A retrospective study of the effects of small-dose aprotinin on blood loss and transfusion needs during total hip arthroplasty

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.

Aprotinin and classic wound drainage are unnecessary in total hip replacement - a prospective randomized trial

BACKGROUND

Classic wound drainage is still common in hip replacement but its benefit is doubtful. The role of systemic administration of proteinase inhibitors like aprotinin to avoid perioperative blood loss is still unclear.

PATIENTS AND METHODS

In a prospective randomized trial, the perioperative blood loss in alloplastic hip replacement under the influence of proteinase inhibitor (aprotinin, Trasylol®) using wound drainage as well as compression treatment alone were compared. 80 patients were prospectively randomized in 4 arms. Patients received either aprotinin or placebo during surgery as well as drainage or targeted external wound compression.

RESULTS

Observing the "drug therapy" aprotinin had no effect on the intra- or postoperative blood loss (p>0.05), a trend to lower postoperative hemoglobin decline was found, but without significance. Thrombosis occurred in neither the aprotinin nor in the placebo group. Two patients had a severe allergic drug reaction and were excluded from the study. Under "non drug therapy" with compression therapy and wound drainage a significant difference in blood loss was found (p<0.001). The blood loss was higher under the wound drainage. There was no influence on the infection rate. Yet we could observe increased bruising under the sole external compression treatment.

CONCLUSION

The administration of aprotinin did not achieve the desired reduction of perioperative blood loss. Hence, costs and two severe allergic drug reactions in our study represent arguments against its use in regular treatment. Furthermore, it seems that wound drainage is neglectable in hip replacement and can be substituted by a sole compression treatment.

Use of antifibrinolytic therapy to reduce transfusion in patients undergoing orthopedic surgery: a systematic review of randomized trials

BACKGROUND

Minimizing bleeding and transfusion is desirable given its cost, complexity and potential for adverse events. Concerns have been heightened by recent data demonstrating that bleeding events may predict worse outcomes and by warnings about the safety of erythropoietic stimulating agents. Prior small studies suggest that antifibrinolytic agents may reduce bleeding and transfusion need in patients undergoing total hip replacement (THR) or total knee arthroplasty (TKA). However, no single study has been large enough to definitively determine if these agents are safe and effective. To address this issue we performed a systematic review of randomized trials describing the use of tranexamic acid, epsilon aminocaproic acid, or aprotinin administration in the perioperative setting.

METHODS

MEDLINE, EMBASE, CINAHL and the Cochrane databases were searched for relevant trials. Two independent reviewers abstracted total blood loss, transfusion requirements, and venous thromboembolism (VTE) rates. Data were combined using the Mantel-Haenszel method and dichotomous data expressed as relative risk (RR) with 95% confidence intervals (CI).

RESULTS

Patients receiving antifibrinolytic agents had reduced transfusion need (RR 0.52; 95% CI, 0.42 to 0.64; P<0.00001), reduced blood loss and no increase in the risk of VTE (RR 0.95% CI, 0.80 to 1.10, I(2)=0%, P=0.531).

CONCLUSIONS

We conclude that antifibrinolytic agents may reduce bleeding and transfusion in patients undergoing THR or TKA who receive appropriate antithrombotic prophylaxis. There is a need for a large, adequately powered prospective study to carefully examine the safety and efficacy of these agents.

Efficacy of aprotinin as a blood conservation technique for adult deformity spinal surgery: a retrospective study

STUDY DESIGN

A retrospective study that involved a total of 82 adult deformity patients who underwent spinal fusion surgery with instrumentation of 6 or more levels.

OBJECTIVE

The purpose of this study is to assess the efficacy and safety of aprotinin in reducing blood loss in adult spinal deformity patients.

SUMMARY OF BACKGROUND DATA

Aprotinin is an antifibrinolytic agent, which has been proven to be effective as a blood-conserving agent in cardiac surgery. This study focused specifically on adult spine deformity patients.

METHODS

This retrospective study analyzed a total of 82 adult deformity patients (patients with diagnosis of adult scoliosis and kyphosis) who underwent spinal fusion surgery with instrumentation of 6 or more levels. Forty-one patients who received aprotinin were compared with a control group of 41 patients who did not receive aprotinin. Specific surgical outcome parameters and postoperative complications were assessed.

