The effect of in vitro recombinant factor VIIA on coagulation parameters for blood taken during liver transplantation.

Recombinant factor VIIa (rFVIIa) has been utilized in pilot studies in orthotopic liver transplantation (OLT) when administered to patients at doses of 68.37 microg/kg and 80 microg/kg. Although some effectiveness in normalizing measurements of coagulation has been demonstrated, the optimal dose for patients undergoing OLT has not been established. This study evaluated the effects of an in vitro equivalent dose of 120 microg/kg of rFVIIa on coagulation parameters when applied to the blood drawn from patients undergoing OLT. Coagulation function was assessed in 10 patients at four points during OLT. These time points were baseline, 5 minutes prior to reperfusion, 10 minutes after reperfusion, and 70 minutes after reperfusion. These patients did not receive rFVIIa perioperatively. At each of these four time points, a native sample was analyzed for prothrombin time (PT) and thromboelastogram. The rFVIIa (6.1 microg/kg or the approximate equivalent dose of 120 microg/kg for a 70 kg patient) was added to a second sample from the same patient. This second sample was also analyzed for PT and thromboelastogram. There was a statistically significant difference in baseline PT between native versus rFVIIa supplemented samples (15.8 +/- 3.21 vs 13.6 +/- 2.36 seconds, P < .02). The maximum amplitude of the thromboelastogram was larger in the native samples at 5 minutes prior to reperfusion (53.5 mm vs 39 mm, P < .02). No significant differences existed in the variables at any of the other sampling times. This study failed to demonstrate a consistent in vitro effect of rFVIIa on the blood taken from patients during OLT.

Risk factors for ischemic optic neuropathy after cardiopulmonary bypass: a matched case/control study.

UNLABELLED: Visual loss (acuity or field) secondary to ischemic optic neuropathy (ION) is a rare but devastating complication of cardiac surgery involving cardiopulmonary bypass (CPB). We determined clinical features and risk factors for ION by a retrospective time-matched, case-control study. ION was identified in 17 (0.06%) patients out of 27,915 patients who underwent CPB between January 1, 1976, and December 31, 1994. For each ION patient, two patients who underwent CPB exactly 2 wk before the ION patient were selected as controls. Data were analyzed by using conditional logistic regression with the 1:2 matched-set feature of 17 cases and 34 controls. Two-tailed P values < or =0.05 were considered significant. From bivariate analysis, smaller minimum postoperative hemoglobin concentration (odds ratio [OR] = 1.9, P = 0.047) and the presence of atherosclerotic vascular disease (OR = 7.0, P = 0.026) were found to be independently associated with ION after CPB, as were smaller minimum postoperative hemoglobin concentration (OR = 2.2, P = 0.027) and preoperative angiogram within 48 h of surgery (OR = 7.2, P = 0.042). In ION patients, 13 (76.5%) of 17 experienced a minimum postoperative hemoglobin value of < 8.5 g/dL, whereas only 14 (41.2%) of 34 control patients experienced values < 8.5 g/dL. IMPLICATIONS: Patients with clinically significant vascular disease history or preoperative angiogram may be at increased risk for ischemic optic neuropathy after cardiac surgery, especially if the hemoglobin remains low in the postoperative period.

Biocompatibility of Trillium Biopassive Surface-coated oxygenator versus uncoated oxygenator during cardiopulmonary bypass.

OBJECTIVE: To determine if the Trillium Biopassive Surface (Medtronic Cardiopulmonary, Minneapolis, MN) coating added to the cardiopulmonary bypass oxygenator reduces inflammatory mediators, blood loss, and transfusion requirements. DESIGN: Prospective, randomized, and blinded human trial. SETTING: Tertiary care academic medical center. PARTICIPANTS: Thirty adult patients undergoing elective coronary artery bypass graft surgery. INTERVENTIONS: Patients received visually identical coated or uncoated oxygenators. MEASUREMENTS AND MAIN RESULTS: Hemoglobin, hematocrit, leukocyte count, platelet count, terminal complement complex, complement activation, myeloperoxidase, beta-thromboglobulin, prothrombin fragment 1.2, plasmin-antiplasmin, heparin concentration, activated coagulation time, and fibrinogen concentration were measured. Blood loss and blood product usage were recorded. In both groups, there were significant inflammatory alterations with the initiation of cardiopulmonary bypass. In the postprotamine samples, the coated oxygenator group had small but significant increases in hemoglobin, hematocrit, and leukocyte count. There were no differences in inflammatory mediators, blood loss, or transfusion requirements between the coated and uncoated groups. CONCLUSION: This human trial of Trillium Biopassive Surface-coated oxygenators did not show clinical benefits or clinically important biochemical results.

