bluuebunny/crossref_metadata_2025 huggingface dataset:
Size makes a difference: use of a low-prime cardiopulmonary bypass circuit and autologous priming in small adults
Authors: Cormack John E , Forest Richard J , Groom Robert C , Morton Jeremy
Published: January 2013

Low hematocrit (Hct < 20) during cardiopulmonary bypass (CPB) is associated with higher mortality and other adverse outcomes. More frequently, low Hct is encountered in patients with small body size and women patients. This prompted us to take an aggressive approach in our care of these patients, involving a strategy for predicting patients at risk of low Hct, with the aid of an electronic worksheet that accurately predicts CPB Hct, and two prevention strategies: use of a low-prime CPB circuit (LP) for all adult patients with a body surface area (BSA) <1.7 m2 and use of autologous circuit priming (AP), in addition to the low-circuit volume in some patients. The two cohorts of patients in whom these techniques were employed were compared to a group matched for body size where our standard adult circuit (STD) was used. There were 233 patients in the standard group, 139 in the LP group, and 68 in the LP/AP group. The CPB circuit prime volume was 1710 ml for the STD group and 1110 ml for the LP group. Use of autologous priming techniques further reduced the prime volume by 545 ± 139 ml. The incidence of low Hct (<20%) during CPB was thus reduced from 70% to 15% ( p = 0.001) when using both techniques together without increasing red blood cell (RBC) transfusions. These changes in perfusion management resulted in a reduction in the incidence of renal complications (STD = 9.4%, LP = 6.5% (ns) and LP/AP = 0%, p = 0.008) and a decrease in hospital mortality (STD = 9.8%, LP = 4.3, p = 0.05 and LP/AP = 0%, p=. 007). Matching the CPB circuit to the patient’s size and use of other prime-reduction strategies can increase Hct levels during CPB and improve outcomes in smaller patients, who are susceptible to increased risk.
Reoperation for a type I aortic dissection: case report
Authors: Wise Robert K , Wiggs Ned T , Dasilva Marcelo C , McCoach Robert M , Pae Walter E , Baer Larry D , Hamilton Lindy J , Hummer Gregory J , Kapp Christopher J , Williams Dennis R
Published: January 2013

Surgery for the repair of a type I aortic dissection presents several difficulties for the surgeon and the perfusionist. One must safely support the patient, while at the same time provide the surgeon with a bloodless field in which to operate. Often, this requires cessation of the circulation for varying amounts of time. Deep hypothermia allows for an extension of the arrest period, while other techniques - retrograde cerebral perfusion and antegrade cerebral perfusion - provide an additional degree of cerebral protection.

Recently, we utilized these techniques concurrently on a 43-year-old female who presented for a reoperation for a type I aortic dissection. Combining these techniques allowed us to adequately support the patient during an anticipated lengthy period of circulatory arrest and insured a successful operation without any adverse cerebral or other organ dysfunction.
Management of anticoagulation and its reversal during paediatric cardiopulmonary bypass: a review of current UK practice
Authors: Codispoti Massimiliano , Mankad Pankaj S
Published: January 2013

Protocols for management of heparin and protamine administration in patients undergoing open-heart surgery have been developed from experience gained mainly in adult practice. However, it has been demonstrated that there are marked differences between paediatric and adult patients in their response to systemic anticoagulation and its reversal. The aim of this study was to obtain an overview of current practice of management of anticoagulation and its reversal from paediatric cardiac surgical units of Great Britain and Ireland. All centres performing paediatric cardiac surgery agreed to participate in the survey ( n = 16). Telephone interviews were carried out with the chief or a senior perfusionist from all participating institutions, which were based on a structured questionnaire compiled specifically for the purpose. The answers were anonymized. At present, in the UK and Ireland, unfractionated heparin is the anticoagulant of choice in all units, with a slight prevalence of porcine mucosal (9/16, 56.5%) versus bovine lung preparation (7/16, 44.0%). The policy for administration of heparin to the patient is uniform, with a dose of 300 IU/kg. However, there is great variability in the amount of heparin added to the prime and to the volume infused during cardiopulmonary bypass (CPB). Monitoring of anticoagulation is achieved by activated coagulation time alone in all but one centre, with lower limits varying between 400 and 750 s. Use of aprotinin is widely accepted, but clinical indications are highly variable. No centre adopts heparin-bonded or heparin-coated circuitry for CPB. Calculation of initial and additional protamine doses followed a variety of criteria, resulting in a very wide distribution of doses. The data obtained highlighted the lack of uniformity among paediatric cardiac surgical units of Great Britain and Ireland with regard to most of the issues related to the management of anticoagulation and its reversal. The striking heterogeneity of our cross-sectional observations clearly underlines the need for prospective, multicentre studies on a national basis to relate different clinical practices to outcome measures.
Whole blood heparin concentrations do not correlate with plasma antifactor Xa heparin concentrations in pediatric patients undergoing cardiopulmonary bypass
Authors: Gruenwald C , de Souza V , Chan A KC , Andrew M
Published: January 2013

This study was designed to test the validity of whole blood heparin concentration (WHBC) measurements using an on-site protamine titration assay with the Hepcon instrument (Medtronic Blood Management, Parker, CO, USA) in pediatric patients less than 1 year old undergoing cardiopulmonary bypass (CPB). The validity of the Hepcon measurements was examined via a test of correlation with the gold standard plasma antifactor Xa activity (anti-Xa) assay. Fifty-one patients (23 females and 28 males) under 1 year old (mean age 5.3 months) were studied prospectively. Blood samples were taken at 5 min into CPB and at the end of CPB for the WBHC, plasma anti-Xa activity, and hematocrit (Hct). The WBHC was converted to plasma heparin level using a formula taking into account the collection of blood into citrate solution and the effect of the citrate on the hematocrit.

