Intraoperative autologous transfusion in primary and revision total hip arthroplasty

Development of machine learning models to predict perioperative blood transfusion in hip surgery

BACKGROUND

Allogeneic Blood transfusion is common in hip surgery but is associated with increased morbidity. Accurate prediction of transfusion risk is necessary for minimizing blood product waste and preoperative decision-making. The study aimed to develop machine learning models for predicting perioperative blood transfusion in hip surgery and identify significant risk factors.

METHODS

Data of patients undergoing hip surgery between January 2013 and October 2021 in the Peking Union Medical College Hospital were collected to train and test predictive models. The primary outcome was perioperative red blood cell (RBC) transfusion within 72 h of surgery. Fourteen machine learning algorithms were established to predict blood transfusion risk incorporating patient demographic characteristics, preoperative laboratory tests, and surgical information. Discrimination, calibration, and decision curve analysis were used to evaluate machine learning models. SHapley Additive exPlanations (SHAP) was performed to interpret models.

RESULTS

In this study, 2431 hip surgeries were included. The Ridge Classifier performed the best with an AUC = 0.85 (95% CI, 0.81 to 0.88) and a Brier score = 0.21. Patient-related risk factors included lower preoperative hemoglobin, American Society of Anesthesiologists (ASA) Physical Status > 2, anemia, lower preoperative fibrinogen, and lower preoperative albumin. Surgery-related risk factors included longer operation time, total hip arthroplasty, and autotransfusion.

CONCLUSIONS

The machine learning model developed in this study achieved high predictive performance using available variables for perioperative blood transfusion in hip surgery. The predictors identified could be helpful for risk stratification, preoperative optimization, and outcomes improvement.

Intraoperative cell salvage in revision hip arthroplasty

Aims

The aim of this study was to perform a systematic review of the evidence for the use of intraoperative cell salvage in patients undergoing revision hip arthroplasty, and specifically to analyze the available data in order to quantify any associated reduction in the use of allogenic blood transfusion, and the volume which is used.

Methods

An electronic search of MEDLINE (PubMed), Embase, Scopus, and the Cochrane Library was completed from the date of their inception to 24 February 2022, using a search strategy and protocol created in conjunction with the PRISMA statement. Inclusion criteria were patients aged > 18 years who underwent revision hip arthroplasty when cell salvage was used. Studies in which pre-donated red blood cells were used were excluded. A meta-analysis was also performed using a random effects model with significance set at p = 0.05.

Results

Of the 283 studies which were identified, 11 were included in the systematic review, and nine in the meta-analysis. There was a significant difference (p < 0.001) in the proportion of patients requiring allogenic transfusion between groups, with an odds ratio of 0.331 (95% confidence interval (CI) 0.165 to 0.663) associated with the use of cell salvage. For a total of 561 patients undergoing revision hip arthroplasty who were treated with cell salvage, 247 (44.0%) required allogenic transfusion compared with 418 of 643 patients (65.0%) who were treated without cell salvage. For those treated with cell salvage, the mean volume of allogenic blood which was required was 1.95 units (390 ml) per patient (0.7 to 4.5 units), compared with 3.25 units (650 ml) per patient (1.2 to 7.0 units) in those treated without cell salvage. The mean difference of -1.91 units (95% CI -4.0 to 0.2) in the meta-analysis was also significant (p = 0.003).

Conclusion

We found a a significant reduction in the need for allogenic blood transfusion when cell salvage was used in patients undergoing revision hip arthroplasty, supporting its routine use in these patients. Further research is required to determine whether this effect is associated with types of revision arthroplasty of differing complexity.

A cost-effectiveness analysis of intraoperative autologous transfusion in adolescent idiopathic scoliosis surgery: a single-centre retrospective study

BACKGROUND

Intraoperative autologous transfusion (IAT) has been used in scoliosis surgery for decades; however, its cost-effectiveness remains debatable. This study aimed to evaluate the cost-effectiveness of IAT in adolescent idiopathic scoliosis (AIS) surgery and identify risk factors of massive intraoperative blood during this surgery.