Effect of abciximab on the outcome of emergency coronary artery bypass grafting after failed percutaneous coronary intervention.

OBJECTIVE: To evaluate the outcome of coronary artery bypass grafting (CABG) for failed percutaneous coronary intervention (PCI) in patients who had received abciximab. PATIENTS AND METHODS: In this retrospective study, we analyzed the records of patients who had PCI at our institution between January 1994 and December 1998 and identified those who had urgent or emergency CABG within 48 hours after PCI. CABG was performed for failed PCI in patients who had ongoing ischemia, hemodynamic compromise, or both. These patients were categorized into 2 groups depending on whether they had been given abciximab during PCI. We compared blood product transfusion requirements, bleeding complications, and frequency of in-hospital adverse events of the 2 groups. RESULTS: Of 5636 patients who had PCI, 77 (1.4%) had urgent or emergency CABG within 48 hours, including 11 who were given abciximab (abciximab group) during PCI and 66 who were not given abciximab (no abciximab group). The 2 groups had similar baseline characteristics. The mean +/- SD time to surgery was 8.4 +/-8.0 hours (median, 6 hours) for the abciximab group vs 12.1 +/- 12.5 hours (median, 4 hours) for the no abciximab group. Major bleeding (Thrombolysis in Myocardial Infarction criteria) occurred in 9 (90%) of 10 patients in the abciximab group vs 48 (77%) of 62 patients in the no abciximab group. The total volumes of intraoperative autotransfusion and transfusion of red blood cells and fresh frozen plasma tended to be higher for the abciximab group. Also, this group received a mean of 13.9 U of platelets vs 3.2 U for the no abciximab group (P<.001). However, no in-hospital deaths occurred among patients in the abciximab group, and adverse events were infrequent and comparable between the 2 groups. No difference was noted between the 2 groups in the frequency of surgical reexploration for bleeding. CONCLUSION: Transfusion requirements are higher for patients who undergo emergency or urgent CABG after having received abciximab during PCI. However, in-hospital adverse events are infrequent and comparable to those for patients who do not receive abciximab.

The accuracy of coagulation tests during spinal fusion and instrumentation.

UNLABELLED: Patients undergoing major spine surgery may acquire a perioperative coagulopathy from dilution of coagulation factors and/or platelets or fibrinolysis. The mechanisms of the coagulopathy and role of coagulation testing during these procedures are poorly defined. Theoretically, coagulation tests could be used perioperatively to determine which patients are at risk for significant bleeding and guide transfusion therapy. We retrospectively evaluated the sensitivity, specificity, and accuracy of coagulation tests in predicting excessive surgical bleeding in 244 consecutive patients undergoing thoracic, lumbar, or sacral spinal fusion with or without instrumentation. Excessive bleeding was reported by the surgeon in 39 of the patients and was defined as recurrent microvascular bleeding despite adequate use of electrocautery and suture or decreased clot formation of blood pooled within the surgical field. Patients with excessive clinical bleeding sustained larger estimated blood losses than those with normal hemostasis. The total number of allogeneic red blood cells, platelets, and fresh frozen plasma units were also larger in patients with excessive bleeding noted during surgery. The intraoperative coagulation tests with the most sensitivity and specificity were the international normalized ratio (INR), prothrombin time (PT), and activated partial thromboplastin time (aPTT). The INR had a sensitivity of 94%, a specificity of 88%, and an accuracy of 0.9 at a value of 1.4 (normal, 0.8-1.2). The PT had a sensitivity of 90%, a specificity of 64%, and an accuracy of 0.73 at a value of 13.5 s (normal, 8.4-12.0 s). The aPTT had a sensitivity of 85%, a specificity of 64%, and an accuracy of 0.71 at a value of 30.9 s (normal, 23-37 s). The thromboelastogram values were of marginal use. We conclude that the INR, PT, and aPTT may be helpful in guiding transfusion therapy in patients undergoing major spine surgery. IMPLICATIONS: Patients undergoing major surgery to the spine often acquire a perioperative coagulopathy. The prothrombin time and activated partial thromboplastin time had the greatest sensitivity and specificity for predicting bleeding in major surgery of the spine. The test values that differentiated normal from excessively bleeding patients could be used to guide transfusion therapy during surgery.

