Autotransfusion after open heart surgery: the oxygen delivery capacity of shed mediastinal blood is maintained

Autotransfusion of mediastinal shed blood after open heart surgery has become a common and accepted procedure in reducing the need for homologous transfusion during the last 15 years. The objectives of the present study were to investigate the oxygen delivery capacity of autotransfused shed mediastinal blood, compared to patient-blood, during cardiopulmonary bypass and in the postoperative period.
Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3-diphosphoglycerate (2,3-DPG) concentration.
Autotransfusion volume ranged from 450–1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3-DPG concentration in the patient-blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3-DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient-blood.
The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient-blood is not influenced by autotransfusion.     

Autotransfusion after open heart surgery: quality of shed mediastinal blood compared to banked blood

The need to conserve a patient's own blood and avoid homologous transfusion is now well recognized. Therefore, techniques designed to reduce requirements for homologous blood transfusions have been developed. One of the methods is autotransfusion of shed mediastinal blood after open-heart surgery. The objectives of the present study were to investigate osmotic fragility and oxygen transport capacity of shed mediastinal blood compared to patient blood and stored packed red blood cells (SAGM).
Shed mediastinal blood from ten consecutive patients undergoing elective cardiac surgery (coronary bypass grafting) was studied and compared to patient blood, 10 units of 3 weeks old and 10 units of 5 weeks old stored packed red blood cells (SAGM). Oxygen transport capacity was investigated by calculation of p50 for oxygen by use of the oxygen status algorithm (OSA 2.0) programme and measurement of 2,3-diphosphoglycerate (2,3-DPG) concentrations. The osmotic fragility was determined using increasing concentrations of saline.
2,3-DPG concentrations in shed mediastinal blood (5,3 mikromol/ml erythrocyte) were within the range measured in patient blood, but significantly higher than SAGM blood ( P <0.001). P50 for oxygen (3.5 kPa) in shed mediastinal blood was not significantly different compared to patient blood, but significantly higher ( P <0.01) compared with stored SAGM blood. The osmotic fragility in shed mediastinal blood was not significantly different compared to patient blood, but significantly lower ( P <0.001) than the osmotic fragility in stored SAGM blood. This suggests that red cells saved from shed mediastinal blood have better oxygen transport capacity and may have longer survival compared to stored blood.     

The inflammatory cytokine response after autotransfusion of shed mediastinal blood

Background : The inflammatory response in patients undergoing cardiac surgery with cardiopulmonary bypass is well known and increased levels of inflammatory cytokines have been shown. High levels of cytokines have been reported in blood drained from the surgical field. The present study aimed to elucidate whether autotransfusion of shed mediastinal blood in itself causes increased cytokine levels in coronary artery bypass graft (CABG) patients.
Methods : A prospective, randomized controlled study was performed in 23 patients having elective uncomplicated CABG. Autotransfusion of shed mediastinal blood was done every hour for 18 h in group I. In group II, the shed mediastinal blood was accumulated for 4 h in the cardiotomy reservoir and then autotransfused every hour for the next 14 h. Plasma levels of tumour necrosis factor-α (TNFα) and interleukin (IL)-1α, IL-1β, IL-6 were measured. In vitro study of cytokine production was performed with or without stimulation (phytohaemagglutinin (PHA) and Escherichia coli (E. coli) lipopolysaccharide (LPS)).
Results : We found high levels of IL-6 in the shed mediastinal blood. However, autotransfusion of shed mediastinal blood did not lead to increased level of cytokines (TNFα, IL-1α, IL-1β and IL-6) in plasma in group I nor in group II. In vitro study showed activation of the leucocytes in the shed mediastinal blood with a significantly increased production of TNFα and IL-6 both in the stimulated and non-stimulated samples.
Conclusion : Shed mediastinal blood contains high levels of IL-6. However, autotransfusion of shed mediastinal does not cause measurable elevations in plasma levels of IL-6. In vitro study shows that autotransfusion activates leucocytes, which may enhance production of inflammatory cytokines.     