RESULTS

The average age of the patients was 47 years and 41 years for the aprotinin group and the control group respectively. Thirty-nine percent of cases and 44% of controls had staged anterior/posterior fusion surgery, 39% of cases and 41% of controls underwent single stage posterior fusion surgery and the remaining 27% of cases and 15% of controls had same day anterior and posterior fusion surgery. The average number of levels fused and instrumented was 11.2 for the aprotinin group and 10.7 for the control group. The differences in mean blood loss and blood returned by cell-saver were statistically significantly lower in the aprotinin group (1324 mL vs. 2113 mL; P = 0.005 and 390 mL vs. 657 mL; P = 0.003). The amount of drainage after surgery was similar (1421 mL vs. 1388 mL; P = 0.982). The aprotinin group received an average of 2.73 units of blood. This was significantly lower than the average 5.02 units that the controls received (P = 0.003). The rate of complications was comparable and no allergic reaction to aprotinin was noted. One case exhibited a transitory elevation of blood urea nitrogen/creatinine which resolved before discharge.

CONCLUSION

The results of our study suggest that the administration of aprotinin is a safe and effective method to reduce blood loss and to decrease the need for transfusions without increasing risk of complication in the younger patients in relatively good general health undergoing spinal deformity surgery requiring 6 or more levels of fusion.

Influence of ultra-low dose Aprotinin on thoracic surgical operations: a prospective randomized trial

Background

The blood saving effect of aprotinin has been well documented in cardiac surgery. In thoracic surgery, very few recent studies, using rather high doses of aprotinin, have shown a similar result. In a randomized prospective trial, we have tested the influence of aprotinin using an ultra-low dose drug regime.

Methods

Fifty-nine patients, mean age 58 ± 13.25 years (mean ± SD) undergoing general thoracic procedures were randomized into placebo (Group A) and treatment group (Group B). The group B (n = 29) received 500.000 IU of aprotinin after induction to anesthesia and a repeat dose immediately after chest closure. A detailed protocol with several laboratory parameters was recorded. Patients were transfused when perioperative Ht was less than 26%.

Results

The two groups were similar in terms of age, gender, diagnosis, pathology, co-morbidity and operations performed. The mean drainage of the first and second postoperative day in group B was significantly reduced (412.6 ± 199.2 vs. 764.3 ± 213.9 ml, p < 0.000, and 248.3 ± 178.5 vs. 455.0 ± 274.6, p < 0.001). Similarly, the need for fresh frozen plasma transfusion was lower in group B, p < 0.035. Both the operation time and the hospital stay were also less for group B but without reaching statistical significance (84.6 ± 35.2 vs 101.2 ± 52.45 min. and 5.8 ± 1.6 vs 7.2 ± 3.6 days respectively, p < 0.064). The overall transfusion rate did not differ significantly. No side effects of aprotinin were noted.

Conclusion

The perioperative ultra-low dose aprotinin administration was associated with a reduction of total blood losses and blood product requirements. We therefore consider the use of aprotinin safe and effective in major thoracic surgery.

Randomized study of aprotinin effect on transfusions and blood loss in primary THA

A projected increase in total hip arthroplasties, shortfalls in blood availability, and awareness of complications of transfusion make blood management in orthopaedic surgery important. In a multicenter, randomized, double-blind, placebo-controlled study, we hypothesized use of aprotinin would reduce blood transfusions (any and allogeneic) and blood loss in total hip arthroplasty. Using an intent-to-treat approach, we recruited 393 patients stratified by preoperative autologous blood donation or none and then randomized them to receive aprotinin (176 patients receiving a 10,000 kallikrein inhibitor units [KIU] test dose, 2 million KIU load, 0.5 million KIU per hour) or placebo (177 patients). We assessed patients at baseline; postoperative days 1, 2, 3, and 7 (or discharge); and 6 +/- 2 weeks. Primary efficacy was percentage of patients having blood transfusion through day 7 or discharge. We based safety on reported adverse events. Aprotinin reduced transfusions by 46% (30 of 176 versus 56 of 177 patients). Aprotinin reduced the total number of any blood units and the number of allogeneic blood units transfused relative to placebo (48 versus 109 units and 30 versus 72 units, respectively). Serious complications were similar in the two groups (placebo, 11%; aprotinin, 10%). Our data suggest full-dose aprotinin is safe and effective in decreasing blood transfusion in total hip arthroplasty.

