In drained blood the concentration of alpha2-antiplasmin was 31% of the preoperative arterial control value. Together with the increased concentrations of PAP to 18076 microg/L and D-dimers to 126 mg/L, this indicates extensive fibrinolytic activity in the closed wound. The postoperative autologous transfusion of drained, untreated blood increased the concentration of PAP from 507 to 2453 microg/L and of D-dimer from 0.7 mg/L to 15.3 mg/L in systemic blood.

CONCLUSION

The systemic concentration of fibrin(ogen) degradation products, indicated by D-dimers, after recirculation of drained, untreated blood might impair coagulation. The extensive activation of plasmin might exhaust available alpha2-antiplasmin in the wound and result in postoperative rebleeding.

Complement split products and pro-inflammatory cytokines in salvaged blood after hip and knee arthroplasty

PURPOSE

To determine whether salvaged autologous blood collected postoperatively contains complement split products (SC5b-9), and pro-inflammatory cytokines (IL-6 and IL-8) and whether there are any differences between blood collected during hip or knee surgery.

METHODS

Fifty-eight consecutive patients undergoing hip or knee replacement surgery were studied. Thirty-eight had postoperative bleeding large enough to require infusion of salvaged blood. The salvaged blood was filtered during collection through a 200 microm filter and before infusion a 40 microm filter was used. Samples for complement and cytokine determinations were drawn from the circulation and from the collected blood.

RESULTS

High concentrations of SC5b-9, IL-6, and IL-8 were found in salvaged blood. The concentrations were higher than in the circulation (P < 0.05). The circulating concentrations of IL-6 and IL-8 were increased 60 min and 12-18 hr after transfusion. There were no differences regarding SC5b-9, IL-6, and IL-8 in the blood collected after hip or knee surgery.

CONCLUSION

Blood collected from a surgical wound contains large concentrations of inflammatory mediators. There were no differences between blood collected during hip or knee surgery.