Red cell loss following orthopedic surgery: the case against postoperative blood salvage

LA TRASFUSIONE DI SANGUE NELLA CHIRURGIA ONCOLOGICA: RUOLO DELLA ERITROPOIETINA RICOMBINANTE UMANA (rHuEPO)

Anemia is common in cancer patients. The pathophysiology is multifactorial, however the most common cause is the anemia of chronic diseases (ACD). In 20-50% of cancer patients, anemia restricts physical activity and quality of life and requires transfusion support. The percentage of patients necessitating transfusion dramatically increases when patients require surgery.

The traditional belief that blood transfusion is an effective and safe therapy has been challenged by a heightened awareness of the infectious and immunologic risks associated with allogeneic blood administration. In cancer patients transfusion-induced immunomodulation may have the potential to significantly increase postoperative infections and cancer recurrence so that it seems reasonable to minimize allogeneic blood exposure.

Several strategies have been adopted to reduce allogeneic transfusion in surgical patients, however to properly select the appropriate blood conservation strategies the blood transfusion requirements for each patient should be defined.

Allogeneic blood transfusion in surgery can be reduced by the introduction of autologous blood (AB) programmes and by the use of rHuEPO, alone or in association with AB techniques. AB donation is currently a standard of care for elective surgical patients but its efficacy is limited by anemia that prevents the donation of the optimal number of AB units. rHuEPO has been shown to significantly increase the volume of AB that anemic patients can predeposit or, used perisurgically, to expand the circulating RBCs mass before surgery. Moreover clinical trials employed rHuEPO in anemic cancer patients with various solid tumors both on and off chemotherapy reporting a significantly increase in Hct in more than 50% of the treated patients. Recently different studies have shown the efficacy of rHuEPO in increasing the volume of AB also in patients with ACD and cancer, thus proving to be a useful addition to existing strategies of blood conservation to minimize exposure to allogeneic blood in surgical cancer patients.

Effect of intra-articular injection of tranexamic acid on postoperative hemoglobin in total hip arthroplasty

Postoperative anemia is a significant risk factor in total hip arthroplasty, leading to increased length of hospital stay and delayed mobility and rehabilitation, and is poorly tolerated by patients with peripheral vascular and cardiovascular disease. Intravenous tranexamic acid, an antifibrinolytic drug, has been shown to reduce postoperative anemia in total joint replacement. Intra-articular administration eliminates the risk of systemic effects, the most concerning of which is thrombosis. Although this method of administering tranexamic acid has been studied in total knee replacement, currently no literature has been published on its efficacy in primary total hip replacement. The purpose of this study was to examine postoperative hemoglobin decrease and the transfusion rate following intra-articular tranexamic acid administration in primary total hip arthroplasty. The authors conducted a retrospective review of 181 consecutive total hip replacements, 91 of which received tranexamic acid. No statistical significance was found between these groups in any of the demographic variables. Postoperative hemoglobin decrease in the control group was 4.4±1.0 g/dL compared with a decrease of 3.6±1.1 g/dL in the tranexamic group, demonstrating an 18% reduction in blood loss (P<.001). No significant difference was found between the number of patients transfused (P=.777) or the number of units used (P=.993). No clotting events were seen in either group. Overall, the study demonstrates that intra-articular tranexamic acid in primary total hip arthroplasty is associated with a significant improvement in postoperative hemoglobin decrease without systemic hypercoagulability.

Topical tranexamic acid reduces transfusion rates in total hip and knee arthroplasty

The efficaciousness of topical tranexamic acid use at the end of knee arthroplasty surgery to reduce blood loss and transfusion requirements has previously been shown. The aim of this study was to retrospectively assess the effectiveness of topical tranexamic acid use, comparing 155 patients undergoing hip and knee arthroplasty surgery in which tranexamic acid was routinely used, to a group of 149 patients from a similar time frame prior to the introduction of tranexamic acid use. The transfusion rate fell from 19.3% to 2.3% for hip arthroplasty patients and from 13.1% to 0% for knee arthroplasty patients; these differences were significant. We also found significant reductions in haemoglobin loss, blood loss and length of stay of 8 g/L, 244 mL and 1.0 days respectively for hip arthroplasties and 15 g/L, 527 mL and 1.2 days respectively for knee arthroplasties following the introduction of tranexamic acid.

[Decrease in allogenic transfusions due to the spread of use of postoperative retransfusion systems in knee replacement surgery]

OBJECTIVES

Surgical teams have several tools in order to reduce the need for postoperative allogenic transfusion. Postoperative autotransfusion of unwashed shed blood has become common practice for total knee replacement surgery since 2006 in our hospital. This study was designed to evaluate if this practice has reduced allogenic blood transfusions.

