Reduction in blood product usage associated with routine use of mini bypass systems in extracorporeal circulation

Conventional or minimized cardiopulmonary bypass support during coronary artery bypass grafting? - An analysis by means of perfusion and body mass index

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86-4.95 L/min vs. 4.1-4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits.

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.

What We have Learned about Minimized Extracorporeal Circulation versus Conventional Extracorporeal Circulation: An Updated Meta-Analysis

Introduction

The benefits of minimized extracorporeal circulation (MECC) compared with conventional extracorporeal circulation (CECC) are still in debate.

Methods

PubMed, EMBASE and the Cochrane Library were searched until November 10, 2014. After quality assessment, we chose a fixed-effects model when the trials showed low heterogeneity, otherwise a random-effects model was used. We performed univariate meta-regression and sensitivity analysis to search for the potential sources of heterogeneity. Cumulative meta-analysis was performed to access the evolution of outcome over time.

Results

41 RCTs enrolling 3744 patients were included after independent article review by 2 authors. MECC significantly reduced atrial fibrillation (RR, 0.76; 95% CI, 0.66 to 0.89; P<0.001; I2 = 0%), and myocardial infarction (RR, 0.43; 95% CI, 0.26 to 0.71; P = 0.001; I2 = 0%). In addition, the results regarding chest tube drainage, transfusion rate, blood loss, red blood cell transfusion volume, and platelet count favored MECC as well.

Conclusions

MECC diminished morbidity of cardiovascular complications postoperatively, conserved blood cells, and reduced allogeneic blood transfusion.

Blood transfusions in cardiac surgery: indications, risks, and conservation strategies

Although red blood cell (RBC) transfusions are frequently used in cardiac operations, an increasing amount of data has demonstrated deleterious consequences. Consequently, the appropriate use of this limited resource is unclear. In this review, we discuss the relationship between anemia and the outcomes of cardiac surgical procedures, the risks associated with RBC transfusion, and the impact of blood transfusions on mortality and morbidity after cardiac operations. The review concludes with a discussion of randomized trials comparing restrictive versus liberal transfusion strategies and a consideration of blood conservation techniques.

Feasibility and safety of minimized cardiopulmonary bypass in major aortic surgery

OBJECTIVES

Conventional cardiopulmonary bypass causes haemodilution and is a trigger of systemic inflammatory reactions, coagulopathy and organ failure. Miniaturized cardiopulmonary bypass has been proposed as a way to reduce these deleterious effects of conventional cardiopulmonary bypass and to promote a more physiological state. The use of miniaturized cardiopulmonary bypass has been reported in low-risk patients undergoing valve and coronary artery bypass graft (CABG) surgery. However, little is known about its application in major aortic surgery.

METHODS

From February 2007 to September 2010, 49 patients underwent major aortic surgery using the Hammersmith miniaturized cardiopulmonary bypass (ECCO, Sorin). Data were extracted from medical records to characterize preoperative comorbidities (EuroSCORE), perioperative complications and the use of blood products. The same data were collected and described for 328 consecutive patients having similar surgery with conventional cardiopulmonary bypass at the Bristol Heart Institute, our twinned centre, during the same period.

RESULTS

The miniaturized cardiopulmonary bypass group had a median EuroSCORE of 8 [inter-quartile range (IQR): 5-11], 13% had preoperative renal dysfunction and 20% of operations were classified as emergency or salvage. Thirty-day mortalities were 6.4; and 69, 67 and 74% had ≥ 1 unit of red cells, fresh frozen plasma (FFP) and platelets transfused, respectively. Eight percent of patients experienced a renal complication, and 8% a neurological complication. The conventional cardiopulmonary bypass group was similar, with a EuroSCORE of 8 (IQR: 6-10); 30-day mortalities were 9.4; and 68, 62 and 74% had ≥ 1 unit of red cells, FFP and platelets transfused, respectively. The proportions experiencing renal and neurological complications were 14 and 5%.

CONCLUSIONS

Our experience suggests that miniaturized cardiopulmonary bypass is safe and feasible for use in major aortic cardiac surgery. A randomized trial is needed to evaluate miniaturized cardiopulmonary bypass formally.

A retrospective comparison of blood transfusion requirements during cardiopulmonary bypass with two different small adult oxygenators

A low haematocrit during cardiopulmonary bypass (CPB) is associated with adverse outcomes and often results in homologous blood transfusions. Oxygenators with improved venous reservoir designs aid in reducing the priming volume. Recently, we changed our small adult oxygenator model from the D905 EOS oxygenator (Dideco, Mirandola, Italy) to the Capiox FX1540 (Terumo Corporation, Tokyo, Japan). We conducted a retrospective study of 42 patents to evaluate the impact of the Capiox FX 1540 on blood transfusion requirements in small patients (body surface area (BSA) up to 1.8 m(2)). The D905 EOS group had a lower minimum intraoperative haematocrit than the FX1540 group (20 ± 3 v 22 ± 4, p = 0.029) with 73% of the patients receiving intraoperative blood transfusions compared with 30% in the FX 1540 group (p = 0.012). Patients in the D905 EOS group received one blood transfusion more during CPB than the FX 1540 patients (p = 0.002). The haematocrits at the end of CPB and in the early postoperative period were identical in both groups. The postoperative ventilation time, length of stay in the intensive care unit and postoperative chest drain bleeding were similar in both groups. In conclusion, the Capiox FX1540 was effective in reducing intraoperative packed red cell transfusions.

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm(2) (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm(2) before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system.

Alternative detox

BACKGROUND

The concept that alternative therapies can eliminate toxins and toxicants from the body, i.e. 'alternative detox' (AD) is popular.

SOURCES OF DATA

Selected textbooks and articles on the subject of AD.

