Influence of intraoperative fluid volume on cardiopulmonary bypass hematocrit and blood transfusions in coronary artery bypass surgery

A hematocrit (Hct) of less than 25% during cardiopulmonary bypass (CPB) and transfusion of homologous packed red blood cells (PRBC) are each associated with an increased probability of adverse events in cardiac surgery. Although the CPB circuit is a major contributor to hemodilution intravenous (IV) fluid volume may also significantly influence the level of hemodilution. The objective of this study was to explore the influence of asanguinous IV fluid volume on CPB Hct and intraoperative PRBC transfusion. After Institutional Review Board approval, a retrospective chart review of 90 adult patients that had undergone an elective, isolated CABG with CPB was conducted. Regression analysis was used to determine if pre-CPB fluid volume was associated with the lowest CPB Hct and the incidence of an intraoperative PRBC transfusion. In separate multivariate analyses, higher pre-CPB fluid volume was associated with lower minimum CPB Hct (p < .0001), and higher minimum CPB Hct was associated with a decreased probability of PRBC transfusion (p < .0001). Compared to patients that received <1600 mL (n = 55) of pre-CPB fluid, those that received >1600 mL (n = 35) had a decreased mean low CPB Hct (22.4% vs 25.6%, p < .0001), an increased incidence of a CPB Hct <25% (74% vs. 38%, p = .0008) and PRBC transfusion (60% vs. 16%, p < .0001), and increased median PRBC units transfused (2.0 vs 1.0, p = .1446) despite no significant difference in gender, age, patient size, baseline Hct, or CPB prime volume. Patients that received a PRBC transfusion (n = 30) received a significantly higher volume of pre-CPB fluid than nontransfused patients (1800 vs. 1350 mL, p = .0039). These findings suggest that pre-CPB fluid volume can significantly contribute to hemodilutional anemia in cardiac surgery. Optimizing pre-CPB volume may preserve baseline Hct and help limit intraoperative hemodilution.     

Coronary artery bypass grafting: an off-pump versus on-pump review

There has been a proliferation in the number of coronary artery bypass grafts (CABG) being performed without the use of cardiopulmonary bypass (CPB). However, the benefits of off-pump coronary artery grafting (OPCAB) are still being determined. The aim of this retrospective review was to compare the perioperative outcomes of CPB patients with OPCAB patients and to identify the patients most likely to benefit from the off-pump procedure. We reviewed the perioperative data of all isolated CABG patients at two metropolitan hospitals for the period of August 2000 to September 2001. The two groups (OPCAB vs. CPB) were further divided into subgroups identifying patients by their predicted mortality (higher-risk and lower-risk) and the number of distal graft anastomoses received (1, 2, 3, 4, or 5). A p value less than .05 was considered significant. Out of the total of 882 patients, 46.2% were OPCAB cases. Both CPB and OPCAB groups were similar in terms of demographics and predicted risk of mortality. Intraoperatively, OPCAB patients had fewer distal graft anastomoses (2.4 +/- 1.0 vs. 3.2 +/- 1.0, p < .001). Postoperatively, patients in the OPCAB group had less chest drainage (889 +/- 588 vs. 989 +/- 662 mls, p < .001), sustained fewer strokes (0.2 vs. 1.9%, p < .05), were transfused less (15.4 vs. 32.5%, p < .001) and were discharged earlier (7.3 +/- 5.6 vs. 8.5 +/- 9.1 days, p < .05). For higher-risk patients, OPCAB was associated with fewer reoperations for bleeding (1.3 vs. 6.4%, p < .05), a lower stroke rate (0 vs. 3.2%, p < .05), and a trend toward lower mortality (7.1 vs. 15.1%, p = .08). However, lower-risk OPCAB patients' stroke incidences (0.5% OPCAB group vs. 1.4% CPB group), and mortality rates (0.5 vs. 0.5%) were similar. Comparisons by number of grafts performed revealed that only the single-grafted OPCAB patients had statistically fewer postoperative complications, reduced chest drainage, and a shorter intensive care stay. Differences between either operation groups in transfusion rates were only statistically significant for the one to three grafted patients, while postoperative stays were similar for patients having four grafts. These results suggest that OPCAB is associated with a reduction in mortality and morbidity, particularly within the higher-risk patients. However, the benefits of OPCAB diminished with an increasing number of distal anastomoses performed.     

