Blood use in patients undergoing repeat coronary artery bypass graft procedures: multivariate analysis

BACKGROUND : The prevailing clinical opinion is that patients undergoing repeat coronary artery bypass graft (CABG) operation require more blood transfusions than do patients undergoing primary CABG operation. To determine the extent of this increased demand and the variables responsible for it, the cases of 196 patients who had undergone primary procedures and 65 patients who had had repeat procedures at the same institution were reviewed. STUDY DESIGN AND METHODS : To analyze the differences in transfusion requirements for these two groups, the following data were obtained: number of transfusions given between the time of surgery and the time of hospital discharge; preoperative hemoglobin (Hb), hematocrit (Hct), prothrombin time, and platelet count; Hb and Hct at hospital discharge; time the patient was on cardiopulmonary bypass; number and type of grafts; estimates of intraoperative blood loss; and chest-tube blood shed during the first 48 hours after surgery. RESULTS : The groups were comparable with respect to age, body weight, preoperative Hb and Hct, number of grafts, and aspirin exposure. Patients in the repeat group had 35-percent greater blood loss and required 75-percent more blood components than did the patients undergoing primary procedures. The mean number of blood components transfused per patient was as follows: red cells, 3.8 +/? 0.5 units in repeat patients and 2.2 +/? 0.2 units in primary patients (p = 0.002); platelets, 2.9 +/? 0.9 vs. 1.1 +/? 0.2 (p = 0.043); fresh-frozen plasma, 1.6 +/? 0.4 vs. 0.8 +/? 0.1 (p = 0.044). Analysis of variables by regression method for repeat patients showed a predictive effect of blood loss (p < 0.0001), prolonged time on cardiopulmonary bypass (p < 0.0001), preoperative Hb (p = 0.0003), and aspirin exposure (p = 0.0094) on red cell transfusion rate in repeat patients (R-square = 0.7778, Prob > f = 0.0001). CONCLUSION : Repeat CABG patients have higher transfusion rates. These findings may be attributed to the increased microvascular bleeding, prolonged time on cardiopulmonary bypass, lower preoperative Hb, and the use of preoperative antiplatelet medications.     

Effect of clopidogrel on bleeding after coronary artery bypass surgery.

OBJECTIVE: Platelet dysfunction is a common cause of bleeding after coronary artery bypass graft surgery. This study explores the effects of clopidogrel on bleeding complications after coronary artery bypass graft surgery. DESIGN: Prospective observational study of patients undergoing coronary artery bypass graft. SETTING: Tertiary care center. PATIENTS: A total of 247 patients undergoing coronary artery bypass graft surgery. INTERVENTIONS: None. MEASUREMENTS: Primary end point was need for reexploration secondary to bleeding. Secondary end points included need for transfusion of blood products and chest tube output. MAIN RESULTS: Eight (3.3%) of 247 patients required reexploration secondary to bleeding. Clopidogrel recipients had higher incidence of reexploration for bleeding (9.8 vs. 1.6, p =.01) with an odds ratio of 6.9 (95% confidence interval, 1.6-30). Clopidogrel also increased the percentage of patients receiving packed red blood cell transfusion (72.6 vs. 51.6%, p =.007), the number of packed red blood cell units (3 vs. 1.6, p =0.0004), and the number of cryoprecipitate units (2.4 vs. 1.2, p =.04) transfused after coronary artery bypass graft surgery. Among clopidogrel recipients, a trend for increased transfusion of platelet units (4.3 vs. 1.7, p =.05) and fresh frozen plasma units (1.1 vs. 0.6, p =.08) also was found. CONCLUSIONS: Preoperative use of clopidogrel in combination with aspirin is associated with increased need for surgical reexploration as well as risk of packed red blood cell and cryoprecipitate transfusions after coronary artery bypass graft surgery.     

