Impact of autotransfusion after coronary artery bypass grafting on oxygen transport

Background: Autotransfusion of shed mediastinal blood after coronary artery bypass grafting (CABG) has been shown to reduce the requirement for allogeneic blood. We have previously demonstrated in non-randomized studies that the oxygen capacity of shed mediastinal blood is similar to the patient's circulating blood and better than stored allogeneic blood. Therefore, we wanted to examine the influence of autotransfusion of shed mediastinal blood on oxygen transport capacity in patients undergoing CABG.
Methods: A prospective, randomized, controlled study involving 120 patients having elective, uncomplicated CABG was performed. The autotransfusion group received transfusion of shed mediastinal blood for 18 h. Both groups received allogeneic red cells if their hemoglobin concentration decreased below 5 mmol/L. Red blood cell 2, 3-diphosphoglycerate (2, 3-DPG) was measured preoperatively and at intervals up to the hospital discharged. Hemodynamic measurements as well as blood gas and hemoglobin measurements from samples of arterial and mixed venous blood were used for calculation of oxygen transport capacity.
Results: During the autotransfusion period only 2 patients (4%) in the autotransfusion group required allogeneic blood compared to 11 patients (20%) in the control group. The 2, 3-DPG levels in the autotransfusion group were unchanged before and after autotransfusion (4.4 vs. 4.3 umol/ml erythrocyte). In the control group, 2, 3-DPG levels decreased from 4.3 to 3.9 umol/ ml erythrocyte during the same period. There were no differences in the other measured parameters for oxygen transport capacity between the groups.
Conclusion: Autotransfusion of shed mediastinal blood conserves the 2, 3-DPG level of the red blood cells, while transfusion of stored blood leads to a decrease in 2, 3-DPG levels. Autotransfusion had no effect on hemodynamic parameters, oxygen delivery or oxygen extraction.     

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.     

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.     

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.     

Safety and efficacy of perioperative cell salvage and autotransfusion after coronary artery bypass grafting: a randomized trial

BACKGROUND: The aim of this study was to ascertain whether cell salvage and autotransfusion after first time elective coronary artery bypass grafting is associated with a significant reduction in the use of homologous blood, a clinically significant derangement of postoperative clotting profiles, or an increased risk of postoperative bleeding. METHODS: Patients were randomized to autotransfusion (n = 98) receiving autotransfused washed blood from intraoperative cell salvage and postoperative mediastinal fluid cell salvage after coronary artery bypass surgery or control (n = 102) receiving stored homologous blood only after coronary artery bypass surgery. RESULTS: There was no statistical difference between the groups in terms of demographics, comorbidity, risk stratification, or operative details. Mean volume of blood autotransfused was 367 +/- 113 mL. Patients in the autotransfusion group were significantly less likely to receive a homologous blood transfusion compared with controls (odds ratio 0.40, 95% confidence interval [CI] 0.22-0.71) and received significantly fewer units of blood per patient compared with controls (0.43 +/- 1.5 vs 0.90 +/- 2.0 U, p = 0.02). There was no difference between the groups in terms of postoperative blood loss, fluid requirements, blood product requirements, or in the incidence of adverse clinical events (p = NS chi(2)). Autotransfusion did not produce any significant derangement of thromboelastograph values or laboratory measures of clotting pathway function (prothrombin time, activated partial thromboplastin time, fibrinogen, and fibrinogen D-dimer levels) when compared with the effect of homologous blood transfusion (p = NS, repeated measures analysis of variance [MANOVA]). CONCLUSIONS: Autotransfusion is a safe and effective method of reducing the use of homologous bank blood after routine first time coronary artery bypass grafting.     

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.     

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.     

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.     

Postoperative autotransfusion of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting

Objectives: The rationale of using autotransfusion of mediastinal shed blood after cardiac surgery is to preserve haemoglobin levels and reduce the need for allogenic blood transfusions. However, the method is controversial and its clinical value has been questioned. We hypothesised that re-transfusion of mediastinal shed blood instead impairs haemostasis after routine coronary artery bypass grafting and thus increases postoperative bleeding. Methods: Seventy-seven consecutive elective coronary artery bypass surgery patients (mean age 67 ± 9 years, 77% men) were included in a prospective, randomised controlled study. The patients were randomised to postoperative re-transfusion of mediastinal shed blood (n = 39) or to a group where mediastinal shed blood was discarded (n = 38). Primary end point was bleeding during the first 12 postoperative hours. Secondary end points were postoperative transfusion requirements, haemoglobin levels, thrombo-elastometric variables and plasma concentrations of interleukin-6, thrombin–anti-thrombin complex and D-dimer. Results: Mean re-transfused volume in the autotransfusion group was 282 ± 210 ml. There was no difference in postoperative bleeding (median 394 ml (interquartile range 270–480) vs 385 (255–430) ml, p = 0.69), proportion of patients receiving transfusions of blood products (11/39 vs 11/38, p = 0.95), haemoglobin levels 24 h after surgery (116 ± 13 vs 116 ± 14 g l⁻¹, p = 0.87), thrombo-elastometric variables, interleukin-6 (219 ± 144 vs 201 ± 144 pg ml⁻¹, p = 0.59), thrombin–anti-thrombin complex (11.0 ± 9.1 vs 14.8 ± 15, p = 0.19) or D-dimer (0.56 ± 0.49 vs 0.54 ± 0.44, p = 0.79) between the autotransfusion group and the no-autotransfusion group. Conclusions: Autotransfusion of small-to-moderate amounts of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting.     