While a nonparametric statistical analysis revealed that the mean corrected values from the Hepcon instrument were not significantly different from the mean anti-Xa values ( p = 0.070 at 5 min on CPB, p = 0.518 at the end of CPB), there was no significant correlation between these values at either 5 min into CPB ( r = 0.113, p = 0.429) or at the end of CPB ( r = -0.247, p = 0.080). The lack of correlation between the two assays may be related to the extreme hemodilution observed during CPB in small children, which leads to very low concentrations of coagulation proteins. Due to this discrepancy, whole blood heparin monitors should be further evaluated in children undergoing CPB.
Pulsatile normothermic cardiopulmonary bypass and plasma catecholamine levels
Authors: Zamparelli R , De Paulis S , Martinelli L , Rossi M , Scapigliati A , Sciarra M , Meo F , Schiavello R
Published: January 2013

The aim of the study was to assess plasma catecholamine levels in patients undergoing myocardial revascularization and relate them to pulsatile (P) and nonpulsatile (NP) normothermic cardiopulmonary bypass (CPB). Twenty-eight patients were randomly assigned to different CPB management: 15 patients were assigned to group ‘P’, 13 patients to group ‘NP’. During normothermic extracorporeal circulation, group ‘P’ received pulsatile perfusion, while group ‘NP’ received nonpulsatile perfusion. Levels of epinephrine and norepinephrine were evaluated during the operation and in the intensive care unit (ICU), at seven time points. Haemodynamic assessment was performed at four time points in the same period. Demographic and surgical data were collected, and the postoperative course was analysed. Epinephrine levels were markedly increased during CPB in both groups, while norepinephrine increased more in group NP in comparison with group P. No significant difference was found in fluid administration, transfusion, drugs usage, or postoperative complications. Normothermic pulsatile CPB seems to achieve reduced levels of norepinephrine. A clinical beneficial effect of this finding was not demonstrated during the study.
Pumpless arteriovenous extracorporeal lung assist: what is its role?
Authors: Grubitzsch Herko , Beholz Sven , Wollert Hans-Georg , Eckel Lothar
Published: January 2013

Extracorporeal lung assist (ECLA) is an established treatment of severe pulmonary failure. Since extracorporeal perfusion is applied in a long-term fashion in this setting, the negative impact on blood compounds is of tremendous importance.

Pumpless arteriovenous ECLA (av-ECLA) is an alternatively introduced technique that focuses on reduced blood traumatization. However, due to determining technical and physiological aspects, its clinical application is limited to a highly selected group of patients. Membrane oxygenators with minimal pressure gradients, as well as stable patients’ haemodynamics providing a sufficient cardiac output, are the most important prerequisites. With respect to recent reports, characteristic features of av-ECLA, with special emphasis on its physiological background, are reviewed. Accordingly, reasonable indications for its beneficial use are discussed.

It is concluded that av-ECLA is a feasible technique when its limitations are accepted. For adequate clinical use, more data concerning indications, as well as time- and technique-related directions are required.
‘When more is less’. Reviewing the safety and cost of cardioplegia delivery
Authors: Jones Bryan , Hodnik David
Published: January 2013

There have been several new cardioplegia delivery systems that have been developed by various manufacturers in the last few years. In this evaluation, the safety and costs associated with the present 4:1 roller pump cardioplegia delivery were compared to the Medtronic Cardioplegia Safety System™ (CSS™). One hundred and five patients participated in a randomized, prospective evaluation. The current cardioplegia delivery system consists of using the 4:1-B MYOtherm XP™ disposable by Avecor Cardiovascular and a Sarns™ MDX 7000 roller pump. The Medtronic Cardiotherm™ disposable cardioplegia unit was used in conjunction with the CSS™. The current delivery system will be referred to as group A and the system under evaluation will be referred to as group B. Two varying techniques are employed for cardioplegia delivery and are based on surgeon preference. An equal distribution of techniques was seen in both groups. Results indicated that in group A, a hemoconcentrator was required 60.3% of the time, whereas in group B, a hemoconcentrator was added only 25.0% of the time. The average total cardioplegia delivered in group A was 6588 cm3 compared to 7123 cm3 in group B. Although this is insignificant, the greatest difference was seen in the amount of crystalloid given. In group A, the crystalloid portion was 1317 cm3 compared to only 877 cm3 in group B. There was equal weight gain and hemodilution postop in both groups. Twenty-five incidences of pressurization of the cardioplegia system occurred during the evaluation, with equal distribution in both groups. This evaluation showed that the CSS™ responded without fail to all pressurization incidences. The Medtronic CSS™ has incorporated several safety systems for pressurization and air embolism protection, which are programmable and preset by the perfusionist. The Avecor disposable has a pressurization valve that activates at a pressure greater than 600 mmHg in the cardioplegia circuit. The Sarns™ MDX 7000 does not incorporate any safety shutoffs. Cost savings were achieved in two areas: hemoconcentrator use and volume of cardioplegia solution required. There was a reduction of 35% in the use of a hemoconcentrator in group B, with more total cardioplegia delivered. The cardioplegia patient cost savings in group B totaled $265.95 per case in the plain cardioplegia group and $315.95 with the amino acid cardioplegia group. The new technology incorporated into the Medtronic CSS™ demonstrated that it could provide more safety with less cost than the current cardioplegia pump system.
Redo cardiac surgery in a Jehovah’s Witness, the importance of a multidisciplinary approach to blood conservation
Authors: Jovanovic S , Hansbro S D , Munsch C M , Cross M H
Published: January 2013