Efficacy of a simple intraoperative transfusion algorithm for nonerythrocyte component utilization after cardiopulmonary bypass.

BACKGROUND: Abnormal bleeding after cardiopulmonary bypass (CPB) is a common complication of cardiac surgery, with important health and economic consequences. Coagulation test-based algorithms may reduce transfusion of non-erythrocyte allogeneic blood in patients with abnormal bleeding. METHODS: The authors performed a randomized prospective trial comparing allogeneic transfusion practices in 92 adult patients with abnormal bleeding after CPB. Patients with abnormal bleeding were randomized to one of two groups: a control group following individual anesthesiologist's transfusion practices and a protocol group using a transfusion algorithm guided by coagulation tests. RESULTS: Among 836 eligible patients having all types of elective cardiac surgery requiring CPB, 92 patients developed abnormal bleeding after CPB (incidence, 11%). The transfusion algorithm group received less allogeneic fresh frozen plasma in the operating room after CPB (median, 0 units; range, 0-7 units) than the control group (median, 3 units; range, 0-10 units) (P = 0.0002). The median number of platelet units transfused in the operating room after CPB was 4 (range, 0-12) in the algorithm group compared with 6 (range, 0-18) in the control group (P = 0.0001). Intensive care unit (ICU) mediastinal blood loss was significantly less in the algorithm group. Multivariate analysis demonstrated that transfusion algorithm use resulted in reduced ICU blood loss. The control group also had a significantly greater incidence of surgical reoperation of the mediastinum for bleeding (11.8% vs. 0%; P = 0.032). CONCLUSIONS: Use of a coagulation test-based transfusion algorithm in cardiac surgery patients with abnormal bleeding after CPB reduced non-erythrocyte allogeneic transfusions in the operating room and ICU blood loss.

Plasma tranexamic acid concentrations during cardiopulmonary bypass.

UNLABELLED: Although tranexamic acid is used to reduce bleeding after cardiac surgery, there is large variation in the recommended dose, and few studies of plasma concentrations of the drug during cardiopulmonary bypass (CPB) have been performed. The plasma tranexamic acid concentration reported to inhibit fibrinolysis in vitro is 10 microg/mL. Twenty-one patients received an initial dose of 10 mg/kg given over 20 min followed by an infusion of 1 mg. kg(-1). h(-1) via a central venous catheter. Two patients were removed from the study secondary to protocol violation. Perioperative plasma tranexamic acid concentrations were measured with high-performance liquid chromatography. Plasma tranexamic acid concentrations (microg/mL; mean +/- SD [95% confidence interval]) were 37.4 +/- 16.9 (45.5, 29.3) after bolus, 27.6 +/- 7.9 (31.4, 23.8) after 5 min on CPB, 31.4 +/- 12.1 (37.2, 25.6) after 30 min on CPB, 29.2 +/- 9.0 (34.6, 23.8) after 60 min on CPB, 25.6 +/- 18.6 (35.1, 16.1) at discontinuation of tranexamic acid infusion, and 17.7 +/- 13.1 (24.1, 11.1) 1 h after discontinuation of tranexamic acid infusion. Four patients with renal insufficiency had increased concentrations of tranexamic acid at discontinuation of the drug. Repeated-measures analysis revealed a significant main effect of abnormal creatinine concentration (P = 0.02) and time (P < 0.001) on plasma tranexamic acid concentration and a significant time x creatinine concentration interaction (P < 0.001). IMPLICATIONS: A 10 mg/kg initial dose of tranexamic acid followed by an infusion of 1 mg.kg(-1).h(-1)produced plasma concentrations throughout the cardiopulmonary bypass period sufficient to inhibit fibrinolysis in vitro. The dosing of tranexamic acid may require adjustment for renal insufficiency.