Blood conservation effect and safety of shed mediastinal blood autotransfusion after cardiac surgery

Autotransfusion of shed mediastinal blood after cardiac surgery has been used to reduce risks related to homologous blood transfusions. To document the efficacy and safety of autotransfusion, we compared clinical findings of 80 patients receiving shed mediastinal blood (autotransfusion group) with those of the control group of 52 patients. The amount of the autotransfusion was limited to 800 ml, given the potentially harmful effects of shed blood transfusion. The mean transfused shed volume was 314 ± 236 ml (S.D.). The serum levels of FDP-E, D-dimer and TAT after autotransfusion were higher in the autotransfusion group than in the control group (p=0.01, p=0.0004, p =0.001, respectively). However, postoperative blood loss and the rate of reexploration for bleeding were similar in the two groups. The patients receiving blood products were fewer in the autotransfusion group than those in the control group (21% vs 44%; p=0.005). Autotransfusion did not increase postoperative complications, including infection. Thus, although autotransfusion of mediastinal shed blood has the potential to affect hemostasis, unless the amount of autotransfusion exceeds 800 ml, it appears that this method is clinically safe and effective as a mean of blood conservation.     

Effects of autotransfusion of mediastinal shed blood on biochemical markers of myocardial damage in coronary surgery

BACKGROUND: Previous studies have shown conflicting results regarding the effect of autotransfusion of mediastinal shed blood after coronary artery bypass grafting (CABG) on the serum levels of myocardial band (MB) isoenzymes of creatine kinase (CK-MB) and cardiac troponins. The effect of autotransfusion on serum levels of human heart fatty acid binding protein (H-FABP), another marker of myocardial necrosis, has not been studied. The aim of the present study was to investigate the effects of autotransfusion of mediastinal shed blood on the serum levels of CK-MB, cardiac troponin T (cTnT), and H-FABP after uncomplicated primary CABG. METHODS: Fifty patients were randomized to post-operative autotransfusion of mediastinal shed blood or no autotransfusion. Blood samples for the analysis of the biochemical markers of myocardial damage were drawn pre-operatively and 1, 4, 12, 24, 48, and 72 h after the termination of cardiopulmonary bypass. Samples from the mediastinal shed blood were collected after 1 and 4 h. RESULTS: The levels of the biochemical markers of myocardial injury were all markedly elevated in mediastinal shed blood. Autotransfusion did not significantly affect the serum levels of cTnT or H-FABP. However, during the early post-operative hours, there was a trend towards a higher level of cTnT and H-FABP in the autotransfusion group. During the first 24 h after surgery, the autotransfusion group had a significantly higher serum level of CK-MB. CONCLUSION: Post-operative autotransfusion of mediastinal shed blood may contribute to elevated serum levels of biochemical markers of myocardial injury.     

Reinfusion of mediastinal blood after heart surgery

BACKGROUND: Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear. METHODS: In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. RESULTS: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. CONCLUSION: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.     

The effect of intraoperative autotransfusion on the oxygen affinity of erythrocytes

Intraoperative autotransfusion provides several advantages over homologous transfusion for the recipient. Since the harvested red cells have a normal 2,3-DPG concentration [15, 18], the decreased oxygen affinity of hemoglobin [26] that occurs in the recipient after the transfusion of stored blood is thought to be avoidable by intraoperative autotransfusion. In a study on the influence of harvested cells on oxygen affinity in patients by Orr and Blenko [18], however, it was not possible to demonstrate the superiority of these erythrocytes over stored red cells in the recipient: whereas 2,3-DPG remained at the preoperative level in both groups after transfusion, oxygen affinity increased postoperatively in the study group but not in the control group. In this study we directly determined oxygen affinity in addition to 2,3-DPG in the harvested cells after processing. The influence on the recipients' oxygen affinity after transfusion was analyzed and compared to that of a group of patients who received only stored blood. PATIENTS and METHODS: Three groups of patients were studied: Group 1 received only autotransfusion blood, group 2 autotransfusion and stored blood, and group 3 only stored blood. For harvesting, centrifugation, and washing of the red cells the Haemonetics Cell Saver (CS III) was used. The p50 value - which is generally accepted as a measurement of oxygen affinity - was determined as described by Müller-Plathe and Müller-Plathe [17]. For analysis of these data, blood was drawn from patients pre- and postoperatively and for the majority of cases also one or more days postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Routine use of autotransfusion following cardiac surgery: experience in 700 patients.

