bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of cardiopulmonary bypass and deep hypothermic circulatory arrest on blood viscoelasticity and cerebral blood flow in a neonatal piglet model
Authors: Ündar Akif , Vaughn William K , Calhoon John H
Published: January 2013

The purpose of this study is to determine the effects of cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) on the viscoelasticity (viscosity and elasticity) of blood and global and regional cerebral blood flow (CBF) in a neonatal piglet model.

After initiation of CPB, all animals ( n = 3) were subjected to core cooling for 20 min to reduce the piglets’ nasopharyngeal temperatures to 18°C. This was followed by 60 min of DHCA, then 45 min of rewarming. During cooling and rewarming, the alpha-stat technique was used. Arterial blood samples were taken for viscoelasticity measurements and differently labeled microspheres were injected at pre-CPB, pre- and post-DHCA, 30 and 60 min after CPB for global and regional cerebral blood flow calculations. Viscosity and elasticity were measured at 2 Hz, 22°C and at a strain of 0.2, 1, and 5 using a Vilastic-3 Viscoelasticity Analyzer.

Elasticity of blood at a strain = 1 decreased to 32%, 83%, 57%, and 61% ( p = 0.01, ANOVA) while the viscosity diminished 8.4%, 38%, 22%, 26% compared to the baseline values ( p = 0.01, ANOVA) at pre-DHCA, post-DHCA, 30 and 60 min after CPB, respectively. The viscoelasticity of blood at a strain of 0.2 and 5 also had similar statistically significant drops ( p < 0.05). Global and regional cerebral blood flow were also decreased 30%, 66%, 64% and 63% at the same experimental stages ( p < 0.05, ANOVA).

CPB procedure with 60 min of DHCA significantly alters the blood viscoelasticity, global and regional cerebral blood flow. These large changes in viscoelasticity may have a significant impact on organ blood flow, particularly in the brain.
Point-of-care testing: inspection preparedness
Authors: Bennett John , Cervantes Cindy , Pacheco Scott
Published: January 2013

Point-of-care testing (POCT) in the operating room has changed dramatically since the implementation of the Clinical Laboratory Improvement Amendments (CLIA ‘88), which became effective in September 1992. With the implementation of CLIA ‘88, the Health Care Financing Administration (HCFA) mandated that human specimen testing ‘for the purpose of diagnosis, prevention, or treatment of any disease or impairment of, or the assessment of the health of human beings’, must be performed by a certified laboratory or testing site.

To attain and maintain accreditation, the need for more stringent and comprehensive documentation has become imperative. The Joint Commission for the Accreditation of Hospitals (JCAHO), the College of American Pathologists (CAPS), HCFA, and state regulatory agencies require data such as staff credentialling, staff training/competency, procedure manuals, quality control logs, quality assurance/corrective action plans, correlation studies, proficiency testing results, and equipment maintenance logs to assure specimens are analyzed in a reliable manner by competent personnel so as not to jeopardize the safety and well being of the patient.

Developing a comprehensive, ongoing survey readiness plan that includes a pre-survey checklist of all the documentation required and having this documentation in order and up to date well in advance of the survey will greatly enhance the probability of a successful survey conducted by the various regulatory agencies.
The effects of modified hemofiltration on inflammatory mediators and cardiac performance in coronary artery bypass grafting
Authors: Bog'a Mehmet , Islamog'lu Fatih , Badak Ismail , Çikirikçiog'lu Mustafa , Bakalim Tamer , Yag'di Tahir , Büket Suat , Hamulu Ahmet
Published: January 2013

Cardiopulmonary bypass increases the blood levels of various immune mediators, thereby leading to a systemic inflammatory response syndrome, e.g. sepsis, with some hemodynamic alterations, such as vasodilatation, tachycardia, and a decrease in systemic vascular resistance. Perioperative hemofiltration is one of the treatment modalities proposed to prevent this syndrome. Modified hemofiltration has been introduced recently by investigators who recommend that the former standard techniques are ineffective in eliminating the inflammatory mediators. The purpose of this study was to determine the effects of the modified technique on these mediators and on hemodynamic parameters.

Forty patients undergoing coronary artery bypass grafting were randomized into equal control and hemofiltered groups. The hemodynamic parameters, as well as blood samples, were taken before and after hemofiltration to assess blood concentrations of interleukin-6, interleukin-8 and neopterin.

The hemodynamic parameters and immune mediator levels did not differ between the two groups during the course of the study, except in the immediate postoperative periods, where cardiac output, cardiac index, and systemic vascular resistance values were significantly greater in the hemofiltered group while there were no differences in the immune mediators.

The results of our study suggest that the effects of modified hemofiltration on immune mediators are still debatable. The improvement found in cardiac performance could be attributed to the prevention of hemodilution and hypervolemia.
Carbon dioxide field flooding techniques for open heart surgery: monitoring and minimizing potential adverse effects
Authors: Nadolny Edward M , Svensson Lars G
Published: January 2013

The use of carbon dioxide for displacement of air in cardiac surgery can have potential adverse effects on blood gas strategies. Presented is a method of monitoring carbon dioxide in the cardiopulmonary bypass circuit and limiting the potential for severe hypercarbia during cardiopulmonary bypass.
Aprotinin in the management of life-threatening bleeding during extracorporeal life support
Authors: Biswas Abhik K , Lewis Leslie , Sommerauer John F
Published: January 2013

