Effects of cardiopulmonary bypass circuit reduction and residual volume salvage on allogeneic transfusion requirements in infants undergoing cardiac surgery

Cardiopulmonary bypass in children may cause severe hemodilution and can lead to excessive perioperative blood loss and high transfusion requirements. Minimization of cardiopulmonary bypass circuit and salvage of red blood cells from the residual volume after the procedure are widely utilized to reduce allogeneic transfusion. We evaluated the effectiveness of those measures introduced in infant cardiac surgery in our institution. This retrospective observational study included 148 consecutive infants between 1 and 12 months of age, with a body weight <10 kg, who underwent an elective cardiac operation between 1997 and 2005. Patients were divided into three groups defined by the circuit prime volume; 700 ml (Group 1), 450 ml (Group 2) and 330 ml (Group 3). In Group 1 residual volume after perfusion was discarded and in Groups 2 and 3 was processed in a cell saving device. Analyzed variables were: perioperative blood loss, transfusion of homologous blood products and cell salvage product, and hematology data. Reduction of the circuit volume significantly diminished use of red blood cell concentrates from 1.6 units to 0.8 units (P<0.0001), and fresh frozen plasma from 1.3 units to 0.4 units (P<0.0001). Utilization of the cell salvage product reduced significantly (P=0.023) the postoperative need for homologous blood transfusion. Therefore, both measures proved to be effective in reducing homologous blood transfusion in infant cardiac surgery.     

Transfusions in patients undergoing cardiac surgery with autologous blood

PURPOSE: Determinants of allogeneic blood use in cardiac surgery include preoperative factors such as female sex, age, body weight, hematocrit and red cell volume. We verified if these variables also predicted the need for allogeneic transfusions when autologous blood is predonated. METHODS: Demographic and intraoperative variables, hemoglobin concentrations and transfusion requirements in patients undergoing cardiopulmonary bypass with autologous blood predonation were reviewed. Multivariate logistic regression and RECPAM tree-growing analyses were applied to identify the preoperative predictors of allogeneic transfusion in these patients. RESULTS: Data from 230 patients included in our autologous blood program between 1995 and 1998 were analysed. Patients undergoing complex/reoperative surgical procedures and patients over age 64yr with a low red cell volume (<2070ml) undergoing simple procedures were more likely to require allogeneic red cells. Younger patients with a low red cell volume undergoing simple procedures carried an intermediate risk. Allogeneic transfusion was avoided in 95% of patients undergoing simple procedures when red cell volume > or = 2070ml. CONCLUSIONS: In our institution, complex/reoperative surgery, low red cell volume and increased age are the main factors associated with the need for allogeneic red cell transfusion despite autologous blood predonation. Knowledge of the factors that limit the effectiveness of predonation with respect to allogeneic blood exposure should help clinicians decide which cardiac surgical patients should be included in autologous blood programs.     

Absence of beneficial effect of acute normovolemic hemodilution combined with aprotinin on allogeneic blood transfusion requirements in cardiac surgery

BACKGROUND: The efficacy of acute normovolemic hemodilution (ANH) in decreasing allogeneic blood requirements remains controversial during cardiac surgery. METHODS: In a prospective, randomized study, 80 adult cardiac surgical patients with normal cardiac function and no high risk of ischemic complications were subjected either to ANH, from a mean hematocrit of 43% to 28%, or to a control group. Aprotinin and intraoperative blood cell salvage were used in both groups. Blood (autologous or allogeneic) was transfused when the hematocrit was less than 17% during cardiopulmonary bypass, less than 25% after cardiopulmonary bypass, or whenever clinically indicated. RESULTS: The amount of whole blood collected during ANH ranged from 10 to 40% of the patients' estimated blood volume. Intraoperative and postoperative blood losses were not different between control and ANH patients (total blood loss, control: 1,411 +/- 570 ml, n = 41; ANH: 1,326 +/- 509 ml, n = 36). Allogeneic blood was given in 29% of control patients (median, 2; range, 1-3 units of packed erythrocytes) and in 33% of ANH patients (median, 2; range, 1-5 units of packed erythrocytes; P = 0.219). Preoperative and postoperative platelet count, prothrombin time, and partial thromboplastin time were similar between groups. Perioperative morbidity and mortality were not different in both groups, and similar hematocrit values were observed at hospital discharge (33.7 +/- 3.9% in the control group and 32.6 +/- 3.7% in the ANH group; nonsignificant) CONCLUSIONS: Hemodilution is not an effective means to lower the risk of allogeneic blood transfusion in elective cardiac surgical patients with normal cardiac function and in the absence of high risk for coronary ischemia, provided standard intraoperative cell saving and high-dose aprotinin are used.     