Although Jehovah’s Witnesses present a particular problem when undergoing surgery because of their refusal to accept stored blood, it is now quite common to undertake uncomplicated cardiac surgery in these patients. Complex or redo cardiac surgery however, is often associated with major blood loss, and is conventionally contraindicated in Jehovah’s Witnesses. We describe the perioperative management of a Jehovah’s Witness who underwent a resternotomy for mitral valve replacement and coronary artery bypass grafting having previously had an aortic valve replacement and mitral valve repair. The importance of a multidisciplinary approach to blood conservation is discussed.
Coronary artery bypass grafting using a miniature right ventricular support system
Authors: Toomasian John M , Aboul-Hosn Walid
Published: January 2013

Cardiopulmonary bypass (CPB) with cardioplegic myocardial preservation has long been the gold standard for surgical care of coronary artery disease. More recently, alternatives to the conventional approach of CPB-myocardial revascularization have been developed. Epicardial stabilizing devices have been used to immobilize areas of the beating heart to provide a stable surface for some coronary anastomoses. These approaches are often limited to anterior aspects of the heart because revascularization of posterior and lateral vessels often requires the heart to be manipulated or contorted. Excessive manipulation can lead to hemodynamic compromise as a result of partially obstructing pulmonary blood flow.

A miniature extracorporeal system has been developed that uses right ventricular support and allows for epicardial surgical procedures to be conducted on a beating heart without standard CPB. The extracorporeal system consists of a coaxial atrial cannula that is connected to a miniature centrifugal pump. Blood is drained from the right atrium, passes through the miniature centrifugal pump and is delivered through the cannula’s inner reinfusion lumen into the pulmonary artery. The entire circuit volume is approximately 30 ml. The system is positioned on the sterile operative field. The pump is controlled by a console positioned adjacent to the patient. The centrifugal pump is capable of delivering blood flow at rates of 1-6 l/min. This extracorporeal system may be of benefit in maintaining adequate cardiac output during epicardial beating heart surgery.
Mechanical circulatory assist for pulmonary embolism
Authors: Misawa Yoshio , Fuse Katsuo , Yamaguchi Tsutomu , Saito Tsutomu , Konishi Hiroaki
Published: January 2013

Optimal management of acute pulmonary embolism remains controversial, despite advances in thrombolytic therapy. Haemodynamic instability and, in particular, right ventricular dysfunction is associated with poor outcomes. Urgent surgical embolectomy has been the treatment of choice in this category of patients. We present two cases in which percutaneous cardiopulmonary support (PCPS) was used as an adjunct to thrombolytic therapy for progressive circulatory collapse secondary to massive acute pulmonary embolism. This experience suggests that PCPS may offer an attractive option for a condition which continues to carry significant morbidity and mortality.
Use of danaparoid sodium (Orgaran®) as an alternative to heparin sodium during cardiopulmonary bypass: a clinical evaluation of six cases
Authors: Fernandes Philip , Mayer Richard , MacDonald James L , Cleland Andrew G , Hay-McKay Christine
Published: January 2013

Heparin-induced thrombocytopenia (HIT) has become more prevalent in today’s cardiac setting and has resulted in the need for alternative anticoagulant therapies.

Danaparoid sodium, one alternative to heparin, has been used in six cardiopulmonary bypass procedures in this hospital. This clinical experience has resulted in the progressive refinement of a protocol for the ‘safe’ clinical use of danaparoid sodium.

Although there were six positive outcomes with the use of danaparoid sodium, alternatives must be explored in order to find the optimal anticoagulant for the treatment of HIT.
Cardioplegia heat exchanger design modelling using computational fluid dynamics
Authors: van Driel Michael R
Published: January 2013

A new cardioplegia heat exchanger has been developed by Sorin Biomedica. A three-dimensional computer-aided design (CAD) model was optimized using computational fluid dynamics (CFD) modelling. CFD optimization techniques have commonly been applied to velocity flow field analysis, but CFD analysis was also used in this study to predict the heat exchange performance of the design before prototype fabrication. The iterative results of the optimization and the actual heat exchange performance of the final configuration are presented in this paper. Based on the behaviour of this model, both the water and blood fluid flow paths of the heat exchanger were optimized. The simulation predicted superior heat exchange performance using an optimal amount of energy exchange surface area, reducing the total contact surface area, the device priming volume and the material costs. Experimental results confirm the empirical results predicted by the CFD analysis.
Hyperthermic intraoperative intraperitoneal chemotherapy for peritoneal carcinomatosis and sarcomatosis using a cardioplegia heat exchanger and a two-pump system: a case report
Authors: Vocelka Craig R , Anderson David L , Crockett Gregory I
Published: January 2013

A 34-year-old male diagnosed with pseudomyxoma peritoneii presented for an exploratory laparotomy and hyperthermic intraoperative intraperitoneal chemotherapy. A circuit using two roller pumps and a cardioplegia administration set was assembled to deliver the chemotherapy perfusate at a consistent temperature. The authors discuss a case in which this treatment modality was used, describing the perfusionist’s role and the circuit design.
Modified ultrafiltration removes serum interleukin-8 in adult cardiac surgery
Authors: Onoe Masahiko , Magara Tatsuo , Yamamoto Yoshio , Nojima Takehisa
Published: January 2013

Cardiopulmonary bypass (CPB) causes an increase in serum cytokine levels and systemic inflamatory responses, which may trigger the onset of various types of postoperative organ failure. In the present study, modified ultrafiltration (MUF) was applied in cases of adult cardiac surgery and an attempt was made to determine whether MUF reduces serum interleukin-8 (IL-8) levels.

