Intraoperative autotransfusion in primary hip arthroplasty. A randomized comparison with homologous blood

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.

Efficacy of Intraoperative Blood Salvage in Cerebral Aneurysm Surgery

Background. The use and effectiveness of intraoperative cell salvage has been analyzed in many surgical specialties. Until now, no data exist evaluating the efficacy of intraoperative cell salvage in cerebral aneurysm surgery. Aim. To evaluate the efficacy and cost effectiveness of intraoperative cell salvage in cerebral aneurysm surgery. Methods. Data were collected retrospectively for all the patients who underwent cerebral aneurysm surgery at our institution between 2013 and 2019. Routinely, we apply blood salvage through autotransfusion. The cases were divided into a ruptured cerebral aneurysm group and a unruptured cerebral aneurysm group. Results. A total of 241 patients underwent cerebral aneurysm clipping. Of all the cerebral aneurysms, 116 were ruptured and 125 were unruptured and clipped electively. Age, location of the aneurysm, postoperative red blood cell count, intraoperative blood loss, and number of allogenic blood cell transfusions were statistically significantly different between the groups. The autotransfusion of salvaged blood could only be facilitated in eight cases with ruptured cerebral aneurysms and in none with unruptured cerebral aneurysms clipped electively (p < 0.01). Additionally, 35 patients with ruptured cerebral aneurysms and one patient with unruptured cerebral aneurysm required allogenic red blood cell transfusion after surgery, and 71 vs. 2 units of blood were transfused (p < 0.0001). In terms of cost effectiveness, a total of EUR 45,189 in 241 patients was spent to run the autotransfusion system, while EUR 13,797 was spent for allogenic blood transfusion. Conclusions. The use of cell salvage in patients with unruptured cerebral aneurysm, undergoing elective surgery, is not effective.

THE USE OF ANTIFIBRINOLYTICS IN HIP TRAUMA SURGERY IN A PUBLIC HEALTH SYSTEM: A PROSPECTIVE STUDY

Objective:

To evaluate the use of tranexamic acid (TXA) and ε-aminocaproic acid (EACA) in reducing blood loss in hip and proximal femur trauma surgery.

Methods:

Prospective study with 49 patients surgically treated in a trauma hospital between Nov/2015 and Feb/2017. The patients were divided in two groups: TXA (n = 24) and EACA (n = 25). The comparison was made according to gender, age at the time of surgery, ASA, fracture and surgery type, estimated blood loss during surgical approach, hemoglobin and hematocrit levels pre and post-operative, and pharmacological cost. The data was processed using SPSS 22.0 with significance level of p < 0,05.

Results:

No significant difference was found in the variables age, gender, ASA and estimated blood loss during surgical approach. No patient needed blood transfusion. When evaluated post-operatively, the hemoglobin and hematocrit values decrease had no significant difference between the antifibrinolytics (p > 0.05). When analyzing total cost for both pharmacological agents, higher cost was observed in EACA than in TXA (US$ 16.09 - US$ 2.73), resulting in a US$ 13.36 addition per patient.

Conclusion:

Antifibrinolytic use was efficient on lowering the total blood loss, without the need of blood transfusion. Level of evidence II, Prospective Comparative Study.

Is Intraoperative Blood Cell Salvage Effective in Hip Surgery?

Objective  The present study aims to evaluate the efficacy of blood cell salvage (CS) as a method of reducing allogeneic blood transfusion in patients submitted to transtrochanteric femoral and hip surgeries due to injury.

Methods  Prospective cohort of 38 patients from a school hospital submitted to hip or trochanteric surgeries and divided into two groups from August 2015 to February 2017. Patients with any malignancy or infectious condition were excluded from the study. Cell savage group (19 patients) received autologous blood using cell saver, whereas control group (19 patients) received just allogeneic blood, if needed. Red blood cell parameters, blood transfusion requirements, and clinical and surgical characteristics, such as age, gender, ASA scale and type of surgery, were compared both preoperatively and postoperatively. Data was processed in SPSS 20.0.

Results  There were no differences in the clinical parameters studied (age, gender and ASA scale). Red blood cell parameters on the first day postoperative were higher in the cell savage group ( p  < 0.05). No significant reduction of intraoperative and postoperative allogeneic blood transfusion requirements was found.

