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Con: Shed mediastinal blood should not be reinfused after cardiac surgery
Con: Shed Mediastinal Blood Should Not Be Reinfused After Cardiac Surgery C. David Mazer, MD, FRCPC HE PREVENTION and treatment of postoperative
bleeding after cardiac surgery are important both to T reduce perioperative complications and to reduce the
exposure of panents to homologous blood products. Postoperative reinfusion of shed mediastinal blood is one of a large array of interventions that have been studied to achieve these goals. In this technique, blood is collected from the chest tubes Into a reservoir under gentle suction and then retransfused into the patient after being passed through a filter. The average retransfuslon volume as approximately 400 to 500 mL but may range from a few hundred milliliters to several hters. The routine use of postoperative autotransfuslon was advocated by Schaff and colleagues x.2 They randomized 114 adult cardiac surgical patients to receive either retransfusion of shed medmstinal blood using a Sorenson autotransfusion system (Sorenson Research Corp., Salt Lake City, UT) or homologous blood only (control group). Total postoperative blood loss and total blood replacement were similar between the two groups, but the autotransfusion group received sigmficantly less banked blood (2.4 _+ 0.3 units v 4.8 - 0.6 units for the control group). They also reported data with the routine use of reinfusion of shed mediastinal blood m 700 adult and pediatric patients. 2 They suggested that autotransfusion reduced the need for postoperative homologous blood transfusions by 50% compared with a historical control group from 2 years previously. However, other studies have failed to demonstrate benefit with postoperative autotransfusion. 3-8 Thurer et al performed a randomazed prospective study of autotransfusion in 113 patients in whom additional techniques also were used to reduce the requirement for homologous transfusion? These techmques included intraoperatwe blood withdrawal and retransfusion after cardiopulmonary bypass (CPB), normovolemic hemodilution, intraoperatlve retransfusion of shed blood, and meticulous surgical hemostasis Use of these techniques alone had reduced their average blood product usage from 8 units per paUent in 1972 to 2.5 units an 1978. The investigators found no statistical difference in postoperatwe chest tube drainage, the number of patients requiring homologous blood, and average blood product replacement or hematocrit at any time postoperatively between patients who had postoperative autotransfusion and those who did not 9 Similarly, subgroup analysis of pataents wath large blood loss ( > 25 mL/kg) also showed no dafference in saving of banked blood in the autotransfusaon
From the Department of Anaesthesia, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada Address pepnnt requests to DI C. David Mazer, Department of Anaesthesia, St Michael's Hospital, 30 Bond St, Toronto, Ontario, Canada M5B 1W8 Copyright © 1995 by W B. Saunders Company 1053-0770/95/0901-001853 00/0 Key words autotransfuston, cardiac surgery, postoperative comphcatlons 100
group. They concluded that the efficacy of remfuslon of shed mediastinal blood "is limited when other actwe attempts to conserve blood a r e u s e d . ''9 The threshold level for transfusion may be an important factor in understanding why some studies suggest a benefit for autotransfuslon, whereas others do not. Schaff et al transfused patients when the hematocnt decreased below 3 5 % , 1 a much higher level than is currently accepted. Studies that accept a lower transfusion trigger (8 to 10 g/dE) have found no difference in the number of patients reqmring packed red blood cells or in the amount of homologous blood products given to postoperatwe autotransfusaon panents compared with control? ,5,9 Thus, the use of other current blood-conserving strategies appears to obviate the benefit of or need for postoperatwe autotransfuslon.