Does multi-vessel off-pump coronary artery bypass grafting reduce post operative morbidity compared to on-pump CABG?

Background Cardiopulmonary bypass (CPB) may contribute to the complications and it is assumed that eliminating cardiopulmonary bypass has the potential of reducing post operative morbidity after coronary artery bypass grafting (CABG). The study was carried out to compare mortality and morbidity in the off-pump and on-pump CABG groups. Methods We prospectively analysed 200 patients undergoing CABG. Group A consists of 100 patients underwent multi-vessel off-pump CABG and group B consists of 100 patients underwent CABG with CPB. The incidence of complications (mortality, re-exploration for bleeding, myocardial infarction, atrial fibrillation, neurological events, new onset renal failure (s. creatinine>1.6 mg/dL) pulmonary complications, length of ICU stay and hospital stay were recorded, analysed and compared. Results OPCAB patients received 2.73±0.61 grafts/patient and on-pump CABG patients received 3.39±0.75 grafts/patient (p value<0.00001). There was no significant statistical difference in mortality, incidence of stroke between OPCAB and CABG with CPB patients. Length of ICU stay was 32.84±4.22 vs 44.85±7.18 hrs (p value<0.00001) and hospital stay was 6.52±0.69 vs 7.94±0.92 days (p value<0.00001) between group A and group B respectively. Incidence of atrial fibrillation was less in OPCAB group 7% vs 12% although it was statistically not significant (p value 0.33). It was observed in our study that there was no significant deference in worsening of existing renal failure between on-pump CABG and OPCAB 6% vs 2% (P value 0.28). Blood utilization was significantly less in OPCAB group (p value<0.001). Conclusion There was no statistically significant difference in terms of mortality, incidence of stroke and new onset renal failure in both groups. But there was lesser incidence of post operative atrial fibrillation, worsening of existing renal failure in off-pump group though statistically not significant. There was significant reduction in blood utilization, length of ICU and hospital stay in OPCAB group.     

The clinical outcome of off-pump coronary artery bypass surgery in the elderly patients

Objective: There has been a body of evidence showing that off-pump coronary artery bypass (OPCAB) may reduce morbidity and mortality in the elderly patients. We reviewed our experience, retrospectively, on elderly patients aged 75 years and older who were operated on using the OPCAB technique. We compared their outcome to a similar group of elderly patients who were operated on using conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) during the same period of time. Methods: Registry data and patients' notes and charts were reviewed for 56 consecutive elderly OPCAB patients (age 78.5±3.5 years) and 87 consecutive CPB patients (age 77.2±2.4 years, P=0.01). Both groups had similar risk factor profiles: Parsonnet score 17.4±4.4 (OPCAB) versus 16.6±5.2 (CPB), P=0.19. We studied in detail their preoperative and postoperative data in order to compare the outcomes of both techniques. Results: The length of stay in the intensive therapy unit (ITU) was 35.4±52.9 h for OPCAB patients and 77.6±144.9 h for CPB patients (P=0.0008). No patient died within 30 days in the OPCAB group, whilst ten (11%) CPB patients (P=0.0066) died within 30 days. The incidence of serious complications (including pulmonary oedema, septicaemia, permanent stroke and renal dysfunction requiring haemofiltration or haemodialysis) was one (2%) in the OPCAB group and 11 (13%) in the CPB group (P=0.028). CPB patients required a significantly higher number ten (12%) of intra-aortic balloon pumps (IABP) inserted compared to only one patient (2%) in the OPCAB group who required IABP insertion (P=0.05). Nine (11%) CPB patients were re-operated on for bleeding compared to no OPCAB patient (0%) needing re-operation, P=0.011. Conclusions: Although the mean age of the OPCAB group was significantly higher than the CPB group, the OPCAB group showed a significant reduction in postoperative serious morbidity, ITU stay and mortality. We believe that such a conclusion may have some effect on the decision-making and cost-effectiveness when performing coronary bypass surgery on the elderly population.     