Conclusion  This study found that CS was not effective in reducing intraoperative and postoperative allogeneic blood transfusion requirements in patients submitted to transtrochanteric femoral and hip surgery.

Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome

PURPOSE

Aseptic loosening in total joint replacement due to insufficient osteointegration is an unsolved problem in orthopaedics. The purpose of the study is to obtain a picture of the initial protein adsorption layer on femoral endoprosthetic surfaces as the key to the initiation of osseointegration.

EXPERIMENTAL DESIGN

The paper describes the first study of femoral stem explants from patients for proteome analysis of the primary protein layer. After 2 min in situ, the stems are explanted and frozen in liquid nitrogen. Proteins are eluted under reducing conditions and analyzed by LC-MS/MS.

RESULTS

After exclusion of proteins identified by a single peptide, the implant proteome is found to consist of 2802 unique proteins. Of these, 77% are of intracellular origin, 9% are derived from the plasma proteome, 8% from the bone proteome, and four proteins with highest specificity score could be assigned to the bone marrow proteome (transcriptome). The most abundant protein in the adsorbed total protein layer is hemoglobin (8-11%) followed by serum albumin (3.6-6%).

CONCLUSIONS

A detailed knowledge of the initial protein film deposited onto the implants, as demonstrated here for the first time, may help to understand and predict the response of the osseous microenvironment to implant surfaces.

Washed cell salvage in surgical patients: A review and meta-analysis of prospective randomized trials under PRISMA

BACKGROUND

Cell salvage is commonly used as part of a blood conservation strategy. However concerns among clinicians exist about the efficacy of transfusion of washed cell salvage.

METHODS

We performed a meta-analysis of randomized controlled trials in which patients, scheduled for all types of surgery, were randomized to washed cell salvage or to a control group with no cell salvage. Data were independently extracted, risk ratio (RR), and weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated. Data were pooled using a random effects model. The primary endpoint was the number of patients exposed to allogeneic red blood cell (RBC) transfusion.

RESULTS

Out of 1140 search results, a total of 47 trials were included. Overall, the use of washed cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 39% (RR = 0.61; 95% CI 0.57 to 0.65; P < 0.001), resulting in an average saving of 0.20 units of allogeneic RBC per patient (weighted mean differences [WMD] = -0.20; 95% CI -0.22 to -0.18; P < 0.001), reduced risk of infection by 28% (RR = 0.72; 95% CI 0.54 to 0.97; P = 0.03), reduced length of hospital stay by 2.31 days (WMD = -2.31; 95% CI -2.50 to -2.11; P < 0.001), but did not significantly affect risk of mortality (RR = 0.92; 95% CI 0.63 to 1.34; P = 0.66). No statistical difference could be observed in the number of patients exposed to re-operation, plasma, platelets, or rate of myocardial infarction and stroke.

CONCLUSIONS

Washed cell salvage is efficacious in reducing the need for allogeneic RBC transfusion and risk of infection in surgery.

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.

Favourable results of a new intraoperative and postoperative filtered autologous blood re-transfusion system in total hip arthroplasty: a randomised controlled trial

PURPOSE

A new intraoperative filtered salvaged blood re-transfusion system has been developed for primary total hip arthroplasty (THA) that filters and re-transfuses the blood that is lost during THA. This system is intended to increase postoperative haemoglobin (Hb) levels, reduce perioperative net blood loss and reduce the need for allogeneic transfusions. It supposedly does not have the disadvantages of intraoperative cell-washing/separating re-transfusion systems, such as extensive procedure, high costs and need for specialised personnel. To re-transfuse as much as blood as possible, postoperatively drained blood was also re-transfused.

METHODS

A randomised, controlled, blinded, single-centre trial was conducted in which 118 THA patients were randomised to an intraoperative autologous blood re-transfusion (ABT) filter system combined with a postoperative ABT filter unit or high-vacuum closed-suction drainage.

RESULTS

On average, 577 ml of blood was re-transfused in the ABT group: 323 ml collected intraoperatively and 254 ml collected postoperatively. Hb level was higher in the ABT vs the high-vacuum drainage group: 11.4 vs. 10.8 g/dl, p = 0.02 on day one (primary endpoint) and 11.0 vs. 10.4 g/dl, p = 0.007 on day three. Total blood loss was less in the autotransfusion group: 1472 vs. 1678 ml, p = 0.03. Allogeneic transfusions were needed in 3.6 % of patients in the ABT group and 6.5 % in the drainage group, p = 0.68.