Contact with the synthetic surfaces of an extracorporeal circuit induces alterations in vascular components, derangements of the coagulation cascade and a systemic inflammatory response. Aprotinin reduces intraoperative and postoperative bleeding in adults undergoing cardiopulmonary bypass; however, trials in children have not had similar favorable results. While there have been some anecdotal reports, there have been no prospective clinical trials exploring the utility of aprotinin in the prevention of or as a therapy for bleeding while on extracorporeal life support (ECLS). We present a case series on our experience utilizing aprotinin for the treatment of life-threatening bleeding during ECLS. The combination of a loading dose followed by a continuous infusion resulted in significant reduction in blood loss and blood product utilization. This suggests that aprotinin may have clinical efficacy in the management of massive blood loss while on ECLS; however, larger controlled trials will be essential to determine the efficacy and appropriate dosing regimens before widespread use in ECLS can be advocated.
A clinical evaluation of platelet function, haemolysis and oxygen transfer during cardiopulmonary bypass comparing the Quantum HF-6700 to the HF-5700 hollow fibre membrane oxygenator
Authors: Chukwuemeka A O , Turtle M RJ , Trivedi U H , Venn G E , Chambers D J
Published: January 2013

The continued improvement of oxygenators is an important aspect of patient safety during cardiopulmonary bypass (CPB). The purpose of this study was to compare the Bard William Harvey HF-5700 oxygenator to the upgraded Bard Quantum HF-6700, which has recently been introduced into clinical practice. No clinical evaluation of this device has been published to date. The two oxygenators differ principally in that the Quantum has a smaller priming volume, achieved at the expense of a smaller membrane surface area which could result in sub-optimal gas exchange characteristics, increased haemolysis and increased platelet dysfunction during CPB.

Twenty adult patients undergoing elective, first time coronary artery bypass grafting (CABG) were randomly assigned either to the HF-5700 ( n=10) or to the HF-6700 ( n=10) group. One patient underwent mitral valve repair in addition to CABG and was excluded from further study. There were no statistically significant differences in either preoperative or operative parameters between the two groups. Samples were obtained at the start of CPB, at 30 min, 60 min, at the end of CPB and at 1 h following termination of CPB.

No significant differences between the two groups were found in oxygen transfer, haemolysis (plasma haptoglobin levels) or platelet function (a novel platelet activating factor (PAF)-induced platelet activation test) at any of the time points during CPB.

It was concluded that the Quantum HF-6700 matches the HF-5700 for the parameters studied, whilst having the advantage of requiring a smaller priming volume.
Preservation of collagen-induced whole blood platelet aggregation by tranexamic acid therapy in primary cardiac valve surgery
Authors: Miyashita Tetsuya , Kamibayashi Takahiko , Ohnishi Yoshihiko , Kobayashi Junjiro , Kuro Masakazu
Published: January 2013

Haemostatic disorder is one of the most common complications following cardiac surgery with cardiopulmonary bypass (CPB). Tranexamic acid reduces blood loss and allogeneic blood transfusion requirement in cardiac surgery. It had been thought that tranexamic acid inhibited fibrinolysis alone following CPB.

In the present study, the haemostatic effects of tranexamic acid (20 mg/kg body weight bolus after induction of anaesthesia followed by continuous infusion at 2 mg/kg/h), including fibrinolysis and platelet function, were investigated in 22 patients (tranexamic acid group n = 12; control group n = 10) undergoing primary cardiac valve surgery.

Fibrinolysis following CPB was reduced significantly in the tranexamic acid group. Following protamine administration, the reduction of collagen-induced whole blood platelet aggregation was mitigated significantly in the tranexamic acid group compared with the control group (36% reduction in the tranexamic acid group vs 58% in the control group; p = 0.011), although platelet counts did not differ between the two groups.

In conclusion, tranexamic acid not only inhibits fibrinolysis directly, but also may preserve platelet function following CPB.
Familial antithrombin-III deficiency during cardiopulmonary bypass: a case report
Authors: Brinks H J , Weerwind P W , Verkroost M WA , Nováková I. , Brouwer M HJ
Published: January 2013

The serine protease inhibitor antithrombin-III (AT-III) is the principal in vivo inhibitor of blood coagulation, inactivating mainly thrombin, but also other serine proteases. Binding of AT-III to heparin dramatically increases its inhibitory effect. AT-III deficiency during cardiopulmonary bypass (CPB) can lead to insufficient anticoagulation which cannot be treated by higher doses of heparin.

A 60-year-old male with familial AT-III deficiency was admitted to our hospital for coronary artery bypass surgery and aortic valve replacement. Four days before the operation, acenocoumarol was stopped and anti-Xanadroparincalcium (Fraxiparine) was started. AT-III activity at that time was 56%. Two hours before the operation, a single dose of 4500 IU AT-III concentrate was administered. Heparinization was performed with 400 IU/kg of porcine mucosal heparin, increasing the activated coagulation time (ACT) from a baseline of 115 to 549 s. AT-III activity at that time was above 100% and the plasma D-dimer concentration was 230 ng/l. ACTs during CPB remained above 999 s, whereas the AT-III activity dropped to 54% and the D-dimer increased up to 500 ng/l at the end of CPB. CPB was terminated uneventfully. Heparin was reversed with 3 mg/kg protamine chloride, decreasing the ACT to 155 s. In the intensive care unit (ICU), the patient received prophylactic Fraxiparine and 1500 IU AT-III, increasing the AT-III activity to 84%. Postoperatively, there was continued blood loss, which necessitated the administration of whole blood and eventually re-exploration.