Minimally invasive coronary artery bypass grafting via a small thoracotomy versus off-pump: a case-matched study

Objective: The minimally invasive coronary artery bypass grafting (MICS CABG) operation performed via a small thoracotomy has not previously been examined in a direct comparison to sternotomy off-pump coronary artery bypass grafting (OPCAB). Methods: We matched, according to age, gender, left ventricular function, and median number of distal anastomoses, 150 patients who underwent MICS CABG via small left thoracotomy, and 150 patients who received sternotomy OPCAB. All operations were performed by the same surgeon. Results: There was no perioperative mortality (0/300). In the MICS CABG group, pump assistance was used in 28/150 (19%) patients, and conversion to sternotomy occurred in 10/150 (6.7%) patients. In the OPCAB group, conversion to on-pump occurred in 3/150 (2.0%) patients. There were four (2.7%) reoperations for bleeding and one (0.7%) for anastomotic revision in each group. The median hospital length of stay was 5 days for MICS CABG (average 5.4), and 6 days for OPCAB (average 7.2) (P = 0.02). New-onset atrial fibrillation occurred in 35 (23%) MICS CABG patients and in 42 (28%) OPCAB patients (P = 0.3). No wound infection occurred with MICS CABG versus six (4.0%) with OPCAB (P = 0.03). A self-limiting left pleural effusion developed in 22 (15%) MICS CABG patients and in six (4.0%) OPCAB patients (P = 0.002). The median time to return to full physical activity was 12 days in MICS CABG patients versus >5 weeks in OPCAB patients (P < 0.001). Conclusions: MICS CABG is a valuable alternative for patients in need of multivessel CABG. The operation appears at least as safe as OPCAB, and associated with shorter hospital length of stay, less wound infections, and faster postoperative recovery than OPCAB.     

Effect of clopidogrel on bleeding and transfusions after off-pump coronary artery bypass graft surgery: impact of discontinuation prior to surgery.

OBJECTIVE: The use of antiplatelet drugs to treat acute myocardial infarction, unstable angina, acute coronary syndrome and secondary prevention following percutaneous coronary interventions is well accepted. However, it constitutes a serious risk of bleeding for patients undergoing coronary artery bypass grafting surgery (CABG). We evaluated the effect of aspirin and clopidogrel (CPDG), both irreversible platelet aggregation inhibitors, on operative bleeding and determined the optimal timing for their discontinuation before surgery. METHOD: Between July 2001 and December 2004, we reviewed our experience with 453 patients undergoing off-pump CABG surgery (OPCAB) who received CPDG (n=101) or not (n=352) preoperatively, and compared the intraoperative and postoperative bleeding to determine risks factors associated with blood or platelet transfusions. RESULTS: Clopidogrel in OPCAB surgery is associated with higher intraoperative (702.24 ml vs 554.13 ml, p=0.03) and postoperative bleeding (864.93 ml vs 603.75 ml, p=0.03). The mean operative blood loss is higher in patients still on CPDG at the time of surgery compared to patients off CPDG at least 72 h before surgery (802 ml vs 554.13 ml, p<0.0001). Blood loss in the later subgroup of patients is comparable to the control group without CPDG (p=NS). Clopidogrel is associated with more platelet transfusions (OR=11.79, [1.48; 93.86]). CONCLUSION: Blood loss is higher in OPCAB patients receiving clopidogrel before surgery. However, discontinuation of clopidogrel three days (72 h) prior to the operation demonstrated a similar blood loss pattern compared to a control group. Clopidogrel is associated with more platelets, but not red blood cell transfusions following OPCAB surgery.     