CONCLUSION

The use of a new intraoperative ABT filter system combined with a postoperative ABT unit resulted in higher postoperative Hb levels and less total blood loss compared with a high-vacuum drain following THA.

Reduction of blood loss with the use of a new combined intra-operative and post-operative autologous blood transfusion system compared with no drainage in primary total hip replacement

Autologous retransfusion and no-drainage are both blood-saving measures in total hip replacement (THR). A new combined intra- and post-operative autotransfusion filter system has been developed especially for primary THR, and we conducted a randomised controlled blinded study comparing this with no-drainage. A total of 204 THR patients were randomised to autologous blood transfusion (ABT) (n = 102) or no-drainage (n = 102). In the ABT group, a mean of 488 ml (sd 252) of blood was retransfused. The mean lowest post-operative haemoglobin level during the hospital stay was higher in the autotransfusion group (10.6 g/dl (7.8 to 13.9) vs 10.2 g/dl (7.5 to 13.3); p = 0.01). The mean haemoglobin levels for the ABT and no-drainage groups were not significantly different on the first day (11.3 g/dl (7.8 to 13.9) vs 11.0 g/dl (8.1 to 13.4); p = 0.07), the second day (11.1 g/dl (8.2 to 13.8) vs 10.8 g/dl (7.5 to 13.3); p = 0.09) or the third day (10.8 g/dl (8.0 to 13.0) vs 10.6 g/dl (7.5 to 14.1); p = 0.15). The mean total peri-operative net blood loss was 1464 ml (sd 505) in the ABT group and 1654 ml (sd 553) in the no-drainage group (p = 0.01). Homologous blood transfusions were needed in four patients (3.9%) in the ABT group and nine (8.8%) in the no-drainage group (p = 0.15). No statistically significant difference in adverse events was found between the groups. The use of a new intra- and post-operative autologous blood transfusion filter system results in less total blood loss and a smaller maximum decrease in haemoglobin levels than no-drainage following primary THR.

The role of tranexamic acid in reducing blood loss in total knee replacement

BACKGROUND

Total knee arthroplasty is associated with significant perioperative blood loss which may necessitate blood transfusion. In this prospective randomised case control study we analysed the efficacy and safety of tranexamic acid in reducing perioperative blood loss and requirement of blood transfusion in total knee arthroplasty.

METHODS

Fourteen patients (group A) undergoing total knee replacement were given intravenous tranexamic acid twice, once ten minutes before tourniquet deflation and once after four hours. Thirteen patients (group B) were observed as a separate group without the administration of the drug. Total perioperative blood loss, need of blood transfusion and D-dimer assay were analysed subsequently.

RESULTS

The average blood loss in the first group was 266.2 ml and in the second group was 667.5 ml (p < 0.001). average requirement of transfusion in both the groups were 0.54 and 1.6 units of blood respectively (p < 0.001). There was no case of deep vein thrombosis or any other untoward effects.

CONCLUSION

Hence from these evidences it was concluded that administration of tranexamic acid during total knee replacement helps to reduce blood loss without increasing the risk of deep vein thrombosis.

Changing transfusion practice in total hip arthroplasty: observational study of the reduction of blood use over 6 years

Patients undergoing primary total hip arthroplasty (THA) have historically been over-transfused. In a district general hospital setting, the authors observed a significant downward trend in blood transfusion requirements in these patients over 6 years after a change in transfusion policy. The purpose of this study was to retrospectively analyze the change in transfusion practice and present the results of the restrictive transfusion policy. All patients undergoing primary THA between January 2003 and December 2008 were identified from hospital records. Pre- and postoperative hemoglobin levels, transfusion trigger hemoglobin, blood transfusion requirements, patient age and sex, 30-day mortality, and length of stay data were analyzed for all patients. A total of 1169 primary THAs were performed. Annual allogeneic blood transfusion requirements reduced progressively from 151 units in 2003 to 90 units in 2008 despite an increase in the number of patients undergoing THA. During this period, the proportion of patients transfused decreased from 35% to 17%. A reduction of mean transfusion trigger hemoglobin from 79 to 73 g/L was observed over the study period. No patient experienced any significant complications as a result of undertransfusion. The authors' institution has steadily restricted the use of blood transfusion in patients undergoing THA to those symptomatic of anemia. Increasing confidence among medical and nursing staff that reduced postoperative hemoglobin levels can be safely tolerated has resulted in a 55% reduction in blood transfusion in patients undergoing THA with no other change of practice.