MATERIAL AND METHODS

A retrospective study comparing two cohorts, group 2004 with patients operated on for total knee replacement during the year 2004, before the use of the retransfusion system, and group 2008, patients operated on in the year 2008, with regular use of the retransfusion system. Gender, preoperative and postoperative haemoglobin levels, total amount of calculated erythrocytes lost, reinfusion of shed blood and allogenic blood transfusion during hospital stay were recorded.

RESULTS

Both groups were similar as regards gender, preoperative and postoperative hemoglobin levels, and total amount of erythrocytes lost. The proportion of transfused patients was significantly lower in group 2008 versus group 2004 (20.18% versus 42.19%), with a relative risk of being transfused of 0.47 and a NNT of 4.54. P=.0017.

CONCLUSIONS

In our hospital the use of postoperative retransfusion systems has reduced the proportion of transfused patients during hospitalization for total knee replacement surgery, although this result cannot be generalized due to the lack of a fixed transfusion trigger.

Use of tranexamic acid is a cost effective method in preventing blood loss during and after total knee replacement

Background & Purpose

Allogenic blood transfusion in elective orthopaedic surgery is best avoided owing to its associated risks. Total knee replacement often requires blood transfusion, more so when bilateral surgery is performed. Many strategies are currently being employed to reduce the amount of peri-operative allogenic transfusions. Anti-fibrinolytic compounds such as aminocaproic acid and tranexamic acid have been used systemically in perioperative settings with promising results. This study aimed to evaluate the effectiveness of tranexamic acid in reducing allogenic blood transfusion in total knee replacement surgery.

Methodology

This was a retrospective cohort study conducted on patients undergoing total knee replacement during the time period November 2005 to November 2008. Study population was 99 patients, of which 70 underwent unilateral and 29 bilateral knee replacement. Forty-seven patients with 62 (49.5%) knees (group-I) had received tranexamic acid (by surgeon preference) while the remaining fifty-two patients with 66 (51.5%) knees (group-II) had did not received any tranexamic acid either pre- or post-operatively.

Results

The mean drop in the post-operative haemoglobin concentration in Group-II for unilateral and bilateral cases was 1.79 gm/dl and 2.21 gm/dl, with a mean post-operative drainage of 1828 ml (unilateral) and 2695 ml (bilateral). In comparison, the mean drop in the post-op haemoglobin in Group-I was 1.49 gm/dl (unilateral) and 1.94 gm/dl (bilateral), with a mean drainage of 826 ml (unilateral) and 1288 ml (bilateral) (p-value < 0.001).

Interpretation

Tranexamic acid is effective in reducing post-operative drainage and requirement of blood transfusion after knee replacement.

Computer-assisted surgery can reduce blood loss after total knee arthroplasty

The aim of this study was to compare blood loss and transfusion requirements in patients undergoing computer-assisted total knee arthroplasty (TKA) and patients operated with conventional instrumentation with intra-medullar guides. A prospective randomized study of 87 patients undergoing a TKA assigned to conventional technique (n = 44) or computer-assisted surgery (n = 43) was conducted. All patients were operated by the same surgeon and in all cases a cemented arthroplasty and deep recovery drainage were used. Both groups were comparable in all variables except for duration of ischemia, which was 13.7 min higher in the computer-assisted group. Blood loss due to drainage was higher in the conventional technique group (613 vs. 447 ml), as was the number of patients in which blood from the blood recovery system was reinfused (53 vs. 23%). Those patients undergoing computer-assisted surgery experienced less bleeding than those operated with the conventional technique. However, hemoglobin drop and allogenic transfusion rate were not statistically different in both groups.

Autologous blood transfusion following total knee arthroplasty: is it always necessary?

A retrospective study of 85 patients undergoing primary total knee replacement (TKR), who also received autologous blood transfusion (ABT) to compensate for the perioperative blood loss. In our series 16.4% of the patients needed allogenic blood transfusion. Of the remaining 83.4% only 49.5% received autologous transfusion. Autologous transfusion was withheld in 34.1% of cases either because the blood volume was inadequate or because the collection time exceeded the recommended time limit. The mean haemoglobin (Hb) level with or without autologous transfusion was 10 g, raising the question of the necessity of using autologous transfusion in primary total TKR.

[Indications for blood transfusion during orthopedic surgery]

Ageing of the population increases the number of large orthopedic surgical interventions in elder people. High perioperative blood loss together with a reduced tolerance to anemia increase the transfusion probability in this patient subgroup. The expected cost explosion in the transfusion system (cost intensive quality management, imbalance between the number of donors and recipients) as well as the remaining transfusion related risk of hemolysis, infection and immunosuppression reflect the high socio-economic significance of the development of institutional transfusion programs. The present article summarizes: (1) the (patho-) physiology of anemia compensation, (2) the decision making for transfusion in healthy patients and patients with cardiovascular disease, and (3) the currently applied pre- and intraoperative techniques to reduce allogeneic transfusion in orthopedic patients.

