A randomized trial on the efficacy of an autologous blood drainage and transfusion device in patients undergoing elective knee arthroplasty

Cell salvage for minimising perioperative allogeneic blood transfusion in adults undergoing elective surgery

BACKGROUND

Concerns regarding the safety and availability of transfused donor blood have prompted research into a range of techniques to minimise allogeneic transfusion requirements. Cell salvage (CS) describes the recovery of blood from the surgical field, either during or after surgery, for reinfusion back to the patient.

OBJECTIVES

To examine the effectiveness of CS in minimising perioperative allogeneic red blood cell transfusion and on other clinical outcomes in adults undergoing elective or non-urgent surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases and two clinical trials registers for randomised controlled trials (RCTs) and systematic reviews from 2009 (date of previous search) to 19 January 2023, without restrictions on language or publication status.

SELECTION CRITERIA

We included RCTs assessing the use of CS compared to no CS in adults (participants aged 18 or over, or using the study's definition of adult) undergoing elective (non-urgent) surgery only.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 106 RCTs, incorporating data from 14,528 participants, reported in studies conducted in 24 countries. Results were published between 1978 and 2021. We analysed all data according to a single comparison: CS versus no CS. We separated analyses by type of surgery. The certainty of the evidence varied from very low certainty to high certainty. Reasons for downgrading the certainty included imprecision (small sample sizes below the optimal information size required to detect a difference, and wide confidence intervals), inconsistency (high statistical heterogeneity), and risk of bias (high risk from domains including sequence generation, blinding, and baseline imbalances). Aggregate analysis (all surgeries combined: primary outcome only) Very low-certainty evidence means we are uncertain if there is a reduction in the risk of allogeneic transfusion with CS (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.59 to 0.72; 82 RCTs, 12,520 participants). Cancer: 2 RCTs (79 participants) Very low-certainty evidence means we are uncertain whether there is a difference for mortality, blood loss, infection, or deep vein thrombosis (DVT). There were no analysable data reported for the remaining outcomes. Cardiovascular (vascular): 6 RCTs (384 participants) Very low- to low-certainty evidence means we are uncertain whether there is a difference for most outcomes. No data were reported for major adverse cardiovascular events (MACE). Cardiovascular (no bypass): 6 RCTs (372 participants) Moderate-certainty evidence suggests there is probably a reduction in risk of allogeneic transfusion with CS (RR 0.82, 95% CI 0.69 to 0.97; 3 RCTs, 169 participants). Very low- to low-certainty evidence means we are uncertain whether there is a difference for volume transfused, blood loss, mortality, re-operation for bleeding, infection, wound complication, myocardial infarction (MI), stroke, and hospital length of stay (LOS). There were no analysable data reported for thrombosis, DVT, pulmonary embolism (PE), and MACE. Cardiovascular (with bypass): 29 RCTs (2936 participants) Low-certainty evidence suggests there may be a reduction in the risk of allogeneic transfusion with CS, and suggests there may be no difference in risk of infection and hospital LOS. Very low- to moderate-certainty evidence means we are uncertain whether there is a reduction in volume transfused because of CS, or if there is any difference for mortality, blood loss, re-operation for bleeding, wound complication, thrombosis, DVT, PE, MACE, and MI, and probably no difference in risk of stroke. Obstetrics: 1 RCT (1356 participants) High-certainty evidence shows there is no difference between groups for mean volume of allogeneic blood transfused (mean difference (MD) -0.02 units, 95% CI -0.08 to 0.04; 1 RCT, 1349 participants). Low-certainty evidence suggests there may be no difference for risk of allogeneic transfusion. There were no analysable data reported for the remaining outcomes. Orthopaedic (hip only): 17 RCTs (2055 participants) Very low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, or if there is any difference between groups for mortality, blood loss, re-operation for bleeding, infection, wound complication, prosthetic joint infection (PJI), thrombosis, DVT, PE, stroke, and hospital LOS. There were no analysable data reported for MACE and MI. Orthopaedic (knee only): 26 RCTs (2568 participants) Very low- to low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, and whether there is a difference for blood loss, re-operation for bleeding, infection, wound complication, PJI, DVT, PE, MI, MACE, stroke, and hospital LOS. There were no analysable data reported for mortality and thrombosis. Orthopaedic (spine only): 6 RCTs (404 participants) Moderate-certainty evidence suggests there is probably a reduction in the need for allogeneic transfusion with CS (RR 0.44, 95% CI 0.31 to 0.63; 3 RCTs, 194 participants). Very low- to moderate-certainty evidence suggests there may be no difference for volume transfused, blood loss, infection, wound complication, and PE. There were no analysable data reported for mortality, re-operation for bleeding, PJI, thrombosis, DVT, MACE, MI, stroke, and hospital LOS. Orthopaedic (mixed): 14 RCTs (4374 participants) Very low- to low-certainty evidence means we are uncertain if there is a reduction in the need for allogeneic transfusion with CS, or if there is any difference between groups for volume transfused, mortality, blood loss, infection, wound complication, PJI, thrombosis, DVT, MI, and hospital LOS. There were no analysable data reported for re-operation for bleeding, MACE, and stroke.

AUTHORS' CONCLUSIONS

In some types of elective surgery, cell salvage may reduce the need for and volume of allogeneic transfusion, alongside evidence of no difference in adverse events, when compared to no cell salvage. Further research is required to establish why other surgeries show no benefit from CS, through further analysis of the current evidence. More large RCTs in under-reported specialities are needed to expand the evidence base for exploring the impact of CS.

Perioperative Allogeneic Red Blood-Cell Transfusion Associated with Surgical Site Infection After Total Hip and Knee Arthroplasty

BACKGROUND

Perioperative allogeneic red blood-cell transfusion is a suspected risk factor for surgical site infection (SSI) after total joint arthroplasty (TJA), but the interrelationships among SSI risk, transfusion dose, preoperative anemia, and the presence of coagulopathies have not been well described.

METHODS

Data on SSI within 1 year after surgery as well as on transfusion with blood products within 30 days after surgery were obtained for 6,788 patients who had undergone primary or revision total hip or knee arthroplasty from 2000 to 2011 in a single hospital system. Multivariate logistic regression modeling was used to determine the independent association between allogeneic red blood-cell transfusion and SSI.