Autologous Versus Allogeneic Transfusion in Aortic Surgery: A Multicenter Randomized Clinical Trial

OBJECTIVE: To evaluate the efficacy of acute normovolemic hemodilution (ANH) and intraoperative cell salvage (ICS) in blood-conservation strategies for infrarenal aortic surgery. SUMMARY BACKGROUND DATA: Recent concerns over the risks of transfusion-related infection have resulted in sharp rises in the cost of blood preparations. Autologous transfusion may be a safe alternative to allogeneic transfusion, which has been associated with immune modulation and postoperative infection. METHODS: This multicenter prospective randomized trial compared standard transfusion practice with autologous transfusion combining ANH with ICS in 145 patients undergoing elective aortic surgery. The primary outcome measures were the proportion of patients requiring allogeneic blood and the volume of allogeneic transfusion. The secondary outcome measures were the frequency of complications, including postoperative infection, and postoperative hospital stay. RESULTS: The combination of ANH and ICS reduced the volume of allogeneic blood transfused from a median of two units to zero units. The proportion of patients transfused was 56% in allogeneic and 43% in autologous. There were no significant differences in complications or length of hospital stay. CONCLUSIONS: Both ANH and ICS were safe and reduced the allogeneic blood requirement in patients undergoing elective infrarenal aortic surgery.     

Predictors of transfusion requirements for cardiac surgical procedures at a blood conservation center

BACKGROUND: Previous studies defining perioperative risk factors for allogeneic transfusion requirements in cardiac surgery were limited to highly selected cardiac surgery populations or were associated with high transfusion rates. The purpose of this study was to determine perioperative risk factors and create a formula to predict transfusion requirements for major cardiac surgical procedures in a center that practices a multimodality approach to blood conservation. METHODS: We performed an observational study on 307 consecutive patients undergoing coronary artery bypass grafting, valve, and combined (coronary artery bypass grafting and valve) procedures. An equation was derived to estimate the risk of transfusion based on preoperative risk factors using multivariate analysis. In patients with a calculated probability of transfusion of at least 5%, intraoperative predictors of transfusion were identified by multivariate analysis. RESULTS: Thirty-five patients (11%) required intraoperative or postoperative allogeneic transfusions. Preoperative factors as independent predictors for transfusions included red blood cell mass, type of operation, urgency of operation, number of diseased vessels, serum creatinine of at least 1.3 mg/dL, and preoperative prothrombin time. Intraoperative factors included cardiopulmonary bypass time, three or fewer bypass grafts, lesser volume of acute normovolemic hemodilution removed, and total crystalloid infusion of at least 2,500 mL. The derived formula was applied to a validation cohort of 246 patients, and the observed transfusion rates conformed well to the predicted risks. CONCLUSIONS: A multimodality approach to blood conservation in cardiac surgery resulted in a low transfusion rate. Identifying patients' risks for transfusion should alter patient management perioperatively to decrease their transfusion rate and make more efficient use of blood resources.     