Storage time of transfused red blood cells and impact on clinical outcomes in hematopoietic stem cell transplantation

BACKGROUND: Red blood cell (RBC) transfusion may prolong recovery in some patients, perhaps due to changes that occur during more prolonged RBC storage. We examined the impact of RBC transfusion and the age of transfused RBC units on clinical outcomes in hematopoietic stem cell transplantation (HSCT). STUDY DESIGN AND METHODS: Data concerning RBC transfusions between Day 0 and Day +30 were analyzed for patients undergoing HSCT (n = 555) at a single institution. “Old” RBC units were defined as those stored for 15 days or longer. RESULTS: The proportion of old RBC units transfused and the mean age of transfused units did not correlate with 100‐day nonrelapse mortality, organ‐specific toxicity, length of stay (LOS), or incidence of intensive care unit (ICU) admission (p > 0.05). In comparing the 71 patients who received only old RBC units with 218 patients who received only “new” RBC units, there was no increase in adverse clinical outcomes after HSCT. Autologous transplant recipients (n = 355, 3.8 units/patient) were more likely to avoid RBC transfusion and received fewer units compared with allogeneic recipients (n = 200, 6.4 units/patient, p < 0.0001). The mean number of transfused RBC units was greater in patients admitted to the ICU (10.5 units vs. 3.7 units/patient, p < 0.01), correlated with longer LOS (p < 0.0001), and correlated with increasing number of organ systems with toxicity of at least Grade 2 (p < 0.0001). CONCLUSION: The importance of RBC storage time does not appear to influence clinical outcomes in HSCT. Patients with increased RBC transfusion requirements have greater toxicity after HSCT. Whether RBC transfusion contributes to toxicity, however, remains unclear.     

The effect of an intraoperative treatment algorithm on physicians' transfusion practice in cardiac surgery

Background : Inappropriate transfusion in cardiac surgery may, in part, be due to empiric transfusion therapy instituted in the absence of timely laboratory data. Therefore, the effect of a transfusion decision algorithm based on intraoperative coagulation monitoring of physicians' transfusion practice and the transfusion outcome was evaluated. Study Design and Methods : In a randomized, controlled trial, cardiac surgical patients determined to have microvascular bleeding at the cessation of cardiopulmonary bypass were assigned to algorithm (A) or standard (S) therapy. Group A was treated with plasma and platelet therapy according to a transfusion algorithm based on on-site coagulation data available within 4 minutes. For Group S, the use of laboratory-based data and the decision to transfuse blood components were at physician discretion. Results : Sixty-six patients were entered into the study (Group A, n = 30; Group S, n = 36). Other than the fact that there were significantly more female patients in Group S than in Group A, no differences between cohorts in regard to perioperative risk factors for blood transfusion needs were identified. Therefore, gender was factored in as a covariate in the statistical analysis. Group A patients received fewer hemostatic blood component units (p = 0.008) and had fewer total donor exposures (p = 0.007) during the entire hospitalization period. Linear regression analysis of the differences in slopes in Groups A and S for the relationships between the red cell volume lost and the red cell volume transfused (p < 0.03), non-red cell units transfused (p < 0.0001), and total number of blood components transfused (p < 0.0001) demonstrated that physicians' transfusion practice was significantly altered by the use of a transfusion algorithm with on-site coagulation data, independent of surgical blood losses. Conclusion : The use of algorithms by transfusion decision makers can serve as an effective physician education intervention.     

Retrograde autologous priming reduces transfusion requirements in coronary artery bypass surgery

The hypothesis was tested whether retrograde autologous priming (RAP) of the cardiopulmonary bypass system, compared to a standard primed system (NON-RAP group), results in less haemodilution and less transfusion of packed red blood cells. Retrospectively, data was collected from the medical charts of one hundred patients undergoing elective coronary artery bypass grafting using cardiopulmonary bypass. Fifty patients where RAP was used have been compared to fifty patients using NON-RAP. The prime volume in the NON-RAP group was 1,627±108 mL versus 782±96 mL in the RAP group (p<0.001). The lowest haematocrit during perfusion was 22% in the NON-RAP group versus 26% when the RAP technique was used (p<0.001). In the NON-RAP group, 26% of the patients received packed red cells in contrast to 6% in the RAP group (p<0.012). A positive association was found between RAP and less transfusion of packed red blood cells (p<0.012). In conclusion, retrograde autologous priming, reducing the prime volume of the cardiopulmonary bypass system, causes less haemodilution and reduces intraoperative transfusion of packed red blood cells.     