Aprotinin may also affect the efficacy of postoperative autotransfusion. Schonberger and colleagues reported that low-dose aprotlnm caused a 50% reduction in the hemoglobin content of shed mediastinal blood. 6 They also found no statistically significant difference in homologous blood transfusions or percentage of pataents transfused using this regimen. Whether other drugs such as tranexamlc acid cause a samllar reduction in the hemogloban content of shed blood is not known. Other studies have suggested that reinfuslon of shed mediastinal blood may actually increase postoperatwe blood loss Shlrvam found that autotransfusion patients receiving preoperative aspirin therapy had higher postoperative blood loss and transfusion requirements than patients not receiving either aspiran or autotransfusaon, a° de Haan and colleagues reported a 43% increase m total postoperatwe blood loss with autotransfusion. 7 They also found elevated concentrations of tissue-type plasmmogen activator and snmulator activity and increased concentrations of fibrlnogen degradation products in shed mediastinal blood The levels also directly correlated wath total postoperative blood loss. They then used in vitro studies to demonstrate that the combination of tissue-type plasminogen activator and fibrin monomers produced severe platelet damage and dysfunctaon. This confirmed their hypothesis that increased bleedlng tendency wath postoperatwe retransfuslon of shed blood was caused by fibrinolysis. Other evidence for severe platelet dysfunctaon in shed mediastmal blood was provided by Kongsgaard et al. xl The mean platelet count determined by electronic counting was 62,000; however, proper counting wath hght microscopy showed a true platelet count of only 10,000 because of the presence of cytoplasmic cell fragments, which are of samilar size to platelets. The platelets present had undergone arreversable platelet actwatlon and an inability to aggregate in response to common stimula. This study thus confirms that the platelets an shed medlastmal blood are fewer m number than prevaously appreciated and also are activated and nonfuncnonal. There as increasing evidence that activated platelets and leukocytes play an important role in
Journal ofCardtothoraclc and VascularAnesthes/a, Vol 9, No 1 (February), 1995' pp 100-102
PRO AND CON
101
reperfuslon injury. 12,13Further studies are needed to determine whether reinfusion of shed medlastlnal blood may actually enhance this phenomenon. Other hematologic abnormalities may be Induced by reinfusion of shed medlastlnal blood. Reservoir blood is characterized by depletion of clotting factors and activation of the fibrinolytic and kallikrein-kinin system. 14,15Although remfuslon of this blood does not usually cause clinical problems, Fuller et al found elevations in the levels of fibrinogen degradation products, D-Dimer, activated partial thromboplastln time, and thrombin clotting time In patients I hour after reinfusion of shed blood. The elevated thrombin clotting time correlated with the volume of remfused blood. Other studies have also found higher D-Dimer levels and lower fibrinogen levels In patients who had received autotransfuslon. 13.16 The infusion of shed mediastinal blood may also cause difficulties In the diagnosis of myocardial infarction. Shed blood contains up to 10,000 unlts/L of creatine kmase, 5% to 10% of which is creatlne kinase MB band, and similar significant elevations of lactic dehydrogenase and serum glutamlc oxaloacetic transaminase. 1718 Remfusion of shed blood causes a 1.5- to 3.7-fold increase in circulating enzyme levels, which persists for up to 24 hours postoperatively. These marked enzyme elevations may either mask or mimic perioperative myocardial Infarction. Thus, relnfuslon of shed medlastmal blood may make the determination of myocardial infarction, a very important marker of outcome and prognosis, difficult or impossible. Concerns have also been raised about the sterility and potential for infection when shed mediastinal blood is reinfused. Bland et al studied intraoperative autotransfusIon using a cell-saver system. 19 Thirty of 31 (96.8%) of mediastinal blood samples were culture-positive, and 24 1% contained endotoxin. The majority of organisms isolated were coagulase-negative staphylococci but also included diphtheroids and gram-negative bacilli. To reduce the chance of infection, it is recommended that postoperative autotransfusion be performed within 4 hours of the start of collection and not longer than 16 hours postoperatively. Nonetheless, several studies of postoperative autotransfusion have confirmed the possibility of bacterial contamination of shed blood with positive culture rates as high as 50%.19,16 Although a definite link between these positive cultures and postoperative infection has not been established, it is important to remember that wound infection is the most powerful predictor of prolonged hospital stay, increasing the mean hospital length of stay from 8.7 to 32.2 days. 20