Platelet glass bead retention predicts bleeding after cardiac surgery.

OBJECTIVE: To determine if the platelet glass bead retention assay can predict bleeding after cardiac surgery. DESIGN: Prospective, observational study. SETTING: Large, tertiary care, academic medical center. PARTICIPANTS: Forty-three adult patients scheduled to undergo elective cardiac surgery employing cardiopulmonary bypass (CPB). MEASUREMENTS AND MAIN RESULTS: Whole blood samples were observed for platelet count, prothrombin time, and platelet (glass bead) retention assay. The platelet retention and prothrombin times were independent univariant and multivariant predictors of bleeding after CPB (r = 0.554, p = 0.0002 and r = 0.655, p = 0.00001). CONCLUSION: The platelet glass bead retention assay measures dynamic platelet function and is sensitive to the CPB-induced adhesion and aggregation defect and correlates with postoperative blood loss. Modification of this platelet function assay used with the prothrombin time may provide a simple and effective diagnostic approach to bleeding after CPB.

Plasma aprotinin concentrations during cardiac surgery: full- versus half-dose regimens.

UNLABELLED: Aprotinin is an effective but expensive drug used during cardiac surgery to reduce blood loss and transfusion requirements. Currently, aprotinin is administered to adults according to a fixed protocol regardless of the patient's weight. The purpose of this study was to determine aprotinin levels in patients receiving full- and half-dose aprotinin regimens by a simple functional aprotinin assay and to design a more individualized aprotinin dosage regimen for cardiac surgical patients. The mean plasma aprotinin concentration peaked 5 min after the initiation of cardiopulmonary bypass (full 401 +/- 92 KIU/mL, half 226 +/- 56 KIU/mL). The mean plasma aprotinin concentration after 60 min on cardiopulmonary bypass was less (full 236 +/- 81 KIU/mL, half 160 +/- 63 KIU/mL). There was large variation in the aprotinin concentration among patients. A statistically significant correlation was found between aprotinin concentration and patient weight (r(2) = 0.67, P < 0.05). IMPLICATIONS: The current dosing schedule for aprotinin results in a large variation in aprotinin plasma concentrations among patients and a large variation within each patient over time. We combined the information provided by our study with that of a previous pharmacokinetic study to develop a potentially improved, weight-based, dosing regime for aprotinin.

Blood loss from coronary angiography increases transfusion requirements for coronary artery bypass graft surgery.

OBJECTIVE: To determine the blood loss associated with coronary angiography and its impact on hemoglobin and transfusion requirements for subsequent coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective chart review. SETTING: Tertiary-care, academic medical center. PARTICIPANTS: A total of 506 adult patients undergoing coronary angiography and CABG surgery. INTERVENTIONS: None (observational study). MEASUREMENTS AND MAIN RESULTS: Coronary angiography was associated with a reduction in hemoglobin of 1.8 g/dL. This reduction in hemoglobin was a significant predictor of allogeneic red blood cell transfusion. CONCLUSION: Coronary angiography contributes to a 1.8 g/dL reduction in hemoglobin concentration before CABG surgery and was associated with increased transfusion of allogeneic blood products. Measures aimed at maintaining red cell volume during coronary angiography, increasing erythropoiesis, or delaying surgery beyond 2 weeks may result in a decrease in transfusion requirements for patients undergoing CABG surgery.

Use of the surgical blood order equation in spinal instrumentation and fusion surgery.

STUDY DESIGN: A retrospective review of 182 cases of adult spine instrumentation and fusion surgery (1994-1995) from one institution. OBJECTIVES: To develop and retrospectively evaluate the use of the surgical blood ordering equation for patients undergoing spinal instrumentation and fusion surgery. SUMMARY OF BACKGROUND DATA: The provision of effective and safe blood and blood products is the primary function of the hospital transfusion service. A quantification of blood bank efficiency is the crossmatch-to-transfusion ratio. The maximal surgical blood order schedule system has been used to improve the efficiency of surgical ordering practices. The current authors have developed a theoretically more efficient system, the surgical blood ordering equation, which incorporates patient factors for ordering red blood cell units for surgical patients. METHODS: The charts of 63 patients with autologous red blood cells available and 119 adult patients with none available, who underwent multilevel spine surgery from January 1994 to July 1995, were reviewed. RESULTS: The surgical blood ordering equation was exactly correct in the ordering for 37 (20.3%) of 182 patients. The maximal surgical blood order schedule was exactly correct in ordering blood for 14 patients (7.6%). Use of the new surgical blood ordering equation to order red blood cells for surgery would result in a lower crossmatch-to-transfusion ratio than with the current system, the maximal surgical blood order schedule, for patients with autologous red blood cells available (1. 0 vs. 1.3) and patients with none available (0.9 vs. 1.2). CONCLUSION: Incorporating patient factors resulted in increased efficiency of blood ordering practices.