Association of ABO-mismatched platelet transfusions with morbidity and mortality in cardiac surgery

BACKGROUND: The transfusion of ABO-mismatched platelets has been associated with increased morbidity and mortality during induction therapy for acute leukemia and allogeneic progenitor cell transplantation. STUDY DESIGN AND METHODS: Reported here is a cohort study of 153 patients undergoing primary coronary artery bypass graft or coronary valve replacement surgery by two surgeons in one institution during 1997 and 1998. All statistics employed nonparametric two-sided tests (Mann-Whitney; Fisher's exact test). RESULTS: Patients receiving at least one ABO-mismatched pool of platelets had a significantly longer hospital stay, more days of fever, greater total hospital charges, and more RBC transfusions. Mortality, hours in the intensive care unit, days on antibiotics, and numbers of platelet transfusions were also greater in recipients of ABO-mismatched platelets, but these differences were of less statistical significance. When the analysis was restricted to the 139 patients who received no more than two pools of platelets, the trends for increased morbidity and mortality (8.6% vs. 1.9%; p = 0.10) in recipients of ABO-mismatched platelets persisted. The number of RBC transfusions required in this latter cohort was 50 percent greater (mean, 6.1 vs. 9.2; p = 0.02), despite the fact that the number of platelet transfusions given was similar (mean, 1.2 vs. 1.3 pools; p = 0.22). CONCLUSIONS: ABO-mismatched platelet transfusions are associated with unfavorable outcomes in cardiac surgery, a relationship that remains unexplained. As this association has been found in three cohort studies in various clinical settings, further investigation of this association is warranted.     

Effect of an assessment of fibrin-based rotational thromboelastometry on blood transfusion and clinical outcomes in cardiovascular surgery: A cohort study

The clinical importance of viscoelastic testing in patient blood management when performing cardiovascular surgery is increasing. We aimed to examine the effect of a blood transfusion protocol including an assessment of fibrin-based rotational thromboelastometry on transfusion volume, mortality, and bleeding complications in patients undergoing cardiac or thoracic aortic surgery. We retrospectively studied a cohort of 376 consecutive patients who underwent cardiopulmonary bypass before (control group: 150 cardiac and 35 thoracic aortic surgeries) and after (assessment group: 154 cardiac and 37 thoracic aortic surgeries) introducing the fibrin polymerization assessment with thromboelastometry in the blood transfusion protocol. The transfusion volume and clinical outcomes were compared between the control and assessment groups, and the standardized (mean) difference (S[M]D) was calculated as an indicator of statistical effect size. Compared with the control group, the assessment group had a lower total blood transfusion volume (mL) in cardiac (2720 ± 1282 vs. 2034 ± 1330, p < 0.0001, [SMD] = 0.68) and thoracic aortic surgeries (5236 ± 2732 vs. 3714 ± 1768, p < 0.0001, SMD = 0.67). The 1-year mortality rates were 1.9 % and 2.7 % in cardiac and thoracic aortic surgeries, respectively. Significant differences were not observed in the 1-year mortality (3.2 % vs. 1.0 %, p = 0.16, relative risk [RR] = 0.32 with 95 % confidence intervals [CI] = 0.06–1.57, SD = 0.15), re-exploration for bleeding (4.8 % vs. 2.6 %, p = 0.28, RR = 0.53 with 95 % CI = 0.18–1.57, SD = 0.12), and major bleeding (17.3 % vs. 13.0 %, p = 0.31, RR = 0.75 with 95 % CI = 0.46–1.22, SD = 0.12) rates between the control and assessment groups. The assessment of fibrin polymerization with thromboelastometry using the blood transfusion protocol reduced the blood transfusion volume in cardiovascular surgery.     