Intraoperative assessment and quantification of coronary artery graft patency performed on or off cardiopulmonary bypass

Within the last 10 years, the incorporation of off-pump coronary artery bypass grafting (OPCAB) into many surgical practices has grown. OPCAB requires the surgeon to operate on a beating heart, and it is generally accepted that OPCAB procedures are more technically demanding. Concerns of possible incomplete revascularizations and decreased graft patency have been noted in the literature. The objective of this study was to evaluate and compare on-pump and off-pump intraoperative coronary artery bypass graft (CABG) flow parameters. Intraoperative flow studies conducted with the Butterfly (Medi-Stim Norge AS, Oslo, Norway) flow meter were analyzed retrospectively on 74 patients. Comparisons were completed between patient groups having had their revascularizations performed on or off cardiopulmonary bypass. Our study revealed significant differences in the mean flow rate through saphenous vein grafts (SVG) to the obtuse marginal artery (OM; p = .014), to the diagonal artery (Diag; p = .003), to the right coronary artery (RCA; p = .001), and to the posterior descending artery (PDA; p = .001). Total blood product use showed significantly increased use of both platelets (PLTs) and cryoprecipitate (Cryo) in the on-pump group (p = .027 and .012, respectively). No differences were found for transfusions of red blood cells (RBCs) or fresh frozen plasma (FFP). Additional findings showed a significantly decreased median length of stay (LOS) for the off-pump group. The on-pump patients had a median hospital stay of 7 days (range, 4-24 days), whereas the off-pump patients had a median stay of 6 days (range, 3-22 days; p = .049). Although we were able to show some significance in the mean flow data supporting increased graft flow with the on-pump technique, we were not able to show an overall increase in all recorded flow characteristics to support one method over another.     

Off-pump coronary artery bypass

OBJECTIVES: Off-pump coronary artery bypass grafting (CABG) on the beating heart has become popular procedure in cardiac surgery and its initial results appeared favorable. We report our early and mid-term results of off-pump CABG performed at Shin-Tokyo Hospital. METHODS: Medical records of patients undergoing off-pump or conventional on-pump CABG from September 1, 1996, to August 31, 1999 were retrospectively reviewed. Patients underwent off-pump CABG were further classified into 2 groups; MIDCAB (Off-pump CABG for single vessel revascularization via a small skin incision) and OPCAB (off-pump CABG mainly approached via midline sternotomy) group. Their preoperative, perioperative, and follow-up data were collected and analyzed. RESULTS: Among a total of 995 cases of CABG, 194 cases were off-pump CABG (male/female 142/52, mean age 66.9). The mean number of distal anastomoses in off-pump CABG was 1.9 +/- 0.9 (1.0 +/- 0.0 in MIDCAB and 2.3 +/- 0.7 in OPCAB), which was significantly fewer than in on-pump CABG (3.6 +/- 1.1), with p < 0.0001. Intubation time (5.3 +/- 5.7 hours in off-pump CABG vs 13.1 +/- 24.2 hours in on-pump CABG), ICU stay (1.7 +/- 1.1 vs 3.2 +/- 3.0 days), and postoperative hospital stay (14.0 +/- 7.9 vs 18.1 +/- 12.1 days) in off-pump CABG were significantly shorter than in on-pump CABG (p < 0.0001). In the off-pump CABG group, there were no in-hospital deaths and 14 major complications, fewer than in on-pump CABG (8 hospital deaths and 114 major complications). Postoperative angiography before hospital discharge was conducted in 80 patients (41.2%) and showed 2 occlusions, giving a graft patency rate of 98.6% in the off-pump group. During follow-up (0.9 +/- 0.6 year) period, there were 5 non-cardiac deaths and 20 cardiac events in the off-pump group. The actuarial survival rate at 36 months was 94.6% for off-pump CABG, showing no significant difference from the rate for conventional CABG patients (95.2% at 36 month, p = NS) The event-free rate was 84.0% at 36 months in off-pump CABG patients; however, which was less favorable than on-pump CABG patients (88.0% at 36 months, p < 0.05). CONCLUSIONS: Both in-hospital and mid-term results for off-pump CABG patients were acceptable. Isolated CABG can thus be safely performed without cardiopulmonary bypass. Advances in coronary stabilization have contributed to these improved results. The observed long-term cardiac events may be related to incomplete revascularization.     