Intraoperative red blood-cell salvage in revision hip surgery. A case-matched study

BACKGROUND: Revision hip arthroplasty is commonly associated with substantial blood loss and the subsequent need for transfusion. This leads to an increased risk of blood-borne infection and hemolytic reactions. The purpose of this study was to demonstrate whether the use of intraoperative red blood-cell salvage in revision hip arthroplasty reduces the overall rate of allogeneic transfusion. METHODS: Forty-seven patients who had undergone revision hip arthroplasty with the use of intraoperative cell salvage were identified. A computer database was used to individually match these patients, for age, sex, and eleven operative variables, to control patients who had undergone revision hip arthroplasty in the same unit without intraoperative cell salvage. Data gathered included the total allogeneic transfusion requirement for each patient, preoperative and postoperative hemoglobin levels, and operative time. RESULTS: The total allogeneic transfusion requirement was significantly lower in the group that had intraoperative cell salvage than in the control group (median, 2 compared with 6 U of packed red blood cells, p = 0.0006), with a median reduction in allogeneic transfusion of 4 U. There was no significant difference in preoperative or postoperative hemoglobin levels between the groups. CONCLUSIONS: The use of intraoperative cell salvage significantly lowered the allogeneic transfusion requirement, which can lead to substantial cost savings. To our knowledge, this is the first study in which the use of intraoperative red blood-cell salvage in revision hip arthroplasty was evaluated by matching patients on the basis of age, sex, and operative variables.     

Risk factors reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum assisted circuits

OBJECTIVES: Open heart surgery without homologous blood transfusion remains difficult in children. The introduction of vacuum-assisted cardiopulmonary bypass circuits to reduce priming volume for pediatric patients has improved the percentage of transfusion-free operations. We retrospectively analyzed blood transfusion risk factors to further reduce blood transfusion requirements after vacuum-assisted circuit introduction. METHODS: From March 1995 to June 1996, 49 patients weighing between 5 and 20 kg underwent cardiac surgery with cardiopulmonary bypass at our institution, excluding hospital deaths. We retrospectively analyzed risk factors influencing blood use in 37 patients with no blood priming in cardiopulmonary bypass after introducing a vacuum-assisted system. Factors selected for univariate analysis were age, body weight, cyanosis, preoperative Hb, operation time, cardiopulmonary bypass time, aortic cross-clamping time, and intraoperative and postoperative bleeding volume. Correlation between total bleeding volume/body weight and cardiopulmonary bypass time was studied by regression analysis. RESULTS: As risk factors, univariate analysis identified cyanotic disease, longer operation time (> 210 minutes), longer cardiopulmonary bypass time (> 90 minutes), longer aortic cross-clamping time (> 45 minutes), greater intraoperative bleeding volume/body weight (> 4 ml/kg), and greater postoperative bleeding volume/body weight (> 15 ml/kg). Regression analysis showed a significant positive correlation between total bleeding volume/body weight and cardiopulmonary bypass time. CONCLUSIONS: Cyanotic disease and long bypass time are risk factors in reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum-assisted circuits. Further efforts are needed, however, to reduce blood transfusion requirements, particularly in these children.     

Efficacy of postoperative blood salvage following total hip arthroplasty in patients with and without deposited autologous units

BACKGROUND: Patients undergoing total hip replacement routinely receive perioperative blood transfusions, increasing their risk of blood-borne disease, isoimmunization, anaphylactic reaction, and hemolytic reaction. The purpose of this retrospective, case-control study was to evaluate the effect of postoperative blood salvage on the need for allogeneic transfusion following total hip replacement. METHODS: We reviewed the medical records of ninety consecutive patients who, during a twelve-month period, had undergone unilateral, elective total hip replacement that included use of a postoperative blood salvage device. For comparison, we reviewed the medical records of ninety consecutive patients who had undergone total hip replacement without postoperative blood salvage. Overall, 156 patients had complete medical records and were included in the study. RESULTS: Eight (10 percent) of the patients who had been treated with a drain and seventeen (23 percent) of the patients who had been treated without a drain received allogeneic transfusions. Of the nineteen patients who had not deposited autologous blood, all six without postoperative blood salvage required allogeneic transfusion. With control for other variables in the model, regression analysis showed a significantly increased risk of allogeneic transfusion among patients who had undergone total hip replacement without postoperative blood salvage (p = 0.0028) and without having predonated autologous units (p = 0.0001). CONCLUSIONS: Despite a limited sample size, the study results showed that postoperative blood salvage significantly reduced the risk of allogeneic transfusion among patients managed with total hip replacement, whether or not they had deposited autologous blood (p < 0.0001). With control for donated units, age, gender, preoperative hematocrit, intraoperative blood loss, and cementless technique, patients who were treated without postoperative blood salvage were approximately ten times more likely to require allogeneic transfusion than were patients who had a drain.     