A randomized trial on the efficacy of an autologous blood drainage and transfusion device in patients undergoing elective knee arthroplasty

The purpose of the study reported here was the determination of the efficacy of a postoperative autologous blood drainage and transfusion device in reducing allogeneic red cell requirements in patients undergoing elective knee arthroplasty. The study was a randomized controlled trial with adult patients undergoing unilateral elective arthroplastic knee surgery. Patients underwent suction drainage, attached to an autologous blood drainage and transfusion device, or standard suction drainage. Allogeneic red cells were given according to strict transfusion guidelines based on blood loss and postoperative hemoglobin values. Outcome measures included the mean number of allogeneic red cell concentrates required and the number of patients in each group who required no transfusion. Patients assigned to standard suction drainage had a mean allogeneic red cell utilization of 1.2 units (SD 1.0), as compared to a mean of 0.4 units (SD 0.8) in the group undergoing drainage with the autologous blood drainage and transfusion device (p = 0.0007). The percentage of patients not requiring allogeneic red cells was significantly higher in the latter group (74.3% vs. 32.5%; p = 0.002). The postoperative drainage and transfusion device was efficacious in reducing the amount of allogeneic red cells required by patients undergoing knee arthroplasty, and its use resulted in a 42 percent reduction in the number of patients requiring allogeneic transfusion.     

Reduction of hemodilution in small adults undergoing open heart surgery: a prospective, randomized trial

BACKGROUND: Given that there is an association between the degree of hemodilution during cardiopulmonary bypass (CPB) and postoperative complications, patients-outcome might be improved if the nadir hematocrit concentration is kept within an optimal range. Smaller patients are more likely to have a low hematocrit during CPB: this phenomenon may be related, at least partially, to the extreme hemodilution induced by a large fixed CPB priming volume. METHODS: Forty patients with a body surface area (BSA) < 1.7 m2 undergoing open heart operations were randomized to either standard CPB with full prime volume (control group) or reduced prime extracorporeal circuit and vacuum-assisted venous drainage (VAVD) (study group). RESULTS: There were no significant differences between the groups with respect to baseline characteristics, body surface area, hematologic profile and operative data. Clinical outcomes were similar. Nadir hematocrit and hemoglobin on bypass were significantly lower in the control group (22 +/- 2.3 vs. 24 +/- 2.5%, p < 0.02 and 7.4 +/- 0.7 vs. 8 +/- 0.9 g/dl, p < 0.04, respectively). Postoperative chest tube drainage was significantly higher in the control group (272 +/- 253 vs. 139 +/- 84 ml, p < 0.04). There was no difference in blood transfusion in the two groups (0.5 +/- 1.14 vs. 1.0 +/- 1.77 units of packed red blood cells (PRBC), p = 0.29). CONCLUSIONS: Lowering CPB priming volume by means of using a small oxygenator and vacuum-assisted venous drainage (VAVD) resulted in a significant decrease of intraoperative hemodilution. This technique should be strongly considered for patients with a small BSA (<1.7 m2) undergoing open heart surgery.     

A randomized controlled pilot study of adherence to transfusion strategies in cardiac surgery

BACKGROUND: It is important to determine the optimal hemoglobin (Hb) concentration for red blood cell (RBC) transfusion for patients undergoing cardiac surgery because increased mortality has been associated with the severity of anemia and exposure to RBCs. Because a definitive trial will require thousands of patients, and because there is variability in transfusion practices, a pilot study was undertaken to determine adherence to proposed strategies. STUDY DESIGN AND METHODS: A single‐center parallel randomized controlled pilot trial was conducted in high‐risk cardiac patients to assess adherence to two transfusion strategies. Fifty patients were randomly assigned either to a “restrictive” transfusion strategy (RBCs if their Hb concentration was 70 g/L or less intraoperatively during cardiopulmonary bypass [CPB] and 75 g/L or less postoperatively) or a “liberal” transfusion strategy (RBCs if their Hb concentration was 95 g/L or less during CPB and less than 100 g/L postoperatively). RESULTS: The percentage of adherence overall was 84% in the restrictive arm and 41% in the liberal arm. Twenty‐two (88%) patients were transfused 99 units of RBCs in the liberal group compared to 13 patients who were transfused 50 units in the restrictive group (p < 0.01). There were no significant differences in individual adverse outcomes; however, more adverse events occurred in the restrictive group (38 vs. 15, p < 0.01). CONCLUSION: Adherence to the evaluated interventions is vital to all randomized controlled trials as it has the potential to affect outcomes. Further pilot studies are required to optimize enrollment and transfusion adherence before a definitive study is conducted.     