RESULTS

There was a dose-dependent association between allogeneic red blood-cell transfusion and SSI, with the infection rate increasing as the transfusion dose increased from 1 unit (odds ratio [OR] = 1.97; 95% confidence interval [CI] = 1.38, 2.79; p < 0.001), to 2 units (OR = 2.20; CI = 1.37, 3.44; p = 0.002), to 3 units (OR = 3.66; CI = 1.72, 7.16; p = 0.001), and to >3 units (OR = 7.40; CI = 4.91, 11.03; p < 0.001) after controlling for medical comorbidities, planned procedure, preoperative anemia, and preexisting coagulopathies. A preexisting bleeding disorder (OR = 2.09; CI = 1.57, 2.80; p < 0.001) and clotting disorder (OR = 1.37; CI = 1.14, 1.64; p = 0.001) and preoperative anemia (OR = 3.90; CI = 3.31, 4.61; p < 0.001) were all independent risk factors for transfusion after adjusting for the planned procedure.

CONCLUSIONS

We found a dose-dependent relationship between allogeneic red blood-cell transfusion and SSI risk after total hip or knee arthroplasty. Additionally, preoperative anemia or a known bleeding or clotting disorder were risk factors for the need for allogeneic red blood-cell transfusion. Our findings underscore the need for preoperative risk assessment, methods to limit surgical tissue injury, and optimized blood conservation strategies.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Application of postoperative autotransfusion in total joint arthroplasty reduces allogeneic blood requirements: a meta-analysis of randomized controlled trials

Background

Total joint arthroplasty is associated with significant blood loss and often requires blood transfusion. However, allogeneic blood transfusion (ABT) may lead to severe problems, such as immunoreaction and infection. Postoperative autotransfusion, an alternative to ABT, is controversial. We conducted a meta-analysis to evaluate the ability of postoperative autotransfusion to reduce the need for ABT following total knee arthroplasty (TKA) and total hip arthroplasty (THA).

Methods

Systematic literature searches for randomized controlled trials were performed using PubMed, Embase, and the Cochrane Library until February 2016. Relative risks (RRs) and weighted mean differences with 95% confidence intervals (CIs) were calculated using fixed-effect or random-effect models; we also evaluated publication bias and heterogeneity.

Results

Seventeen trials with a total of 2314 patients were included in the meta-analysis. The pooled RRs of ABT rate between autotransfusion and the regular drainage/no drainage groups for TKA and THA were 0.446 (95% CI = 0.287, 0.693; p < 0.001) and 0.757 (95% CI = 0.599, 0.958; p = 0.020), respectively. In the subgroup analysis performed in TKA patients according to control interventions, the pooled RRs were 0.377 (95% CI = 0.224, 0.634; p < 0.001) (compared with regular drainage) and 0.804 (95% CI = 0.453, 1.426, p = 0.456) (compared with no drainage). In the subgroup analysis performed for THA, the pooled RRs were 0.536 (95% CI = 0.379, 0.757, p < 0.001) (compared with regular drainage) and 1.020 (95% CI = 0.740, 1.405, p = 0.904) (compared with no drainage).

Conclusions

Compared to regular drainage, autotransfusion reduces the need for ABT following TKA and THA. This reduction is not present when comparing autotransfusion to no drainage. However, the reliability of the meta-analytic results concerning TKA was limited by significant heterogeneity in methods among the included studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1710-2) contains supplementary material, which is available to authorized users.

Do autologous blood transfusion systems reduce allogeneic blood transfusion in total knee arthroplasty?

PURPOSE

To study whether autologus blood transfusion systems reduce the requirement of allogneic blood transfusion in patients undergoing total knee arthroplasty.

METHODS

A comprehensive search of the published literature with PubMed, Scopus and Science direct database was performed. The following search terms were used: (total knee replacement) OR (total knee arthroplasty) OR (TKA) AND (blood transfusion) OR (autologous transfusion) OR (autologous transfusion system). Using search syntax, a total of 748 search results were obtained (79 from PubMed, 586 from Science direct and 83 from Scopus). Twenty-one randomized control trials were included for this meta-analysis.

RESULTS

The allogenic transfusion rate in autologus blood transfusion (study) group was significantly lower than the control group (28.4 and 53.5 %, respectively) (p value 0.0001, Relative risk: 0.5). The median units of allogenic blood transfused in study control group and control group were 0.1 (0.1-3.0) and 1.3 (0.3-2.6), respectively. The median hospital stay in study group was 9 (6.7-15.6) days and control group was 8.7 (6.6-16.7) days. The median cost incurred for blood transfusion per patient in study and control groups was 175 (85.7-260) and 254.7 (235-300) euros, respectively.

CONCLUSION

This meta-analysis demonstrates that the use of auto-transfusion systems is a cost-effective method to reduce the need for and quantity of allogenic transfusion in elective total knee arthroplasty.

LEVEL OF EVIDENCE

Level I.

The efficacy and safety of autologous blood transfusion drainage in patients undergoing total knee arthroplasty: a meta-analysis of 16 randomized controlled trials

Background

Autologous blood transfusion drainage (ABTD) has been used for many years to reduce blood loss in total knee arthroplasty (TKA). We evaluate the current evidence concerning the efficiency and safety of ABTD used in TKA compared with conventional suction drainage (CSD).

Methods

We performed a systematic literature search of the PubMed, Embase, Cochrane Library and four Chinese databases. All randomized controlled trials (RCTs) that compared the effects of ABTD versus CSD in TKA were included in the meta-analysis.

Results

Sixteen RCTs involving 1534 patients who compared the effects of ABTD versus CSD were included. Five of the RCTs were performed in Asia, ten in Europe, and one in North America. Patients in the ABTD group had a lower blood transfusion rate (OR: 0.25 [0.13, 0.47]; Z = 4.27, P < 0.0001) and fewer units transfused per patient (WMD: −0.68 [−0.98, −0.39]; Z = 4. 52, P < 0.00001) than did patients in the CSD group. Wound complications, deep vein thrombosis, febrile complications, post-operative hemoglobin days 5–8, drainage volume, and length of hospital stay did not differ significantly between the two types of drainage systems.

Conclusion

This meta-analysis suggests that ABTD is a safe and effective method that yields a lower blood transfusion rate and fewer units transfused per patient in TKA compared with CSD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1301-7) contains supplementary material, which is available to authorized users.

Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis

Background

Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage.