Aprotinin in Major Orthopedic Surgery: A Systematic Review of Randomized Controlled Trials

Aprotinin therapy is a promising strategy for reducing blood loss and blood transfusion requirements. The efficacy and safety of aprotinin in orthopedic surgery, however, remain controversial. We searched electronic databases for randomized controlled trials on the efficacy and safety of the use of aprotinin in orthopedic surgery. Thirteen trials that included a total of 506 patients who underwent major orthopedic surgery were analyzed. The pooled intraoperative and perioperative blood loss was significantly less in the aprotinin-treated patients than in the control patients (weighted mean difference [WMD] for intraoperative blood loss = -229 mL, 95% confidence interval [CI] = -367 to -91 mL, P = 0.0011; WMD for perioperative blood loss = -557 mL; 95% CI = -860 to -254 mL; P < 0.0001). The pooled amounts of red blood cell (RBC) units (U) transfused intraoperatively and perioperatively were significantly less in the aprotinin-treated patients than in the control patients (WMD for intraoperative RBC U = -1.1 U; 95% CI = -1.7 to -0.4 U; P = 0.0001; WMD for perioperative RBC U = -1.1 U; 95% CI = -1.7 to -0.5 U; P < 0.0001). Aprotinin was not associated with an increased incidence of deep vein thrombosis (odds ratio = 0.39; 95% CI = 0.14 to 1.05, P = 0.061). The authors conclude that aprotinin reduces the intraoperative and perioperative blood loss and allogeneic blood transfusion requirement and may not be associated with increased risk of deep vein thrombosis in the presence of pharmacological or mechanical prophylaxis in patients undergoing major orthopedic surgery.

Aprotinin and epsilon aminocaproic acid are effective in reducing blood loss after primary total hip arthroplasty--a prospective randomized double-blind placebo-controlled study

A prospective randomized double-blind placebo-controlled study was undertaken to determine the efficacy and mechanism of action of two antifibrinolytic drugs aprotinin and epsilon aminocaproic acid (EACA) in reducing blood loss in primary unilateral total hip arthroplasty (THA). Aprotinin was administered as a bolus of 2 x 10(6) kallikrein inhibitor units (KIU) followed by 0.5 x 10(6) KIU h(-1) for 3 h, EACA was given as 10 g over 30 min followed by 5 g over 3 h. The median postoperative blood loss 24 h postoperatively was reduced from 450 mL in the placebo group to 180 mL for aprotinin (60% reduction, P < 0.001) and to 210 mL for EACA (53% reduction, P < 0.01). In this population, there was no reduction in the perioperative transfusion requirements. The mechanism of both drugs was independent of platelets as indicated by flow cytometric measurement of change of their expression of P-selectin, platelet-monocyte aggregates, V/Va and CD40 ligand. There were no thrombotic or infective complications and no adverse events were attributable to use of either drug. Infusion of either aprotinin or EACA at the doses described is a safe and effective means of reducing blood loss after THA. These therapies provide a means of reducing blood loss in THA patients.

Evidence-based review of the role of aprotinin in blood conservation during orthopaedic surgery

Aprotinin is a serine protease inhibitor with antifibrinolytic properties that has been approved as a blood-conserving drug in cardiac surgery by the United States Food and Drug Administration. On the basis of the current evidence from Level-I trials, we make a grade-A recommendation for use of the high-dose aprotinin regimen in hip and spine surgery. Because of conflicting data, the low-dose aprotinin therapy as well as the use of aprotinin in patients with cancer cannot be recommended (grade-I recommendation). High-quality randomized trials are necessary to determine the optimal (and minimal) therapeutic dose of aprotinin and the optimal time of aprotinin administration during surgery.

Aprotinin and major orthopedic surgery

Aprotinin is a potent pharmacological agent that reduces bleeding and limits blood transfusion requirements in current surgical practice. Many studies have been conducted in orthopedic surgery. In several trials performed in total hip replacement (THR) and total knee replacement (TKN) patients, aprotinin only moderately decreased blood-loss-replacement requirements. Conversely, when aprotinin was used in patients at high risk for bleeding (cancer, sepsis, redone surgery), it developed a potent hemostatic activity and decreased blood transfusion significantly. No increase in deep vein thrombosis and pulmonary embolism was observed. The only major side effect could be the potential occurrence of an anaphylactoid reaction. Prophylactic administration of aprotinin should be considered in extensive spine surgery and in high-risk major orthopedic operations. The decision to use aprotinin should be guided by a risk/benefit analysis.

