bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegan alternative for fermented milk products: Preparation and some properties
Authors: Khrundin Dmitrii
Published: July 2023

Rice is relatively easy to digest by humans, and the presence of starch provides the organism with slow energy. In addition, the absence of lactose makes it possible to provide a complete diet for people suffering from allergies or individual intolerance to cow’s milk components. Therefore, the creation of analogues to traditional dairy and fermented milk products is a timely and in-demand task. The use of biotechnology methods allows not only to obtain a product with original organoleptic characteristics, but also to enrich it with metabolites of lactic acid bacteria, to give pre- and probiotic properties. The issues of obtaining fermented rice base (FRB) as a basis for alternative vegan products have been studied. It is shown that with the ratio of solid and liquid phases in the rice base – 1:2, respectively, favourable conditions were created for the development of lactic acid bacteria. It was found that additional treatment (partial enzymatic hydrolysis at a temperature of 40 ± 2 °C for 60 minutes) mixtures before fermentation improves the adaptation of the microbiota to this substrate. In addition, the taste of the rice base improves: a pronounced sweetness appears, the flour flavour disappears, the consistency becomes more viscous. The process of fermentation (for 12 hours at a temperature of 38-40 °C) of rice base was studied, the dynamics of acid accumulation depending on the introduced cultures of lactic acid bacteria was studied. The expediency of applying pectin (1% and 2% by weight) is shown to regulate the consistency of the FRB. The FRB samples received a high sensory evaluation.
Rapid freezing of ground meat: Discrete heat transfer
Authors: Lifentseva Lyudmila , Korotkiy Igor , Rasschepkin Alexander , Korotkaya Elena
Published: July 2023

The paper deals with the optimum conditions for quick freezing of ground meat by continuous and discrete heat transfer. We constructed curves of temperature changes and heat flux during quick freezing of semi-processed meats (ground beef). It was revealed that an increase in the heat flux and a reduction of freezing period by about 1.4 times occurs when the temperature of the cooling medium decreases from -20 С to -40С at air speed of 6 m/s. Comparative characteristics of the change in the freezing duration and the speed of the process by continuous and discrete heat transfer methods are shown. It is proved that with discrete heat transfer, the freezing period lasts 20 minutes, with continuous heat transfer it takes 26 minutes. The paper presents a thermograph and the kinetics of heat transfer during freezing under discrete mode conditions. The quality indicators of ground meat are considered depending on the conditions of heat transfer, as well as the change in the physical and chemical properties of the food after freezing and during storage.
Efficient control of the productivity of agrophytocenosis of soybean (Glicyne max (L.) Merill)
Authors: Troyan Tatiana
Published: July 2023

Around the world, there is a surging demand for soy, the ‘king of beans’. Soy is a globally traded foodstuff produced in both temperate and tropical regions and is a major source of protein and vegetable oils. In the conditions of the Kaliningrad region, the duration of soybean vegetation in soddy-weakly podzolic gleyic light loamy soil, with the medium reaction close to neutral, high and very high content of mobile phosphorus, and exchangeable potassium attains 144 days. The agrophytocenosis productivity is controlled through application of different mineral and bacterial fertilizers. Analysis of variance of the experimental data obtained in the study showed a pronounced relationship of 0.71 for the effect of the fertilizer system on quantitative indicators of the biological yield of soybean seeds. The effectiveness of the microbial-plant system of soybean cultivar Merlin and strains of nodule bacteria Bradyrhizobium japonicum, under optimal conditions, increased the crop yield to 4.43 t/ha, which is 2.11 t/ha higher compared to the control and 1.01 t/ha higher relative to the experimental option with carbamide fertilizer.
Evaluation of the effectiveness of feed additives in the diet of trout
Authors: Kuchko Tamara , Matrosova Svetlana , Vapirov Vladimir
Published: July 2023