Shed mediastinal blood may contain a variety of other unwanted compounds or cells that may complicate or contraindicate its use. Clots may form in the reservoir bags, especially at higher bleeding rates, s Anticoagulatlon of the shed blood may then be required, somewhat of a paradox in a briskly bleeding patient. Plasma hemoglobin, a nephrotoxin, is present in concentrations of 150 to 400 mg/dL. 4,15,16 Although autotransfusion does not lead to renal failure in normal subjects, its safety has not been estabhshed in patients with renal disease. Other contraindications to the use of postoperative autotransfusion include the presence of malignancy or infection at the collection site (because they may be disseminated with reinfusion), the use of mlcrofibrillar hemostatic agents (which may cause mlcroemboli), or the presence of contagious viral markers (which may be risks to health care personnel handling the blood). Some authors have recommended washing of shed mediastlnal blood before retransfuslon to eliminate unwanted elements. 3 However, this increases the time between collection and transfusion and adds to the cost. In addition, with more handling, there is greater risk of contamination of the shed blood and increased risk of disease transmission to caregivers. Technical problems may limit the use (thus, the costeffectiveness) of postoperative autotransfusion. 2,8In Schaff's study, only 46% of adult and 33% of p e d i a m c patients actually received autotransfusion, although the autotransfusion device was routinely applied to all patients. 2 Reevaluation of transfusion practices and increasing awareness and use of other blood conservation measures have reduced the need for blood products. Many patients now receive no blood transfusions. In the study by Schonberger et al, 80% of patients who did not have autotransfusion required no blood products. 6 Thus, even if postoperative autotransfusion were conclusively shown to be effective, it would be unnecessary and/or unused m the majority of patients. In summary, many studies have shown that reinfusion of shed mediastlnal blood does not reduce either postoperative blood loss or reqmrements for homologous transfusion, especially when other currently recommended strategies such as predonation, normovolemic hemodilution, antlfibrinolytic drugs, meticulous surgical hemostasis, and acceptance of a lower transfusion trigger are employed. Shed medlastinal blood also contains many undesirable substances that may complicate the perloperatlve management of the cardiac surgical patient. Its routine use cannot therefore be endorsed.
REFERENCES
1. Schaff HV. Hauer JM, Bell WR, et al AutotransfusIon of shed medlastmal blood after cardiac surgery A prospective study. J Thorac Cardlovasc Surg 75"632-641, 1978 2. Schaff HV. Hauer J, Gardner TJ, et al Routine use of autotransfuslon following cardiac surgery Experience in 700 patients Ann Thorac Surg 27 493-499, 1979 3 Grlffith LD, Billman GF, Dally PO, et al Apparent coagulopa-
thy caused by infusion of shed mediastlnal blood and ItS prevention by washing of the lnfusate Ann Thorac Surg 47 400-406, 1989 4 Ward HB, Smith RR, Landis KP, et al Prospective, randomized trial of autotransfuslon after routine cardiac operations [see comments] Ann Thorac Surg 56'137-141, 1993 5. Roberts SR, Early GL, Brown B, et al' Autotransfuslon of unwashed mediastmal shed blood falls to decrease banked blood
102