METHODS

The medical records of 402 patients who underwent AIS surgery were reviewed. The patients were divided into different groups according to the intraoperative blood loss volume (group A: ≥500 to < 1000 mL, B: ≥1,000 to < 1,500 mL, and C: ≥1,500 mL) and whether IAT was used (i.e., IAT and no-IAT groups). The volume of blood loss, volume of transfused allogeneic red blood cells (RBC), and RBC transfusion costs were analysed. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors of massive intraoperative blood loss (≥ 1,000 mL and ≥ 1,500 mL). A receiver operating characteristic (ROC) curve was used to analyse the cut-off values of the factors contributing to massive intraoperative blood loss.

RESULTS

In group A, no significant difference was observed in the volume of allogeneic RBC transfused during and after procedure between the IAT and no-IAT groups; however, total RBC transfusion costs was significantly higher in the IAT group. In groups B and C, the patients in the IAT group compared with those in the no-IAT group had a lower volume of allogeneic RBC transfused during the operation and on the first day after the operation. However, in group B, the total RBC transfusion cost in the patients who used IAT was significantly higher. In group C, total RBC transfusion cost in the patients who used IAT was significantly lower. The number of fused vertebral levels and Ponte osteotomy were found to be independent risk factors for massive intraoperative blood loss. ROC analysis showed that more than eight and 10 fused vertebral levels predicted ≥ 1,000 mL and ≥ 1,500 mL intraoperative blood loss, respectively.

CONCLUSION

The cost-effectiveness of IAT in AIS was related to the volume of blood loss, and when the blood loss volume was ≥ 1,500 mL, IAT was cost-effective, drastically reducing the demand for allogeneic RBC and total RBC transfusion cost. The number of fused vertebral levels and Ponte osteotomy were independent risk factors for massive intraoperative blood loss.

Optimising the use of cell salvage in revision hip arthroplasty

BACKGROUND

Intraoperative cell salvage is an established method to reduce the requirement for and the volume of allogenic blood transfusion but adds to the financial cost of performing surgery.

AIMS

The primary aim of this study was to determine which patients and what type of revision hip surgery benefit most from intraoperative cell salvage.

METHODS

This observational study included patients who underwent revision hip surgery performed by the senior author at a single orthopaedic unit. The cohort was divided into single and two-component revision groups; then, the transfusion requirement combined with analysis of patient factors was used to create a decision-making protocol.

FINDINGS

The two-component group had a significantly higher number of cases using cell salvage and a higher total transfusion volume. Patients who required postoperative allogenic blood transfusions had a higher mean age, were less likely to have received tranexamic acid and had a lower preoperative haemoglobin level.

CONCLUSION

Based on these results, a decision-making protocol was developed for when to use cell salvage in revision hip surgery.

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.

Postoperative Blood Salvage and Autotransfusion for Adult Spinal Deformity: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

The aim of this study was to determine whether postoperative blood salvage and autotransfusion versus traditional closed suction drainage reduces the rate of homologous blood transfusions in patients undergoing surgery for adult spinal deformity.

SUMMARY OF BACKGROUND DATA

The use of intraoperative blood salvage has become commonplace in spine surgery; however, the collection and reinfusion of blood drained from the wound postoperatively have not been employed routinely because of increased cost and questionable benefit.

METHODS

Adult patients undergoing long posterior fusions were randomized to either a blood salvage and reinfusion system (OrthoPat - Group 1) or a standard subfascial closed suction drain (Group 2). Blood collected in Group 1 was reinfused according to the manufacturer's protocol. Reinfusion drains were converted to standard closed suction drains when output was <50 mL during 4 hours, and drains were removed when output was minimal. Patients received autologous or homologous blood transfusions when hemoglobin (Hg) <8 g/dL or they had symptomatic anemia.