Intraoperative blood management in joint replacement surgery

Interest is growing in blood conservation and avoidance of transfusion in patients undergoing orthopedic surgery, especially in the field of joint replacement. Several methods have proven successful in reducing intraoperative blood loss, which can translate into lessened allogeneic and autologous transfusion requirements. Available techniques include acute normovolemic hemodilution, hypotensive anesthesia, intraoperative blood salvage, specialized cautery, topical hemostatic agents, and pharmacologic agents given in the perioperative period. The greatest potential benefit arises in operations with greater expected blood loss or in special situations such as in patients with religious issues, bilateral joint replacement, coagulation disorders, or significant preoperative anemia.

A direct antifibrinolytic agent in major orthopedic surgery

Aprotinin is a potent pharmacological agent that reduces bleeding. In current surgical practices, the rate of blood transfusions has decreased with the use of aprotinin. Recently, studies using aprotinin have been conducted in orthopedic surgery. Several trials have been performed in patients undergoing total hip replacement and total knee replacement. Aprotinin moderately decreased blood loss in these patients. When aprotinin was used in patients with a high-risk of bleeding (ie, patients with cancer, sepsis, or undergoing reoperation), potent hemostatic activity occurred and the rate of blood transfusions significantly decreased. No increase in deep vein thrombosis and pulmonary embolism was observed. One adverse effect was the potential occurrence of an anaphylactoid reaction. Prophylactic administration of aprotinin should be considered in extensive spine surgery and in high-risk orthopedic operations. The decision to use aprotinin can be guided by a risk/benefit analysis.

The management of perioperative bleeding

Excess perioperative bleeding remains a major complication following surgery, resulting in increased morbidity and mortality. The principal causes of non-surgical haemostatic perioperative bleeding are a pre-existing undetected bleeding disorder, related to the nature of the operation itself or from coagulation abnormalities arising from massive blood loss. Very often, it is a combination and coexistence of various pathologies. Identifying patients at risk remains a major component of preventing excessive blood loss. Understanding the haemostatic changes occurring in the perioperative period, especially in complex procedures like cardiopulmonary bypass and orthotopic liver transplantation is crucial in developing new strategies for the management of perioperative bleeding. Pharmacological interventions, especially aprotinin, tranexamic acid, desmopressin and increasingly, recombinant VIIa are being used both in prophylaxis and therapeutically to stop bleeding. The use of near patient testing like thromboelastography and platelet function analyser has allowed for more detailed assessment of the various steps of haemostasis. One of the main goals is to reduce the usage of allogeneic blood transfusion and its attendant risks.

Aprotinin versus placebo in major orthopedic surgery: a randomized, double-blinded, dose-ranging study

We conducted a prospective, multicenter, double-blinded, dose-ranging study to compare the risk/benefit ratio of large- and small-dose aprotinin with placebo after major orthopedic surgery. Fifty-eight patients were randomized into three groups: Large-Dose Aprotinin (4 M kallikrein inactivator unit [KIU] bolus before surgery followed by a continuous infusion of 1 M KIU/h until the end of surgery), Small-Dose Aprotinin (2 M KIU bolus plus 0.5 M KIU/h), and Placebo. Bleeding was measured and calculated. Bilateral ascending venography was systematically performed on the third postoperative day. Measured and calculated blood loss decreased in the Large-Dose Aprotinin group (calculated bleeding, whole blood, hematocrit 30%, median [range], 2,023 mL [633-4,113] as compared with placebo, 3,577 mL [1,670-21,758 mL]). The total number of homologous and autologous units was also significantly decreased in the Large-Dose Aprotinin group (2 U [0-5 U] as compared with placebo, 4 U [0-42 U]). No increase in deep vein thrombosis or pulmonary embolism was observed in the aprotinin groups. Large-dose aprotinin was safe and effective in dramatically reducing the measured and calculated bleeding and the amount of transfused red blood cell units after major orthopedic surgery.

IMPLICATIONS

Large doses of aprotinin decrease blood loss and transfusion amount in major orthopedic surgery.