Preoperative autologous donation versus cell salvage in the avoidance of allogeneic transfusion in patients undergoing radical retropubic prostatectomy

There are many methods for preventing allogeneic blood administration during radical retropubic prostatectomy, and many of these methods have been compared with each other, but no studies have compared preoperative autologous donation (PAD) and cell salvage (CS). In this study, we evaluated these two methods in patients undergoing radical retropubic prostatectomy. In a prospective cohort model, allogeneic exposure in patients from one surgeon who routinely had his patients donate blood before surgery was compared with that in patients from a different surgeon who predominantly used CS. Fifty patients were enrolled in the study: 26 in the PAD group and 24 in the CS group. No difference in allogeneic exposure was seen between the two groups. A significant difference was seen in the volume of red blood cells lost (891 +/- 298 mL versus 1134 +/- 358 mL in the PAD and CS groups, respectively). We conclude that PAD and CS are equivalent in their ability to avoid allogeneic transfusion. Larger surgical blood loss in the CS group would suggest that in a more rigorously designed study, CS might provide better allogeneic avoidance than PAD. IMPLICATIONS: In this prospective cohort study, cell salvage and preoperative autologous donation were compared with respect to their ability to avoid allogeneic transfusion. There was a suggestion that cell salvage might offer better allogeneic transfusion avoidance.     

Fast-track cardiac anesthesia in patients with sickle cell abnormalities.

We conducted a retrospective review of 10 patients with sickle cell trait (SCT) and 30 patients (cohort control) without SCT undergoing first-time coronary artery bypass graft surgery with cardiopulmonary bypass. Demographic, perioperative management, and outcome data were collected. Both groups were matched according to age, weight, duration of surgery, and preoperative hemoglobin (Hb) concentration. Distribution of gender, medical conditions, pharmacological treatment, and preoperative left ventricular function were similar between the groups. The comparisons were analyzed in respect to postoperative blood loss and transfusion rates, as well as duration of intubation, intensive care unit, and hospital length of stay (LOS). All patients underwent fast-track cardiac anesthesia. A combination of cold crystalloid and blood cardioplegia was used. The lowest nasopharyngeal temperature was 33 degrees C. There were no episodes of significant hypoxemia, hypercarbia, or acidosis. None of the patients had sickling crisis during the perioperative period. The postoperative blood loss was 687 +/- 135 vs 585 +/-220 mL in the SCT and control groups, respectively. The trigger for blood transfusion during cardiopulmonary bypass was hematocrit <20% and Hb <75 g/L postoperatively. Three SCT patients (30%) and 10 control patients (33%) received a blood transfusion. Median extubation time was 4.0 vs 3.9 h; intensive care unit LOS was 27 vs 28 h; and hospital LOS was 6.0 vs 5.5 days in the SCT and control groups, respectively. There were no intraoperative deaths. One patient in the SCT group died from multiorgan failure 2 mo after surgery. IMPLICATIONS: Fast-track cardiac anesthesia can be used safely in patients with sickle cell trait undergoing first-time coronary artery bypass graft surgery. Extubation time and intensive care unit and hospital length of stay are comparable to those of matched controls, and blood loss and transfusion requirements are not increased. A hematocrit of 20% seems to be a safe transfusion trigger during cardiopulmonary bypass in these patients.     