Methods

PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3–5, length of hospital stay and wound infections after TKA surgery.

Results

The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3–5, length of hospital stay and wound infections.

Conclusions

Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-0993-z) contains supplementary material, which is available to authorized users.

Is postoperative cell salvage necessary in total hip or knee replacement? A meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to determine whether there are hematological or clinical differences with the use of postoperative cell salvage after total knee (TKR) and hip replacement (THR).

METHODS

A systematic literature review based on PubMed, EMBASE, the Cochrane Library Database in any language regarding postoperative cell salvage following TKR or THR was performed. High quality of randomized controlled trials were identified. The data was analyzed using Rev Man 5.2.

RESULTS

19 randomized controlled trials (12 in TKR, 4 in THR and 3 in both) about 3482 patients were identified and included in this meta-analysis. Postoperative cell salvage significantly reduced the allogeneic blood transfusion requirement after TKR (RR = 0.46, 95% CI = 0.30 to 0.72) and THR (RR = 0.46, 95%CI = 0.32 to 0.68). It also demonstrated a higher level of postoperative Hemoglobin (MD = 0.26 g/dL, 95%CI = 0.15 to 0.37) with the use of postoperative cell salvage. No significant differences were detected regarding length of hospital stay, the incidence of febrile reaction, wound infection and deep vein thrombosis.

CONCLUSION

The results strengthen the fact that postoperative cell salvage is effective and safe to reduce the rate of transfusion after TKR and THR. As the relatively poor methodological quality and heterogeneity, further research is needed to confirm its safety and cost-effectiveness.

Cell Salvage in Hip and Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Cell salvage is used to reduce allogeneic red blood-cell (RBC) transfusions in total hip arthroplasty (THA) and total knee arthroplasty (TKA). We performed a meta-analysis to assess the effectiveness of cell salvage to reduce transfusions in THA and TKA separately, and to examine whether recent trials change the conclusions from previous meta-analyses.

METHODS

We searched MEDLINE through January 2013 for randomized clinical trials evaluating the effects of cell salvage in THA and TKA. Trial results were extracted using standardized forms and pooled using a random-effects model. Methodological quality of the trials was evaluated using the Cochrane Collaboration's tool for risk-of-bias assessment.

RESULTS

Forty-three trials (5631 patients) were included. Overall, cell salvage reduced the exposure to allogeneic RBC transfusion in THA (risk ratio [RR], 0.66; 95% confidence interval [CI], 0.51 to 0.85) and TKA (RR, 0.51; 95% CI, 0.39 to 0.68). However, trials published in 2010 to 2012, with a lower risk of bias, showed no significant effect of cell salvage in THA (RR, 0.82; 95% CI, 0.66 to 1.02) and TKA (RR, 0.91; 95% CI, 0.63 to 1.31), suggesting that the treatment policy regarding transfusion may have changed over time.

CONCLUSIONS

Looking at all trials, cell salvage still significantly reduced the RBC exposure rate and the volume of RBCs transfused in both THA and TKA. However, in trials published more recently (2010 to 2012), cell salvage reduced neither the exposure rate nor the volume of RBCs transfused in THA and TKA, most likely explained by changes in blood transfusion management.

Blood conservation strategies in orthopedic surgeries: A review

In orthopedics management of surgical blood loss is an important aspect which has evolved along with modern surgeries. Replacement of lost blood by transfusion alone is not the answer as was considered earlier. Complications like infection and immune reaction due to blood transfusion are a major concern. Today numerous techniques are available in place of allogenic blood transfusion which can be employed safely and effectively. In this article we have reviewed these techniques, their merits and demerits.

Autologous bone plugs in unilateral total knee arthroplasty

BACKGROUND

The purpose of this study was to compare blood loss, declines in hemoglobin (HgB) and hematocrit (HcT) levels, and required homologous transfusions for patients who either had the femoral intramedullary defect left open or filled with an autologous bone plug during total knee arthroplasty (TKA). We hereby present our results of autologous bone plugs in unilateral TKA.

MATERIALS AND METHODS

A retrospective chart review was performed on 55 patients diagnosed with osteoarthritis (OA) who had undergone unilateral TKA. Twenty six patients had the femoral defect filled with an autologous bone plug and 29 did not. Lateral releases and patella replacements were not performed. Drained blood was reinfused when appropriate.

RESULTS

MEAN BLOOD LOSS AND MEAN BLOOD REINFUSED WERE SIMILAR FOR THE PLUGGED (LOSS: 960.8 ± 417.3 ml; reinfused: 466.7 ± 435.9 mL) and unplugged groups (loss: 1065.9 ± 633.5 ml, P = 0.38; reinfused: 528.4 ± 464.8 ml, P = 0.61). Preoperative HgB (14.3 ± 1.4 g/dL, P = 0.93) and HcT levels (42.2 ± 4.6%, P = 0.85) were similar across plug conditions. HgB and HcT levels declined similarly for the plugged (2.7 ± 1.2 g/dl and 7.9 ± 4.0%) and unplugged groups (3.0 ± 0.9 g/dl, P = 0.16 and 9.0 ± 2.6%, P = 0.16), respectively. Of patients, one in the plugged group and none in the unplugged group required homologous transfusions (P = 0.5).

CONCLUSION

The autologous bone plug does not appear to reduce the need for homologous blood transfusions following unilateral TKA.

Transfusion drains versus suction drains in total knee replacement: meta-analysis

PURPOSE

The use of autologous blood transfusion drains in orthopaedic surgery has been the subject of debate for several years. The aim of this meta-analysis was to review the use of autologous blood transfusion drains in total knee replacement.

METHODS

The primary outcomes were as follows: the number of patients requiring homologous blood transfusion, pre-operative haemoglobin and post-operative haemoglobin days 5-7. The secondary outcome measures for the meta-analysis were drainage volume, length of hospital stay, average number of units transfused per patient, post-operative wound infection, and deep vein thrombosis.

RESULTS

Eight randomised controlled trials met the inclusion criteria and were included in this analysis. Autologous transfusion drains were associated with a decrease in the number of patients requiring post-operative blood transfusion (pooled odds ratio = 0.36, 95% CI = 0.15-0.85, P = 0.02), the number of units transfused per patient (weighted mean difference = -0.84 (95% CI = -1.13 to -0.56), P < 0.0001), and length of hospital stay (weighted mean difference = -0.25 (95% CI = -0.48 to -0.01), P = 0.04).