Postoperative autologous blood transfusion drain or no drain in primary total hip arthroplasty? A randomised controlled trial

PURPOSE

Postoperative maintenance of high haemoglobin (Hb) levels and avoidance of homologous blood transfusions is important in total hip arthroplasty (THA). The introduction of a postoperative drainage autologous blood transfusion (ABT) system or no drainage following THA has resulted in reduction of homologous blood transfusion requirements compared with closed-suction drains. The purpose of this study was to examine which regimen is superior following THA.

METHODS

A randomised controlled blinded prospective single-centre study was conducted in which 100 THA patients were randomly allocated to ABT or no drainage. The primary endpoint was the Hb level on the first postoperative day.

RESULTS

The postoperative collected drained blood loss was 274 (±154) ml in the ABT group, of which 129 (±119) ml was retransfused (0-400). There was no statistical difference in Hb levels on the first postoperative day (ABT vs no drainage: Hb 11.0 vs 10.9 g/dl), on consecutive days (day 3: Hb 10.7 vs 10.2, p = 0.08) or in total blood loss (1,506 vs 1,633 ml), homologous transfusions, pain scores, Harris Hip Score, SF-36 scores, length of hospital stay or adverse events.

CONCLUSIONS

The use of a postoperative autologous blood retransfusion drain did not result in significantly higher postoperative Hb levels or in less total blood loss or fewer homologous blood transfusions compared with no drain.

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.

Peri-operative blood management in elective orthopaedic surgery. A critical review of the literature

Blood loss during orthopaedic procedures can be extensive and the need for allogeneic blood is a common requirement. However, blood transfusion conceals a number of well-recognised risks and complications and blood products have become more expensive because of their specific preparation procedure. Surgical technique, awareness of the problem and restriction of transfusion triggers are important factors affecting the management of blood loss. Several studies have additionally shown the efficacy of epoetin injections in increasing the pre-operative haemoglobin level. On the other hand, the true benefit of pre-operative autologous donation, acute normovolemic haemodilution and COX-2 selective NSAIDs remains under dispute. Regarding the role of platelet rich plasmapheresis, fibrin sealing and anti-fibinolytic drugs more data are needed. Hypotensive epidural anaesthesia seems to be an advantageous method in minimising peri-operative blood loss. However, this is not a widely performed technique in orthopaedic surgery. In addition, post-operative blood cell saving systems after total knee or hip arthroplasty have been reported to significantly minimise allogeneic blood transfusions when compared to control groups. It can be concluded that many interventions diminish more or less allogeneic blood transfusion in elective orthopaedic surgery. Nevertheless more prospective studies are needed and appropriate algorithms should be applied in peri-operative blood loss management. This review presents an overview of the available interventions which aim to diminish the use of allogeneic blood in elective orthopaedic surgery.

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.

Particle separation using ultrasound can radically reduce embolic load to brain after cardiac surgery

BACKGROUND

Microembolism during cardiopulmonary bypass has been suggested as being the predominant cause of neurocognitive disorders after cardiac surgery. Shed blood, normally retransfused into the patient during cardiopulmonary bypass, is a major source of lipid microemboli in the brain capillaries. A newly developed technique based on acoustic standing-wave separation of particles in fluid in microchannels, with the capacity to remove lipid particles in blood, is presented.

METHODS

A separator consisting of eight parallel, high-fidelity microfabricated channels was actuated with an ultrasound field to create a standing wave. Three different concentrations of lipid particles (diameter, 0.3 microm) were added to blood samples with increasing hematocrits and introduced into the separator channels to separate lipid particles and erythrocytes.

RESULTS

The mean separation rates for lipid particles were 81.9% +/- 7.6% and for erythrocytes 79.8% +/- 9.9%, and both were related to the hematocrit level of the incoming blood sample. The procedure was atraumatic and did not cause hemolysis.