Use of an oxygen therapeutic as an adjunct to intraoperative autologous donation to reduce transfusion requirements in patients undergoing coronary artery bypass graft surgery

BACKGROUND: The benefits of intraoperative autologous donation (IAD) in reducing the need for allogeneic blood transfusion in surgery have been debated for several years. The purpose of this study was to determine if IAD alone or in conjunction with hemoglobin raffimer (HR) confers a reduction in red cell or blood component transfusion compared with results in standard clinical practice. STUDY DESIGN: The Phase III clinical trial was a multicenter, randomized, double-blind study to determine the efficacy and safety of HR versus 10% pentastarch when used to facilitate IAD in 299 patients undergoing primary coronary artery bypass grafting. The patients received HR or pentastarch as an adjunct to IAD immediately before cardiopulmonary bypass. Results were compared with transfusion requirements for 150 matched patients in the reference group. RESULTS: The frequency of allogeneic RBC transfusion in the HR, pentastarch, and reference groups was 56%, 76%, and 95%, respectively. The number of allogeneic red cell units used was 49 in the HR group, 104 in the pentastarch group, and 480 in the reference group (p < 0.001). The total number of non-RBC units administered was 150 in the HR group, 238 in the pentastarch group, and 270 in the reference group. CONCLUSIONS: In this study, patients treated with HR in conjunction with IAD received fewer transfusions overall and a lower volume of allogeneic RBCs and non-RBC allogeneic blood products than did the two comparison groups. This confers a real benefit on the overall blood supply by decreasing use and increasing availability.     

改良超滤对婴幼儿心脏手术输血的影响

目的　观察改良超滤技术在婴幼儿体外循环心血管手术中对输血及术后出血的影响。方法　 6 0例接受体外循环下心血管手术的先天性心脏病患儿 ,均分为对照组 (不接受任何超滤 )、常规超滤组 (CUF组 )和改良超滤组 (MUF组 )。观察术中库血用量、血浆用量、血球压积的变化及术后2 4h出血量 ,并用SSPS/PC进行统计学处理。结果　MUF组库血用量、血浆用量、术后 2 4h出血量显著低于对照组和CUF组 (P <0 0 1) ,且滤出水量明显多于CUF组 (P <0 0 1)。结论　在婴幼儿心血管手术中 ,改良超滤可有效排出体内水分 ,提高血球压积 ,明显减少输血及术后出血 ,是节约用血的重要手段之一。     

A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective coronary artery bypass surgery

BACKGROUND: We performed this study to determine the dose-response of hemoglobin raffimer administered in conjunction with intraoperative autologous donation in patients undergoing coronary artery bypass grafting surgery. A secondary objective was to evaluate hemoglobin raffimer for reducing the incidence of allogeneic red blood cell transfusions. METHODS: This was a phase II, single-blind, multicenter, placebo-controlled, open-label study. Patients undergoing coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation were randomized to receive a single dose of hemoglobin raffimer or control (10% pentastarch). Patients were sequentially enrolled in a dose block of 250, 500, 750, and 1000 mL. RESULTS: Sixty patients received hemoglobin raffimer (n = 30) or control (n = 30). Hemoglobin raffimer was well tolerated. Most (98%) adverse events were mild or moderate in severity. There was an expected dose-dependent increase in the incidence of blood pressure increases and jaundice in hemoglobin raffimer-treated patients. In a dose-pooled analysis of hemoglobin raffimer versus control, increased blood pressure (43% vs 17%), nausea (37% vs 33%), and atrial fibrillation (37% vs 17%) were the most frequently reported adverse events. All serious adverse events were considered unrelated or unlikely to be related to study drug. No hemoglobin raffimer-treated patient required an intraoperative allogeneic red blood cell transfusion, compared with 5 (17%) pentastarch-treated patients (P =.052). This advantage of hemoglobin raffimer was maintained at 24 hours after surgery (7% vs 37%; P =.010) and up to 5 days after surgery (10% vs 47%; P =.0034). CONCLUSIONS: Hemoglobin raffimer was not associated with any serious adverse events in patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation in a dose-response study up to 1000 mL. Hemoglobin raffimer was effective in facilitating decreased exposure or avoidance of allogeneic red blood cell transfusions when used in conjunction with intraoperative autologous donation.     