An autotransfusion technique has been developed for collection and reinfusion of shed mediastinal blood. This system has been routinely applied in the postoperative management of 592 consecutive adult and 108 pediatric cardiac surgical patients. Two hundred seventy-one adult patients (46%) and thirty-six pediatric patients (33%) actually received autologous blood. Autotransfusion volume ranged from 50 to 21,350 ml per patient. In 1976 at our institution, homologous transfusion requirements averaged 8.4 +/- 0.7 units per adult patient. During 1978, with the routine use of postoperative autotransfusion, bank blood transfusions were lowered to 4.2 +/- 0.3 units per patient (p less than 0.001). In contrast to perioperative autotransfusion techniques, collection and reinfusion of shed mediastinal blood is particularly useful for intravascular volume replacement in patients with serious postoperative bleeding.     

Coronary surgery without cardiotomy suction and autotransfusion reduces the postoperative systemic inflammatory response

Background

Cardiotomy suction and autotransfusion of mediastinal shed blood may contribute to the inflammatory response after cardiac surgery. We compared inflammatory activation, myocardial injury, bleeding, and hemoglobin levels in patients undergoing coronary surgery with or without retransfusion of cardiotomy suction blood and mediastinal shed blood.

Methods

Twenty-nine patients were included in a prospective randomized study. Cardiotomy suction blood and mediastinal shed blood were either retransfused or discarded. Plasma concentrations of the cytokines tumor necrosis factor-α and interleukin-6 and complement factor C3a were measured preoperatively and 10 minutes, 2 hours, and 24 hours after cardiopulmonary bypass. C-reactive protein, erythrocyte sedimentation rate, troponin-T, and hemoglobin levels were analyzed preoperatively, and 24 and 48 hours after cardiopulmonary bypass. Postoperative bleeding the first 12 hours was registered.

Results

Baseline data did not differ between the groups. Plasma concentrations of tumor necrosis factor-α, interleukin-6, and C3a increased after surgery in both groups but significantly less in the group without cardiotomy suction and autotransfusion. The peak delta values in the no-retransfusion group was 36% (tumor necrosis factor-α), 47% (interleukin-6), and 75% (C3a) of the values in the retransfusion group. C-reactive protein, erythrocyte sedimentation rate, and troponin-T increased after surgery in both groups without intergroup differences. Postoperative bleeding and hemoglobin levels did not differ between the groups. No patient received homologous blood transfusion.

Conclusions

Coronary surgery without retransfusion of cardiotomy suction blood and mediastinal shed blood reduces the postoperative systemic inflammatory response.     

Autotransfusion in coronary artery bypass grafting: disparity in laboratory tests and clinical performance.

OBJECTIVE: Autotransfusion during and after cardiac surgery is widely performed, but its effects on coagulation, fibrinolysis, and inflammatory response have not been known in detail. METHODS: Hemostatic and inflammatory markers were extensively studied in 40 coronary artery bypass patients undergoing a consistent intraoperative and postoperative autotransfusion protocol. An identical autotransfusion protocol was applied to 4916 consecutive coronary patients and the overall clinical results were evaluated in this large patient population. RESULTS: The autologous blood pooled before bypass remained nearly inactivated after storage. A slight elevation of thrombin-antithrombin complex and prothrombin fragment 1.2, as well as plasmin/alpha(2)-antiplasmin complex was found in the content of the extracorporeal circuit after surgery, indicating thrombin formation and fibrinolytic activity. Also some increase of beta-thromboglobulin was present. In the mediastinal shed blood, complete coagulation, as evidenced by the absence of fibrinogen, had taken place and all parameters described above were extremely elevated. However, no thrombin activity was detected. As for the inflammatory response, moderately increased levels of complement activation products, terminal complement complex, and interleukin-6 traced in the extracorporeal circuit reached very high levels in mediastinal shed blood. Autotransfusion of the residual extracorporeal circuit blood and the mediastinal drainage was followed by elevation of most of these markers in circulating plasma. On the other hand, no correlating harmful effects were recorded in the study patients or in the consecutive 4916 patients. Coagulation disturbances were rare and allogeneic transfusions were required in fewer than 4% of all patients. CONCLUSIONS: The hemostatic and immunologic systems were moderately activated in the autologous blood remaining in the extracorporeal circuit, whereas the mediastinal shed blood was highly activated in all aspects. However, autotransfusion had no correlating clinical side-effects and the subsequent exposure to allogeneic blood products was minimal.     