requirements in patients undergoing aortocoronary bypass surgery Am J Surg 162:477-480, 1991 6. Schonberger JP, Bredee J, Speekenbrlnk RG, et al. Autotransfusion of shed blood contributes additionally to blood saving in patients receiving aprotinln (2 million KIU). Eur J Cardlo-Thorac Surg 7'474-477, 1993 7. de Haan J, Schonberger J, Haan J, et al Tissue-type plasmmogen activator and fibrin monomers synergistically cause platelet dysfunction during retransfuslon of shed blood after cardiopulmonary bypass. J Thorac Cardiovasc Surg 106:1017-1023, 1993 8. Adan A. Brutel de la Riviere A, Haas F, et al' Autotransfusion of drained medlastlnal blood after cardiac surgery. A reappralsal. Thorac Cardlovasc Surg 36'10-14, 1988 9. Thurer RL, Lytle BW, Cosgrove DM, et al: Autotransfusion following cardiac operations A randomized, prospective study. Ann Thorac Surg 27.500-507, 1979 10 Shxrvanl R: An evaluation of clinical aspects of postoperative autotransfusion, either alone or in conjunction with pre-operatwe aspirin, in cardiac surgery Br J Clln Pract 45'105108, 1991 11 Kongsgaard UE, Hovig T, Brosstad F, et al' Platelets in shed mediastmal blood used for postoperative autotransfuslon Acta Anaesthesiol Scand 37.265-268, 1993 12. Kurose I. Anderson DC, Mxyasaka M. et al Molecular determinants of reperfusion-induced leukocyte adhesion and vascular protein leakage Circ Res 74 336-343, 1994
C DAVID MAZER
13 Seekamp A, Till GO, Mulligan MS, et al Role of selectlns in local and remote tissue injury following lschemla and reperfusmon. Am J Pathol 144.592-598, 1994 14. Fuller JA, Buxton BF, Plcken J, et al' Haematologlcal effects of relnfused mediastlnal blood after cardiac surgery [see comments] Med J Aust 154.737-740, 1991 15 Kongsgaard UE, Tollofsrud S, Brosstad F, et al' Autotransfusion after open heart surgery Characteristics of shed mediastinal blood and its influence on the plasma proteases in circulating blood. Acta Anaestheslol Scand 35.71-76, 1991 16. Eng J, Kay PH, Murday AJ, et al: Postoperative autologous transfusion m cardiac surgery A prospective, randomlsed study Eur J Cardio Thorac Surg 4 595-600, 1990 17 Wahl GW, Felns RH, Alfieres G, et al Relnfuslon of shed blood after coronary operation causes elevation of cardiac enzyme levels Ann Thorac Surg 53.625-627. 1992 18. De Paulls R, Bassano C, Rice1 A, et al Enzyme levels in shed blood after cardiac operations Ann Thorac Surg 56 1001-1003, 1993 19 Bland LA, Vlllarlno ME, Ardulno MJ, et al. Bacteriologic and endotoxm analysis of salvaged blood used in autologous transfusions during cardiac operations J Thorac Cardiovasc Surg 103 582-588, 1992 20 Welntraub WS, Jones EL, Craver J, et al Determinants of prolonged length of hospital stay after coronary bypass surgery Circulation 80'276-284, 1989
bleeding after cardiac surgery are important both to T reduce perioperative complications and to reduce the
exposure of panents to homologous blood products. Postoperative reinfusion of shed mediastinal blood is one of a large array of interventions that have been studied to achieve these goals. In this technique, blood is collected from the chest tubes Into a reservoir under gentle suction and then retransfused into the patient after being passed through a filter. The average retransfuslon volume as approximately 400 to 500 mL but may range from a few hundred milliliters to several hters. The routine use of postoperative autotransfuslon was advocated by Schaff and colleagues x.2 They randomized 114 adult cardiac surgical patients to receive either retransfusion of shed medmstinal blood using a Sorenson autotransfusion system (Sorenson Research Corp., Salt Lake City, UT) or homologous blood only (control group). Total postoperative blood loss and total blood replacement were similar between the two groups, but the autotransfusion group received sigmficantly less banked blood (2.4 _+ 0.3 units v 4.8 - 0.6 units for the control group). They also reported data with the routine use of reinfusion of shed mediastinal blood m 700 adult and pediatric patients. 2 They suggested that autotransfusion reduced the need for postoperative homologous blood transfusions by 50% compared with a historical control group from 2 years previously. However, other studies have failed to demonstrate benefit with postoperative autotransfusion. 3-8 Thurer et al performed a randomazed prospective study of autotransfusion in 113 patients in whom additional techniques also were used to reduce the requirement for homologous transfusion? These techmques included intraoperatwe blood withdrawal and retransfusion after cardiopulmonary bypass (CPB), normovolemic hemodilution, intraoperatlve retransfusion of shed blood, and meticulous surgical hemostasis Use of these techniques alone had reduced their average blood product usage from 8 units per paUent in 1972 to 2.5 units an 1978. The investigators found no statistical difference in postoperatwe chest tube drainage, the number of patients requiring homologous blood, and average blood product replacement or hematocrit at any time postoperatively between patients who had postoperative autotransfusion and those who did not 9 Similarly, subgroup analysis of pataents wath large blood loss ( > 25 mL/kg) also showed no dafference in saving of banked blood in the autotransfusaon