Blood coagulation and autologous blood transfusion in cardiac surgery

Study Objective: To review the basic pathophysiology of altered coagulation associated with cardiopulmonary bypass and autologous blood transfusion in cardiac surgery.

Design: Review of rational use of heparin, mechanisms and treatment of coagulation disorders, and autologous blood transfusion.

Setting: Cardiac surgery in community and academic hospitals.

Patients: Adult cardiac surgical patients.

Main Results: Heparin is most commonly used for anticoagulation during cardiopulmonary bypass. Although activated clotting time is widely used to assess heparin-induced anticoagulation, the minimum time to prevent clotting during cardiopulmonary bypass remains unclear. Activated clotting time is affected by many factors other than heparin, such as antithrombin III, blood temperature, platelet count, and age. The rational use of activated clotting time still must be defined.

The frequency of abnormal bleeding after cardiopulmonary bypass is significant. Although inadequate surgical hemostasis is the most frequent cause of bleeding, altered coagulation often is present. A decreased number of functional platelets is one of the important causes of bleeding diathesis. Platelet dysfunction is induced by perioperative medication such as aspirin. Cardiopulmonary bypass decreases functional platelets by degranulation, fragmentation, and loss of fibrinogen receptors. Medications such as prostacyclin and iloprost may be useful to protect these platelets. Desmopressin increases factor VIII:C and von Willebrand's factor, leading to a decrease in bleeding time. Desmopressin may be useful to decrease blood loss in repeat cardiac operations, complex cardiac surgery, and abnormal postoperative bleeding.

Patients undergoing coronary artery bypass grafting immediately after streptokinase infusion also are at risk for abnormal bleeding. Transfusion of fresh frozen plasma and cryoprecipitate may be necessary.

Autologous blood transfusion is cost-effective and the safest way to avoid or decrease homologous blood transfusion. Predonation, intraoperative salvage, and postoperative salvage are encouraged. Erthroprotein may be useful in increasing the amount of predonation red cells.

Conclusions: Coagulation disorders in cardiac surgery are caused by many factors, such as heparin, platelet dysfunction, and fibronolysis. Rational use of blood component therapy and medications such as heparin, protamine, and desmorpessin are mandatory. Autologous blood transfusions is very useful in decreasing or obviating the use of homologous blood transfusion.     

Temporary bacteremia due to intraoperative blood salvage during cardiovascular surgery

BACKGROUND: The significance of positive blood cultures obtained after intraoperative blood salvage is unclear. METHODS: Sixty-four patients who underwent cardiopulmonary bypass and 52 patients with use of a blood salvage device underwent blood culture and examination of inflammatory responses. RESULTS: Positive blood cultures of transfused blood were identified in 16% of patients who underwent cardiopulmonary bypass and 67% with blood salvage. Thoracic operations utilizing either device demonstrated positive cultures in 21% of cases, whereas 70% of abdominal operations demonstrated positive cultures. However, on postoperative day 1, all blood cultures were negative. In addition, there was no significant difference in the inflammatory responses between culture-positive and culture-negative groups. CONCLUSIONS: Although there is a high incidence of positive blood culture present during blood salvage and abdominal surgery, postoperative host responses are similar in both groups. These data support the safe use of intraoperative blood salvage in elective cardiovascular surgery with attention to routine sterile technique.     

Off-pump versus on-pump coronary artery bypass surgery: does the pump influence outcome?