Autotransfusion After Coronary Artery Bypass Surgery: Is There Any Benefit?

Postoperative salvage autotransfuslon of shed mediastinal blood, using the cardiotomy reservoir, is an inexpensive technique whose efficacy and safety are evaluated in this study. We randomized 75 consecutive patients into two groups. The autotransfusion group (n = 42) received autotransfusion after the completion of the coronary artery bypass grafting (CABG) until the dralnage was ≤ 50 mL per hour for 2 consecutive hours. The control group (n = 33) was treated with standard chest drainage. Both groups received homologous blood transfusion when the hematocrit fell below 30%. Packed red cells were required post-operatively in 84.8% of the control group and 80.9% of the autotransfusion group (p = NS). Postoperative colloid fluid replacement (excluding autotransfusion fluid) did not differ significantly between the groups. The prothrombin time was significantly higher in the autotransfusion group 24 hours postoperatively (p = 0.03). The fibrin degradation products were elevated only In the serum of the autotransfusion patients (p < 0.002). More febrile patients were seen in the autotransfusion group although not significantly more than the controls. The autotransfusion group received more red cells than the control group, but it lost more red cells in the medlastlnal drains. In conclusion, the autotransfusion of shed mediastinal blood has not proved beneficial in reducing the Postoperative requirements in homologous blood in patients undergoing coronary artery bypass grafting (CABG). (J Card Surg 1994;9:314–321)     

Limited effectiveness of intraoperative autotransfusion in major back surgery.

BACKGROUND AND OBJECTIVE: The efficiency of intraoperative autotransfusion in scoliosis surgery is poorly known but needs to be evaluated, not least because of the large blood losses in these patients. This is a retrospective analysis of transfusion requirements of 43 such patients. METHODS: Records from 43 patients were studied. During surgery, the shed blood was salvaged and washed in an autotransfusion device (AT1000 Autotransfusion Unit) and a suspension of red cells was reinfused. RESULTS: Fifty-eight per cent of the intraoperative blood loss was salvaged. The total blood loss during the patients' hospital stay was calculated from the haemoglobin balance; 24% of this loss was salvaged by the device. Moreover, 36 of the patients needed allogeneic blood transfusion. CONCLUSION: The efficiency of the autotransfusion device was relatively low in relation to the total extravasation, mainly because the postoperative blood loss is substantial.     

Autotransfusion decreases blood usage following cardiac surgery -- a prospective randomized trial

INTRODUCTION: 10% of blood issued by the National Blood Service (220,000) is utilised in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We tested the efficacy of autotransfusion of washed postoperative mediastinal fluid in a prospective randomized trial. PATIENTS AND METHODS: 166 patients undergoing coronary artery bypass grafting (CABG), valve or CABG + valve procedures were randomized into three groups. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a packed cell volume (PCV) < 30. When applicable, group A patients received washed post-operative drainage fluid. Group B all received blood processed from the cardiopulmonary bypass (CPB) circuit following separation from CPB and if appropriate washed post-operative drainage fluid. Group C were controls. Groups were compared using analysis of variance. RESULTS: There was no significant difference in age, sex, type of operation, CPB time and preoperative Hb and PCV between the groups. Blood requirements were as shown. [table - see text] Twelve patients in group A and 10 in group B did not require a homologous transfusion following processing of the mediastinal drainage fluid. CONCLUSION: Autotransfusion of washed postoperative mediastinal fluid can decrease the amount of homologous blood transfused following cardiac surgery. There was no demonstrable benefit in processing blood from the CPB circuit as well as mediastinal drainage fluid.     