RESULTS

Thirty-four patients were randomized into Group 1 and 36 patients into Group 2. There were no differences in preoperative or intraoperative parameters. Patients in Group 1 had higher hemoglobin levels on postoperative day (POD) 2 and POD 3 compared to those in Group 2. However, there was no significant difference in the percentage of patients requiring homologous blood transfusion between the two groups (41% Group 1 vs. 60% Group 2, P = 0.17). Similarly a subgroup analysis in patients with estimated blood loss >2000 mL also showed no difference in homologous blood transfusion rates (67% Group 1 vs. 76% Group 2, P = 0.58). There were no differences in the rate or type of postoperative complications.

CONCLUSION

Postoperative blood salvage and reinfusion result in a higher hemoglobin level in the early postoperative period, but does not significantly reduce the need for homologous blood transfusion.

LEVEL OF EVIDENCE

1.

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.

Acute Kidney Injury Secondary to Cell Saver in Posterior Spinal Fusion

BACKGROUND

Autologous blood transfusion, commonly referred to as cell saver, is frequently used in spinal fusion to salvage red blood cells because of the risk of significant intraoperative blood loss. This case report describes a case of acute kidney injury (AKI) secondary to cell saver use. Our objective is to increase the knowledge about the process of red blood cell salvage and this exceedingly rare complication.

METHODS

Chart and renal biopsy results for a single case were reviewed and reported in this retrospective study.

RESULTS

A healthy 18-year-old male patient underwent posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis with utilization of intraoperative autologous blood transfusion. The patient subsequently developed hematuria and AKI with a peak creatinine of 13.9 mg/dL. An extensive clinical workup, including autoimmune serology, excluded any identifying causes. A renal biopsy showed pigment-induced acute tubular necrosis.

CONCLUSIONS

This case, to our knowledge, is the first and only case report of AKI secondary to cell saver demonstrated by renal biopsy. The literature has shown both the benefit of cell saver by decreasing the need for allogeneic transfusion and the risk of transient hematuria. However, this case demonstrates the importance of monitoring patients for potential complications.

Intraoperative blood salvage in revision total hip arthroplasty: who benefits most?

The purpose of the present study was to identify factors that predict reinfusion following intraoperative blood salvage (IOBS). We retrospectively identified 298 patients who underwent aseptic revision total hip arthroplasty at our institution between February 2005 and January 2007. Of these, 160 (53.7%) received reinfusion from IOBS. In the reinfusion group, an average of 850 mL (range, 300-4300) of fluid was collected and an average of 270 mL (range, 135-1350) of red blood cells was returned. Exchange of both the femoral and acetabular components, use of a trochanteric osteotomy, increased body mass index, and advanced age were associated with reinfusion. Based on these results, surgeons may consider using IOBS on patients with these preoperative characteristics.

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.

Cell Saver: is it beneficial in scoliosis surgery?

STUDY DESIGN

Review of the use of Cell Saver in a non-randomized group of patients undergoing spinal fusion for scoliosis.

OBJECTIVES

To determine the efficacy of the use of Cell Saver for spinal fusions for scoliosis. Although Cell Saver is widely used in scoliosis surgery, it is not clear whether its use decreases the need for other transfusions or whether there are certain patients more likely to benefit from its use. The blood collected by Cell Saver intraoperatively is not always of sufficient volume to be returned to the patient, and there are no current guidelines addressing the amount that is likely to be returned to the patient.

PURPOSE

The purpose of this study was to determine: Does use of Cell Saver reduce the need for other transfusions in scoliosis surgery? Is there an amount of blood loss at which Cell Saver is likely to be returned?

MATERIALS AND METHODS

The study group consisted of 95 children who had undergone posterior spinal fusion between January 2002 and March 2004 with one of two surgeons. One surgeon used Cell Saver, the other surgeon did not. Of the total, 58 patients who underwent posterior spinal fusion with the use of Cell Saver (group 1) were compared with the 37 (group 2) who underwent the same procedure without the use of Cell Saver.