CONCLUSION

The results of our study highlight both likely clinical and economic benefits within total knee replacement surgery. The clinical benefits of autologous transfusion drains in the total knee replacement surgery suggested by this meta-analysis include a reduced requirement for post-operative blood transfusion and a shorter length of hospital stay. However, further large-scale high-powered randomized controlled trials are recommended to further elucidate subtle effects of autologous drains on post-operative outcome following total knee replacement.

LEVEL OF EVIDENCE

II.

Alternative procedures for reducing allogeneic blood transfusion in elective orthopedic surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

Prospective comparative study of two different autotransfusion methods versus control group in total knee replacement

AIM

The aim of this study was to evaluate the efficacy of two different autotransfusion methods in total knee replacement (TKR) performed without tourniquet, in comparison to allogeneic blood transfusion (ABT) only.

METHOD

In a comparative study, 248 patients with knee osteoarthritis were randomized in three groups: in control Group 85 the patients underwent only ABT post-operatively, in Group 1 (n:92) an intraoperative and postoperative autotransfusion were utilized, and in Group 2 (n:71) only a postoperative autotransfusion was applied. Post-operative ABT was utilized according to predetermined criteria.

RESULTS

Comparing Group 0 to Group 1 and 2 the difference in need for ABT post-operatively was statistically highly significant (p < 0.001) even when the results were analyzed classifying the patients according to the preoperative Hb levels. The difference between Group 1 and 2 was not significant.

CONCLUSION

According to the results of this study, auto-transfusion reduces the need for ABT in TKR performed without tourniquet.

Cell salvage for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have prompted reconsideration of the use of allogeneic (from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of cell salvage in reducing allogeneic blood transfusion and the evidence for any effect on clinical outcomes.

SEARCH STRATEGY

We identified studies by searching CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1950 to June 2009), EMBASE (1980 to June 2009), the internet (to August 2009) and bibliographies of published articles.

SELECTION CRITERIA

Randomised controlled trials with a concurrent control group in which adult patients, scheduled for non-urgent surgery, were randomised to cell salvage (autotransfusion) or to a control group who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and the risk of bias assessed. Relative risks (RR) and weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated. Data were pooled using a random-effects model. The primary outcomes were the number of patients exposed to allogeneic red cell transfusion and the amount of blood transfused. Other clinical outcomes are detailed in the review.

MAIN RESULTS

A total of 75 trials were included. Overall, the use of cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 38% (RR 0.62; 95% CI 0.55 to 0.70). The absolute reduction in risk (ARR) of receiving an allogeneic RBC transfusion was 21% (95% CI 15% to 26%). In orthopaedic procedures the RR of exposure to RBC transfusion was 0.46 (95% CI 0.37 to 0.57) compared to 0.77 (95% CI 0.69 to 0.86) for cardiac procedures. The use of cell salvage resulted in an average saving of 0.68 units of allogeneic RBC per patient (WMD -0.68; 95% CI -0.88 to -0.49). Cell salvage did not appear to impact adversely on clinical outcomes.

AUTHORS' CONCLUSIONS

The results suggest cell salvage is efficacious in reducing the need for allogeneic red cell transfusion in adult elective cardiac and orthopaedic surgery. The use of cell salvage did not appear to impact adversely on clinical outcomes. However, the methodological quality of trials was poor. As the trials were unblinded and lacked adequate concealment of treatment allocation, transfusion practices may have been influenced by knowledge of the patients' treatment status potentially biasing the results in favour of cell salvage.

Cell salvage for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood, have prompted reconsideration of the use of allogeneic (blood from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of cell salvage in reducing allogeneic blood transfusion and the evidence for any effect on clinical outcomes.

SEARCH STRATEGY

We identified studies by searching CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1950 to June 2009), EMBASE (1980 to June 2009), the Internet (to August 2009) and bibliographies of published articles.

SELECTION CRITERIA

Randomised controlled trials with a concurrent control group in which adult patients, scheduled for non-urgent surgery, were randomised to cell salvage (autotransfusion), or to a control group, who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and the risk of bias assessed. Relative risks (RR) and weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated. Data were pooled using a random effects model. The primary outcomes were the number of patients exposed to allogeneic red cell transfusion, and the amount of blood transfused. Other clinical outcomes are detailed in the review.

MAIN RESULTS

A total of 75 trials were included. Overall, the use of cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 38% (RR=0.62: 95% CI 0.55 to 0.70). The absolute reduction in risk (ARR) of receiving an allogeneic RBC transfusion was 21% (95% CI 15% to 26%). In orthopaedic procedures the RR of exposure to RBC transfusion was 0.46 (95% CI 0.37 to 0.57) compared to 0.77 (95% CI 0.69 to 0.86) for cardiac procedures. The use of cell salvage resulted in an average saving of 0.68 units of allogeneic RBC per patient (WMD=-0.68; 95% CI -0.88 to -0.49). Cell salvage did not appear to impact adversely on clinical outcomes.

AUTHORS' CONCLUSIONS

The results suggest cell salvage is efficacious in reducing the need for allogeneic red cell transfusion in adult elective cardiac and orthopaedic surgery. The use of cell salvage did not appear to impact adversely on clinical outcomes. However, the methodological quality of trials was poor. As the trials were unblinded and lacked adequate concealment of treatment allocation, transfusion practices may have been influenced by knowledge of the patients' treatment status potentially biasing the results in favour of cell salvage.

A prospective randomised controlled trial of autologous retransfusion in total knee replacement

We undertook a prospective randomised controlled trial to investigate the efficacy of autologous retransfusion drains in reducing the need for allogenic blood requirement after unilateral total knee replacement. We also monitored the incidence of post-operative complications. There were 86 patients in the control group, receiving standard care with a vacuum drain, and 92 who received an autologous drain and were retransfused postoperatively. Following serial haemoglobin measurements at 24, 48 and 72 hours, we found no difference in the need for allogenic blood between the two groups (control group 15.1%, retransfusion group 13% (p = 0.439)). The incidence of post-operative complications, such as wound infection, deep-vein thrombosis and chest infection, was also comparable between the groups. There were no adverse reactions associated with the retransfusion of autologous blood. Based on this study, the cost-effectiveness and continued use of autologous drains in total knee replacement should be questioned.