The case presented illustrates an uneventful treatment of a patient with a hereditary AT-III deficiency undergoing CPB. In spite of an uneventful treatment with AT-III pre-CPB, administration of prophylactic AT-III concentrate after surgery should be considered with caution, as this might increase the postoperative morbidity.
Leukocyte filtration in the early reperfusion phase on cardiopulmonary bypass reduces myocardial injury
Authors: Matheis G. , Scholz M. , Gerber J. , Abdel-Rahman U. , Wimmer-Greinecker G. , Moritz A.
Published: January 2013

Improved myocardial protection and cardiopulmonary bypass (CPB) have limited, but not abolished, intraoperative myocardial damage due to surgical reperfusion injury after release of the aortic crossclamp. In this double-blind, randomized study, we evaluated whether short-term leukocyte filtration during reperfusion may further reduce myocardial damage. Thirty-eight patients with coronary artery disease were randomly assigned to CPB with (group I; n = 19) or without leukocyte filtration (group II; n = 19). There was no difference in bypass time or crossclamp time between the groups. No patient in group I required catecholamines, whereas three patients in group II were supported with adrenaline or dobutamine on the first and second postoperative day. In addition, troponin T plasma levels were lower in group I ( p < 0.05), whereas other markers for tissue injury (CK, CK-MB, LDH, S- GOT and S100B) did not differ. In conclusion, leukocyte filtration during reperfusion may further improve CPB by reducing myocardial damage.
Clinical evaluation of nine hollow-fibre membrane oxygenators
Authors: Segers P AM , Heida J F , de Vries I , Maas C , Boogaart A J , Eilander S
Published: January 2013

In a comparative study we investigated the performance characteristics of nine hollow-fibre oxygenators. In a clinical setting, 10 units of each type of oxygenator were tested for oxygen exchange, transoxygenator pressure drop, heat exchanger performance and blood trauma. The oxygenators included are Maxima PRF Plus, Affinity, Forté, Affinity NT, Quantum, Optima, Capiox 1.8, Hilite and Quadrox. Ninety patients scheduled for elective coronary bypass surgery were enrolled in the study. Cardiotomy suction blood was not allowed to mix with the circulating blood. Samples were taken preoperatively (t1), immediately after cooling and crossclamping of the aorta (t2), during rewarming (t3), and postoperatively (t4). The results showed that under clinical conditions all of the tested oxygenators are well capable of meeting the normal and above-normal oxygen needs. The Quantum and Affinity NT are the best performing oxygenators with respect to oxygen transfer. The Quantum oxygenator with a small membrane surface area of 1.9 m2 has also the highest oxygen transfer per square metre. A direct relationship between shunt fraction and blood flow could not be established in all oxygenators. The lowest shunt fraction at 4 litres blood flow was seen in the Maxima, Quantum and Affinity NT groups (15%). At near physiological PaO2-values, we noticed a negative influence on the shunt fraction. Large differences exist in pressure drop between the oxygenators under standardized conditions with circulating priming, as well as during bypass. The lowest pressure drop was noticed in the Quadrox and Affinity NT, the highest in the Quantum, Capiox and Optima. However, we did not measure any differences in pressure drop after cooling and during re-warming. Differences exist between the heat exchanger performances. The Quadrox oxygenator is the most efficient, while the Maxima has the smallest performance factor. It was not possible to calculate heat exchanger performance for the Hilite due to incorrect temperature measurement. The high pressure gradients in some of the devices did not result in higher haemolysis. Plasma free haemoglobin values were low in each oxygenator. There are no differences in platelet drop postoperatively. The influence on blood trauma of the higher pressure drop in some of the tested devices, in combination with the higher centrifugal pump revolutions needed to overcome this gradient, has to be studied with longer perfusion times.
Cardiac surgical patients exposed to heparin-bonded circuits develop less postoperative cerebral dysfunction than patients exposed to non-heparin-bonded circuits
Authors: Mongero L B , Beck J R , Manspeizer H E , Heyer E J , Lee K , Spanier T A , Smith C R
Published: January 2013

A prospective randomized trial was used to study the incidence of cerebral dysfunction in patients undergoing cardiopulmonary bypass (CPB) with heparin-bonded vs non-heparin-bonded circuits. Although the etiology of postoperative cerebral dysfunction is controversial, activation of the systemic inflammatory response may play a role.

After institutional approval and informed written consent, 39 elective coronary artery bypass (CABG) patients were studied. A battery of neuropsychometric tests (NPMTs) was performed preoperatively, and 5 days and 6 weeks postoperatively. Significant change in NPMT performance was defined as a 25% or greater decrease in postoperative performance, compared to baseline. The number of abnormal tests per patient was calculated. Analysis using the Mann-Whitney rank test was performed for the first follow-up.

Patients randomized to heparin-bonded circuits had fewer abnormal NPMTs (>1 abnormal test) on postoperative day 5 (58 vs 70%, n=19 and 20) than patients randomized to non-heparin-bonded circuits. Patients exposed to heparin-bonded circuits had fewer abnormal tests (>1 abnormal test) at 6 weeks (36 vs 63%, n=14 and 16).