A multivariable model for predicting the need for blood transfusion in patients undergoing first-time elective coronary bypass graft surgery

BACKGROUND: The incidence of blood transfusion in coronary artery bypass graft (CABG) surgery remains high. Preoperative identification of those at high risk for requiring blood will allow for the cost-effective use of some blood conservation modalities. Multivariable analysis techniques were used in this study to develop a prediction rule for such a purpose. STUDY DESIGN AND METHODS: Data were prospectively collected for all patients undergoing elective first-time CABG surgery from January 1997 to September 1998 at a tertiary-care teaching hospital (n = 1007). The prediction rule was developed on the first two-thirds of the sample by using logistic regression methods to examine the relationship of patient demographics, comorbidities, and preoperative Hb with perioperative blood transfusion. The remaining one-third of the sample was used to validate the rule. RESULTS: The transfusion rate was 29.4 percent. The prediction rule included preoperative Hb (g/dL, OR 0.928, p<0.0001), weight (kg, OR 0.938, p<0.0001), age (years, OR 1.037, p<0.01), and sex (male/female, OR 0.493, p<0.01); receiver operating characteristic = 0.86. When externally validated, the rule had a sensitivity of 82.1 percent and a specificity of 63.6 percent (at a selected probability cutoff). CONCLUSION: A simple and valid prediction rule is developed for predicting the risk of blood transfusion in patients undergoing first-time elective CABG surgery.     

Beneficial effects of using a minimal extracorporeal circulation system during coronary artery bypass grafting

Background: In this study, we assessed clinical results by using a minimal extracorporeal circuit (MECC) and compared it to a conventional cardiopulmonary bypass (CPB) system in patients undergoing coronary artery bypass grafting (CABG) procedures. Methods and Materials: From August to October 2006, forty consecutive patients undergoing isolated CABG procedures were randomly assigned to either a miniaturized closed circuit CPB with the Maquet-Cardiopulmonary MECC system (Group M, n=20) or to a conventional CPB system (Group C, n=20). Clinical outcomes were observed before, during and after the operation. Besides evaluating the perioperative clinical data, serial blood venous samples were obtained after induction, 30 minutes after CPB initiation, 2h, 6h, 12h, and 24h post-CPB. The focus of our study was on myocardial damage (cTnI), neutrophil and platelet counts, activated partial thromboplastin time (aPTT) and free hemoglobin. Results: Both the transfusion of packed red blood cells and fresh frozen plasma were significantly lower in Group M compared to Group C (p<0.05). The levels of cTnI were lower in Group M at 2h, 6h and 12h post-CPB than in Group C (p<0.01). The values of aPTT in Group M recovered to normal levels after surgery, but were prolonged in Group C at early post-CPB and were statistically longer than Group M at 2h, 6h, and 12h post-CPB (p<0.05). The concentrations of free hemoglobin in Group C were higher than in Group M during and post-CPB, and there was a statistical difference at 2h post-CPB (p<0.05). Conclusion: In conclusion, the MECC system is a safe alternative for patients who undertake extracorporeal circulation (ECC) for CABG surgery. Lower transfusion requirements and less damage to red cells may further promote the use of MECC systems, especially in higher risk patients.     

Immunohematologic complications of ABO-unmatched liver transplants

Transplantation of ABO-unmatched livers has been associated with the development of donor-derived antibody (DDAb) and hemolysis. Nine (22%) of 41 consecutive patients undergoing liver transplantation at our institution received 10 ABO-unmatched livers. Five (56%) of nine patients developed DDAbs and hemolysis. All five patients were group A1 and received group O livers. DDAbs appeared a mean of 9.2 +/- 2.8 (1 SD) days after surgery and persisted for 15.2 +/- 10.3 days. All patients with DDAbs developed hemolysis. During the period when DDAbs were demonstrable, the hemoglobin dropped by a mean of 4.8 g per dL (48 g/L), and the patients were transfused with a mean of 7.8 +/- 2.3 units of group O red cells. One patient with hemolysis underwent exchange transfusion for acute renal failure. Patients with hemolysis required significantly more red cells postoperatively (15.0 vs. 6.9 units, p = 0.04) than did ABO-matched patients. None of the parameters examined (age, recipient or donor gender, secretor status, rejection, or donor isoagglutinin titers) were predictive of DDAb or hemolysis, although hemolysis occurred in three of four cases in which donor serum IgG anti-A titers were > or = 128, as opposed to one of four cases in which titers were < 128. Because recipients of ABO-unmatched livers are at high risk for transiently developing DDAb and hemolysis with associated morbidity, the prophylactic use of donor-type red cells for surgery and after operation is justified.     