A prospective study of aspirin's effect on red blood cell loss in cardiac surgery

The effect of aspirin on red blood cell (RBC) loss and blood transfusions was evaluated prospectively in 100 consecutive patients, with normal bleeding times, undergoing elective coronary artery bypass (CABG) surgery. Patients taking 85-325 mgm of aspirin daily up to or within 48 hours of surgery (the "aspirin" group) were compared to patients not taking aspirin or those who had discontinued aspirin at least 4 days before surgery (the "no-aspirin" group). RBC loss was determined by measuring preoperative and postoperative RBC volume using RISA and 51Cr techniques. There were no significant differences, respectively, between the aspirin and no-aspirin groups for: RBC loss (1158 +/- 67 ml vs 1129 +/- 47 ml, p = 0.737), chest tube drainage (925 +/- 31 ml vs 844 +/- 70 ml, p = 0.553), and gm% discharge Hemoglobin (Hgb) (9.94 +/- 0.32 vs 9.49 +/- 1.4, p = 0.0148). Strict criteria for blood transfusions were employed: (1) intraoperative hematocrit of less than 21%, (2) postoperative Hgb of less than 7 gm% for patients less than 70 years old and (3) postoperative Hgb of less than 8 gm% for patients greater than 70 years old. There were no significant differences, respectively, between the aspirin and no-aspirin groups for units of blood transfused (1.32 +/- vs 1.21 +/- 0.20, p = 0.843) and patients not receiving transfusions during the entire hospitalization (44% vs 50%). Patients taking 85-325 mgm of aspirin with a normal bleeding time undergoing elective CABG did not have increased RBC loss or increased transfusion requirements. These results indicate it is not necessary to delay elective CABG surgery for the purpose of discontinuing aspirin.     

Off-pump versus on-pump coronary artery bypass surgery and postoperative pulmonary dysfunction

OBJECTIVE: To investigate how off-pump coronary artery bypass grafting (CABG) affects postoperative pulmonary function when compared with on-pump CABG. DESIGN: Prospective clinical study. SETTING: University-affiliated teaching hospital. PARTICIPANTS: Adult patients (n = 39) undergoing elective coronary artery bypass surgery with or without cardiopulmonary bypass. INTERVENTIONS: Two groups of patients were compared: 19 consecutive patients undergoing off-pump CABG surgery and 20 consecutive patients undergoing conventional CABG surgery. MEASUREMENTS AND MAIN RESULTS: Pulmonary function tests (flow volume loops and lung volumes with plethysmography) were done preoperatively and 72 hours postoperatively. Arterial blood gases and PaO2/FIO2 were measured at various stages. Sequential chest x-rays were obtained and evaluated for pleural changes, pulmonary edema, and atelectasis. In both groups, PaO2/FIO2 ratios decreased progressively throughout the perioperative period, with no significant differences between the groups at any stage during the study. There was a significant decline in postoperative pulmonary function tests in both groups, but there was no difference between groups at 72 hours postoperatively. No differences were found in the time to extubation, atelectasis scores, or postoperative complications. CONCLUSIONS: Off-pump CABG does not confer major protection from postoperative pulmonary dysfunction compared with CABG surgery with CPB. Strategies for minimizing pulmonary impairment after CABG surgery should be directed to factors other than the use of CPB.     

Heparin anticoagulation in patients undergoing off-pump and on-pump coronary bypass surgery

Purpose The authors analyzed the coagulation data of patients who underwent on-pump coronary artery bypass graft (CABG) or off-pump coronary artery bypass surgery (OPCAB) in a randomized prospective trial. Methods CABG and OPCAB patients received heparin anticoagulation at 400 U·kg⁻¹, and 180 U·kg⁻¹ plus 3000 U every 30 min, respectively. In addition, OPCAB patients received a rectal aspirin, 650 mg, during the procedure. Perioperative coagulation test results (platelet count, fibrinogen, prothrombin time, partial thromboplastin time [PTT], activated clotting time [ACT], and thromboelastography [TEG; Haemoscope] were collected from CABG (n = 99) and OPCAB (n = 98) patients. Residual heparin activity after protamine was measured, using an anti-activated factor X (Xa) assay, in 10 patients from each group. Results Our study showed that the current anticoagulation regimen in the OPCAB patients achieved a peak ACT of 445 ± 73 s, and it preserved platelet counts and fibrinogen levels. A residual heparin effect was detected, with residual anti-Xa heparin activity of 0.2 U·ml⁻¹ up to 2 h after surgery in the OPCAB group. Despite the residual anticoagulation, the OPCAB group had a similar TEG index of native blood, postoperative chest tube drainage, and non-erythrocyte transfusion rate as compared with the CABG group. Conclusion We have shown that the heparin anticoagulation regimen in OPCAB patients does not lead to an immediate hypercoagulable state. Total doses of heparin and protamine were lower in the OPCAB group compared with the CABG group, and there was a residual heparin effect on TEG and PTT in the early postoperative period in the OPCAB group.     