Clinically informative measures of the effect of drugs or other interventions

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Several comparative measures (ratios, differences, or the number needed to treat) are used to express the effect of a drug or another intervention. These measures can vary in the way they are affected by the background risk measured from the reference group.

WHAT THIS STUDY ADDS

This paper reviews the formulation, interpretation and limitations of measures of effect. We describe a little-known parameter, the attained effect or clinical result ratio, a positive reformulation of the relative risk difference, and suggest how available parameters can be best used to summarize results of studies of the effect of drugs. AIMS Measures to compare two drugs are often affected by the background risk in the reference group; a ceiling effect results when the background risk is small. We review measures of the effect of drugs, including a special formulation of the relative risk difference, the attained effect or clinical result ratio, that addresses background risk and ceiling effect.

METHODS

Existing measures are the risk and odds ratios, the absolute and relative risk differences, and the number needed to treat. The attained effect is defined as the observed gain in success (the difference of proportion of success between the two interventions), divided by the maximum attainable gain, the maximum proportion of success one can expect. We illustrate the relationship between these measures with published results of two meta-analyses.

RESULTS

In studies of the effectiveness of cell salvage, the baseline risk ranged between 8 and 95%. This variability affected the risk difference and number needed to treat, while the attained effect, with a ceiling residual risk of 2%, showed that the gain in success was half the maximum attainable gain. In studies of the effectiveness of therapy in patients infected by the human immunodeficiency virus, where the baseline risk was less variable, and there was no ceiling effect, the maximum attained effect indicated that the gain could be much smaller.

CONCLUSION

The attained effect, interpreted as the proportion of effectiveness that remains to gain for future interventions, can usefully complete the number needed to treat as a clinically informative effect measure.

Safety of autologous drainage blood reinfusion following total knee arthroplasty prepared with hydrogen peroxide

In a clinical in vivo study, wound blood collected from an autologous reinfusion drain of patients undergoing elective total knee arthroplasty was examined to investigate if hydrogen peroxide bone surface preparation had an adverse effect on blood destined to be reinfused. The post-operative drain blood of thirty-eight patients was collected after pre-implantation bone preparation being performed either with or without the use of hydrogen peroxide. Filtered drain blood samples were analyzed and mean results for treatment / control groups respectfully were: haemoglobin (g/L) 98.6/100.9, p=0.7221; haemoglobin change from baseline (g/L) -39.1/-32.9, p=0.2117; MCV (fL) 94.6/93.1, p=0.2897; MCV change from baseline (fL) 2.0/2.5, p=0.6417; potassium (mmol/L) 4.5/4.6, p=0.8212; free haemoglobin (g/L) 1.2/1.3, p=0.4387; methaemoglobin (%) 0.2/0.2, p=0.8112; presence of echinocytes (%) 14/18, p=1.0000. These were all within safe limits for reinfusion. Under the study conditions, application of hydrogen peroxide followed by thorough lavage of the knee joint did not appear to result in any untoward degradation of the extravasated blood that might preclude its use for postoperative autologous drainage blood reinfusion.

Efficacy, safety and user-friendliness of two devices for postoperative autologous shed red blood cell re-infusion in elective orthopaedic surgery patients: A randomized pilot study

To determine the safety, efficacy and user-friendliness of two different postoperative autologous blood re-infusion systems, an open, randomized, controlled study was performed. Eligible consecutive primary and revision total hip and knee replacement patients were randomized for one of the two systems or for a control group in which shed blood was not re-infused. The nursing staff scored user-friendliness. Patients were monitored after re-infusion. In all three patient groups, a restrictive transfusion trigger was used. Sixty-nine of 70 randomized patients were evaluated. Ease of use, efficacy and safety of both re-infusion systems were comparable. There was no difference in allogeneic blood use between the groups. Thirty per cent of the patients re-infused with autologous blood developed a mainly mild, febrile transfusion reaction. No other adverse reactions were seen. Signs of coagulopathy after re-infusion were not found. In multivariate analysis, autologous re-infusion was an independent factor associated with a shorter hospital stay. Both postoperative autologous blood re-infusion systems were of equal efficacy and safety. The contribution of autologous wound blood re-infusion to reduce allogeneic transfusions must be investigated in a larger study.

Cell salvage for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood, have prompted reconsideration of the use of allogeneic (blood from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of cell salvage in reducing allogeneic blood transfusion and the evidence for any effect on clinical outcomes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Current Contents and the websites of international health technology assessment agencies. The reference lists in identified trials and review articles were also searched, and study authors were contacted to identify additional studies. The searches were updated in January 2004.

SELECTION CRITERIA

Controlled parallel group trials in which adult patients, scheduled for non-urgent surgery, were randomised to cell salvage, or to a control group, who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently screened search results, extracted data and assessed methodological quality. The main outcomes measures were the number of patients exposed to allogeneic red cell transfusion, and the amount of blood transfused. Other outcomes measured were re-operation for bleeding, blood loss, post-operative complications (thrombosis, infection, non-fatal myocardial infarction, renal failure), mortality, and length of hospital stay (LOS).

MAIN RESULTS

Overall, the use of cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 39% (relative risk [RR] = 0.61: 95% confidence interval [CI] 0.52 to 0.71). The absolute reduction in risk (ARR) of receiving an allogeneic RBC transfusion was 23% (95% CI 16% to 30%). In orthopaedic procedures the RR of exposure to RBC transfusion was 0.42 (95% CI 0.32 to 0.54) compared to 0.77 (95% CI 0.68 to 0.87) for cardiac procedures. The use of cell salvage resulted in an average saving of 0.67 units of allogeneic RBC per patient (weighted mean difference was -0.64; 95% CI -0.89 to -0.45). Cell salvage did not appear to impact adversely on clinical outcomes.

AUTHORS' CONCLUSIONS

The results suggest cell salvage is efficacious in reducing the need for allogeneic red cell transfusion in adult elective surgery. However, the methodological quality of trials was poor. As the trials were unblinded and lacked adequate concealment of treatment allocation, transfusion practices may have been influenced by knowledge of the patients' treatment status biasing the results in favour of cell salvage.