Results suggested that the attenuation of systemic inflammation by heparin-bonded CPB circuits may lower the incidence of cerebral injury in cardiac surgical patients.
Albumin in the pump prime: its effect on postoperative weight gain
Authors: Zarro Debra L , Palanzo David A , Phillips Theodore G
Published: January 2013

An investigation was conducted to determine whether adding albumin to the prime of the cardiopulmonary bypass circuit had any effect on postoperative weight gain. Patients undergoing non-emergency myocardial revascularization for coronary artery disease were divided into two groups. Group I (albumin) received 250 ml of 5% human albumin in their pump prime, whereas group II (control) served as controls. The same surgeon, anesthesia technique, perfusion circuit and conduct, and postoperative management were employed for all patients in the study. No statistically significant differences could be found between the groups for any of the variables studied, including fluid intake during surgery and the first 24 h postoperation, urine output, fluid balance and postoperative weight gain.

The authors conclude from this investigation that adding 250 ml of 5% human albumin to the pump prime has no effect on postoperative weight gain. The next step could be to examine the effect of using larger amounts of albumin or plasma volume expanders in the pump prime.
Evaluation of a new point of care heparin test for cardiopulmonary bypass: the TAS heparin management test
Authors: Wallock Michael , Jeske Walter P , Bakhos Mamdouh , Walenga Jeanine M
Published: January 2013

Patients undergoing cardiopulmonary bypass (CPB) require anticoagulation with heparin to avoid thrombosis within the bypass circuit. The common method used to monitor the degree of anticoagulation is the activated clotting time (ACT). We evaluated a novel point of care device, the TAS (Pharmanetics, Raleigh, NC, USA) heparin management test (HMT), for its suitability in monitoring anticoagulation during CPB. In vitro analysis showed a dose-response ( r2=0.988) of the HMT from 0.078-10.0 U/ml heparin, covering the range of heparin used during cardiac surgery (2-5 U/ml). Fifty randomly selected patients undergoing CPB were studied. Preheparin clotting times for these patients were 143±32 s for the HMT and 146±18 s for the ACT; 435±60 s HMT and 438±39 s ACT during CPB; 145±50 s HMT and 128±14 s ACT post-protamine ( r2=0.797). ε-Aminocaproic acid treatment for inhibition of fibrinolysis did not affect the HMT. We conclude that the HMT correlates well with the ACT and may be useful for monitoring heparin during CPB. Advantages of the HMT are small sample volume and good sensitivity to heparin.
Emergency redo mitral valve replacement in a 27-year-old pregnant female with a clotted prosthetic mitral valve, preoperative fetal demise and postoperative ventricular assist device: a case report
Authors: Oles Dawn , Berryessa Richard , Campbell Kelly , Bhatti Muhammad Akram
Published: January 2013

A 27-year-old Laotian woman with a St Jude mechanical mitral valve became pregnant, requiring a change in her anticoagulant after the first trimester when her warfarin sodium (coumadin) was replaced with enoxaparin sodium (lovenox). Her prosthetic valve clotted and became dysfunctional. She was 16 weeks pregnant and was taken to the operating room for emergency surgery for replacement of the valve. The fetus had not been viable for 1-2 weeks, but still remained in utero. The clotted valve was replaced with another St Jude valve of a slightly smaller diameter (27 mm). The patient could not be weaned from bypass so a right ventricular assist device (RVAD) was inserted. The patient was weaned from the RVAD after 2 days of support. Two days following removal of the RVAD the fetus spontaneously aborted. The patient had a long, complicated hospital course and was discharged 3 months later. She subsequently died 4 months after discharge of a cerebral hemorrhage from excessive anticoagulation.
A cardiopulmonary bypass score system to assess quality of perfusion performance
Authors: Jegger D , Ruchat P , Horisberger J , Boone Y , Pierrel N , Seigneuil I , von Segesser L K
Published: January 2013

During cardiopulmonary bypass, the perfusionist maintains physiological parameters laid down in protocols; this is his or her performance capability. In order to assess his or her performance we need to be able to analyse these physiological parameters objectively. We defined six parameters, pH, BE, PaCO2, PaO2, ACT and oesophageal temperature and gave them ideal values of 7.40 ± 0.05, 0.0 ± 2.5 mmol/l, 39.0 ± 3.0 mmHg, 150 ± 50 mmHg, 540 ± 60 s and 37.2 ± 0.2°C, respectively. We established ranges and a score system: ± one standard deviation of the mean for a score of zero; between ± one and two standard deviations for a score of one; and greater than ± two standard deviations for a score of two. We captured and analysed the most outlying value, with respect to known normal values, for each parameter recorded on the pump sheet. This was performed for 100 consecutive patients. Mean ± standard deviation (medians) values for pH, BE, PaCO2, PaO2, ACT and oesophageal temperature were 7.41 ± 0.07 (7.41), -1.85 ± 2.37 mmol/l (-1.85 mmol/l), 34.6 ± 5.42 mmHg (34.0 mmHg), 320 ± 96.2 mmHg (317 mmHg), 558 ± 164 s (503 s) and 37.3 ± 0.5°C(37.4°C), respectively. We then analysed what percentage of our 100 patients fell within each score range for each of the six parameters. This is an efficient means in analysing whether the perfusionist abides by the protocols, what quality is supplied to the patient, does he or she react when he or she is faced with parameters that are out of range and finally advocating in-line blood gas monitoring. This is another step towards our goal of total quality management.
A genetically engineered human Kunitz protease inhibitor with increased kallikrein inhibition in an ovine model of cardiopulmonary bypass
Authors: Ohri Sunil K , Parratt Rachel , White Tyler , Becket Jenny , Brannan John J , Hunt Beverley J , Taylor Kenneth M
Published: January 2013

A recombinant human serine protease inhibitor known as Kunitz protease inhibitor (KPI) wild type has functional similarities to the bovine Kunitz inhibitor, aprotinin, and had shown a potential to reduce bleeding in an ovine model of cardiopulmonary bypass (CPB). The aim of this study was to assess KPI-185, a modification of KPI-wild type that differs from KPI-wild type in two amino acid residues and which enhances anti-kallikrein activity in a further double-blind, randomized study in an ovine model of CPB, and to compare with our previous study of KPI-wild type and aprotinin in the same ovine model. Post-operative drain losses and subjective assessment of wound ‘dryness’ showed no significant differences between KPI-185 and KPI-wild type, despite the significant enhancement of kallikrein inhibition using KPI-185 seen in serial kallikrein inhibition assays.