Autotransfusion of washed shed mediastinal fluid decreases the requirement for autologous blood transfusion following cardiac surgery: a prospective randomized trial

Objectives: The National Blood Service issues 2.2 million units of blood per year, 10% of these (220 000) are utilized in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We test the efficacy of autotransfusion following surgery in a prospective randomized trial. Methods: One hundred and twelve patients undergoing CABG, valve or CABG+valve procedures were randomized into two groups. Group A received washed postoperative drainage fluid and group C were controls. The indication for transfusion was a postoperative haemoglobin (Hb) <10 g/l or a PCV<30. There was no significant difference in preoperative and operative variables between the groups. Results: Twenty-eight patients in group A and 46 in group C required homologous transfusion (P=0.0008). Group A patients required 298±49 ml of banked blood per patient, group C 508±49 ml (P=0.003). There was no difference in total blood required (volume autotransfused+volume banked blood transfused) between the groups (group A 404±50 ml, group C 508±50 ml) or in mean total mediastinal fluid drainage (group A 652±51 ml, group C 686±50ml). The mean Hb concentration was significantly higher in group A on day 1 (11.2 g/dl±51 vs.10.6 g/dl±13 (P=0.002)). No morbidity was associated with autotransfusion. Conclusion: Autotransfusion can decrease the amount of homologous blood transfused following cardiac surgery. This represents a benefit to the patient and a decrease in cost to the health service.     

Reinfusion of unwashed salvaged blood after total knee arthroplasty in patients with rheumatoid arthritis

Autotransfusion with unwashed salvaged blood (USB) is effective for avoiding allogeneic blood transfusion (ABT) in patients undergoing total knee arthroplasty (TKA). We performed a retrospective study to determine the percentage of patients receiving ABT and the volume of postoperative blood drainage after introduction of autotransfusion with USB for patients with rheumatoid arthritis (RA) undergoing TKA. In 100 patients without autotransfusion (group 1) and 100 patients receiving autotransfusion of USB (group 2), we compared the number of patients who required ABT, as well as the postoperative drainage volume, ABT volume, and autotransfusion volume. In group 1, 83% of the patients received ABT, while only 47% received ABT in group 2, and there was a significant decrease (p < 0.001). However, the postoperative drainage volume was significantly increased in group 2 (p < 0.001).     

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 (millilitres 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 conservation for myocardial revascularization. Is it cost effective?

A total of 284 patients undergoing myocardial revascularization were prospectively studied to determine if the use of intraoperative autotransfusion or intraoperative autotransfusion plus postoperative reinfusion of shed mediastinal blood decreased transfusion requirements and the use of one or both techniques was cost effective. The Haemonetics Cell Saver System was used for intraoperative autotransfusion and the Sorenson Receptaseal autotransfusion system for postoperative reinfusion of shed mediastinal blood. During Phase 1, the Cell Saver System was used for 57 patients and 93 patients served as a control group. During Phase 2, the Cell Saver System plus the autotransfusion system were used in 43 patients and 91 patients were in the control group. Separate parallel analyses to compare the blood conservation groups to control groups were conducted for each phase of the study. The patient groups were comparable with regard to age, sex, preoperative red cell mass, preoperative hematocrit value, number of bypasses, and use of internal mammary grafts. Blood conservation techniques resulted in significant reductions in the use of bank blood. During Phase 1, Cell Saver System patients received an average of 2.8 units of packed cells versus 4.7 units for control patients. Transfusion was avoided entirely in 14% of Cell Saver System patients compared to 3% of control patients. During Phase 2, patients subjected to both the Cell Saver System and the autotransfusion system received an average of 1 unit of packed red cells versus 3 units for control patients. Transfusion was required in only 42% of patients subjected to both the Cell Saver System and the autotransfusion system compared to 85% of control patients. Multiple logistic regression analysis confirmed that the use of the Cell Saver System in Phase 1 and the Cell Saver System and autotransfusion system in Phase 2 were each independently predictive of decreased transfusion requirements. The total "blood-related costs" (including cost for all bank blood products plus Receptaseal and Cell Saver System equipment) was slightly lower for the blood conservation patients in both Phase 1 ($555.00 versus $615.00, no significant difference) and Phase 2 ($373.00 versus $426.00, no significant difference). Intraoperative use of the Cell Saver System is associated with substantial savings of bank blood, and the addition of postoperative reinfusion of shed mediastinal blood results in further bank blood savings. The use of blood conservation techniques is cost effective; that is, the costs incurred for the blood conservation equipment are more than offset by the resultant dollar savings for blood products.     