CONCLUSIONS

Particle separation by means of an acoustic standing-wave technique can be used for atraumatic and effective removal of lipid particles from blood, with the possible clinical implication of reducing neurocognitive complications after cardiopulmonary bypass.

Combined use of autologous transfusion techniques to avoid allogeneic transfusion in spinal fusion surgery with instrumentation

This study conducted a retrospective review of the medical records of 321 patients to delineate the efficacy of the combined use of autologous transfusion (AT) techniques. Transfusion profiles between an AT and homologous transfusion (HT) group were compared. A much lower proportion of patients were exposed to allogeneic blood in the AT group (13%) than in the HT group (98%, p<0.001). In the AT group, a significantly smaller proportion of patients were exposed to allogeneic blood in patients transfused with three or four AT techniques (8%) than those with one or two techniques (29%, p<0.05). A febrile reaction (11% of patients) after a reinfusion of post-operatively shed blood was the only side effect associated with an AT. In conclusion, an AT is effective for preventing the exposure of allogeneic blood in spinal fusion surgery. The combined use of multiple AT techniques may further improve its efficacy.

Blood loss in patients for total knee arthroplasty

Ninety-four patients with osteoarthritis (OA) and 180 with rheumatoid arthritis (RA) undergoing unilateral total knee arthroplasty (TKA) were analyzed to clarify the necessity for preoperative autogenous blood deposition or homologous blood transfusion. Two hundred and twenty-four and 50 patients underwent TKA with cement and without cement, respectively. The difference in average blood loss in patients between with (372 ml) and without cementation (449 ml) was significant. In the OA group the average blood loss significantly decreased after cementation but not in the RA group. Although the rate of avoiding transfusion in the OA group did not significantly decrease with the use of cement (92.4% vs. 93.3%), that in the RA group did (80% to 57.1%). Eight of 159 patients with hemoglobin level (Hb) of 11.0 g/dl or higher received homologous blood transfusion. Of these eight patients five had associated disorders. Only one patient with Hb of 12.0 g/dl or higher underwent homologous blood transfusion. Patients with Hb of 12.0 g/dl or higher are not indicated for preoperative autologous blood deposition. In patients with Hb between 11.0 and 12.0 g/dl preoperative blood deposition may be planned after consideration of general condition and complication. Patients with Hb lower than 11.0 g/dl should undergo preoperative blood deposition.

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.

Angiotensin-converting enzyme gene polymorphism may influence blood loss in a geriatric population undergoing total hip arthroplasty

OBJECTIVES

To evaluate how angiotensin-converting enzyme (ACE) gene polymorphism is associated with perioperative blood loss in hip arthroplasty in a geriatric population.

DESIGN

A case-control study of subjects consecutively undergoing total hip arthroplasty.

SETTING

A department of orthopedic surgery in Italy.

PARTICIPANTS

One hundred five patients, mean age +/- standard deviation 68.6 +/- 10.4, undergoing total hip arthroplasty.

MEASUREMENTS

ACE gene polymorphism was analyzed using polymerase chain reaction. Decrement of hemoglobin (Hb) and hematocrit (Ht) was calculated as the difference between the preoperative and the lowest postoperative value, measured 1, 2, and 3 days after surgery. Total blood loss was calculated as the sum of intra- and postoperative blood loss.

RESULTS

Patients carrying the deletion homozygous and insertion/deletion heterozygous genotypes of the ACE gene show a higher decrement of Hb (P <.01) and Ht (P <.01) and higher total blood loss (P <.007) after hip surgery than subjects carrying the insertion (II) homozygous. The role of ACE gene polymorphism seems hypertension independent. Logistic regression analysis showed that II genotype reduces total blood loss.

CONCLUSIONS

This is the largest study evaluating the distribution of ACE gene genotypes in patients undergoing hip arthroplasty and the first investigating the association between bleeding and ACE gene polymorphism. Our data suggest that II genotype is associated with lower total blood loss.

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.

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

BACKGROUND

The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.

METHODS

In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (mililitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.

RESULTS

Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r2 = 0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0-4 u). However, 32% of such patients required allogeneic blood.

CONCLUSIONS

Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.