These preliminary findings support the hypothesis that kallikrein inhibition is not the major mechanism by which Kunitz inhibitors such as aprotinin reduce perioperative bleeding.
The effect of priming techniques of ultrafiltrators on blood rheology: an in vitro evaluation
Authors: Glogowski Kimberly R , Stammers Alfred H , Niimi Kevin S , Tremain Kimberly D , Muhle Michelle L , Trowbridge Cody C
Published: January 2013

The increased interest of using ultrafiltration during cardiopulmonary bypass (CPB) has mandated a re-evaluation of the hematological effects of this blood conservation process. ‘Rinse-free’ ultrafiltrators can be primed using either crystalloid or blood prior to use. It is unknown whether one priming technique results in superior results in ultrafiltration quality. An in vitro circuit was designed to evaluate the Sorin/COBE HC1400 ( n=6), the Lifestream HC70 ( n=6), and the Terumo/Sarns HC11 ( n=6). All test conditions were conducted at a blood flow rate of 250 ml/min and a transmembrane pressure of 250 mmHg. Samples were drawn and analyzed at four distinct time points for hematocrit, total protein, plasma free hemoglobin, interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNFα). The HC11 had significantly greater percent increases in hematocrit under the blood priming protocol (29.2 ± 7.9) than either the HC1400 (11.0 ± 7.8, p<0.03) or the HC70 (11.9 ± 7.8, p<0.04). When crystalloid priming was compared to blood priming, the HC1400 and HC70 produced significant percent increases in hematocrit and total protein levels. The HC1400 devices produced significantly less plasma free hemoglobin when primed with crystalloid rather than blood (43.6 ± 38.3 vs 21.3 ± 5.6, p<0.01). There were no significant differences between devices or priming techniques for IL-6, IL-8 or TNF levels. In conclusion, the efficiency of the ultrafiltrators was elevated when primed with crystalloid before use. Cytokine levels were relatively unchanged with priming techniques, while plasma free hemoglobin levels were reduced with those devices previously primed with crystalloid.
Life and death of a cardiac myocyte: principles of cellular biology
Authors: Basile-Borgia Annette E , Ware Vassie C
Published: January 2013

If the future of extracorporeal circulation is to include approaches to enhance localized or widespread distribution of cells, and/or gene transfer for augmentation of cardiac function, it is imperative that we gain an increased understanding of the mechanisms that define the cardiac myocyte phenotype. The purpose of this paper is to review the natural history of the cardiac myocyte.

A variety of signals determine the cellular processes that characterize birth, growth, differentiation and death of cardiomyocytes. Examined here are primary aspects of the molecular genetics of growth and development, including signal transduction, protein phosphorylation, the cell division cycle, and transcriptional activation. This review is intended to be an update on insights into molecular aspects of the cell, with emphasis on gene expression during cardiac myogenesis and a discussion of its relevance to the field of extracorporeal circulation. In addition, the current status of research in myogenesis is presented.
An in vitro study of the effects of isoflurane on oxygen transfer
Authors: Muhle Michelle L , Stammers Alfred H , Tremain Kimberly D , Niimi Kevin S , Glogowski Kimberly R , Trowbridge Cody C , Yang Tianyu
Published: January 2013

A common anesthetic technique utilized during cardiopulmonary bypass (CPB) includes the use of various inhalation agents, such as isoflurane. The purpose of this study was to evaluate the effects of this agent on oxygen transfer during CPB.

An in vitro model was designed using bovine blood. Blood flow was held constant at 2 l/min, while gas flow was manipulated at 1 and 3 l/min. The percentage of inspired oxygen (FiO2) was set at 50 and 100%, and isoflurane was manipulated to 1.0, 3.0 and 5.0%. Blood gas analysis, oxygen transfer, and inlet and outlet isoflurane concentrations were measured at each of the given conditions. A total of 12 trials with four oxygenators were conducted.

In the four oxygenators used in our study, no significant differences in oxygenator performance were found. At conditions of 1 l/min gas flow, 50% FiO2 and 1% isoflurane, there were no significant changes in O2 transfer between baseline and measurements taken during isoflurane administration (100.18 ± 12.49 vs 102.35 ± 10.99 ml O2/min, p=0.8031). At 3 l/min gas flow, 100% FiO2 and 5% isoflurane, no significant differences were found (142.35 ± 10.76 vs 154.04 ± 8.95 ml O2/min, p=0.1459). The only significant differences found for oxygen transfer were between 50 and 100% FiO2, all other conditions being set equal (102.35 ± 10.99 vs 137.68 ± 8.62 ml O2/min, p=0.0023).