Intraoperative moderate acute normovolemic hemodilution associated with a comprehensive blood-sparing protocol in off-pump coronary surgery

We evaluated the blood-sparing effects of intraoperative moderate acute normovolemic hemodilution (ANH) combined with intraoperative tranexamic acid treatment and shed blood reinfusion in patients undergoing off-pump coronary artery bypass (OPCAB). One-hundred consecutive OPCAB patients (baseline hematocrit >34%) were prospectively randomized to tranexamic acid treatment (control group; 50 patients) or to tranexamic acid treatment plus normovolemic (1:1 replacement with colloids) withdrawal of 17% +/- 2% of the circulating blood volume (ANH group; 50 patients). All patients had shed blood reinfused with intraoperative bleeding in excess of 250 mL. The requirement for allogeneic transfusions, based on strict a priori defined criteria, was the primary end point of the study. Hematochemical evaluations, bleeding, major complications, and other outcomes were also recorded. Demographics, baseline hematochemical data, and operative characteristics were similar in the two groups. Patients in the ANH group had a median of 850 mL of blood withdrawn and showed a lower intraoperative minimum hematocrit (31% vs 37%; P < 0.0001). Two patients in the ANH group versus 10 patients in the control group (odds ratio, 0.17; 95% confidence interval, 0.03-0.89; P = 0.028) required transfusion of a significantly smaller number of packed red blood cell units (5 vs 24; P < 0.001). Postoperative hematochemical variables, bleeding, and outcomes were similar in the two groups of patients. Moderate ANH, combined with tranexamic acid administration and on-demand shed blood reinfusion, may reduce allogeneic transfusion requirements in OPCAB patients. IMPLICATIONS: We studied the blood-sparing effects of moderate acute normovolemic hemodilution (ANH) in 100 patients undergoing off-pump coronary surgery (OPCAB). Combined with tranexamic acid administration and shed blood reinfusion when the intraoperative bleeding exceeded 250 mL, ANH was effective in reducing the number of OPCAB patients who required allogeneic transfusions and the number of packed red blood cell units transfused.     

Preoperative autologous blood donation with cardiac surgery

BACKGROUND: Preoperative autologous blood donation is commonly used to reduce exposure to homologous blood transfusions among patients undergoing elective cardiac surgery. The purpose of this study was to ascertain how much volume of predonated autologous blood need to avoid of homologous blood transfusion in cardiac procedure. METHODS: One hundred twenty-eight patients underwent scheduled cardiac procedure between January 1998 and December 1999. Group 1: 400 ml predonated, operation without cardiopulmonary bypass (CPB) [n = 33], group 2: 800 ml predonated, operation without CPB (n = 23), group 3: 800 ml predonated, operation with CPB (n = 36), group 4: 1,200 ml predonated, operation with CPB (n = 36). Surgical procedures underwent only off-pump coronary artery bypass grafting (OPCAB) in groups 1 and 2. In groups 3 and 4 included coronary artery bypass grafting (CABG), valve replacement, CABG + valve replacement and atrial septal defect repair. RESULTS: There were no significant differences in mean body weight, mean preoperative hematocrit values or mean volume of intraoperative blood loss between groups 1 and 2. There were no significant differences in mean age, mean body weight, mean preoperative and postoperative day-7 hematocrit values, mean volume of intraoperative blood loss or mean CPB time between groups 3 and 4. The mean postoperative day-7 hematocrit value was significantly lower in group 1 than in group 2. Homologous blood transfusion was avoided in 63.6% of those with predonation of group 1 versus 100% at group 2 (p < 0.05), 86.1% at group 3 versus 94.4% at group 4 (p < 0.05). In group 3, all patients who underwent redo operation or CABG + valve replacement needed homologous blood transfusion. CONCLUSIONS: Autologous blood transfusion is effective for reducing the homologous blood requirement. It also seems that predonation of 800 ml may be sufficient to avoid homologous blood transfusion in cardiac surgery, however predonation of 1,200 ml is desirable in cases of redo operation or CABG + valve replacement.     