RESULTS

Of those in group 1, 34 received Cell Saver blood back as an intraoperative autologous transfusion (IAT) (59%). Patients in the Cell Saver group were just as likely to receive non-Cell Saver transfusions as those in the control group (P = 0.12). Of the 39 patients who lost more than 500 cc of blood, 34 received IAT (87%). No patient who lost less than 500 cc of blood received IAT.

CONCLUSION

The use of Cell Saver does not reduce the need for other transfusions in scoliosis surgery. The amount of blood loss at which Cell Saver is likely to be returned is 500 cc. We demonstrated no benefit in the use of Cell Saver in our patient population.

Intraoperative red blood-cell salvage in revision hip surgery. A case-matched study

BACKGROUND

Revision hip arthroplasty is commonly associated with substantial blood loss and the subsequent need for transfusion. This leads to an increased risk of blood-borne infection and hemolytic reactions. The purpose of this study was to demonstrate whether the use of intraoperative red blood-cell salvage in revision hip arthroplasty reduces the overall rate of allogeneic transfusion.

METHODS

Forty-seven patients who had undergone revision hip arthroplasty with the use of intraoperative cell salvage were identified. A computer database was used to individually match these patients, for age, sex, and eleven operative variables, to control patients who had undergone revision hip arthroplasty in the same unit without intraoperative cell salvage. Data gathered included the total allogeneic transfusion requirement for each patient, preoperative and postoperative hemoglobin levels, and operative time.

RESULTS

The total allogeneic transfusion requirement was significantly lower in the group that had intraoperative cell salvage than in the control group (median, 2 compared with 6 U of packed red blood cells, p = 0.0006), with a median reduction in allogeneic transfusion of 4 U. There was no significant difference in preoperative or postoperative hemoglobin levels between the groups.

CONCLUSIONS

The use of intraoperative cell salvage significantly lowered the allogeneic transfusion requirement, which can lead to substantial cost savings. To our knowledge, this is the first study in which the use of intraoperative red blood-cell salvage in revision hip arthroplasty was evaluated by matching patients on the basis of age, sex, and operative variables.

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.

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

Aprotinin is a proteinase inhibitor that reduces blood loss in total hip arthroplasty when administered in large doses. Little is known about the capability of smaller doses of aprotinin in reducing blood loss and transfusion needs in this surgical setting. We reviewed the medical records of 372 patients who had undergone unilateral primary total hip arthroplasty under general anaesthesia during a 6-year period (1989 to 1994) at our institution. Successively, 193 patients had and 179 patients had not received aprotinin in a dose of 20,000 kallikrein inhibitor units per kilogram body weight intravenously before surgery. Neither the volume of red blood cells lost nor that of red blood cells transfused during hospitalization differed significantly between the patients who had and those who had not received aprotinin (520 +/- 406 vs. 549 +/- 394 mL and 463 +/- 379 vs. 475 +/- 367 mL; P = 0.49 and P = 0.76 respectively). These results suggest that small-dose aprotinin was not effective in reducing blood loss and transfusion needs in patients undergoing unilateral primary total hip replacement.

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.

Blood salvage after total hip and total knee arthroplasty

We performed a prospective study to determine the effect of postoperative collection and reinfusion of unwashed, filtered, salvaged blood alone and in combination with preoperative predeposited blood on the transfusion requirements of 375 patients treated with a total hip or total knee replacement. 208 patients were managed with postoperative blood salvage with use of the CBC ConstaVac autotransfusion system and closed suction drainage. Another 50 patients predeposited 1-4 units of autologous blood, before the operation, in addition to postoperative blood salvage. The remaining 117 patients were used as controls and were transfused with homologous blood from the blood bank. Postoperative reinfusion of salvaged blood decreased the need for homologous transfusion after hip and knee arthroplasty (mean 2.7 units) compared to controls (mean 4.2 units). The combination of postoperative reinfusion of salvaged blood and predeposited autologous blood was associated with the lowest requirements for homologous blood transfusions (mean 1.7 units).