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)     

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 of shed mediastinal blood after cardiac surgery: a prospective study

In a randomized prospective study of patients having cardiac surgery, autologous blood collected from mediastinal tubes was autotransfused preferentially in 63 patients (ATS), whereas 51 patients received bank blood for transfusion (control). Comparison of the two groups showed no significant difference in regard to age, sex, operations performed, or total postoperative bleeding (ATS 813 +/- 121 ml. per square meter versus control 711 +/- 93 ml. per square meter; N.S.) Although mean postoperative blood replacement was similar in the two groups (ATS 4.3 +/- 0.6 units per patient versus control 4.8 +/- 0.6 units per patient), requirements for transfusion of stored bank blood were reduced by 50 percent in the ATS group (ATS 2.4 +/- 0.3 units per patient versus control 4.8 +/- 0.6 units per patient; p less than 0.005). Coagulation studies demonstrated that this blood was defibrinogenated; yet it contains significantly more platelets and clotting factors than does bank blood. In this study, autotransfusion of shed mediastinal blood was safe and simple. It significantly reduced bank blood requirements and resulted in substantial financial savings for the patients and the hospital.     

Effect of shed blood retransfusion on pulmonary perfusion after total knee arthroplasty: a prospective controlled study

Postoperative shed blood retransfusion (autotransfusion) is a commonly used salvage method following major surgical operations, such as total knee arthroplasty (TKA). The systemic effects of shed blood are still unclear. We studied the effect of residual substances in the retransfused shed blood, on lung perfusion after TKA. Fifteen unilateral and one bilateral TKAs were performed with autotransfusion (the study group) and 15 unilateral and three bilateral TKAs were performed in a control group. Lung X-rays, arterial blood gases (ABG), D-dimer values, and lung perfusion scintigraphies were performed preoperatively and postoperatively. A mean of 300.0 +/- 335.6 ml of bank blood was needed in the autotransfusion group and a mean of 685.7 +/- 365.5 ml of bank blood was needed in the control group (p=0.001). There was a postoperative segmental perfusion defect at the lateral segment of the superior lobe of the left lung in one patient of the control group and he also had risk factors for thrombosis. Although both groups had a decrease in lung perfusion postoperatively, there were no significant differences among the groups regarding the lung perfusion scintigraphy, chest X-rays, ABG, and D-dimer values. In conclusion, although pulmonary perfusion diminishes following TKA, shed blood retransfusion does not add any risk to pulmonary perfusion.     

Autotransfusion of mediastinal blood in cardiac surgery

A series of 135 adults undergoing cardiac surgery was randomized to an autotransfusion group (n = 67) or a control group (n = 68). In the autotransfusion group mediastinal blood was collected and reinfused during the first 6 postoperative hours. Blood from the reservoir was taken for bacteriologic culture at the end of that time. The postoperative blood was comparable in the two groups. The average requirement of bank blood was 2.7 units in the autotransfusion group and 3.3 units in the controls (p less than 0.05). The average volume of autotransfusion blood was 336 ml. There were no clinical infections in the autotransfusion group, although 19% of the cultures were positive, and no apparent alteration of the coagulation mechanisms arose from infusion of autologous blood. No clinically significant intergroup differences were found in hematologic, renal or hepatic parameters, neurologic function or use of antibiotics.     

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).     