Costs, clinical outcomes, and health-related quality of life of off-pump vs. on-pump coronary bypass surgery.

BACKGROUND: Off-pump coronary bypass surgery avoids the potential complications of cardiopulmonary bypass. However, its acceptance depends on medical and economic outcome. The aim of this prospective non-randomised study was to compare functional and economic outcome of off-pump and on-pump surgery at 1-year follow-up. METHODS: 102 patients (pts) treated with either off-pump (60pts) or on-pump surgery (42pts) were studied. Pts with left ventricular dysfunction, recent myocardial infarction (<1 month), renal impairment, valve surgery, previous stroke or coagulopathy were excluded. Variable and fixed costs were obtained for each treatment group during operative and postoperative care. In-hospital endpoints included all-cause mortality and complications (defined as excessive bleeding [>6 units blood transfusion], peri-operative myocardial infarction, atrial fibrillation, stroke, and infection). All cause mortality; cost-effectiveness and quality of life were assessed 1 year after surgery. RESULTS: The in-hospital mortality was similar in the two treatment groups. Off-pump group had significantly fewer postoperative complication rate (off-pump 41% vs. on-pump 72%, p=0.001). The mean in-hospital cost was lower for off-pump surgery (off-pump 6.515+/-926 euro vs. on-pump 9.872+/-1.299 euro, p<0.0001) as well as the mean length of hospital stay (off-pump 4.93+/-0.93 days vs. on-pump 6.58+/-1.04 days, p<0.0001). At 1 year, all cause mortality, quality of life indices, return to work rate and treatment satisfaction was similar in both groups. CONCLUSION: Off-pump myocardial revascularization maintains the advantages of conventional surgery in terms of survival and freedom from cardiac events while reducing the in-hospital cost.     

Immunologic changes after transfusion of autologous or allogeneic buffy coat-poor versus white cell-reduced blood to patients undergoing arthroplasty. I. Proliferative T-cell responses and the balance of helper and suppressor T cells

BACKGROUND: Donor white cells (WBCs) contained in red cell (RBC) transfusions are thought to provoke down-regulation of T-cell-mediated immunity. This study investigated this topic in otherwise healthy patients receiving buffy coat-depleted or WBC-filtered RBCs and undergoing standardized perioperative management. STUDY DESIGN AND METHODS: Patients undergoing elective orthopedic surgery (primary hip and knee replacement surgery) were enrolled in a prospective study. Perioperative changes in T-cell proliferation (stimulation with phytohemagglutinin and mixed lymphocyte culture) and T-cell balance (T-lymphocytes, helper T cells, and suppressor T cells) were compared after random assignment to allogeneic buffy coat-depleted (Group 2, n = 8) or WBC-reduced RBC (Group 3, n = 11) transfusion regimens. Recipients of autologous buffy coat-depleted RBC transfusions (n = 15) served as controls (Group 1). RESULTS: Compared to that in autologous transfusion recipients, alloantigen-induced T-cell proliferation was significantly reduced in recipients of allogeneic WBC-reduced RBCs (Day 3, p = 0.0274). After the transfusion of allogeneic buffy coat-depleted RBCs, a weak trend toward decreased T-cell proliferation was observed (p = 0.0933) and the numbers of CD4+ T cells were also significantly lower (Day 7, p = 0.0389). On Day 10, alloantigen-induced T-cell proliferation remained significantly below baseline after transfusion of WBC-reduced RBCs (p = 0.05), the numbers of CD3+ cells decreased in allogeneic RBC recipients (Group 2, p = 0.078; Group 3, p = 0.05), and those of CD8+ cells decreased significantly after the transfusion of allogeneic buffy coat-depleted RBCs (p = 0.0234) concomitant with an increased CD4:CD8 ratio (p = 0.0391). CONCLUSION: Results of the present study confirm the hypothesis of impaired T-cell-mediated immunity after allogeneic transfusion.     