Efficacy and cost considerations of intraoperative autologous transfusion in spinal fusion for idiopathic scoliosis with predeposited blood

STUDY DESIGN

One hundred five patients with adolescent idiopathic scoliosis who underwent posterior spinal instrumentation and fusion with predeposited autologous blood, with or without intraoperative autologous transfusion, were reviewed.

OBJECTIVE

To determine the benefit/nonbenefit of intraoperative autologous transfusion in diminishing the need for homologous blood and influencing post-operative hematocrit values in healthy adolescents undergoing spinal fusion for scoliosis.

SUMMARY OF BACKGROUND DATA

A steady increase in the use of intraoperative autologous transfusion in recent years has occurred without guidelines regarding which procedures and patient populations would be best served. Previous studies have failed to determine the cost effectiveness and actual reduction in homologous blood exposure attributable to intraoperative autologous transfusion in adolescents who have undergone preoperative phlebotomy.

METHODS

Fifty-five adolescents (intraoperative autologous transfusion group) who underwent posterior instrumentation and fusion for idiopathic scoliosis with the use of an intraoperative autologous transfusion device were compared to 50 patients (control group) who underwent the same procedure without the intraoperative autologous transfusion device.

RESULTS

The average percent salvage of red blood cells by the intraoperative autologous transfusion device was 35%. The control group utilized significantly more of the predonated autologous blood than the intraoperative autologous transfusion group (1.34 units/case vs. 1.78 units/case, P < 0.05). Homologous blood usage was the same in both groups. Two patients in the intraoperative autologous transfusion group required nondirected homologous blood (total of four units), compared to three patients in the control group (total of four units) (P = 0.048). Using multiple regression analysis, the total number of transfusions was significantly correlated with the estimated blood loss and the duration of surgery in both groups. Postoperative hematocrit levels were slightly higher in the control group, but there was not a significant difference.

CONCLUSIONS

The addition of intraoperative autologous transfusion to a preoperative phlebotomy program had no benefit on homologous blood exposure or post-operative hematocrit changes in this population. Blood requirements for this procedure can be met less expensively and more reliably by merely donating one's own blood.

Hypotensive epidural anesthesia for total hip arthroplasty: a review

Hypotensive epidural anesthesia provides arterial hypotension to maintain a mean arterial pressure of 50 mmHg and it can be used to reduce blood loss during total hip replacement. The technique combines an extensive epidural blockade with an intravenous infusion of low-dose epinephrine. This results in arterial hypotension, but with preservation of central venous pressure, heart rate, stroke volume, cardiac output, and an augmentation of blood flow to the lower extremity. The technique does not appear to adversely affect cardiac, renal, or cerebral function and is used safely in patients with hypertension, ischemic heart disease, and in the elderly. Intraoperative blood losses during primary total hip replacement are between 100 and 300 mL. Perioperative transfusions have declined with the introduction of the technique. Radiological evidence of improved fixation of cemented acetabular components has been observed. Rates of deep-vein thrombosis are low: 2-3% proximal deep-vein thrombosis with an overall rate of 10%. In-hospital mortality is 0.1%; lower than previously published rates. In conclusion, hypotensive epidural anesthesia is safe and provides a number of advantages over conventional anesthetic techniques for total hip replacement.

Prospective randomized evaluation of blood salvage techniques for primary total hip arthroplasty

A controlled, randomized, prospective study was performed evaluating the need for perioperative blood salvage for primary total hip arthroplasty patients who had donated autologous blood before surgery. One hundred fifty-three patients able to donate at least 2 units of autologous blood were divided into four groups. In group 1 (35 patients), intraoperative and postoperative Cell-Saver (Haemonetics, Braintree, MA) was employed. In group 2 (40 patients), a postoperative Solcotrans (Smith & Nephew Richards, Memphis, TN) reinfusion protocol was followed. In group 3 (40 patients), a closed-suction Hemovac drain (Zimmer, Warsaw, IN) was placed. In group 4, (38 patients), no drain was used. Decisions for transfusion were based on clinical and laboratory parameters and made in conjunction with medical consultation. All autologous blood was routinely reinfused. There was no statistically significant difference in transfusion requirements or wound complications among the four groups. Hemoglobin and hematocrit changes between groups also were not statistically significant, but a power test suggested insufficient patient numbers for absolute reliability of this observation. Only five patients (3.3%) in this study received homologous blood. Four of these patients were in the Solcotrans group and one was in the Cell-Saver group. Two reoperations were performed: one for hematoma (Solcotrans group) and one for a sewn-in drain. It is concluded that expensive perioperative blood salvage techniques are usually not needed in patients who have a primary total hip arthroplasty without cement and who have donated 2 units of blood before operation.