A comparison of bleeding and transfusion in patients who undergo coronary artery bypass grafting via sternotomy with and without cardiopulmonary bypass

OBJECTIVE: To determine whether there is a difference between on-pump cardiopulmonary bypass (CABG) and off-pump coronary artery bypass grafting (OPCAB) without heparin reversal with regard to bleeding, transfusion requirements, and incidence of surgical re-exploration of the mediastinum. DESIGN: Retrospective chart review. SETTING: A large academic medical center. PARTICIPANTS: Two hundred adult patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred CABG patients were compared with 100 OPCAB patients. Statistical significance was measured with P values of 相似文献   

非体外循环和体外循环冠状动脉旁路移植术在二次冠状动脉旁路移植术中的应用

目的研究对比在二次冠状动脉旁路移植术(re-CABG)患者中分别采用非体外循环和体外循环下冠状动脉旁路移植术(off-pump CABG和on-pump CABG)的临床早期结果,探讨通过合理手术方式的选择,提高re-CABG的手术疗效。方法自2000年4月到2006年6月,21例首次CABG后因心绞痛复发患者在阜外心血管病医院接受了re-CABG手术,其中10例行off-pump CABG(off-pump组),11例行on-pump CABG(on-pump组)。两组患者术前性别、年龄、体重、心肺功能、心绞痛程度、左心室舒张期末内径、射血分数、合并高血压、糖尿病等方面差异无统计学意义(P>0.05)。结果 On-pump组中患者术后死亡1例,冠状动脉远端吻合口数多于off-pump组(P<0.05);off-pump组无手术死亡,在手术时间、术后呼吸机辅助时间、胸腔引流液量、输血量和手术后住院时间等方面,均明显少于on-pump组(P<0.05)。结论 Off-pump CABG和on-pump CABG技术在re-CABG中都可以取得满意疗效,off-pump CABG下施行re-CABG安全可靠。     

老年人非体外循环冠状动脉旁路移植术的心肌保护作用

目的比较70岁以上老年人非体外循环冠状动脉旁路移植术(OPCAB)和体外循环冠状动脉旁路移植术(CABG)围术期心肌损伤程度,探讨OPCAB的心肌保护效果。方法30例老年患者分为两组,A组15例,为CABG组,B组15例,为OPCAB组。分别于术前、术中30min、术中1h、术后6h、12h、24h、72h、120h取静脉血标本,分别测定心肌肌钙蛋白I(cTnI)水平和CKMB活性;另外记录围手术期各项临床指标。结果OPCAB组术后辅助呼吸时间较CABG组短(P<0.01),而且主动脉球囊反搏和输血例数较低(P<0.05)。CABG组与OPCAB组cTnI、CKMB的术前水平相,术后6hcTnI即有升高而后下降,术后30min至72h均较OPCAB组明显升高(P<0.05或0.01)。结论与CABG相比,OPCAB的心肌损伤较轻,心肌保护效果较好。     

The effect of acute normovolemic hemodilution on homologous blood requirements and total estimated red blood cell volume lost