Efficacy of autologous fresh whole blood or platelet-rich plasma in adult cardiac surgery

BACKGROUND: Transfusing fresh autologous blood during cardiac surgery may improve hemostasis and decrease the need for transfusion. STUDY DESIGN AND METHODS: A prospective randomized study was performed with fresh whole blood (WB) obtained by intraoperative hemodilution (IH) and with platelet-rich plasma (PRP) obtained by perioperative apheresis from adult cardiac surgery patients. RESULTS: Seventy patients were randomly assigned to three arms: 24 to the PRP arm, 18 to the IH arm, and 28 to serve as controls. A mean of 924 +/− 130 mL of WB was collected from the IH group, and a mean of 650 +/− 124 mL of PRP was collected from the PRP group (mean, 1.42 +/− 0.74 × 10(11) platelets); these components were transfused after bypass. Preoperative measures were similar among groups. Intraoperatively, the groups did not differ in bypass time, estimated blood loss, number of transfusions, or proportion receiving transfusion(s). Postoperatively, control patients had more mediastinal drainage (736 mL vs. 476 mL [IH] and 463 mL [PRP]; p = 0.014), but there was no difference in the proportion of patients requiring red cell transfusion (p = 0.87), the hemoglobin at discharge (p = 0.20), or the length of hospitalization (p = 0.57). CONCLUSION: Although a hemostatic benefit manifested as reduced postoperative bleeding was observed, this study does not support the use of fresh blood components obtained by IH or PRP collection during low-risk cardiac surgery. Additional studies are needed to assess whether more aggressive component collection or the use of these techniques in high- risk cases may have a greater impact on clinical outcome variables, including transfusion.     

Transfusion of red cells is associated with increased incidence of bacterial infection after colorectal surgery: a prospective study

BACKGROUND: Several studies suggest that perioperative blood transfusion is a major independent risk factor for postoperative bacterial infections. Transfusion-induced immunosuppression is thought to mediate this effect. STUDY DESIGN AND METHODS: In a randomized clinical trial comprising 697 patients with colorectal cancer, the relationship between two types of red cell components (buffy coat- depleted packed red cells and white cell-reduced [filtered] packed red cells) and postoperative bacterial infections was analyzed. RESULTS: Both types of red cells appeared to be associated with a greater incidence of postoperative infection than was no transfusion (39 vs. 24%, p < 0.01). A dose-response relationship could be demonstrated: the corrected relative risk was 1.6 for 1 to 3 units of red cells and 3.6 for more than 3 units. Multivariate analyses identified the transfusion of red cells and tumor location as the only significant independent risk factors for postoperative bacterial infection. CONCLUSION: Because allogeneic white cells, plasma, microaggregates, citrate, and platelets could be ruled out as risk factors for transfusion-associated postoperative infections, it is hypothesized that the transfusion of red cells is a potentially detrimental factor that transiently impairs the clearance of bacteria by phagocytic cells.     

输血支持在造血干细胞移植中的应用

背景:接受造血干细胞移植的患者经常需要血液制品输注支持,而患者对红细胞和血小板输注的需求差异非常大,这主要依赖于造血干细胞移植的类型和患者本身的疾病性质。目的:评价中山大学附属中山医院接受造血干细胞移植患者移植期间输血的需求和数量。方法:收集中山大学附属中山医院2004-01/2010-06接受造血干细胞移植患者的资料,包括移植的适应证、移植的类型、CD34+细胞的数量、红细胞和血小板的输注数量、费用、脱离输注时间以及中性粒细胞和血小板植入时间;红细胞输注的阈值是血红蛋白计数为70g/L,而血小板的输注阈值是计数为20×109L-1。研究分析了患者移植期间红细胞和血小板输注的需求、输注量、输血费用,以及患者的生存情况。结果与结论:自体造血干细胞移植组中有14例(93%)患者,而异基因造血干细胞移植组中有35例(90%)患者显示了造血细胞植入和脱离输注证据。自体造血干细胞移植组取得脱离红细胞输注天数为14.6d,明显短于异基因造血干细胞移植组。与异基因造血干细胞移植组比较,自体造血干细胞移植组红细胞输注单位明显减少;而异基因造血干细胞移植组的红细胞输注费用明显高于自体造血干细胞移植组。输血花费昂贵,但却是造血干细胞移植中必不可少的一部分,异基因造血干细胞移植组需要更多的输血支持。脱离输注时间有望成为评估造血干细胞移植成功的指标。     