In conclusion, increasing concentrations of isoflurane up to 5% does not affect the efficiency of oxygen transfer in an in vitro circuit. Further studies are necessary to evaluate the effects in an in vivo setting.
Circuit and protocol for hypoxic hyperthermic isolated limb perfusion to treat malignant melanoma
Authors: Innet Leanne M , Haripershad Vellimah , Van Den Berg Jon , Cooper Leonard
Published: January 2013

In the treatment of cancer, isolated limb perfusion (ILP) allows what would be a lethal systemic dose of cytotoxic drugs to be administered directly to a tumour site of an extremity. Unfortunately, ILP is a complex, expensive, time-consuming treatment that requires general anaesthesia, vascular surgery and expertise with extracorporeal circuits that may not be available outside a cardiac centre. By streamlining the traditional ILP protocols and eliminating the oxygenator from the circuit, an equally safe and effective technique of hypoxic hyperthermic isolated limb perfusion has been developed.
Biomaterial development for cardiopulmonary bypass
Authors: Gourlay T
Published: January 2013

Cardiopulmonary bypass (CPB) is dependent on materials foreign to the patient for its successful application. When blood comes into contact with these so-called biomaterials, an inappropriate inflammatory response, which can be life-threatening in some patients, may develop. The reason for this inappropriate activation of host defence mechanisms is not entirely clear, however a number of strategies have evolved over the years to minimize this unwanted sequelae of CPB. These strategies include surface coating of the materials of the circuit, using new materials thought to improve biocompatibility, and using a number of pharmacological interventions designed to suppress the inflammatory response. Recently, there has been some evidence which indicates that the plasticizer employed in the polyvinyl chloride (PVC) tubing of the CPB circuit may play a part in the development of the inflammatory response. The work described in this paper tends to support this thesis. These studies showed that by washing the plasticizer from the surface of the PVC tubing, the biocompatibility, as reflected in the upregulation of CD11b on the surface of neutrophils, was enhanced. Furthermore, the use of non-plasticized substitutes for PVC had a similar effect. The benefit from removing the plasticizer was similar to that gained from surface coating with heparin, one of the conventional approaches to reducing the inflammatory response to CPB.
Aprotinin: is it prothrombotic?
Authors: Poullis M , Landis R C , Taylor K M
Published: January 2013

Controversy continues as to whether aprotinin (Trasylol) is prothrombotic. The recent discovery of the thrombin receptor family, known as the protease-activated receptor family (PAR) has been essential in aiding our understanding of the mechanism of action of aprotinin. Our results show that aprotinin has no effect on platelet aggregation induced by adrenaline, adenosine diphosphate, phorbol-12-myristate-13-acetate, collagen or PAR 1 agonist peptide. However, aprotinin inhibits thrombin-induced platelet activation as assessed by macroaggregation, microaggregation and platelet membrane calcium flux. Aprotinin inhibits proteolytic activation of platelets, but platelets can still be activated by non-proteolytic mechanisms.
Thyroid function in neonates with severe respiratory failure on extracorporeal membrane oxygenation
Authors: Stewart Dan L , Ssemakula Noah , MacMillan Duncan R , Goldsmith L Jane , Cook Larry N
Published: January 2013

The object was to study thyroid function in neonates with severe respiratory failure on extracorporeal membrane oxygenation (ECMO) and determine whether abnormal thyroid function correlates with prognosis. Total and free thyroxine (T4, FT4), total and free triiodothyronine (T3, FT3), reverse triiodothyronine (rT3), thyroid-stimulating hormone, and thyroxine binding globulin were measured in 14 newborn infants with severe respiratory failure (age 1-30 days) from samples collected before anesthesia for cannula placement, at 30, 60, and 360 min after initiation of ECMO, and on days 2, 4, 6, and 8. The patients were divided into survivors and non-survivors for statistical analyses. No differences were noted between survivors and non-survivors in the pre-ECMO mean serum concentrations of the thyroid function tests analyzed. In nine survivors, mean serum T4, FT4, T3, FT3, and rT3 all declined significantly within 30-60 min after initiation of ECMO, compared to baseline values. The values for all mean serum concentrations recovered completely and exceeded baseline between days 2 and 8. In five non-survivors, the decline of all mean serum values was not statistically significant and recovery to baseline was not achieved. The ratios of mean serum concentration of rT3/FT3were significantly different between survivors and non-survivors across all times during the ECMO course ( p λ 0.0005). These findings indicate that abnormalities in thyroid function occur in neonates with severe respiratory failure on ECMO and that the rT3/FT3 ratio correlates with prognosis over the ECMO course. Survival was associated with a significant reduction of serum thyroid hormone concentrations followed by recovery. We speculate that, in neonates with respiratory failure on ECMO, adaptive mechanisms which enhance survival include the capacity to down-regulate the pituitary-thyroid axis.
Prolonged extracorporeal life support for bridging to transplant: technical and mechanical considerations
Authors: Frazier Elizabeth A , Faulkner Sherry C , Seib Paul M , Harrell James E , Van Devanter Stephen H , Fasules James W
Published: January 2013

Through July 1995, the Extracorporeal Life Support Organization (ELSO) registry listed 87 patients who received extracorporeal life support (ECLS) as a bridge to cardiac transplantation with a survival rate of 41%. At Arkansas Children’s Hospital, 17 patients (aged between two days and 24 years) with diagnoses of dilated cardiomyopathy (seven), postcardiotomy (seven) and acute viral myocarditis (three) were bridged with ECLS. Mechanical complications only occurred in two patients, neither of which necessitated withdrawal of ECLS. Decompression of the left heart was performed in 11 patients, six via a surgically placed vent and five with a blade/balloon atrial septostomy. Documented infection occurred in 11/17 patients, but only one patient died from infection. Fifteen of 17 patients (88%) recovered or were transplanted, of which 13 (76%) were discharged home. With left-heart decompression and appropriate treatment of infection, ECLS may be used as a bridge to cardiac transplantation or until the return of cardiac function.
Neurone-specific enolase and Sangtec 100 assays during cardiac surgery: part II - must samples be spun within 30 min?
Authors: Sapsed-Byrne S , Gao F , Harris D N F
Published: January 2013