Nine patients who underwent cardiovascular surgery with CPB and MUF between June 1996 and June 1997 were compared with nine control patients who underwent cardiovascular surgery without MUF in the same period. Modified ultrafiltration was performed, based on a method proposed elsewhere. Serum IL-8 was measured by enzyme immunoassay at the start of CPB, immediately after CPB, immediately after MUF and 3 h after MUF.

The mean filtrated volume was 1550.0 ± 173.2 ml. In the MUF group, haematocrit increased significantly from 21.2 ± 2.0 to 24.9 ± 3.3% (p = 0.0008), while systolic blood pressure increased from 97.5 ± 16.7 to 116.5 ± 23.9 mmHg (p = 0.0024) after MUF. In contrast, there were no changes in either haematocrit or blood pressure in the control group. In the MUF group, serum IL-8 was reduced from 69.5 ± 33.5 to 58.9 ± 32.4 pg/ml after MUF (p = 0.0029), whereas it was not reduced in the control group.

The results of the present study suggest that MUF has beneficial effects on postoperative haemodynamics, and can reduce serum IL-8 levels in adult cardiac surgery.
Comparison of tumor necrosis factor-α effect on the expression of iNOS in macrophage and cardiac myocytes
Authors: Sanders D Bradford , Larson Douglas F , Hunter Kyler , Gorman Mark , Bo Yang
Published: January 2013

Proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), are elevated during cardiopulmonary bypass (CPB), heart failure, and inflammatory cardiac and systemic diseases. Elevated TNF-α has been linked to diminished cardiac function, decreased systemic vascular resistance, as well as renal and pulmonary dysfunction. It is understood that myocardial tissues can express TNF-α, which results in the induction of inducible nitric oxide synthase (iNOS) leading to a significant decline in cardiac function and other direct effects. The hypothesis of this study was to determine if TNF-α would stimulate iNOS and its product nitric oxide (NO) similarly in immortalized macrophage and cardiac myocytes. Cultured macrophages (RAW 264.7) and cardiac myocytes (HL-1) were placed into two treatment groups and a control. The treatments included: (1) TNF-α and lipopolysaccharide (LPS); and (2) LPS, TNF-α, interleukin-1β (IL-1β) and interferon-γ (IFN-γ) incubated for 8 h. The macrophage expression of iNOS increased by 365% ( p < 0.01) and its product, NO, increased proportionally. The expression of iNOS in the cardiac myocyte did not increase with TNF-α and LPS. However, with the addition of IFN-α and IL-1β iNOS increased to 140% of control ( p < 0.05). Myocyte cGMP and NO did not increase significantly with TNF-α treatment. This study suggests that HL-1 myocyte iNOS cannot be induced by TNF-α, unlike macrophage iNOS. Furthermore, the resultant cardiac dysfunction, secondary to proinflammatory cytokines effects, is regulated via diverse pathways.
Treatment of sepsis in cardiac surgery: role of immunoglobulins
Authors: Sablotzki A , Mühling J , Dehne M G , Zickmann B , Silber R E , Friedrich I
Published: January 2013

Cardiopulmonary bypass (CPB) is associated with an injury that may cause pathophysiological changes such as systemic inflammatory response syndrome, multiple organ dysfunction syndrome, and mediator-induced multiorgan failure. Systemic endotoxinaemia, release of proinflammatory cytokines, and interactions between neutrophils and endothelium have been reported to correlate with a high incidence of organ dysfunction, infection and sepsis following cardiac surgery. This review discusses the dysregulation of the immune response as a major reason for the higher susceptibility to infections following cardiac surgery, various treatment strategies to reduce CPB-induced inflammation, and especially the prophylactic use of immunoglobulins in cardiac surgery.
The side-effects of cardiopulmonary bypass on the lungs: changes in bronchoalveolar lavage fluids
Authors: Alat İlker , Yüksel Münevver , Büket Suat , Nalbantgil Sanem , Aşkar Fatma , Bayındır Ülkü , Taşbakan Sezai , Kokuludag Ali , Veral Ali
Published: January 2013

Although technical refinements have improved the safety of cardiac operations, postoperative dysfunction of lung and other organs occurs frequently after cardiopulmonary bypass (CPB). The aim of the present study was to search the aetiopathogenesis of pulmonary complications due to CBP. Ten patients with stable coronary artery disease, undergoing coronary artery bypass grafting (CABG) surgery, were included in the study. Forty bronchoalveolar lavage (BAL) fluid samplings were performed in the 10 patients. Samples were obtained at the following time periods: (1) preoperatively; (2) at the end of the first hour after anaesthetic induction; (3) at the conclusion of 30 min of crossclamp on CPB; and (4) at the conclusion of 20 h after the end of CPB, postoperatively. Cell contents of bronchoalveolar lavage fluid, alveolar macrophage viability, eosinophil cationic protein (ECP) levels and myeloperoxidase (MPO) concentrations were analysed in each bronchoalveolar lavage fluids.