BACKGROUND: This study assessed hospitalization outcome differences for patients undergoing off-pump coronary artery bypass (OPCAB) grafting compared with patients having coronary artery bypass grafting with cardiopulmonary bypass. STUDY DESIGN: We conducted a nested case-control study from an 8-year, hospitalization cohort (n = 7,905) in which the data were collected prospectively. Inclusion criteria included a coronary artery bypass graft only and age greater than 18 years. Cases were patients undergoing OPCAB (n = 360) and controls were patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (n = 1,080). Cases were matched to controls 1:3 on five variables: age (+/- 3 years), gender, diabetes, New York Heart Association Functional Classification, and surgical year (+/- 3 years). The 13 outcomes of interest were mortality, length of hospitalization, ICU length of stay, return to ICU, ventilator time, intraoperative complications, pulmonary complications, neurologic complications, renal complications, gastrointestinal complications, sternal wound infections, highest postoperative creatine kinase level, and units of blood products given during the procedure. Using logistic regression we controlled for eight confounding variables. RESULTS: Patients undergoing OPCAB had a significantly shorter length of hospitalization (relative risk [RR] = 0.95; 95% CI, 0.91-0.99%), fewer pulmonary complications (RR = 0.45; 95% CI, 0.22-0.88%), fewer intraoperative complications (RR = 0.04; 95% CI, 0.0048-0.31%) fewer blood product units given (RR = 0.31; 95% CI, 0.14-0.42%) and lower postoperative creatine kinase (RR = 0.99; 95% CI, 0.98-0.99%). There were no considerable differences for the remaining nine outcomes, including mortality and neurologic complications. CONCLUSIONS: Patients undergoing OPCAB had a considerably shorter length of hospitalization, had fewer pulmonary and intraoperative complications, and received a lower volume of blood products.     

Comparison of two technics of cardiopulmonary bypass (conventional and mini CPB) in the trans-and postoperative periods of cardiac surgery

Objective

This study aimed to compare the effects of two different perfusion techniques: conventional cardiopulmonary bypass and miniature cardiopulmonary bypass in patients undergoing cardiac surgery at the University Hospital of Santa Maria - RS.

Methods

We perform a retrospective, cross-sectional study, based on data collected from the patients operated between 2010 and 2013. We analyzed the records of 242 patients divided into two groups: Group I: 149 patients undergoing cardiopulmonary bypass and Group II - 93 patients undergoing the miniature cardiopulmonary bypass.

Results

The clinical profile of patients in the preoperative period was similar in the cardiopulmonary bypass and miniature cardiopulmonary bypass groups without significant differences, except in age, which was greater in the miniature cardiopulmonary bypass group. The perioperative data were significant of blood collected for autotransfusion, which were higher in the group with miniature cardiopulmonary bypass than the cardiopulmonary bypass and in transfusion of packed red blood cells, which was higher in cardiopulmonary bypass than in miniature cardiopulmonary bypass. In the immediate, first and second postoperative period the values of hematocrit and hemoglobin were higher and significant in miniature cardiopulmonary bypass than in the cardiopulmonary bypass, although the bleeding in the first and second postoperative days was higher and significant in miniature cardiopulmonary bypass than in the cardiopulmonary bypass.

Conclusion

The present results suggest that the miniature cardiopulmonary bypass was beneficial in reducing the red blood cell transfusion during surgery and showed slight but significant increase in hematocrit and hemoglobin in the postoperative period.     

体外循环期间血液稀释和红细胞输注与肾脏和其他内脏损伤生化标记物的相关性

背景体外循环中血液稀释是导致血细胞比容下降的主要原因。血细胞比容降低往往导致血液向组织运氧能力下降,从而需要输注浓缩红细胞。本研究的目的是探讨手术中血细胞比容和输注同种异体血与手术后肾脏和其他脏器损伤标记物的关系。方法选择50例连续冠状动脉旁路移植手术的患者作为研究对象,通过测定乳酸水平来评价全身组织缺氧程度。测定尿中N-乙酰-β-D-氨基葡糖苷酶（NAG）和肠脂肪酸结合蛋白（IFABP）的浓度来评估肾脏及其他内脏器官的缺血程度。回顾性地根据体外循环过程中最低血细胞比容的水平将患者分为2组（Hct〈24％或≥24％）进行分析。结果血细胞比容较低组（〈24％）手术中乳酸浓度和手术后NAG和IFABP的浓度均高于血细胞比容较高组（≥24％;P〈0．05）。低血细胞比容分别与高乳酸水平（R^2=0．150,P〈0．01）和高NAG（R^2=0．138,P〈0．01）及IFABP（R^2=0．107,P〈0．0k）浓度相关。体外循环期间输注红细胞与较高乳酸水平（R^2=0．089,P〈0．05）、NAG浓度（R^2=0．431,P〈O．01）及IFABP浓度（R^2=0．189,P〈O．01）相关。结论研究结果表明手术中血液稀释至血细胞比容低于24％和输注红细胞都与肾脏及其他内脏器官损伤标记物相关。     