Sangtec 100 (S-100) (Sangtec Medical, Sweden) and neurone-specific enolase (NSE) assays are showing promise in the assessment of cerebral damage following cardiopulmonary bypass (CBP). The manufacturer’s instructions state, however, that samples must be spun and frozen within 30 min, which is inconvenient for serial studies. We, therefore, investigated whether storing blood samples at room temperature (RT) or 4°C for up to 48 h affected the measured levels.

Blood samples were taken before and after CBP in six patients and stored for 15 min, 4, 8, 24 or 48 h at RT or 4°C. S-100 and NSE levels did not alter in either ‘before surgery’ or CPB samples when stored for up to 48 h at 4°C. There was a small, nonsignificant rise when stored at RT. Samples may, therefore, be collected throughout long operations or stored overnight without affecting NSE or S-100 plasma levels.
Neurone-specific enolase and Sangtec 100 assays during cardiac surgery: part III - does haemolysis affect their accuracy?
Authors: Gao F , Harris D N F , Sapsed-Byrne S , Sharp S
Published: January 2013

Neurone-specific enolase (NSE) and Sangtec 100 (S-100) are useful for detecting cerebral damage during cardiopulmonary bypass (CPB). However, red cells contain NSE, and the haemolysis frequently caused by CPB could produce a false rise in NSE; S-100 is not found in red cells and should not be affected. We, therefore, compared the effects of haemolysis on NSE and S-100 to see if correction was necessary and possible.

From seven patients, serial dilutions of haemolysed red cells were added to plasma (1/64-1/2048), measured for absorption at 540 nm and assayed for NSE and S-100.

S-100 concentrations showed no change with haemolysis. Measured NSE increased significantly with haemolysis >1/512 (an increase of 6.6 μg/ml): a correction formula is presented. In 39/48 patients after CPB, mean haemolysis was <1/256 and would not need any correction. NSE and S-100 assay can, therefore, be used throughout CPB, which allows both glial and neuronal damage to be studied.
Conventional haemofiltration during routine coronary bypass surgery
Authors: Babka Ronald M , Petress James , Briggs Richard , Helsel Robert , Mack John
Published: January 2013

The use of conventional ultrafiltration during cardiopulmonary bypass (CPB) has been well recognized as an efficient modality of therapy to reverse the effects of deliberate haemodilution. Routine use of the haemofilter was prospectively studied on 60 patients undergoing coronary artery bypass surgery. Group A consisted of 30 patients on whom the ultrafiltrator was used and compared to group B who did not receive the ultrafiltration technique. The COBE 1200 ultrafiltration device was used. The results of the study demonstrated that, in group A, the mean total amount of ultrafiltrate collected during bypass was 2510 ± 804 ml per patient. The mean 24-h postoperative blood loss was 440 ± 192 ml in group A and 451 ± 136 ml in group B. The average bank blood transfused was 0.6 ± 1.3 units per patient in group A and 0.75 ± 1.5 units per patient in group B. Postoperative weight gain in group A averaged 3.5 ± 3.45 lb per patient, compared to 4.8 ± 3.7 lb per patient in group B. Postoperative length of stay averaged 6.4 ± 1.5 days per patient in group A and 6.4 ± 2.1 days per patient in group B. Overall patient charges averaged $33 706 ± 8348 per patient in group A and $33 041 ± 7674 per patient in group B. It was concluded that routine use of ultrafiltration during routine coronary artery bypass surgery with CPB offers no improvement in the quality of care nor does it decrease the patient’s overall charges.
Surgical management of catheter tip thrombus: surgical therapy for right atrial thrombus and fungal endocarditis (Candida tropicalis) complicating paediatric sickle-cell disease
Authors: Hollingsed Michael J , Morales J Mark , Roughneen Patrick T , Burch Kenneth D
Published: January 2013

The use of indwelling central catheters for long-term administration of hyperalimentation, chemotherapy or other intravenous therapies is increasing. This unusual presentation of a catheter-induced right atrial thrombus was complicated by fungal infection. We present a case of a paediatric sickle-cell patient who underwent surgical removal of a right atrial thrombus secondary to fungal ( Candida tropicalis) endocarditis from an indwelling catheter. Successful thrombus removal utilizing cardiopulmonary bypass and subsequent discharge underscores the importance of surgical therapy in treating this important complication.
Outcomes analysis in cardiac surgery
Authors: Groom Robert C , Morton Jeremy R , Lefrak Edward A
Published: January 2013

From early age, we are taught to break apart problems, to fragment the world. This apparently makes complex tasks and subjects more manageable, but we pay a hidden enormous price. We can no longer see the consequence of our actions; we lose our intrinsic connection to a larger whole.1
The relative safety of an oxygenator
Authors: Svenmarker Staffan , Häggmark Sören , Jansson Erica , Lindholm Ronny , Appelblad Micael , Åberg Torkel
Published: January 2013