Predictors of blood transfusions in spinal instrumentation and fusion surgery.

STUDY DESIGN: A retrospective review of 244 adult spine instrumentation and fusion surgery cases (1994-1995) from one institution. OBJECTIVES: To ascertain the predictors of blood transfusions for adult patients undergoing different types of multilevel spine surgery. SUMMARY OF BACKGROUND DATA: Blood loss and transfusion requirements during and after multilevel spine surgeries have always been perceived as great. Identifying the predictors of blood transfusion with this type of surgery may aid in reducing the amount of blood loss and the transfusion requirements. METHODS: The charts of 244 adult patients who underwent multilevel spine surgery from January 1994 to July 1995 were retrospectively reviewed. RESULTS: A large percentage of patients required blood transfusion. The significant determinants for increased amounts of allogeneic red blood cell units transfused on the day of surgery using linear multiple regression modeling were low preoperative hemoglobin concentration, tumor surgery, increased number of posterior levels surgically fused, history of pulmonary disease, decreased amount of autologous blood available, and no use of the Jackson table (R2 = 0. 63). The significant determinants for an increased amount of autologous red blood cell units transfused on the day of surgery using linear multiple regression modeling were increased autologous red blood cells available, low preoperative hemoglobin concentration, and increased number of posterior levels surgically fused (R2 = 0. 60). CONCLUSION: The need for transfusion is associated with multiple factors, suggesting that a multifaceted, integrated approach may be necessary to reduce this risk.

Does intraoperative hetastarch administration increase blood loss and transfusion requirements after cardiac surgery?

UNLABELLED: Hetastarch is used for intravascular volume expansion in cardiac surgery. Studies show conflicting effects of intraoperative hetastarch administration on postoperative bleeding. Hetastarch was routinely used for volume expansion during cardiovascular surgeries at our institution until its use was discontinued intraoperatively. We performed a retrospective chart review on patients undergoing primary coronary artery bypass grafting, valve repair or replacement requiring cardiopulmonary bypass (n = 444), 234 of which received intraoperative hetastarch and 210 did not. There was no difference in demographics, cardiac surgery, or cardiopulmonary bypass duration between the two groups. Blood loss for 0-4 h postoperatively was 377 +/- 244 mL in the group not receiving hetastarch compared with 515 +/- 336 mL in the group that received hetastarch (P < 0.001). For 0-24 h postoperatively, blood loss was 923 +/- 473 mL versus 1,283 +/- 686 mL in the absence and presence of hetastarch, respectively (P < 0.001). Allogeneic transfusion requirements (cryoprecipitate, fresh frozen plasma, and platelets) were larger in the hetastarch group (all P < 0.001). Nearly all (99%) patients in the hetastarch group received less than the manufacturer's recommended dose (20 mL/kg) of hetastarch. IMPLICATIONS: Our large retrospective study suggests that intraoperative use of hetastarch in primary cardiac surgery with cardiopulmonary bypass may increase bleeding and transfusion requirements. A large prospective study is needed to determine if intraoperative administration of hetastarch should be avoided during cardiovascular surgery.

Comparison of blood-conservation strategies in cardiac surgery patients at high risk for bleeding.