Safety, efficacy, and cost of intraoperative cell salvage and autotransfusion after off-pump coronary artery bypass surgery: a randomized trial

OBJECTIVE: We evaluated, in a randomized controlled trial, the safety and effectiveness of intraoperative cell salvage and autotransfusion of washed salvaged red blood cells after first-time coronary artery bypass grafting performed on the beating heart. METHODS: Sixty-one patients undergoing off-pump coronary artery bypass grafting surgery were prospectively randomized to autotransfusion (n = 30; receiving autotransfused washed blood from intraoperative cell salvage) or control (n = 31; receiving homologous blood only as blood-replacement therapy). Homologous blood was given according to unit protocols. RESULTS: The groups were well matched with respect to demographic and comorbid characteristics. Patients in the autotransfusion group had a significantly higher 24-hour postoperative hemoglobin concentration (11.9 g/dL; SD, 1.41 g/dL) than those in the control group (10.5 g/dL; SD, 1.37 g/dL) (mean difference, 1.02 g/dL; 95% confidence interval, 1.60-0.44 g/dL; P = .0007), as well as a 20% reduction in the frequency of homologous blood product use (11/31 vs 5/30; P = .095). Autotransfusion of washed red blood cells was not associated with any derangement of thromboelastograph values or laboratory measures of clotting pathway function (prothrombin time, activated partial thromboplastin time, and fibrinogen levels), increased postoperative bleeding, fluid requirements, or adverse clinical events. There was no statistical difference between groups in the total operation, hospitalization, and management costs per patient (median difference, USD 1015.90; 95% confidence interval, -USD 2260 to USD 206; P = .11). Conclusions Intraoperative cell salvage and autotransfusion was associated with higher postoperative hemoglobin concentrations, a modest reduction in transfusion requirements, no adverse clinical or coagulopathic effects, and no significant increase in cost compared with controls. This study supports its routine use in off-pump coronary artery bypass grafting surgery.     

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.     

Reinfusion of Mediastinal Blood in CABG Patients: Impact on Homologous Transfusions and Rate of Re-exploration

A bstract Background : Reinfusion of mediastinal shed blood after cardiac surgery has been used in some centers to reduce exposure to homologous blood transfusions. The method has not been widely applied mostly because some studies have failed to demonstrate a significant benefit. Methods : A group of 675 consecutive patients undergoing first-time, isolated coronary artery bypass surgery (CABG) was studied. Prospective data was collected on the first 375 patients receiving autotransfusion (ATS) of mediastinal shed blood. The charts of 338 patients immediately preceding the institution of the ATS program at our institution (NO ATS group) were retrospectively reviewed. Transfusion of homologous blood products and rate of re-exploration for bleeding were closely monitored. Results : The two groups were identical. The net blood loss was significantly less in the ATS group than in the NO ATS group (1013 ± 431 cc vs 1371 ± 631 cc, p < 0.0001). Rate of exploration for postoperative bleeding was 1.5% in the ATS group and 5.0% in the NO ATS group (p < 0.01). In the ATS group, 51.9% of patients were not exposed to any homologous blood product (vs 17.8% in the NO ATS group, p < 0.0001). The ATS patients received on the average 2.9 ± 7.2 units of blood products versus 6.4 ± 9.7 units in the NO ATS group (p < 0.0001). Conclusion : Reinfusion of mediastinal shed blood significantly reduces exposure to homologous blood transfusions and rate of re-exploration. The ATS system reduces the number of re-explorations for coagulopathy-related postoperative hemorrhage.     

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.     

Autotransfusion after cardiac operation. Assessment of hemostatic factors

Reinfusion of mediastinal blood after coronary bypass grafting reduces the need for homologous transfusion with its hazards. To determine the efficacy of autotransfusion using the cardiotomy reservoir used during operation as a postoperative collection system, we studied the characteristics of reservoir blood (minimum 500 ml, mean 810 ml) and compared the hematologic profiles of 21 patients before and after blood infusion. The mean hematocrit value of the shed blood was 25% +/- 7%, platelet count 60,000 +/- 39,000/microliter, fibrinogen 19 +/- 25 mg/dl, and factor VIII 11% +/- 7%. The fibrinopeptide A concentration was 400 ng/ml, and the B beta 15-42 peptide was 28 +/- 14 pmol/ml. These values indicate defibrination of the blood before collection (no clots were found in the reservoirs), and no significant differences were detected between the types of reservoirs used (Bentley, n = 10, Shiley, n = 11). Infusion of reservoir blood between 500 and 1860 ml did not significantly affect the factor VIII, fibrinopeptide A, or B beta 15-42 peptide levels. Fibrinogen levels increased from 254 to 395 mg/dl (p less than 0.001). Only six of 21 patients received bank blood before discharge. These findings indicate that extensive coagulation occurs within the mediastinum before the blood is collected, that mediastinal blood can be safely infused without inducing fibrinolysis or disseminated intravascular coagulation, and that use of the cardiotomy reservoir is a safe and inexpensive method of autotransfusion after coronary artery bypass grafting.