Analysis of prospectively registered incidents related to cardiopulmonary bypass (CPB) was initiated to establish the incident rate for 10 different oxygenator brands employed over a seven-year period in 5000 clinical perfusions. A general safety index (SI) was defined as the number of recorded incidents in a given series of oxygenators divided by its total number and multiplied by 100. Specific SI was calculated for each of the following categories: high-pressure drop, debris, gas exchange, leakage, material failure and oxygenator change-out. An SI of 0.2 was arbitrarily set as a reference and an acceptable safety level. An estimate of the relative risk for a particular oxygenator brand was compared with the reference by calculating the odd’s ratio with a 95% confidence interval. The mean SI was determined to be 1.6, ranging from 0 for the Maxima CBAS and the Cobe CML to 2.92 for the Safe oxygenator. The dominating specific type of incident was HPD with an SI of 0.81 followed by debris, SI = 0.71. A systematic analysis of adverse events in CPB may be used to evaluate and to set standards, a method already employed in the pharmaceutical industry. Our results indicate that oxygenator safety margins may vary between different brands.
Neutrophil adhesion molecule expression during cardiopulmonary bypass: a comparative study of roller and centrifugal pumps
Authors: Macey M G , McCarthy D A , Trivedi U H , Venn G E , Chambers D J , Brown K A
Published: January 2013

The purpose of this study was to determine whether adhesion molecules and markers of cell activation were preferentially increased on blood neutrophils during cardiopulmonary bypass (CPB) and whether such effects were influenced by the use of a roller pump or a centrifugal pump. Forty-six patients undergoing open heart surgery were randomly allocated into either the roller or centrifugal groups. Blood (1 ml volumes) was removed from arterial and venous lines immediately before and 1 h after the start of bypass. Whole blood samples were immunolabelled and flow cytometry used to measure the distribution and expression of the adhesion molecules CD11b, CD18, CD62L on neutrophils, monocytes and lymphocytes, in addition to CD64 on neutrophils and monocytes, and CD14 on monocytes. The expression of CD11b was significantly enhanced on neutrophils in arterial and venous samples from both the roller pump (mean 84% and 100% increase, respectively; p < 0.001) and centrifugal pump (mean 74% and 73% increase, respectively; p < 0.001) groups. Neutrophil L-selectin expression increased to a small but significant extent in arterial and venous samples from the centrifugal pump group (mean 16% increase; p < 0.001) and in venous samples from the roller pump group (mean 10% increase; p < 0.01). Neither the percentage of neutrophils bearing CD11b/CD18, CD62L and CD64, nor the expression of adhesion molecules on lymphocytes and monocytes were modified by 1 h of bypass. These results suggest that patients subjected to CPB with roller or centrifugal pumps are equally at risk to neutrophil activation that could lead to increased interaction of these cells with blood vessel walls.
Potential problems with simplified selective cerebral perfusion - experimental investigations and clinical improvements
Authors: Gehron J , Wozniak G , Dapper F , Schindler E , Hehrlein F W
Published: January 2013

Currently the most used perfusion techniques during aortic arch surgery to prevent cerebral damage include hypothermic circulatory arrest, retrograde cerebral perfusion and selective cerebral perfusion (SCP). The application of simplified SCP, which does not require deep hypothermia, has become an alternative procedure for brain protection. Including the physiological principle of autoregulated cerebral blood flow, cerebral perfusion flow is not predetermined, but differentiated from the different cannula sizes for the lower and upper body perfusion. In a mock circulation loop, we could show that resistance changes in the two compartments led to flow shifts between the systemic and brachiocephalic regions. In addition to mechanical factors, cerebral perfusion is determined from physiological changes. In practice, these shifts can be initiated with disrupted autoregulation due to ph-stat management or dramatic pressure changes. To prevent mismatched cerebral perfusion extended perioperative monitoring was included in our clinical setting. With bilateral somatosensory evoked potentials, a computer-aided topographical electroencephalometry system, transcranial doppler-sonography and jugular venous bulb saturation, we could provide a sufficient bihemispheric perfusion. Between 1990 and 1995 we operated on 21 patients using SCP. Intraoperatively no signs of cerebral ischaemia due to inadequate perfusion could be observed. Only temporary neurological changes were found postoperatively. In summary, the simplified SCP, despite its physiological basis, is intricately involved in control and influence. We think that the application of SCP is safe if extended neurophysiological monitoring is included in the clinical setting.
The protective effect of a leucocyte removal filter on the lung in open-heart surgery for ventricular septal defect
Authors: Komai Hiroyoshi , Naito Yasuaki , Fujiwara Keiichi , Takagaki Yusaku , Noguchi Yasuzo , Nishimura Yoshiharu
Published: January 2013

We elucidated the protective effect of a leucocyte removal filter on cardiopulmonary bypass (CPB)-induced lung dysfunction during open-heart surgery for ventricular septal defect (VSD). Forty-six VSD patients were divided into two groups: (a) a control group of 22 patients in whom the banked blood was used to prime the CPB circuit, and (b) a leucocyte removal group of 24 patients in whom a leucocyte removal filter was used for priming and every supplement of banked blood during and after the operation. The respiratory index immediately after the CPB was significantly lower in the leucocyte removal group than in the control group (2.23 ± 0.22 vs 3.90 ± 0.68; p < 0.05). The duration of stay in the intensive care unit was significantly shorter in the leucocyte removal group (3.0 ± 0.4 vs 4.1 ± 0.4 days; p < 0.05). These data suggest that the use of a leucocyte removal filter for blood added to the CPB prime or administered after CPB may have protective effects on lung function after open heart surgery for VSD patients.