Autotransfusion--bacterial contamination during hip arthroplasty and efficacy of cefuroxime prophylaxis. A randomized controlled study of 40 patients

40 patients undergoing primary hip arthroplasty, given autologous processed blood transfusion, were randomized a receive no antibiotic prophylaxis (group A, n 20) or cefuroxime (1.5 g single injection; group B, n 20). Bacterial contamination at various steps in the autotransfusion procedure was assessed in liquid and solid culture media. The operation field and the wound drainage blood were never contaminated either of the groups but some of the suction tips were. Parts of the Vacufix blood collection bags of group A contained bacteria, but none in group B. Processed red blood cell concentrates in both groups showed bacterial growth. Greater blood loss did not increase the contamination rate in general. Isolated bacteria included the species Staphylococcus epidermidis, coagulase-negative staphylococci and Propionibacteria in both groups, but with different cell counts. In addition, Corynebacterium bovis et minutissimum and Moraxelle were identified in group A. In conclusion, autologous blood transfusion was a safe procedure. If contamination occurred, the bacterial count was low, and the bacteria of low pathogenicity. Antibiotic prophylaxis with cefuroxime reduced this contamination of suction tips and collection bags and limited the transfer of autologous blood products.

Cytokine and coagulation characteristics of retrieved blood after arthroplasty

OBJECTIVES

To investigate cytokine and coagulation/fibrinolysis characteristics in blood retrieved from wounds using an autotransfusion system, and to compare the cytokine pattern in the retrieved blood with those in the systemic circulation and in the initial portion of drainage blood from the wound.

DESIGN

Prospective controlled clinical study.

SETTING

The postoperative ward of a University hospital.

PATIENTS AND PARTICIPANTS

Blood retrieval was performed over a period of 4-6 h on patients who had just undergone arthroplasty (nine hips, one knee). In five other cases involving hip arthroplasties, the initial portion of drainage blood was studied.

MEASUREMENTS AND RESULTS

Coagulation/fibrinolysis parameters were analyzed in blood retrieved using the Stryker Consta Vac system. Concentrations of tumor necrosis factor alpha (TNF), interleukin-1 beta (IL-1) and interleukin-6 (IL-6) were analyzed in the retrieved blood, in the systemic circulation of the patients at the beginning and at the end of blood retrieval and in the initial portion of drainage blood from the surgical area. In the retrieved blood, the activities of thrombin, kallikrein and plasmin were increased, antithrombin and free protein S were decreased, and in all samples IL-6 was >1000 pg/ml. Postoperative plasma concentrations of IL-6 rose from a median value of 0 to 116 pg/ml (p <0.01). Four patients had circulating TNF concentrations (range: <15-50 pg/ml). Plasma IL-1 was not detected. TNF and IL-1 were detected in all samples of initial blood from the surgical area and IL-6 in one sample.

CONCLUSION

Hypercoagulability and high concentrations of IL-6 were present in the retrieved blood. The cytokine pattern in the initial portion of blood from the surgical area differed from those in the retrieved blood and in the systemic circulation.

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.

Intraoperative autotransfusion in hip arthroplasty. A retrospective study of 214 cases with matched controls

The transfusion requirements in 214 patients who received intraoperatively collected autologous blood during total hip arthroplasty (Study Group) were compared with 214 age- and sex-matched controls who received homologous bank blood (Control Group). There were 132 patients with primary operations, 27 bilateral, and 55 revisions in each group. In the Study Group, there was a reduction in the amount of homologous blood transfusion, intraoperatively as well as totally, and also in postoperative blood loss in all three operation subsets. The Study and Control Groups were equal in pre- and postoperative hemoglobin and hematocrit values.

Autologous blood transfusion in revision hip arthroplasty. A prospective, controlled study of 30 patients

In a prospective, randomized study of the efficacy and effects of autologous blood transfusion in revision hip arthroplasty, 30 patients were randomly allocated into two groups. The Control Group received homologous blood transfusion. The Study Group deposited 2-3 units of blood preoperatively, intraoperative blood salvage was used, and no homologous blood was transfused intraoperatively. There was a smaller postoperative blood loss in the Study Group. The preoperative hemoglobin values were lower in the Study Group, but one week postoperatively they were higher than in the Control Group. The decrease in the values of AT III and protein C was lower in the Study Group. The combination of preoperative blood donation and intraoperative blood salvage reduced blood loss and homologous blood transfusion in revision hip arthroplasty.