While the percentage of preoperative macrophages was 85.90% and the percentage of preoperative neutrophils was 2.40%, they were 77.00% and 11.30% in the postoperative samples, respectively. Mean alveolar macrophage viability was 96.20% preoperatively and 90.40% in the postoperative period. Preoperative eosinophil cationic protein mean concentration was < 2 μg/l and mean response value (RV) was 28.80. Pre-operative mean myeloperoxidase concentration was 7.66 ng/ml. Postoperative eosinophil cationic protein mean response value was 63.40 and mean myeloperoxidase concentration was 59.25 ng/ml. There were significant differences between third and final samples with regard to both neutrophil percentages ( p = 0.028) and MPO levels ( p = 0.005). While the preoperative mean PaO2 value was 89.39 mmHg and mean SaO2 value was 97.12%, they were calculated in the postoperative arterial blood specimens of patients, without inhaling O2, as 65.31 mmHg and 93.84%. These changes between blood gas analyses reflect the impairment of the lungs ( p = 0.009 and p = 0.007, respectively). Neither alveolar macrophage viability nor ECP levels changed significantly between consecutive periods. However, when the results of the first and fourth samples were compared, we saw the cumulative effects of CPB, in that alveolar macrophages lost their viability and ECP mean RVs rose. These changes were statistically significant ( p = 0.027 and p = 0.013, respectively). However, postoperative ECP levels were not like those found in a patient with asthma. Also, changes between alveolar macrophage percentages ( p = 0.028), between neutrophil percentages ( p = 0.036) and between MPO concentrations ( p = 0.005) were statistically significant. Again, changes in neutrophil percentages between first and final samples correlated with changes in MPO levels between same periods ( r = 0.657, p = 0.039).
Veno-venous bypass in liver transplantation: heparin-coated perfusion circuits reduce the activation of humoral defense systems in an in vitro model
Authors: Scholz Tim , Solberg Rigmor , Okkenhaug Cecilie , Videm Vibeke , Gallimore Michael J , Mathisen Øystein , Pedersen Thore , Mollnes Tom E , Bergan Anstein , Søreide Odd , Klintmalm Göran B , Aasen Ansgar O
Published: January 2013

We studied the effects of bypass circuit surface heparinization on kallikrein-kinin, coagulation, fibrinolytic and complement activation in a closed model system for simulating veno-venous bypass (VVBP) in orthotopic liver transplantation (OLT).

The circuits were identical to those in routine use during clinical OLT in our institution. Fresh whole human blood diluted 1: 2 with Ringer’s acetate was circulated at a non-pulsatile flow (2 l/min) and at a constant temperature (37.5°C) for 12 h. In 10 experiments, the entire inner surface of the circuits was coated with end-point attached heparin (HC). In the remaining 10, non-treated PVC tubing was used (NC). Components of the plasma kallikrein-kinin, coagulation, fibrinolytic and complement systems were analyzed using functional techniques (chromogenic peptide substrate assays) and enzyme immunoassays at baseline, 3 and 12 h.

Significant activation of the initial (C3bc) and terminal (TCC) components of the complement system were found in both the NC and HC groups after 3 and 12 h: C3bc: NC: baseline =4 (3.5-7.7), 3 h=17.3* (12.5-27), 12 h=31* (17.7-63.6), HC: baseline=4.9 (3.2-6.8), 3 h=9* (6-14.4), 12 h=13.7* (7.4-18.1). TCC: NC: baseline=0.4 (0.2-0.6), 3 h=5* (0.8-11.9), 12 h: 13.1* (4.2-25.7). HC: baseline=0.5 (0.1-0.6), 3 h=0.6* (0.1-0.8), 12 h=1.2* (0.3-2) AU/ml; median and range (*: p<0.05). The C3bc and TCC concentrations were significantly higher in the NC group at 3 and 12 h, compared to the HC group: C3bc (NC vs. HC group): 3 h, p<0.001; 12 h, p<0.001. TCC (NC vs. HC group): 3 h, p<0.001; 12 h, p<0.001. Significant increases in the values of thrombin-antithrombin complexes ( p<0.003), prothrombin fragment 1+2 ( p<0.006) and plasmin-α2-antiplasmin complexes ( p=0.016) were found in the non-coated group, but not in the heparin-coated group during the observation period, showing that the coagulation and fibrinolytic systems were activated in the non-coated circuits.

We conclude that heparin-coating of the internal surface of the extracorporeal perfusion circuit used for VVBP reduces activation of the plasma cascade systems in a closed venous system in vitro.
Factor VLEIDEN and cardiopulmonary bypass: investigation of haemostatic parameters and the effect of aprotinin using an ex vivo model
Authors: Linden M D , Schneider M , Erber W N
Published: January 2013