Background: Acute normovolemic hernodilution combined with retransfusion is one of the various techniques proposed to avoid homologous blood transfusion in cardiac surgery. The purpose of the present paper is to study the effect of the volume of autologous blood collected pre-cardiopulmonary bypass (CPB) on homologous blood requirements and total estimated red blood cell (RBC) volume lost in coronary artery bypass grafting (CABG) surgery.
Methods: Following induction of anesthesia, sequestration of one (5–8 ml/kg; Group I, n=14) or two units (12–15 ml/kg; Group 11, n=14) of fresh autologous blood was performed under electrocardiographic and hernodynamic control. Group III (n= 14) was designated as the control group. Autologous blood was reinfused at the conclusion of CPB.
Results: The use of homologous blood in the study groups was significantly less than in the control group. High-volume phlebotomy did not make a significant difference in the requirement of the homologous blood, while causing a mild increase in the total estimated RBC volume lost. No significant differences could be demonstrated in preoperative, post-CPB and discharge hematocrit levels and postoperative blood drainage between the groups.
Conclusion: Acute intraoperative hemodilution with high- and low-volume phlebotomy reduced the homologous blood requirements similarly regardless of the amount of phlebotomy.     

Off-pump versus on-pump coronary bypass in high-risk subgroups

BACKGROUND: Cardiopulmonary bypass (CPB) has pathophysiologic sequelae that may be more severe in high-risk subsets. We wanted to determine whether off-pump coronary bypass (OPCAB) could optimize outcomes. METHODS: Our database of 242 OPCAB patients undergoing complete revascularization was compared to a base of 483 CABG patients undergoing CPB. Results were compared for the overall series and in the following high-risk subsets: 80 years of age or older, ventricular dysfunction (ejection fraction (EF) < or = 0.25), prior neurologic event or renal failure, chronic obstructive pulmonary disease (COPD), and reoperation. RESULTS: In the overall series, OPCAB significantly reduced the incidence of intraoperative transfusion requirements and showed a trend toward reduced morbidity in terms of postoperative neurologic and renal complications, prolonged ventilator requirement greater than 3 days, and bleeding requiring reexploration. Mortality was less in the OPCAB group (0.4% versus 2.7%, p = not significant). Similar results were achieved in the following high-risk subgroups (n = off-pump/on-pump): 80 years of age or older (n = 28/58), EF less than or equal to 25% (n = 13/26), preoperative neurologic event (n = 25/36), preoperative renal failure (n = 27/46), COPD (n = 33/43), and reoperation (n = 28/76). OPCAB decreased the incidence of prolonged ventilation in COPD patients (0/33 [0%] versus 4/43 [9.3%] p = not significant) and decreased the incidence of renal complications in the elderly (1/28 [3.6%] versus 9/58 [15.5%] p = not significant). Off-pump coronary bypass reduced but did not eliminate neurologic events in the elderly (2/28 [7.1%] versus 8/58 [13.8%] p = not significant). CONCLUSION: Off-pump coronary bypass significantly reduced the incidence of transfusion requirement compared to the CPB counterparts and had a consistent trend in reducing morbidity and mortality overall and in all high-risk subsets. Neurologic events are not eliminated in OPCAB.     

Off-pump coronary artery bypass grafting attenuates proinflammatory markers

Objective: Cardiac surgery with cardiopulmonary bypass (CPB) has been considered the main causative factors of postoperative inflammatory reactions. The aim of this study was to compare surrogate markers of the proinflammatory response in patients who underwent coronary artery bypass grafting (CABG) with or without CPB. Methods and Results: Twenty patients undergoing first-time CABG were enrolled in the study, 10 with and 10 without CPB. Blood samples were drawn at the following times: at the anesthetic induction, the end of surgery, and thereafter at 12 and 24 hours postoperatively. Neutrophil elastase, interleukin (IL)-6 , and serum soluble Fas were chosen to evaluate the extent of the systemic inflammatory response. The groups were similar in terms of age, gender ratio, number of grafts per patient. There were no operative mortality or serious postoperative complications. Two of each group received blood transfusion postoperatively. Neutrophil elastase showed a significantly higher value in the on-pump group compared with the off-pump group at the end of surgery. Soluble Fas level showed a higher value at the end of surgery compared with baseline, while it had no significant changes in the off-pump patients. IL-6 levels in the on-pump group were consistently higher compared to the off-pump group but showed no statistically significant differences between the groups. Conclusion: Compared with off-pump CABG, on pump CABG induced higher serum levels of proinflammatory markers including neutrophil elastase and soluble Fas.     

Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements

The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation. Keywords: cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.