Soluble CD40 ligand accumulates in stored blood components, primes neutrophils through CD40, and is a potential cofactor in the development of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a form of posttransfusion acute pulmonary insufficiency that has been linked to the infusion of biologic response modifiers (BRMs), including antileukocyte antibodies and lipids. Soluble CD40 ligand (sCD40L) is a platelet-derived proinflammatory mediator that accumulates during platelet storage. We hypothesized that human polymorpho-nuclear leukocytes (PMNs) express CD40, CD40 ligation rapidly primes PMNs, and sCD40L induces PMN-mediated cytotoxicity of human pulmonary microvascular endothelial cells (HMVECs). Levels of sCD40L were measured in blood components and in platelet concentrates (PCs) implicated in TRALI or control PCs that did not elicit a transfusion reaction. All blood components contained higher levels of sCD40L than fresh plasma, with apheresis PCs evidencing the highest concentration of sCD40L followed by PCs from whole blood, whole blood, and packed red blood cells (PRBCs). PCs implicated in TRALI reactions contained significantly higher sCD40L levels than control PCs. PMNs express functional CD40 on the plasma membrane, and recombinant sCD40L (10 ng/mL-1 mug/mL) rapidly (5 minutes) primed the PMN oxidase. Soluble CD40L promoted PMN-mediated cytotoxicity of HMVECs as the second event in a 2-event in vitro model of TRALI. We concluded that sCD40L, which accumulates during blood component storage, has the capacity to activate adherent PMNs, causing endothelial damage and possibly TRALI in predisposed patients.

Haemoglobin levels following unicompartmental knee arthroplasty: influence of transfusion practice and surgical approach

A retrospective review was undertaken of preoperative and day 3 postoperative haemoglobin (Hb) levels in all unicompartmental knee arthroplasty (UKA) procedures performed by a single surgeon. Sixty-six UKAs were performed using the same prosthesis through an open approach with patella eversion. This group was compared with 212 UKAs performed using a minimally invasive approach without patella eversion, with an implant and instrumentation specifically devised for this approach. Both groups were well matched for patient demographics, surgical and anaesthetic techniques, thromboprophylaxis, and postoperative regimes. All patients received transfusions with pre-donated blood, except the unilateral minimally invasive approach group. An analysis of covariance was undertaken to examine the influence of the surgical approach and whether surgery was unilateral or bilateral, taking into account preoperative Hb levels and units of blood transfused. The average fall in Hb following UKA, adjusted for other variables, was 2.73 g/dl with an open approach compared to 1.82 g/dl with a minimally invasive approach. This difference was significant (p=0.0044). The average postoperative Hb in the minimally invasive group was 12.05 g/dl (range, 8.8 to 15.8 g/dl). Patients undergoing unilateral minimally invasive UKA are unlikely to develop symptomatic anaemia and should not be required to predonate blood or undergo transfusion.

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.

Clinical efficacy of postoperative autologous transfusion of filtered shed blood in hip and knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) or total hip arthroplasty (THA) regularly results in postoperative requirement of blood transfusion. Because of the disadvantages of allogeneic blood transfusion (ABT) such as the risk of transfusion-associated infections, incompatibility-related transfusion fatalities, or immunomodulatory effects, a continuing effort to reduce allogeneic blood transfusion is important. For this purpose, the effect of reinfusion of drain blood, via a postoperative wound drainage and reinfusion system, on the need for allogeneic blood transfusion was evaluated.

STUDY DESIGN AND METHODS

Using a prospective observational quality assessment design, we compared 135 patients scheduled for TKA or THA with a historic group of 96 patients. In the study group the Bellovac ABT autotransfusion system was used. The shed blood was returned either when 500 mL were collected or at most 6 hours after surgery. Compared were the preoperative, postoperative, and discharge hemoglobin, as well as the number of allogeneic blood transfusions.

RESULTS

There were no statistical differences between preoperative, postoperative, and discharge hemoglobin levels. Autologous transfusion reduced the number of patients receiving ABT overall from 35 percent (control) to 22 percent (study). The decrease of allogeneic transfusion requirement was most significant after TKA: from 18 percent to 6 percent (p < 0.001).

CONCLUSION

We conclude that the Bellovac ABT device reduces allogeneic blood transfusions in TKA and THA.

Effect of autologous salvaged blood on postoperative natural killer cell precursor frequency

BACKGROUND

Immunosuppression after major surgery increases the risk of infections. Natural killer cells play a pivotal part in defence against infection. We aimed to investigate the immunomodulatory effects of different types of postoperative blood transfusion by use of a new assay for measuring the frequency of peripheral blood natural killer precursor cells (NKpf assay).

METHODS

We measured the natural killer cell precursor (NKp) frequency before and 5 days after surgery in 120 patients undergoing joint replacement surgery. The patients were assigned to one of five groups according to the type of transfusion received: non-transfused (n=32), allogeneic non-leukodepleted blood (eight), allogeneic leukodepleted blood (30), autologous predeposited blood (ten), and autologous salvaged blood collected within the first 24 h after surgery (40). We also measured interferon gamma and interleukin 10 concentrations before and after surgery.

FINDINGS

The mean postoperative NKp frequency for all patients was lower than the preoperative values, except in patients receiving autologous salvaged blood, which was higher than all other groups (p<0.0001). Postoperative NKp frequencies for patients receiving allogeneic or autologous predeposited blood responded similarly (p=0.99), but these patients had lower NKp frequencies than did the non-transfused group (p<0.0001). Postoperative interferon gamma concentrations were higher in the autologous salvaged blood group (p<0.0001) than in other groups, which did not differ from each other. Interleukin 10 concentrations were similar across all groups (p=0.49).

INTERPRETATION

Immunosuppression associated with surgery and blood loss was reflected in a reduced frequency of NKp and decreased interferon gamma. This immunosuppression was reversed by transfusion of autologous salvaged blood, suggesting that this fluid contained immunostimulants.

Reduction of blood transfusion rates in unilateral total knee arthroplasty by the introduction of a simple blood transfusion protocol

We prospectively studied blood transfusion practices within a single institution before and after the introduction of a blood transfusion protocol in consecutive patients undergoing unilateral total knee arthroplasty. Data were collected on 393 patients (group I) prior to and 295 patients (group II) after the introduction of the protocol. Following the introduction of the protocol, patients with preoperative haemoglobin of less than 11 g/dl were cross-matched prior to surgery. The criterion for postoperative transfusion was postoperative haemoglobin of less than 8.5 g/dl or a symptomatic patient with haemoglobin of greater than 8.5 g/dl. This change in practice reduced the transfusion rates from 31% in group I to 11.9% in group II. It reduced the non-utilisation of blood from 64 to 1%. There were no adverse outcomes related to the introduction of the protocol.