It has been suggested that aprotinin results in significantly increased risk for perioperative thrombotic complications in patients with Factor VLEIDEN (F5L) due to its ability to competitively inhibit activated protein C (APC) function in vitro. No clinical studies have been performed to assess the effect of aprotinin on APC function of F5L in vivo. We developed an ex vivo model to mimic the effects of cardiopulmonary bypass with the exclusion of the patient in order to assess APC function. Blood from normal ( n = 2) and F5L heterozygous donors ( n = 2) was treated with aprotinin or placebo (saline). The blood was heparinized, added to the prime and circulated at 2 l/min through a modified cardiopulmonary bypass circuit. After 60 min of circulation, the heparin was neutralized with protamine sulfate. Blood samples, drawn at specific time points, were analysed for APC ratio. Results showed a decrease in APC ratio for both F5L and normal bloods with the addition of aprotinin (18% and 40%, respectively). APC ratios also decreased with the commencement of extracorporeal circulation for all bloods, resulting in an APC ratio of 1.35 in normal placebo-treated blood and 0.67 in F5L placebo-treated blood. The combined effect of aprotinin and extracorporeal circulation resulted in APC ratios of 0.90 for normal blood and 0.63 for F5L blood, corresponding to a severe dysfunction of APC intraoperatively (reference range 1.9-4.0). The data from this model predict an increased risk of perioperative thrombosis due to inhibition of APC function in cardiac surgical patients heterozygous for the F5L mutation. Aprotinin further compounds the severity of APC dysfunction, though the effect is more severe in normal blood. The ex vivo model employed was an effective tool for the investigation of the haemostatic effect of aprotinin. This model may be exploited for other applications such as the investigation of novel or emerging haemostatic agents prior to clinical trial.
Apoptosis in the ischemic reperfused myocardium
Authors: Holleyman Carl R , Larson Douglas F
Published: January 2013

Recovery of the myocardium from an ischemic event depends on the reperfusion of the ischemic area. Resumed blood flow to the tissue restores the metabolic substrates necessary for energy production and cell survival. Paradoxically, ischemic reperfusion (I/R) can result in further damage to the myocardium (I/R injury) through an acute inflammatory response mediated by cytokines, neutrophils, macrophages, and reactive oxygen species. These events can trigger cardiomyocyte death through either necrosis or apoptosis. This report will focus on the apoptosis process, which is an organized, active, and gene-directed process of cell self-destruction that can be initiated by intracellular genetic programs, or second messenger pathways inside the cell upon extracellular stimulation by signaling molecules or stress. Awareness of the apoptotic process in cardiomyocytes and endothelial cells is relevant to myocardial preservation during cardiopulmonary bypass compared with off-pump cornary artery bypass procedures. Pharmacological interventions of the signaling pathways that control apoptosis provide an opportunity for new therapeutic approaches to reduce I/R injury in the heart. This review of apoptosis will introduce the perfusionist to apoptosis in the I/R heart, discuss some of the metabolic pathways that initiate it, and report on developing strategies to prevent it.
Effects of retrograde autologous priming on blood transfusion and clinical outcomes in adults: a meta-analysis
Authors: Sun P , Ji B , Sun Y , Zhu X , Liu J , Long C , Zheng Z
Published: January 2013

Objective:

Reducing the priming volume is an effective means of decreasing hemodilution and blood transfusion during cardiopulmonary bypass (CPB). The patient’s own blood was used to replace the crystalloid in the CPB circuit by retrograde autologous priming (RAP) in order to decrease the priming volume. Therefore, we performed a meta-analysis to investigate whether RAP could reduce blood transfusion and improve clinical outcomes.

Materials and Methods:

A comprehensive search was conducted for randomized, controlled trials (RCTs) exploring RAP in PubMed, Embase, The Cochrane Library, Google Scholar and Chinese literature databases (WanFang, WeiPu and CNKI). Clinical parameters and outcomes were focused on the lowest hematocrit (Hct) during CPB, the number of patients transfused blood intraoperatively, the number of patients transfused blood perioperatively, the number of blood units transfused, 24-hour chest tube drainage, hours to extubation, length of ICU stay, and length of hospital stay.

Results:

Ten trials, with a total of 1123 patients, were included. The number of patients transfused blood intraoperatively (RR = 0.39, 95% CI = [0.29, 0.53], p<0.00001, I2 = 40%) and perioperatively (RR = 0.53, 95% CI = [0.43, 0.66], p<0.00001, I2 = 0%) and the number of blood units transfused (SMD = -0.53, 95% CI = [-0.73, -0.33], p<0.00001, I2 = 14%) were all significantly reduced in the RAP group. No differences in the hours to extubation (SMD = -0.11, 95% CI = [-0.33, 0.12], p=0.37, I2 = 0%) and the length of ICU stay (SMD = -0.17, 95% CI = [-0.41, 0.08], p=0.18, I2 = 0%) were observed between the two groups.

Conclusion:

Compared to conventional priming, RAP could reduce transfusion in adults significantly, but had no effect on clinical outcomes, comparing to conventional priming. Further studies involving RAP are expected to investigate if this technique is beneficial to the patient.
The use of extracorporeal membrane oxygenation in patients with Gram-negative or viral sepsis
Authors: Stewart Dan L , Cruz Teddy V Dela , Ziegler Craig , Goldsmith Linda J
Published: January 2013

To evaluate the use of extracorporeal membrane oxygenation (ECMO) in patients with Gram-negative or viral sepsis, a survey of ECMO centres comprising the Extracorporeal Life Support Organization was conducted. Data collected from neonatal and paediatric intensive care units included patient demographics, indicators of infection, presence of cardiac instability and respiratory criteria for ECMO. One-hundred-and-seven patients with documented sepsis were divided into survivors and nonsurvivors. Prior to ECMO, the patients with a persistent metabolic acidosis ( p < 0.008) and/or hypotension requiring more than two inotropic agents ( p < 0.02) to support blood pressure were less likely to survive. Also, patients with Gram-positive infections (77%) were more likely to survive their ECMO course than those with Gram-negative (60%) or viral infections (40%).