AREAS OF AGREEMENT

The principles of AD make no sense from a scientific perspective and there is no clinical evidence to support them.

AREAS OF CONTROVERSY

The promotion of AD treatments provides income for some entrepreneurs but has the potential to cause harm to patients and consumers.

GROWING POINTS

In alternative medicine, simplistic but incorrect concepts such as AD abound. AREAS TIMELY FOR RESEARCH: All therapeutic claims should be scientifically tested before being advertised-and AD cannot be an exception.

Prospective, Randomized Study Comparing Two Different Minimized versus Conventional Cardiopulmonary Bypass Systems

Objective

Conventional cardiopulmonary bypass (CCPB) is a major trigger of inflammatory response. We aimed to assess the impact of two different minimized cardiopulmonary bypass systems (mini-CPB) with and without Bioline-coating compared with CCPB regarding organ function, inflammatory response, and early clinical outcome.

Methods

In a prospective, randomized study, 120 patients underwent elective coronary artery bypass grafting and were randomized into three groups: mini-CPB using a Bioline-coated (group A, n = 40) or an uncoated (group B, n = 40) circuit, or CCPB (group C, n = 40). Cytokines (interleukin-6, interleukin-8, and tumor necrosis factor-alpha), myocardial markers (creatine kinase [CK], CK-MB, and troponin-T), hematocrit, and platelet counts were measured up to 48 hours postoperatively. Early clinical outcome was assessed at 3 months postoperatively.

Results

Demographics, number of distal anastomoses, ventilation time, blood loss, intensive care unit, and hospital stay were comparable (P = not significant). Extracorporeal circulation and cross-clamp time were significantly longer in group A and B versus C (P < 0.005). No significant differences could be found in the release of interleukin-6, interleukin-8, and tumor necrosis factor-alpha among groups. Myocardial markers were significantly reduced in group A and B versus group C (P < 0.001). Hematocrit and platelet counts did not differ among the groups. No differences could be found in early clinical outcome up to 3 months.

Conclusions

This study showed significant better myocardial preservation with lower CK-MB and troponin-T levels in both mini-CPB groups. No significant differences could be found in terms of inflammation, hematologic effects, and early clinical outcome.

Cardiopulmonary bypass and edema: physiology and pathophysiology

Edema is a common morbidity following cardiopulmonary bypass (CPB) and can result in injury to many organs, including the heart, lungs, and brain. Generalized edema is also common and can lead to increased post-operative hospital stay and other morbidities. Pediatric patients are more susceptible to post-CPB edema and the consequences are more severe for this population. Hemodilution and systemic inflammatory responses are two suspected causes of CPB-related edema; however, the mechanisms involved are far from understood. Also, the common strategies to improve edema have not been completely successful and there is a need for new strategies at maintaining a fluid balance of patients as close to physiological as possible, especially for pediatric patients. An integrative approach to understanding edema is necessary as the forces involved in fluid homeostasis are dynamic and interdependent. Therefore, this review will focus on the physiology of fluid homeostasis and the pathologies of fluid shifts during CPB which lead to general edema as well as tissue-specific edema.

Can a mini-bypass circuit improve perfusion in cardiac surgery compared to conventional cardiopulmonary bypass?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the 'mini-bypass technique' can give a reduction in complications after cardiac surgery compared to the conventional cardiopulmonary bypass circuit. Altogether 144 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that 10 out of these 14 studies show reduced hemodilution, 7 show reduced red blood cell transfusion, 2 show reduced fresh frozen plasma use (one showing increased use), and 2 show reduced platelet use. Three studies show reduced postoperative blood loss, but one shows increased blood loss. Three studies show better renal function. Four studies show a better cardiac index and 2 show shorter intensive care unit stay. One study found an increased minute volume and reduced oxygenation for one hour post-mini-bypass. Six studies find significantly reduced inflammatory markers, and 5 measure superior myocardial protection. There are several anecdotal references to a 'learning curve' with this technique but no significant morbidity with complications arising from this were found. Mini-bypass seems to be a promising technique with many documented benefits in studies reporting as many as 1000 patients undergoing this technique.

Aortic surgery using total miniaturized cardiopulmonary bypass

PURPOSE

Few centers have attempted aortic surgery using miniaturized cardiopulmonary bypass (MCPB) systems due to concerns of air handling. The extra corporeal circuit optimized (ECCO) total MCPB system uses a venous air removal device and a parallel soft-shell reservoir that allows for venting of the heart. At our institution, total MCPB is used for all coronary artery bypass graft patients. Our objective was to assess the suitability of the ECCO total MCPB system during aortic surgery.

DESCRIPTION

Fifty consecutive and unselected aortic procedures using the ECCO system were undertaken. Surgical feasibility, air removal ability, and blood transfusion requirements were audited to determine the efficacy of this technique.

EVALUATION

The bypass time was 81.6 +/- 28.0 minutes and the ischemic time was 56.7 +/- 18.9 minutes. Total MCPB handled 1,910 +/- 404 mL of vented blood with 96 venous air removal device activations noted. The blood product transfusion rate was 12%, which was below the surgical transfusion rate for our unit. There were no complications.

CONCLUSIONS

Aortic surgery can be undertaken safely and effectively using the ECCO total MCPB system.

Coagulation and fibrinolytic protein kinetics in cardiopulmonary bypass

The development of Cardiopulmonary Bypass (CPB) catopulted the field of cardiothoracic surgery into a new dimension--one that changed the lives of individuals with congenital and acquired heart disease worldwide. Despite its contributions, CPB has clear limitations and creates unique challenges for clinicians and patients alike, stemming from profound hemostatic pertubations and accompanying risk for bleeding and possibly thrombotic complications.