Effects of ventilation and nonventilation on pulmonary venous blood gases and markers of lung hypoxia in humans undergoing total cardiopulmonary bypass

OBJECTIVE: To assess the effects of lung oxygenation and ventilation vs. lung collapse on pulmonary markers of lung hypoxia. DESIGN: A prospective, nonrandomized, nonblinded comparative study. SETTING: University department of anesthesiology and cardiothoracic surgery. SUBJECTS: Twelve adult patients undergoing coronary bypass grafting requiring total cardiopulmonary bypass. INTERVENTIONS: Single lung ventilation during total cardiopulmonary bypass (tidal volume, 150 mL; respiratory rate, 6 breaths/min; inspiratory oxygen fraction, 0.5) while the contralateral lung was allowed to collapse completely without oxygenation. MEASUREMENTS AND MAIN RESULTS: At the beginning and at the end of total cardiopulmonary bypass (duration, 59-65 mins), blood was aspirated from the right and left pulmonary veins and the radial artery for measurement of blood gases and concentrations of endothelin-1, big-endothelin, thromboxane B2, lactate, and lactate dehydrogenase. Nonventilation during total cardiopulmonary bypass compared with ventilation resulted in lower pulmonary venous P(O2) values (57+/-15 torr [7.6+/-2.0 kPa] vs. 103+/-23 torr [13.7+/-3.1 kPa]) and higher thromboxane B2 concentrations (488+/-95 pg/mL vs. 434+/-92 pg/mL). The concentrations of endothelin-1, big-endothelin, lactate, and lactate dehydrogenase in the pulmonary veins did not differ significantly between nonventilated and ventilated lungs. CONCLUSIONS: Development of pulmonary tissue hypoxia during 1 hr of nonventilation and cardiopulmonary bypass with completely inhibited pulmonary arterial blood flow is unlikely, suggesting that enough oxygen is stored in or is provided to the collapsed lung. Thus, nonventilation during total cardiopulmonary bypass does not appear to contribute to postoperative respiratory dysfunction by causing pulmonary tissue hypoxia. These results, however, do not exclude that mechanical factors of ventilation might benefit the lung during cardiopulmonary bypass.     

Normothermic Cardiopulmonary Bypass Increases Heparin Requirements Necessary to Maintain Anticoagulation

Objective. With the practice of warm cardiopulmonary bypass (CPB) at our institution we have observed an apparent increase in heparin requirements. CPB temperature predictability affects pharmacokinetics and differences in drug metabolism can be expected. We hypothesized that heparin requirements would increase with increasing CPB temperature. Methods. Following Institutional Review Board approval, we reviewed the charts of 354 patients undergoing primary coronary artery bypass graft surgery. We recorded patient demographic data, CPB duration, heparin requirements, and temperature during CPB. CPB was conducted between 24 °C and 37 °C. The Spearman's correlation coefficient, Pearson chi-square, and rank-sum tests were used for data analysis. Results. Core temperature during CPB correlated with heparin requirements (r = 0.13, p < 0.02). However, CPB duration was shorter in warm patients than in cold patients (r = –0.455, p < 0.0001). Additional heparin requirements adjusted for duration of CPB (units/minute) were also significantly greater in the warm group (p = 0.018). Conclusions. Maintenance of adequate heparin anticoagulation during CPB is clinically important. Warm CPB patients required more heparin per minute than those undergoing cold CPB. More frequent assessment of anticoagulation and administration of additional heparin should be considered in patients undergoing warm CPB.