Although survival is less in septic infants than in infants with traditional respiratory failure placed on ECMO, sepsis should not be a contraindication to the use of ECMO. The parents should be informed of the chances of survival with each type of sepsis or respiratory infection (if known), so that a truly informed decision can be made by the parents. We feel that the additional information regarding Gram-negative and viral sepsis should assist the clinician in this goal.
Effects of heparin coating on the expression of CD11b, CD11c and CD62L by leucocytes in extracorporeal circulation in vitro
Authors: Høgevold H E , Moen O , Fosse E , Venge P , Bråten J , Andersson C , Lyberg T
Published: January 2013

Leucocyte adhesion molecules are involved in the leucocyte-endothelial interaction and in the activation of coagulation and binding of complement and endotoxin. Thus, they are important in inflammation, systemic acute phase reaction, ischaemia reperfusion injury and resistance against infections. The expression of the adhesion molecules CD11b, CD11c and CD62L on leucocytes and changes in plasma products of neutrophil activation (myeloperoxidase, lactoferrin) and complement activation (C3bc, SC5b-9 (TCC)) were examined in an extracorporeal circulation (ECC) model and the effects of Carmeda bioactive surface (CBAS) heparin coating ( n = 7) of the circuits were compared to uncoated control circuits ( n = 5). In this model, new ‘unactivated’ cells mobilized from the bone marrow could not interfere with descriptive measures of cell activation as seen in in vivo studies. In the control group, CD11b and CD11c were upregulated on monocytes and granulocytes during ECC, whereas CD62L was downregulated. Heparin coating reduced the increase in CD11b and CD11c on granulocytes ( p < 0.02 at 2 h), but the delayed increase in CD11c on monocytes and the delayed downregulation of CD62L on granulocytes and monocytes did not reach statistical significance. Further, heparin coating also reduced the initial decrease in the absolute cell counts of monocytes and granulocytes ( p = 0.01 at 2 h), reflecting reduced adhesion to the oxygenator/tubing. The increases in plasma myeloperoxidase, lactoferrin, C3bc and TCC were lower in the heparin-coated group compared to the control group. The increases in plasma myeloperoxidase and lactoferrin correlated significantly to the increase in CD11b ( r = 0.71, p = 0.02 and r = 0.64, p = 0.05, respectively) and CD11c ( r = 0.72, p = 0.008 and r = 0.72, p = 0.008, respectively) on granulocytes, suggesting interacting regulatory pathways in the process of neutrophil adhesion, activation and degranulation. Thus, in this in vitro ECC model, heparin coating of oxygenator/tubing sets reduced leucocyte activation and leucocyte adhesion-related phenomena.
The effect of protamine on the epicardial microflow and the graft flow in open-heart surgery
Authors: Belboul Ali , Al-Khaja Najib
Published: January 2013

To evaluate the effect of coronary revascularization on myocardial perfusion and surgical outcome regarding graft flow, we used laser Doppler flowmetry to assess the epicardial microcirculation in patients undergoing coronary artery bypass grafting (CABG) or valve replacement (VR) and electromagnetic flowmetry to measure graft flow in the CABG group.

In the CABG group, the preoperative mean laser Doppler flow rate (LDF) in the epicardium of the left ventricle significantly increased at the end of cardiopulmonary bypass (CPB) (22 ± 7 arbitrary units (AU) to 60 ± 13 AU, p < 0.001). This value further increased 10 min after protamine infusion (66 ± 14 AU, p < 0.01), but was significantly reduced 30 min later (51 ± 14 AU, p < 0.002). Compared to the post-CPB value (34 ± 10 ml/min) before protamine infusion, the mean graft flow (ml/min) to this area significantly increased 10 min after protamine infusion (41.3 ± 10 ml/min, p < 0.001) but significantly decreased 30 min later (29 ± 9 ml/min, p < 0.001). The preoperative mean LDF in the VR group was significantly higher than in the CABG group ( p < 0.01). In the CABG group, there was a positive correlation between the LDF and graft flow at the end of CPB ( r = 0.788) and 10 ( r = 0.767) and 30 ( r = 0.784) min after protamine infusion.

This study shows that coronary bypass grafting increases the myocardial microcirculation which, together with graft flow. could give an early indication of the effect of surgery on myocardial microcirculation. Furthermore, protamine was found to be one of the factors contributing to graft flow reduction postoperatively and, therefore, newer methods of heparin reversal may be desirable.
A comparison of gaseous emboli release in five membrane oxygenators
Authors: Beckley Philip D , Shinko Paul D , Sites Jeffrey P
Published: January 2013

The purpose of this study was to compare the air handling capability of five currently used membrane oxygenators: the Avecor Affinity™, the Bentley® SpiralGold™, the Medtronic Maxima Plus™, the Sarns Turbo™ and the Sorin Monolyth™ M. A circuit was constructed to include a hardshell venous reservoir and roller pump. Pressure monitoring sites and ultrasonic microbubble detection probes were located proximal and distal to the oxygenator. An air injection/infusion site was provided proximal to the roller pump inlet. Each circuit was primed with fresh anticoagulated bovine blood, adjusted to a haematocrit of 25% and maintained at 38 ± 1°C. Three different bolus amounts of air (10, 20 and 40 cm3) were injected at three blood flow rates (3, 4.5 and 6 l/min). A 1-min infusion of air delivered at 1 ml/s was also administered at three blood flow rates (3, 4.5 and 6 l/min). The hardshell reservoir was also completely emptied at each flow rate to simulate a massive air infusion.