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.

Survey of autologous blood transfusion activity in England (2001)

Better Blood Transfusion' (Department of Health (1998) HSC 1998/224) stressed the need for National Health Service Trusts to explore the feasibility of autologous blood transfusions and raise patient awareness of these techniques. The development of an appropriate strategy to promote autologous transfusion requires an understanding of current use, along with constraints to increasing practice. Past surveys have shown unchanging attitudes to autologous transfusion (Torrella et al. (2001) Transfusion Medicine, 11, 15-19), but detailed information regarding the extent of autologous transfusion in England and North Wales was not available. This survey, carried out in 2001, considered autologous transfusion under four headings: predeposit autologous donation, acute normovolaemic haemodilution, intra-operative cell salvage and postoperative cell salvage. Questionnaires were returned from 265/310 (85.4%) hospitals served by the National Blood Service. Sixty per cent of respondents performed at least one autologous technique, although practice was limited to a few clinicians within each hospital. Predeposit donation was the most widespread technique but involved very few patients. Intra- and postoperative cell salvage techniques were practised in fewer hospitals but on many more patients. The main constraints to increasing use of autologous techniques were perceived to be logistical, but removal of constraints may only result in small increases in individual practice. More clinicians need to be encouraged to utilize appropriate, evidence-based autologous techniques.

Cell salvage for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood, have prompted reconsideration of the use of allogeneic (blood from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of cell salvage in reducing allogeneic blood transfusion and the evidence for any effect on clinical outcomes.

SEARCH STRATEGY

Articles were identified by: computer searches of MEDLINE, EMBASE, Current Contents (to July 2002), the Cochrane Controlled Trials Register (Issue 2, 2002) and websites of international health technology assessment agencies. References in the identified trials and review articles were searched and authors contacted to identify additional studies.

SELECTION CRITERIA

Controlled parallel group trials in which adult patients, scheduled for non-urgent surgery, were randomised to cell salvage, or to a control group, who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed using criteria proposed by Schulz et al. (Schulz 1995) and Jadad et al. (Jadad 1996). Main outcomes measured were: the number of patients exposed to allogeneic red cell transfusion, and the amount of blood transfused. Other outcomes measured were: re-operation for bleeding, blood loss, post-operative complications (thrombosis, infection, non-fatal myocardial infarction, renal failure), mortality, and length of hospital stay (LOS).

MAIN RESULTS

Overall, the use of cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 40% (relative risk [RR] = 0.60: 95% confidence interval [CI] = 0.51 to 0.70). The absolute reduction in risk (ARR) of receiving an allogeneic RBC transfusion was 23% (95%CI = 16% to 30%). In orthopaedic procedures the relative risk (RR) of exposure to RBC transfusion was 0.42 (95%CI = 0.32 to 0.54) compared to 0.78 (95%CI = 0.68 to 0.88) for cardiac procedures. The use of cell salvage resulted in an average saving of 0.64 units of allogeneic RBC per patient (weighted mean difference [WMD] = -0.64: 95%CI = -0.86 to -0.46). Cell salvage did not appear to impact adversely on clinical outcomes.

REVIEWER'S CONCLUSIONS

The results suggest cell salvage is efficacious in reducing the need for allogeneic red cell transfusion in adult elective surgery. However, the methodological quality of trials was poor. As the trials were unblinded and lacked adequate concealment of treatment allocation, transfusion practices may have been influenced by knowledge of the patient's treatment status biasing the results in favour of cell salvage.

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.

Autologous blood transfusion in total knee replacement surgery

We compared allogeneic blood usage for two groups of patients undergoing total knee replacement surgery (TKR). Patients were randomized to receive either their post-operative wound drainage as an autotransfusion (n=115) after processing or to have this wound drainage discarded (n=116). Allogeneic blood was transfused in patients of either group whose haemoglobin fell below 9 g dl(-1). Only 7% of patients in the autotransfusion group required an allogeneic transfusion compared with 28% in the control group (P<0.001). There was no hospital mortality and only 3% mortality from all causes at the study completion, which spanned 6 months to 3 yr. There was a higher incidence of infection requiring intervention in the allogeneic group (P<0.036). Total patient costs were Pound Sterling 113 greater in the autotransfusion group. We conclude that in this type of surgery post-operative cell salvage is a safe and effective method for reducing allogeneic blood use.

Are there simple measures to reduce the risk of HIV infection through blood transfusion in a Zambian district hospital?

OBJECTIVE

To quantify the potential impact of simple measures to reduce the risk of iatrogenic HIV infection through blood transfusion in a Zambian district hospital.

METHODS

Three studies were conducted at St. Francis' Hospital, Katete, Zambia: (1) From 1991 to 1995 HIV seroprevalence among all listed blood donors and the impact of proper subgroup selection were studied retrospectively; (2) the sensitivity of locally used rapid antibody assays (HIV-spot/Wellcozyme HIV 1 & 2) for the detection of HIV in donor blood and the influence of the expiration date of the tests on this sensitivity were determined prospectively from June 1993 until March 1994 by screening all consecutive surgical patients and blood donors; (3) the number of unnecessary blood transfusions was determined retrospectively from January 1995 through January 1996 and prospectively from February 1996 through March 1996, and possibilities to reduce the total number of blood transfusions were considered.

RESULTS

(1) Excluding prisoners, who have an HIV seroprevalence of 19-25%, from the donor population significantly reduces the overall HIV seroprevalence from 13-16% to 8-9% (P < 0. 01). (2) Under local circumstances the sensitivity of the used rapid antibody assays was 6.8-17.9% lower than claimed by the manufacturer. Usage of non-expired tests increased the sensitivity significantly from 88.2% to 91.7% (P < 0.05). (3) None of the 294 studied blood transfusions can be classified as inappropriate according to international standards.

CONCLUSIONS

Simple measures such as proper subgroup selection among blood donors and correct use of non-expired tests may decrease the risk of iatrogenic HIV transmission. Stricter indications for blood transfusions will not substantially reduce the number of transfusions.