From the Department of Anaesthesia, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada Address pepnnt requests to DI C. David Mazer, Department of Anaesthesia, St Michael's Hospital, 30 Bond St, Toronto, Ontario, Canada M5B 1W8 Copyright © 1995 by W B. Saunders Company 1053-0770/95/0901-001853 00/0 Key words autotransfuston, cardiac surgery, postoperative comphcatlons 100
group. They concluded that the efficacy of remfuslon of shed mediastinal blood "is limited when other actwe attempts to conserve blood a r e u s e d . ''9 The threshold level for transfusion may be an important factor in understanding why some studies suggest a benefit for autotransfuslon, whereas others do not. Schaff et al transfused patients when the hematocnt decreased below 3 5 % , 1 a much higher level than is currently accepted. Studies that accept a lower transfusion trigger (8 to 10 g/dE) have found no difference in the number of patients reqmring packed red blood cells or in the amount of homologous blood products given to postoperatwe autotransfusaon panents compared with control? ,5,9 Thus, the use of other current blood-conserving strategies appears to obviate the benefit of or need for postoperatwe autotransfuslon.
Aprotinin may also affect the efficacy of postoperative autotransfusion. Schonberger and colleagues reported that low-dose aprotlnm caused a 50% reduction in the hemoglobin content of shed mediastinal blood. 6 They also found no statistically significant difference in homologous blood transfusions or percentage of pataents transfused using this regimen. Whether other drugs such as tranexamlc acid cause a samllar reduction in the hemogloban content of shed blood is not known. Other studies have suggested that reinfuslon of shed mediastinal blood may actually increase postoperatwe blood loss Shlrvam found that autotransfusion patients receiving preoperative aspirin therapy had higher postoperative blood loss and transfusion requirements than patients not receiving either aspiran or autotransfusaon, a° de Haan and colleagues reported a 43% increase m total postoperatwe blood loss with autotransfusion. 7 They also found elevated concentrations of tissue-type plasmmogen activator and snmulator activity and increased concentrations of fibrlnogen degradation products in shed mediastinal blood The levels also directly correlated wath total postoperative blood loss. They then used in vitro studies to demonstrate that the combination of tissue-type plasminogen activator and fibrin monomers produced severe platelet damage and dysfunctaon. This confirmed their hypothesis that increased bleedlng tendency wath postoperatwe retransfuslon of shed blood was caused by fibrinolysis. Other evidence for severe platelet dysfunctaon in shed mediastmal blood was provided by Kongsgaard et al. xl The mean platelet count determined by electronic counting was 62,000; however, proper counting wath hght microscopy showed a true platelet count of only 10,000 because of the presence of cytoplasmic cell fragments, which are of samilar size to platelets. The platelets present had undergone arreversable platelet actwatlon and an inability to aggregate in response to common stimula. This study thus confirms that the platelets an shed medlastmal blood are fewer m number than prevaously appreciated and also are activated and nonfuncnonal. There as increasing evidence that activated platelets and leukocytes play an important role in
Journal ofCardtothoraclc and VascularAnesthes/a, Vol 9, No 1 (February), 1995' pp 100-102
PRO AND CON
101
reperfuslon injury. 12,13Further studies are needed to determine whether reinfusion of shed medlastlnal blood may actually enhance this phenomenon. Other hematologic abnormalities may be Induced by reinfusion of shed medlastlnal blood. Reservoir blood is characterized by depletion of clotting factors and activation of the fibrinolytic and kallikrein-kinin system. 14,15Although remfuslon of this blood does not usually cause clinical problems, Fuller et al found elevations in the levels of fibrinogen degradation products, D-Dimer, activated partial thromboplastln time, and thrombin clotting time In patients I hour after reinfusion of shed blood. The elevated thrombin clotting time correlated with the volume of remfused blood. Other studies have also found higher D-Dimer levels and lower fibrinogen levels In patients who had received autotransfuslon. 