At any given blood flow, outlet microbubble counts were usually higher with greater bolus amounts of air. When indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 25%, Affinity™ 7%, Monolyth™ 5%, Maxima™ 3% and SpiralGold™ 1%. With a constant air infusion of 1 ml/s, greater outlet microbubble counts were associated with higher blood flow rates. Again, when indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 44%, Affinity™ 25%, Maxima™ 19%, Monolyth™ 16% and SpiralGold™ 0%. All oxygenators deprimed when the hardshell reservoir was emptied and all shed microbubbles into the outlet blood except the SpiralGold™.

The results of this study indicate that air handling is not a simple function of blood flow pattern (i.e. top to bottom versus bottom to top), but also includes dynamics associated with oxygenator design, fibre arrangement and flow resistance.
Coagulopathic-induced membrane dysfunction during extracorporeal membrane oxygenation: a case report
Authors: Stammers Alfred H , Fristoe Lance W , Christensen Kevin , Deptula Joseph , Sydzyik R Troy , Zavadil Douglas , Willett Lynne
Published: January 2013

This paper describes an unusual complication of membrane dysfunction during extracorporeal membrane oxygenation (ECMO) for treatment of neonatal respiratory distress. A 2.8-kg term infant presented to our facility in severe respiratory distress and was diagnosed with primary pulmonary hypertension. After routine priming of the extracorporeal circuit, the patient was placed on veno-arterial ECMO with 8 F arterial and 12 F venous cannulae. Transfusion criteria were established which included trigger values of the following: platelet count 100 000/μl, fibrinogen 150 mg/dl, haematocrit 40%. The ECMO course was uneventful until approximately the 132nd hour on support when the patient developed a consumptive coagulopathy, as evidenced by 55-60% reductions in both platelet count and fibrinogen concentrations, despite transfusion therapy. Total autogeneic blood product transfusion during the first 120 h of ECMO averaged 4.4 ± 2.2 ml/h, while the transfusion rate for the final 35 h was 7.8 ± 3.5 ml/h. Coinciding with this rise in transfusion requirements was an increase in transmembrane pressure from 0.29 to 1.52 mmHg/ml blood flow.

The patient was separated from ECMO after 175 h due to a continuing coagulopathy and haemothorax. The patient was then treated with nitric oxide therapy before succumbing on the twelfth postoperative day due to refractory respiratory failure. The circuit was dissected and significant clots found in both the venous bladder and oxygenator. In addition, approximately one-third of the membrane compartment had a ‘fused’ circumferential pattern of dessicated clot which interrupted blood path continuity. In conclusion, this report describes an unusual complication of the ECMO oxygenator that occurred during long-term extracorporeal life support which most likely resulted from a coagulopathy.
Use of blood products in cardiac surgery
Authors: Renton M C , McClelland D BL , Sinclair C J
Published: January 2013

The quantity of blood products used perioperatively during cardiac surgery is known to vary widely between institutions. This study looked at the amount of blood products used perioperatively in 74 consecutive elective cardiac operations in one institution. The results are compared with those from other European centres and a cost analysis carried out.

On average 2.33 ± 0.74 (95% confidence interval 1.93-2.77) units of red cell concentrate were transfused perioperatively per patient. Six (8%) patients received no blood products.

In addition a number of preoperative factors were studied in an attempt to identify predictors of transfusion requirements. Age, preoperative haemoglobin, female sex and red cell mass were all found to have some predictive value.

In the face of increasing demands on a limited supply of blood products we question the need for crossmatching more than four units of red cell concentrate in elective cardiac surgery.
Monitoring aortic root effluent during retrograde cardioplegia delivery
Authors: Mannebach Patrick C , Sistino Joseph J
Published: January 2013

Continuous monitoring of myocardial protection during aortic crossclamping is not always performed, due to limitations with current technology. The purpose of this study was to use readily available technology to evaluate the effectiveness of retrograde cardioplegia delivery by monitoring the aortic root vent effluent.

The CDI 400, a commonly used blood monitoring device, was used to monitor changes in temperature, pO2, pCO2, and pH by placing a 1/4-inch CDI Quick Cell and probe in the aortic root vent line prior to each case. Twenty adult patients undergoing coronary bypass surgery were involved in the study, which resulted in 48 doses of retrograde cardioplegic solution. The study revealed a significant correlation between the temperature of the cardioplegia solution and the temperature of the aortic root effluent ( p <0.001, r = 0.88). The cardioplegia temperature did not correlate with the change in effluent pO2 ( p = NS) or the degree of effluent temperature change ( p = NS). Furthermore, the change in effluent temperature was not influenced by the amount of cardioplegia solution delivered ( p = NS), or the time between administrations ( p = NS). Both the decreasing and increasing trends of the effluent pO2 significantly correlated with the cardioplegia solution flow rate ( p = 0.034, r = 0.32 and p = 0.013, r = 0.37, respectively), but not with the time between doses (p = NS) or volume of cardioplegia solution delivered ( p = NS). The increase in effluent pO2 did correlate with the coronary sinus pressure ( p < 0.001, r = 0.48).

Measuring aortic root vent effluent may be used to assure the successful delivery of retrograde cardioplegic solution and aid in the detection of various procedural problems. Once the trends from this technique are established by the surgical team, they may be used to adjust cardioplegic solution administration and provide documentation of myocardial protection.