Blood conservation in cardiac surgery. Preliminary results with an institutional commitment.

To evaluate the effect of blood conservation in cardiac surgery, use of blood products was analyzed in patients undergoing CABG before and after implementation of blood conservation techniques. Age, sex, coronary anatomy, ejection fraction, cardiopulmonary bypass time, and the preoperative hematocrit, platelet count, and clotting studies were similar in both groups. Methods of blood conservation included autologous transfusion of blood withdrawn before bypass, autotransfusion of shed mediastinal blood, strict protocols for transfusion, and acceptance of normovolemic anemia. With blood conservation, 25.5% of patients received no transfusions and 54.9% received blood only. Significant reductions (p less than 0.001) were achieved in the transfusion of blood from 6.8 +/- 2.4 to 2.3 +/- 2.6 units per patient and of plasma from 2.5 +/- 2.2 to 0.6 +/- 2.0 units per patient. Reductions in the use of platelets and cryoprecipitate were substantial, although not significant. Total donor exposure was reduced significantly from 13.1 +/- 7.3 to 4.3 +/- 6.7 donors per patient. The postoperative hematocrit was significantly lower and remained so at discharge. However, 30 days later there was no difference. This reduction in transfusion requirements decreased costs and donor exposure.     

Institutional variability in red blood cell conservation practices for coronary artery bypass graft surgery. Institutions of the MultiCenter Study of Perioperative Ischemia Research Group

OBJECTIVE: To assess whether substantial institutional variability exists in red blood cell conservation practices associated with coronary artery bypass graft (CABG) surgery. DESIGN: Prospective, randomized patient enrollment and data collection. SETTING: Twenty-four U.S. academic institutions participating in the Multicenter Study of Perioperative Ischemia. PARTICIPANTS: A well-defined subset of primary CABG surgery patients (n = 713) expected to be at low risk for bleeding and exposure to allogeneic transfusion. INTERVENTIONS: None (observational study). MEASUREMENTS AND MAIN RESULTS: Frequency of use of red blood cell conservation techniques was determined among institutions. Correlation was determined between use of each technique and transfusion of allogeneic red blood cells and between use of each technique and median institutional blood loss. Significant variability (p < 0.01) was detected in institutional transfusion practice with respect to the use of predonated autologous whole blood, normovolemic hemodilution, red cell salvage, and reinfusion of shed mediastinal blood. The frequency of institutional use of these techniques was not associated with allogeneic transfusion (r2 < 0.15) or blood loss (r2 < 0.10) in the low-risk population of patients examined. CONCLUSIONS: Institutions vary significantly in perioperative blood conservation practices for CABG surgery. Further study to determine the appropriate use of these techniques is warranted.     

Intraoperative autotransfusion in aortic aneurysm operations combined with temporary external shunt

Intraoperative autotransfusion was done in nine patients who underwent major vascular surgery for thoracic aortic aneurysms including one total abdominal aneurysm using temporal external shunt. After general heparinization (1mg/kg), shed blood was collected by Sorenson Autotransfusion System with local heparinization. After confirming ACT longer than 300-400 second, 425-3700 ml, averaged 1804 ml, of shed blood was reinfused to the patients by gravity flow. The reinfusion rate of shed blood was 43.1 +/- 15.8%. There were no deaths and no complications referable to autotransfusion. Although mild hemolysis was observed immediately after surgery, plasma free hemoglobin level returned to normal in the first operative day and no renal failure occurred. The volume of bleeding after surgery was not differed from that of control. Microembolism was not evident clinically. We concluded that intraoperative autotransfusion is safe and useful procedure in major vascular surgery if proper anticoagulation is done.