13.16 The infusion of shed mediastinal blood may also cause difficulties In the diagnosis of myocardial infarction. Shed blood contains up to 10,000 unlts/L of creatine kmase, 5% to 10% of which is creatlne kinase MB band, and similar significant elevations of lactic dehydrogenase and serum glutamlc oxaloacetic transaminase. 1718 Remfusion of shed blood causes a 1.5- to 3.7-fold increase in circulating enzyme levels, which persists for up to 24 hours postoperatively. These marked enzyme elevations may either mask or mimic perioperative myocardial Infarction. Thus, relnfuslon of shed medlastmal blood may make the determination of myocardial infarction, a very important marker of outcome and prognosis, difficult or impossible. Concerns have also been raised about the sterility and potential for infection when shed mediastinal blood is reinfused. Bland et al studied intraoperative autotransfusIon using a cell-saver system. 19 Thirty of 31 (96.8%) of mediastinal blood samples were culture-positive, and 24 1% contained endotoxin. The majority of organisms isolated were coagulase-negative staphylococci but also included diphtheroids and gram-negative bacilli. To reduce the chance of infection, it is recommended that postoperative autotransfusion be performed within 4 hours of the start of collection and not longer than 16 hours postoperatively. Nonetheless, several studies of postoperative autotransfusion have confirmed the possibility of bacterial contamination of shed blood with positive culture rates as high as 50%.19,16 Although a definite link between these positive cultures and postoperative infection has not been established, it is important to remember that wound infection is the most powerful predictor of prolonged hospital stay, increasing the mean hospital length of stay from 8.7 to 32.2 days. 20
Shed mediastinal blood may contain a variety of other unwanted compounds or cells that may complicate or contraindicate its use. Clots may form in the reservoir bags, especially at higher bleeding rates, s Anticoagulatlon of the shed blood may then be required, somewhat of a paradox in a briskly bleeding patient. Plasma hemoglobin, a nephrotoxin, is present in concentrations of 150 to 400 mg/dL. 4,15,16 Although autotransfusion does not lead to renal failure in normal subjects, its safety has not been estabhshed in patients with renal disease. Other contraindications to the use of postoperative autotransfusion include the presence of malignancy or infection at the collection site (because they may be disseminated with reinfusion), the use of mlcrofibrillar hemostatic agents (which may cause mlcroemboli), or the presence of contagious viral markers (which may be risks to health care personnel handling the blood). Some authors have recommended washing of shed mediastlnal blood before retransfuslon to eliminate unwanted elements. 3 However, this increases the time between collection and transfusion and adds to the cost. In addition, with more handling, there is greater risk of contamination of the shed blood and increased risk of disease transmission to caregivers. Technical problems may limit the use (thus, the costeffectiveness) of postoperative autotransfusion. 2,8In Schaff's study, only 46% of adult and 33% of p e d i a m c patients actually received autotransfusion, although the autotransfusion device was routinely applied to all patients. 2 Reevaluation of transfusion practices and increasing awareness and use of other blood conservation measures have reduced the need for blood products. Many patients now receive no blood transfusions. In the study by Schonberger et al, 80% of patients who did not have autotransfusion required no blood products. 6 Thus, even if postoperative autotransfusion were conclusively shown to be effective, it would be unnecessary and/or unused m the majority of patients. In summary, many studies have shown that reinfusion of shed mediastlnal blood does not reduce either postoperative blood loss or reqmrements for homologous transfusion, especially when other currently recommended strategies such as predonation, normovolemic hemodilution, antlfibrinolytic drugs, meticulous surgical hemostasis, and acceptance of a lower transfusion trigger are employed. Shed medlastinal blood also contains many undesirable substances that may complicate the perloperatlve management of the cardiac surgical patient. Its routine use cannot therefore be endorsed.