A meta-analysis of the effectiveness of cell salvage to minimize perioperative allogeneic blood transfusion in cardiac and orthopedic surgery. International Study of Perioperative Transfusion (ISPOT) Investigators

Concern about risks of allogeneic transfusion has led to an interest in methods for decreasing perioperative transfusion. To determine whether cell salvage reduces patient exposure to allogeneic blood, we performed meta-analyses of randomized trials, evaluating the effectiveness and safety of cell salvage in cardiac or orthopedic elective surgery. The primary outcome was the proportion of patients who received at least one perioperative allogeneic red cell transfusion. Twenty-seven studies were included in the meta-analyses. Cell salvage devices that do not wash salvaged blood were marginally effective in cardiac surgery patients when used postoperatively (relative risk [RR] = 0.85, 95% confidence interval [CI] = 0.79-0.92). Devices that wash or do not wash salvaged blood considerably decreased the proportion of orthopedic surgery patients who received allogeneic transfusion (RR = 0.39, 95% CI = 0.30-0.51 and RR = 0.35, 95% CI 0.26-0.46, respectively). No studies of cell savers that wash salvaged blood during cardiac surgery were included. Cell salvage did not appear to increase the frequency of adverse events. We conclude that cell salvage in orthopedic surgery decreases the risk of patients' exposure to allogeneic blood transfusion perioperatively. Postoperative cell salvage in cardiac surgery, with devices that do not wash the salvaged blood, is only marginally effective.

IMPLICATIONS

This meta-analysis of all published randomized trials provides the best current estimate of the effectiveness of cell salvage and is useful in guiding clinical practice. We conclude that cell salvage in orthopedic surgery decreases the proportion of patients requiring allogeneic blood transfusion perioperatively, but postoperative cell salvage is only marginally effective in cardiac surgery.

Quality of reinfused drainage blood after total knee arthroplasty

Reinfusion of postoperative wound drainage blood has become an attractive alternative in primary total knee and hip arthroplasty. Quality of the drainage blood was studied with respect to content of extracellular bioactive substances and coagulation split products. Using the HandyVac ATS autotransfusion system, drainage blood was collected and reinfused within 6 hours postoperatively from 10 patients undergoing primary total knee arthroplasty. Blood samples were collected from the patients immediately after and 1 hour after opening of the tourniquet and after reinfusion of drainage blood. Samples were also collected from the drainage blood immediately before and at the end of reinfusion. The leukocyte-derived and platelet-derived bioactive substances histamine, eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO), plasminogen activator inhibitor type 1 (PAI-1), and activated complement factor C3(C3a) and various coagulation factors and split products were analyzed in patient and drainage blood samples. None of the patients received additional predonated autologous blood or allogeneic blood components during the study period. Within 6 hours postoperatively, 250 to 1,000 mL drainage blood was collected and reinfused. Histamine, ECP, EPX, MPO, PAI-1, and C3a content was significantly increased in drainage blood immediately before and at the end of reinfusion. Reinfusion did not change the concentration of these substances in samples from the patients. Coagulation factors and various split products showed that drainage blood was defibrinated. Reinfusion of drainage blood did not change the coagulative capacity of the patients. Drainage blood appears to be defibrinated and contains various extracellular leukocyte-derived and platelet-derived bioactive substances. Reinfusion does not change the coagulative capacity or the concentration of bioactive substances of patients.

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.

Blood transfusion strategies for total knee arthroplasty: minimizing autologous blood wastage, risk of homologous blood transfusion, and transfusion cost

In this nonrandomized study, alternative strategies were suggested to 10 orthopaedic surgeons to minimize autologous blood wastage, the risk of homologous blood transfusion, and cost associated with blood product usage after total knee arthroplasty (TKA). One hundred fifty-five patients with 177 consecutive TKAs over a 2-year period were studied. Group 1 patients had undergone unilateral TKA and did not predonate; 1A patients (n = 19) were drained with a Hemovac, and 1B patients (n = 28) with a postoperative blood recovery system. Group 2 patients (n = 47) predonated one packed red blood cell (pRBC) unit. Group 3 patients (n = 20) predonated 2 pRBC units. Group 4 patients had undergone bilateral sequential TKAs (n = 21) and had predonated 2 pRBC units. Group 5 patients (n = 14) had undergone revision TKA procedures and their blood requirements were individualized. Group 6 patients (n = 6) had preexisting anemia and were excluded from the study. There was no significant difference in total blood loss (909 mL) between groups. Female sex was associated with significantly lower admission hematocrit. Homologous blood was required for 4% of patients in the entire study and the percentage was not statistically different between groups. Twenty-five percent of patients who predonated autologous pRBCs did not use all or some of it. In group 1, the postoperative blood recovery system had a significant effect on reducing postoperative hematocrit drop (P = .0001), but it was not a significant factor if autologous pRBCs were available. The costs associated with group 1A were significantly less (P = .0001) compared with the other groups; group 1A had the highest admission hematocrit (43.2). Transfusion with autologous pRBCs was related to lower admission hematocrit rather than to increased postoperative blood loss. An algorithm is presented to provide cost-effective management of blood products after TKA.

Perioperative interventions to decrease transfusion of allogeneic blood products

OBJECTIVE

To discuss some of the many options available for decreasing perioperative transfusion of allogeneic blood products.

DESIGN

We review the issues that focus on the goal of developing an appropriate transfusion strategy in consideration of the individual patient's preexisting conditions, physiologic requirements, perioperative stress, and coagulation status.

RESULTS

Increased awareness of transfusion-related morbidity from allogeneic blood products has resulted in increased development and application of alternatives to allogeneic transfusion. Preoperative donation and perioperative collection of autologous blood and blood products decrease exposure to allogeneic blood. Pharmacologic agents, such as antifibrinolytics, may also decrease the need for allogeneic transfusion. Perioperative use of laboratory tests of coagulation function facilitates the rapid and specific diagnosis of coagulation disorders.

CONCLUSION

Physicians now have considerable appreciation of the risks and benefits of blood product transfusion. This knowledge has resulted in conservative and scientific approaches to therapy for perioperative bleeding and coagulopathy.

Transfusion and surgery

In this survey of transfusion in surgery, we have attempted to provide the surgeon with an understanding of the problems associated with homologous transfusion and a practical knowledge of treatment strategies and alternatives designed to reduce homologous blood exposure. Such a review cannot be encyclopedic. Our hope is that it will serve the reader as a stimulus to examine his or her transfusion practices and as a guide for future self-learning.