BACKGROUND: Aprotinin and tranexamic acid are routinely used to reduce bleeding in cardiac surgery. There is a large difference in agent price and perhaps in efficacy. METHODS: In a prospective, randomized, partially blinded study, 168 cardiac surgery patients at high risk for bleeding received either a full-dose aprotinin infusion, tranexamic acid (10-mg/kg load, 1-mg x kg(-1) x h(-1) infusion), tranexamic acid with pre-cardiopulmonary bypass autologous whole-blood collection (12.5% blood volume) and reinfusion after cardiopulmonary bypass (combined therapy), or saline infusion (placebo group). RESULTS: There were complete data in 160 patients. The aprotinin (n = 40) and combined therapy (n = 32) groups (data are median [range]) had similar reductions in blood loss in the first 4 h in the intensive care unit (225 [40-761] and 163 [25-760] ml, respectively; P = 0.014), erythrocyte transfusion requirements in the first 24 h in the intensive care unit (0 [0-3] and 0 [0-3] U, respectively; P = 0.004), and durations of time from end of cardiopulmonary bypass to discharge from the operating room (92 [57-215] and 94 [37, 186] min, respectively; P = 0.01) compared with the placebo group (n = 43). Ten patients in the combined therapy group (30.3%) required transfusion of the autologous blood during cardiopulmonary bypass for anemia. CONCLUSIONS: The combination therapy of tranexamic acid and intraoperative autologous blood collection provided similar reduction in blood loss and transfusion requirements as aprotinin. Cost analyses revealed that combined therapy and tranexamic acid therapy were the least costly therapies.

Possible guidelines for autologous red blood cell donations before total hip arthroplasty based on the surgical blood order equation.

OBJECTIVES: To determine, in patients undergoing total hip arthroplasty (THA), clinical predictive criteria for preoperative autologous blood donation and to propose guidelines to increase the efficiency and reduce the cost of preoperative autologous blood donation. PATIENTS AND METHODS: In this retrospective analysis of 165 adult patients undergoing primary THA, a stepwise regression analysis was used to determine which clinical variables predict erythropoiesis in patients donating autologous blood before THA. The surgical blood order equation (SBOE), which includes values for hemoglobin lost at surgery, preoperative hemoglobin level, and minimal acceptable hemoglobin level, was used to estimate the number of units of red blood cells (RBCs) needed for each patient at surgery and thus identify which patients should have made preoperative autologous blood donations. RESULTS: The statistically significant indicators for RBC production were predonation hemoglobin concentration (P<.001) and male sex (P=.003). Combining the regression equation for erythropoiesis with the SBOE allowed development of guidelines for the use of preoperative autologous RBC donation and erythropoietic therapy. For primary THA surgery, a patient with a predonation hemoglobin level higher than 14.7 g/dL does not need preoperative autologous donation. Preoperative autologous RBC donation would be effective for men with hemoglobin concentrations of 14.7 g/dL or less and for women with predonation hemoglobin levels of 13.2 to 14.7 g/dL. In women whose hemoglobin level is less than 13.2 g/dL, erythropoietic therapy should accompany autologous donation. CONCLUSION: Incorporation of patient factors with the SBOE system may result in increased efficiency and decreased cost of autologous blood ordering practices before THA.

Desmopressin does not reduce bleeding and transfusion requirements in congenital heart operations.

BACKGROUND: Desmopressin (DDAVP) has been evaluated in many randomized clinical trials as a means to reduce blood loss and transfusion of allogeneic blood in cardiac operation requiring cardiopulmonary bypass. Desmopressin reduces blood loss in adult patients with excessive bleeding after cardiac operation. Its usefulness in patients undergoing complex congenital heart repair with cardiopulmonary bypass is unproved. METHODS: Sixty patients younger than 40 years of age scheduled for complex congenital heart operation (44 redo, 16 primary) were enrolled in this prospective, randomized, double-blind trial. Desmopressin 0.3 microg/kg or placebo was administered 10 minutes after protamine administration. Transfusion requirements and postoperative blood loss were recorded. Differences were analyzed using analysis of variance with a p value of 0.05 or less used to denote statistical significance. RESULTS: There were no differences in demographic or surgical characteristics between the DDAVP or placebo groups. There was no difference in blood loss and transfusion requirements between the DDAVP and placebo groups. During the intraoperative postinfusion time period, the median blood loss for redo patients was 343 versus 357 mL/m2 for placebo versus DDAVP, respectively, and for primary patients, the median blood loss was 277 versus 228 mL/m2. CONCLUSIONS: The prophylactic use of DDAVP to reduce excessive bleeding or transfusion requirements in patients undergoing complex congenital heart operations is not warranted.