REFERENCES
1. Schaff HV. Hauer JM, Bell WR, et al AutotransfusIon of shed medlastmal blood after cardiac surgery A prospective study. J Thorac Cardlovasc Surg 75"632-641, 1978 2. Schaff HV. Hauer J, Gardner TJ, et al Routine use of autotransfuslon following cardiac surgery Experience in 700 patients Ann Thorac Surg 27 493-499, 1979 3 Grlffith LD, Billman GF, Dally PO, et al Apparent coagulopa-
thy caused by infusion of shed mediastlnal blood and ItS prevention by washing of the lnfusate Ann Thorac Surg 47 400-406, 1989 4 Ward HB, Smith RR, Landis KP, et al Prospective, randomized trial of autotransfuslon after routine cardiac operations [see comments] Ann Thorac Surg 56'137-141, 1993 5. Roberts SR, Early GL, Brown B, et al' Autotransfuslon of unwashed mediastmal shed blood falls to decrease banked blood
102
requirements in patients undergoing aortocoronary bypass surgery Am J Surg 162:477-480, 1991 6. Schonberger JP, Bredee J, Speekenbrlnk RG, et al. Autotransfusion of shed blood contributes additionally to blood saving in patients receiving aprotinln (2 million KIU). Eur J Cardlo-Thorac Surg 7'474-477, 1993 7. de Haan J, Schonberger J, Haan J, et al Tissue-type plasmmogen activator and fibrin monomers synergistically cause platelet dysfunction during retransfuslon of shed blood after cardiopulmonary bypass. J Thorac Cardiovasc Surg 106:1017-1023, 1993 8. Adan A. Brutel de la Riviere A, Haas F, et al' Autotransfusion of drained medlastlnal blood after cardiac surgery. A reappralsal. Thorac Cardlovasc Surg 36'10-14, 1988 9. Thurer RL, Lytle BW, Cosgrove DM, et al: Autotransfusion following cardiac operations A randomized, prospective study. Ann Thorac Surg 27.500-507, 1979 10 Shxrvanl R: An evaluation of clinical aspects of postoperative autotransfusion, either alone or in conjunction with pre-operatwe aspirin, in cardiac surgery Br J Clln Pract 45'105108, 1991 11 Kongsgaard UE, Hovig T, Brosstad F, et al' Platelets in shed mediastmal blood used for postoperative autotransfuslon Acta Anaesthesiol Scand 37.265-268, 1993 12. Kurose I. Anderson DC, Mxyasaka M. et al Molecular determinants of reperfusion-induced leukocyte adhesion and vascular protein leakage Circ Res 74 336-343, 1994
C DAVID MAZER
13 Seekamp A, Till GO, Mulligan MS, et al Role of selectlns in local and remote tissue injury following lschemla and reperfusmon. Am J Pathol 144.592-598, 1994 14. Fuller JA, Buxton BF, Plcken J, et al' Haematologlcal effects of relnfused mediastlnal blood after cardiac surgery [see comments] Med J Aust 154.737-740, 1991 15 Kongsgaard UE, Tollofsrud S, Brosstad F, et al' Autotransfusion after open heart surgery Characteristics of shed mediastinal blood and its influence on the plasma proteases in circulating blood. Acta Anaestheslol Scand 35.71-76, 1991 16. Eng J, Kay PH, Murday AJ, et al: Postoperative autologous transfusion m cardiac surgery A prospective, randomlsed study Eur J Cardio Thorac Surg 4 595-600, 1990 17 Wahl GW, Felns RH, Alfieres G, et al Relnfuslon of shed blood after coronary operation causes elevation of cardiac enzyme levels Ann Thorac Surg 53.625-627. 1992 18. De Paulls R, Bassano C, Rice1 A, et al Enzyme levels in shed blood after cardiac operations Ann Thorac Surg 56 1001-1003, 1993 19 Bland LA, Vlllarlno ME, Ardulno MJ, et al. Bacteriologic and endotoxm analysis of salvaged blood used in autologous transfusions during cardiac operations J Thorac Cardiovasc Surg 103 582-588, 1992 20 Welntraub WS, Jones EL, Craver J, et al Determinants of prolonged length of hospital stay after coronary bypass surgery Circulation 80'276-284, 1989