Postoperative blood salvage in total knee arthroplasty using the Solcotrans autotransfusion system

One hundred forty-four patients who underwent primary total knee arthroplasty were examined in a prospective controlled study to determine the efficacy and safety of a postoperative wound drainage autotransfusion system (Solcotrans, Smith & Nephew Richards, Memphis, TN). The patients were divided into two groups: control group 1 comprised 88 (61%) patients who either received a Hemovac disposable drainage system (63 patients) or the Solcotrans system and had inadequate drainage for autotransfusion (25 patients). Experimental group 2 comprised 56 (39%) patients who received a Solcotrans drainage system and were autotransfused. The Solcotrans proved itself safe. No sepsis, transfusion reactions, or coagulopathies were associated with autotransfusion, which averaged 524 mL. There were no significant differences between groups 1 and 2 when comparing preoperative and postoperative hemoglobins and hematocrits. The Solcotrans system did not lower homologous blood requirements. Only 1.6% (2 patients) of all patients who autodonated at least 2 units of autologous blood (122 patients) were in need of a homologous blood transfusion in the postoperative period. Thus, although safe, the Solcotrans system was not proven effective in the management of primary total knee arthroplasty patients.

Cell quality of salvaged blood after total knee arthroplasty. Drain blood compared to venous blood in 32 patients

We used the ConstaVac drainage retransfusion system in 32 patients operated on with cemented tricompartmental knee arthroplasty. The mean total postoperative bleeding was 1.1 L of which 0.7 L was retransfused within 8 hours postoperatively. Samples were taken from the venous blood and drain blood at 2 hours and 6-8 hours postoperatively. The drain blood had low counts for leukocytes and thrombocytes as compared to venous blood, and fibrinogen was almost absent. Incubation at room temperature slightly lowered glucose and pH which made the erythrocytes swell. There was a slight hemolysis in the drain blood at 2 hours. At 6-8 hours the shed blood was closer to normal, especially with regard to hemolysis, but there was a further decrease in glucose. Within this time, there was no change in acidity and no further swelling of the erythrocytes. No clinical adverse reactions were observed and we consider the observed cellular and chemical changes to be of little importance. The quality of filtered drain blood within the analyzed time limit is considered acceptable for clinical use.

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.

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

To study the quality and effect of blood produced by the cell saver compared with homologous blood in total hip arthroplasty, 40 patients were randomly divided into two groups. One group received autologous blood using the cell saver, whereas the second group served as a control, and received homologous bank blood. Hematologic and coagulation parameters of the patients were assessed both preoperatively and postoperatively. Samples from the autologous and the homologous blood were obtained before reinfusion, and were assessed as regards hematologic and biochemical parameters. The autologous blood satisfied all the intraoperative transfusion requirements of the autologous group and 75 percent of the total transfusion requirements. The operative and postoperative blood losses--hence, the total blood loss--were less in the autologous than in the control group. The autologous blood had a high hemoglobin, white blood cell, and plasma hemoglobin content and MCV compared with the homologous blood. Postoperatively, there were no differences as regards the hematologic parameters studied. There was no evidence of intravascular hemolysis in the autologous group. Postoperatively, in both groups, AT III, plasminogen, and protein C decreased. Other coagulation parameters were within normal limits in both groups. Intraoperative autotransfusion is safe and effective, and should be considered in hip arthroplasty to reduce the risks associated with homologous blood transfusion.