Blood conservation for critically ill patients

Anemia may be the most common illness of critically ill patients. The majority of critically ill patients are anemic at admission to the intensive care unit (ICU), and hemoglobin concentrations typically decline during the first 3 days of ICU stay. Hemoglobin continues to decline for patients with sepsis and higher severity of illness. This patient population may be at particular risk of adverse consequences of anemia given the cardiovascular, respiratory, and metabolic compromise frequently encountered during critical illness. The etiology of anemia of critical illness is multifactorial, resulting from phlebotomy, gastrointestinal bleeding, coagulation disorders, blood loss from vascular procedures, renal failure, nutritional deficiencies,bone marrow suppression, and impaired erythropoietin response.

Blood conservation in the intensive care unit

OBJECTIVE

To describe blood conservation strategies for critically ill patients.

DATA SOURCES

By using a predefined strategy, we searched the electronic databases of Medline, EMBASE, CINAHL, the Cochrane database of systematic reviews, Cochrane central register of controlled trials, ACP Journal Club, Database of abstracts of reviews and effects, and HealthSTAR for descriptions and evaluations of strategies of blood conservation among critically ill patients.

DATA SUMMARY

A number of blood conservation strategies have been used to prevent or treat anemia among critically ill patients. These include restrictive diagnostic phlebotomy using small-volume or pediatric phlebotomy tubes, point-of-care and inline bedside microanalysis, minimization of diagnostic sample waste, minimization of routine multiple daily phlebotomies, red blood cell salvage and antifibrinolytic agents for bleeding patients, consideration of removal of central venous and arterial catheters when no longer required for physiologic monitoring, threshold-based transfusion policy, and healthcare professional education.

CONCLUSIONS

There are many strategies of blood conservation for critically ill patients. The effects of these strategies on phlebotomy volumes, hemoglobin and hematocrit levels, transfusion requirements, clinical outcomes, as well as intensive care unit and laboratory resources and costs should be further evaluated.

Autologous blood transfusion after total knee arthroplasty: a randomized, prospective study comparing predonated and postoperative salvage blood

A randomized, prospective study of the use of allogeneic blood was performed in a consecutive series of patients who underwent primary total knee arthroplasty (TKA) and had autologous transfusion either from one unit of predonated autologous blood or from postoperative unwashed blood salvage. In this study, 83 patients (88 knees) were included, with 47 knees in the salvage group and 41 in the predonation group. There were no differences between groups in average age, height, and weight, or gender, diagnoses, or anesthesia type. No significant difference was seen between the groups in the prevalence of allogeneic blood transfusion (5% for the predonation group and 0% for salvage group). Postoperative blood salvage was as effective as predonated autologous blood in preventing the risk associated with allogeneic blood after TKA.

Perioperative hemodilution

Acute normovolemic hemodilution (ANH) entails the removal of blood from a patient either immediately before or shortly after induction of anesthesia and the simultaneous replacement with cell-free fluid, preferably synthetic colloids with a predictable volume effect (6% dextran 60/70, 6% hydroxyethyl starch 200,000 and 130.000, respectively). Hemodilution is part of the concept for avoiding or limiting the use of allogeneic blood and should be considered for patients undergoing elective surgery free of contraindications and presenting with an initial hemoglobin concentration > or = 12 g/dl and an anticipated blood loss of > or = 1500 ml. The efficacy of ANH, judged by the necessity to transfuse homologous blood, depends on the preoperative (initial) hematocrit, the target hematocrit (to which hemodilution is performed), and the preset intra- and postoperative transfusion trigger. In the past data from clinical trials have shown that in healthy subjects a target hematocrit of 20-25% (7.0-8.0 g/dl hemoglobin concentration) is feasible and safe for the patient. The lower the target hemoglobin concentration, the more extensive monitoring is required: intraoperative target hemoglobin concentrations of 5.0 g/dl and less have been tolerated by young surgical patients without adverse effects. The safety as well as efficacy of acute normovolemic hemodilution in terms of reducing homologous blood transfusion requirements have been demonstrated in various clinical studies. ANH therefore is regarded an integral part of programs aimed at reducing the need for homologous blood, and can thus be successfully combined with preoperative autologous blood deposition, intraoperative blood salvage and carefully adjusted surgical techniques.