A prospective, randomized study of cardiopulmonary bypass temperature and blood transfusion.

BACKGROUND: We hypothesized that normothermic cardiopulmonary bypass (CPB) would be associated with decreased blood loss and allogeneic transfusion requirements relative to hypothermic CPB. METHODS: After obtaining institutional review board approval and informed patient consent, we conducted a prospective, randomized study of 79 patients undergoing CPB for a primary cardiac operation at normothermic (37 degrees C) (n = 44) or hypothermic temperature (25 degrees C) (n = 35). Blood loss and transfusion requirements in the operating room and for the first 24 hours in the intensive care unit were determined. A paired t test and rank sum tests were used. A p value of less than 0.05 was considered significant. RESULTS: The normothermic and hypothermic CPB groups did not differ in demographic variables, CPB or cross-clamp duration, heparin sodium or protamine sulfate dose, prothrombin time, or thromboelastogram results. There were no differences between the two CPB groups in blood loss or transfusion requirements. CONCLUSIONS: We found that when there was no difference in duration of CPB, normothermic and hypothermic CPB groups demonstrated similar blood loss and transfusion requirements even though other studies have shown hypothermia induces platelet dysfunction and alters the activity of the coagulation cascade.

Temperature and duration of cardiopulmonary bypass influence transfusion requirements.

STUDY OBJECTIVE: To determine the influence of temperature and duration of cardiopulmonary bypass (CPB) on blood loss and transfusion requirements. DESIGN: Retrospective chart review. SETTING: Tertiary care, academic medical institution. MEASUREMENTS AND MAIN RESULTS: The charts of 378 patients who had undergone primary elective coronary artery bypass graft surgery were studied. Systemic perfusion of CPB had been conducted between 20 degrees C and 37 degrees C in all patients. Patient demographic, temperature during CPB, duration of CPB, blood loss, and transfusion requirements were all recorded. Hypothermic CPB patients had minor increases in requirements for transfusion of red blood cells (RBC; p = 0.01), fresh frozen plasma (FFP; p = 0.01), platelets (PLT; p = 0.003), and total (allogeneic and autologous) blood products (p < 0.001). Multivariate analysis revealed that decreased temperature after adjusting for duration was predictive of allogeneic (RBC, FFP, PLT, and cryoprecipitate) and total (allogeneic and autologous) transfusion requirements. The duration of CPB correlated with decreased temperature (r = -0.455; p < 0.0001). After adjusting for temperature, duration was only predictive of total (allogeneic and autologous) transfusion requirements. CONCLUSIONS: The institution of warm CPB has many ramifications for clinical practice. The hypothermic induced platelet dysfunction and increased duration associated with cold CPB may contribute to the minor increases in transfusion requirements. However, temperature appears to be a weak factor, neither supporting nor refuting the use of warm or cold CPB.

A prospective randomized trial of the surgical blood order equation for ordering red cells for total hip arthroplasty patients.

BACKGROUND: The majority of crossmatched blood is for surgical patients, and most of it is never transfused. An alternative system for ordering red cell (RBC) units, called the surgical blood order equation (SBOE), which incorporates specific patient variables for surgical patients, has been developed. STUDY DESIGN AND METHODS: A prospective double-blind randomized trial compared the SBOE with the maximal surgical blood order schedule (MSBOS) system for ordering allogeneic RBC units in 60 patients undergoing total hip arthroplasty. Autologous RBCs were available for none of the patients. RESULTS: There were no differences in patient demographic, surgical, or laboratory variables at any time. The median number (range) of allogeneic RBC units ordered was 2 (2-3) for the MSBOS and 0 (0-3) for the SBOE (p<0.0001). The SBOE ordered the correct number of RBC units for 58 percent of patients, while the MSBOS did so for 7 percent (p<0.0001). The SBOE had a lower crossmatch-to-transfusion ratio than the MSBOS (0.83 vs. 4.12). Costs were also lower with the SBOE. CONCLUSION: Incorporation of patient factors in the use of the SBOE system resulted in increased efficiency of blood-ordering practices for total hip arthroplasty.