Blood salvage in total hip and knee arthroplasty in a community hospital: a retrospective study

PURPOSES: To assess the results of postoperative and intra-operative blood salvage in patients undergoing total knee and hip arthroplasty, respectively, and to determine if both methods of blood salvage reduce allogeneic transfusion. METHODS: Of 229 patients who attempted blood salvage, 114 of 152 patients who underwent total knee arthroplasty received the salvaged blood postoperatively, 35 of 77 patients who underwent total hip arthroplasty received the salvaged blood intra-operatively. Various data were collected to assess whether certain factors resulted in autologous and/or allogeneic blood transfusions. RESULTS: Patients that received postoperative salvaged blood after total knee arthroplasty generally had higher postoperative levels of haemoglobin and haematocrit compared to those who did not. Patients with autologous blood transfusion following cemented knee surgery were less likely to require allogeneic blood transfusion. For hip arthroplasty patients, postoperative levels of haemoglobin and haematocrit were similar in both groups who received and did not receive salvaged blood. Lower preoperative haemoglobin and haematocrit levels correlated with a greater likelihood of autologous and/or allogeneic blood transfusion for both knee and hip arthroplasty patients. CONCLUSIONS: Although total knee arthroplasty patients who received salvaged blood had higher haemoglobin levels on the first postoperative day, the receipt of salvaged blood did not significantly reduce the incidence of allogeneic blood transfusion, because salvaged blood was a kind of blood loss. However, reinfusion of salvaged blood may reduce the number of units of allogeneic blood used. Given the short supply of allogeneic blood and its risks of transmitting disease, intra-operative and postoperative blood salvage carries clear advantages.     

Absence of Beneficial Effect of Acute Normovolemic Hemodilution Combined with Aprotinin on Allogeneic Blood Transfusion Requirements in Cardiac Surgery

Background: The efficacy of acute normovolemic hemodilution (ANH) in decreasing allogeneic blood requirements remains controversial during cardiac surgery.

Methods: In a prospective, randomized study, 80 adult cardiac surgical patients with normal cardiac function and no high risk of ischemic complications were subjected either to ANH, from a mean hematocrit of 43% to 28%, or to a control group. Aprotinin and intraoperative blood cell salvage were used in both groups. Blood (autologous or allogeneic) was transfused when the hematocrit was less than 17% during cardiopulmonary bypass, less than 25% after cardiopulmonary bypass, or whenever clinically indicated.

Results: The amount of whole blood collected during ANH ranged from 10 to 40% of the patients' estimated blood volume. Intraoperative and postoperative blood losses were not different between control and ANH patients (total blood loss, control: 1,411 +/- 570 ml, n = 41; ANH: 1,326 +/- 509 ml, n = 36). Allogeneic blood was given in 29% of control patients (median, 2; range, 1-3 units of packed erythrocytes) and in 33% of ANH patients (median, 2; range, 1-5 units of packed erythrocytes;P = 0.219). Preoperative and postoperative platelet count, prothrombin time, and partial thromboplastin time were similar between groups. Perioperative morbidity and mortality were not different in both groups, and similar hematocrit values were observed at hospital discharge (33.7 +/- 3.9% in the control group and 32.6 +/- 3.7% in the ANH group; nonsignificant)