The cost-effectiveness of postoperative recovery of RBCs in preventing transfusion-associated virus transmission after joint arthroplasty

BACKGROUND

The return of joint drainage after hip and knee arthroplasty is a widely used but expensive blood-conservation technique.

STUDY DESIGN AND METHODS

A Markov decision analysis model was used to evaluate the cost-effectiveness of postoperative RBC recovery in preventing viral complications of allogeneic transfusion.

RESULTS

In the baseline analysis, using an RBC-recovery device saves 5 quality-adjusted minutes of longevity at an average incremental cost of $53. This corresponds to $5.7 million per quality-adjusted life year. This figure was most sensitive to the direct cost differences of allogeneic versus recovered RBCs and to the volume of RBCs recovered per device. Such devices would save health care resources if they cost less than $73 or if they were applied only in cases where joint drainage was between 600 and 1100 mL.

CONCLUSION

For most clinical situations, postarthroplasty RBC recovery does not appear to be as cost-effective as most other medical interventions. Clinical attention should be directed toward developing protocols for the preferential use of postoperative RBC-recovery devices in situations where they provide the greatest benefit.

Blood conservation in patients undergoing non-cardiac surgery

Concerns about the safety, inventory, and cost of allogeneic blood have led to a renewed interest in blood conservation. Autologous blood collection techniques, including preoperative autologous donation, acute normovolemic hemodilution, and perioperative blood recovery are routinely used as alternatives to allogeneic transfusion. In the future, these techniques may be combined with pharmacological strategies, such as presurgical erythropoietin therapy or red cell substitutes, to reduce further the need for allogeneic blood.

Postoperative blood salvage in hip and knee arthroplasty. A prospective study on cost effectiveness in 161 patients

We conducted a prospective controlled study on 161 patients who underwent primary or revision total hip or knee arthroplasty to assess the efficacy and limitations of postoperative blood salvage. The actual quantity of blood salvaged after washing, the theoretical increase in hemoglobin concentration caused by its reinfusion and the cost of this procedure were studied. The mean amount of packed red cells after washing was 117 g. The average increase in hemoglobin concentration, which theoretically would have been achieved by retransfusion, was 0.47 g/dL. One third of the devices used were discarded as not effective enough and, in order to obtain an increase of 1 g/dL in the hemoglobin concentration, an average of 3.4 postoperative Solcotrans Plus Orthopaedic devices were used. To obtain the same increase in hemoglobin concentration as that given by an allogeneic blood transfusion, the overall cost of materials alone was more than five times the price of a single blood unit transfusion.

Fatal air embolism due to perioperative blood recovery

This study was initiated to investigate the incidence of acute mortality from air embolism associated with perioperative blood recovery and the causative factors and common characteristics of such fatalities. All facilities providing transfusion services in New York State are required to report severe adverse reactions to, and the total number of, transfusion and blood recovery procedures performed. Relevant data for the period from January 1990 to June 1995 were tabulated. During this time, 127,586 perioperative blood recovery procedures were performed, and 8,955,619 conventional blood components were transfused. The frequency of fatal air embolism after readministration of recovered blood was approximately 1:30,000-1:38,000; none followed conventional transfusion. Characteristics common to the fatalities (including an additional case reported before the study interval) were examined; all involved reinfusion of recovered blood under pressure. In the population studied, the incidence of fatal air embolism after the perioperative readministration of recovered blood was significantly higher than that after conventional transfusion. A model of such a system demonstrated that as much as 200 mL of air could enter the circulation in as little as 4 s, rendering visual detection and intervention extremely difficult. Education and guidelines to reduce the risk and mortality associated with this procedure are recommended.

Autologous blood transfusion: evaluation of an alternative strategy in reducing exposure to allogeneic blood transfusion

The perceived risk of transfusion-transmitted disease led to the rejuvenation of autologous blood transfusion (ABT). ABT, a process in which the blood donor and recipient are the same, is increasingly becoming an integral component of the elective surgical protocol in many institutions. Various methods of ABT are being utilized. These include: preoperative blood donation, in which the patient donates blood prior to surgery and the blood is stored for an expected need during or after surgery; acute normovolemic hemodilution, in which blood is collected immediately prior to surgery and replaced with cell free fluids and then returned to the patient upon need; intraoperative blood salvage in which blood is collected from the surgical field and is reinfused after being washed and finally, postoperative blood salvage in which collected shed blood from surgical drains is reinfused to the patient. Although ABT is known to reduce the risk of allogeneic blood transfusion, it is not risk free and should be evaluated in relation to the patient's clinical picture. The combination of various methods of ABT in addition to the proper utilization of blood may consequently lead to the elimination of patients' exposure to allogeneic blood transfusion in many surgical procedures.