The paper studied the effect of feed bioadditives Levabon Rumen E and Digestarom P.E.P. 1000 and a complex of organic acids on the dynamics of mass accumulation, indices of visceral organs, anatomical pathological changes, and hematological parameters of juvenile trout. The maximum positive effect on the morphophysiological parameters and health of fish was revealed for yeast in combination with a phytobiotic as a feed bioadditive. The immune response was found to increase in fish fed bioadditives. A complex of organic acids adversely affects the state of the visceral organs and tissues of fish. A combined use of feed additives in the diet of juvenile trout is recommended in the following concentrations: 2% Levabon Rumen E and 1.5% Digestarom P.E.P. 1000. This combination helps to reduce intensive development of pathological processes in adult fish and improve the physiological parameters of juvenile trout.
The effect of organic fertilizers on the productivity of winter rapeseed in the conditions of the Kaliningrad region
Authors: Tereshchenko Svetlana , Mudrova Lilia
Published: July 2023

Winter rapeseed is a valuable oilseed and fodder crop. In the conditions of the Kaliningrad region, the cultivation of winter rapeseed is economically profitable, it is one of the leading crops; it occupies from 15 to 30% in the crop rotation. Conducted research in the Pravdinsky municipal district, on the fields of Pravdinskoye pig breeding JSC in 2018-2020. Winter rapeseed is demanding of nutrients throughout the growing season. Livestock farming is actively developing in the Kaliningrad region; therefore, the study into the application of organic fertilizers to increase crop productivity is of current relevance. Swine manure, which is primarily a nitrogen-potassium fertilizer, is a valuable quick-acting fertilizer. Liquid organic fertilizers are applied during the main fertilizing procedure minimizing odor and increasing application efficiency. The aim of the study was to investigate the effect of pig manure fraction on the productivity of winter rapeseed. All research results confirmed statistical data. Based on the results, conclusions were drawn.
The use of low-grade heat in dehydration processes of agricultural products
Authors: Loginovskiy Sergey , Rasshchepkin Aleksandr , Gushchin Alexey , Poturaev Vyacheslav
Published: July 2023

Dehydration is one of the main technological processes in the production of food and pharmaceutical products. Dehydration allows products to extend their shelf life, or is an intermediate step in product manufacturing. An important direction in improving the efficiency of production of agricultural products is to control the consumption of heat and electricity. It has been established that waste heat can be used as a free efficient source of low-potential energy for the drying process. This article discusses the benefits of using a heat pump for the drying processes of agricultural products. Heat pump drying can obtain high quality products at low energy costs. A comparative analysis of the convective drying method using a heat pump with other modern dehydration methods of agricultural products was carried out. It was revealed that convective drying with the use of a heat pump is the most advantageous method of dehydration of agricultural complex products.
Heparin-Induced Thrombocytopenia and Extracorporeal Membrane Oxygenation: A Case Report and Review of the Literature
Authors: Pollak Uri , Yacobobich Joanne , Tamary Hannah , Dagan Ovdi , Manor-Shulman Orit
Published: July 2023

Heparin-induced thrombocytopenia (HIT) is an immune-mediated coagulation side effect of heparin therapy characterized by thrombocytopenia and by a paradoxical prothrombotic state following heparin exposure when thrombotic or thromboembolic events accurse, the condition is classified as Heparin-induced thrombocytopenia with thrombosis (HITT). We report a case of HITT with evidence of small-vessel arterial thrombosis in a 5-day-old newborn receiving extracorporeal membrane oxygenation (ECMO) for congenital diaphragmatic hernia, and our attempt of bivalirudin alternative treatment. We also review previous reports regarding HIT and ECMO with the alternative management in this unique population.
Inhaled Carbon Monoxide Attenuates Myocardial Inflammatory Cytokine Expression in a Rat Model of Cardiopulmonary Bypass
Authors: Pulido Juan N. , Neal James R. , Mantilla Carlos B. , Agarwal Shvetank , Lee Won-Yeon , Scott Phillip D. , Hubmayr Rolf D. , Zhan Wen-Zhi , Sieck Gary C. , Farrugia Gianrico , Ereth Mark H.
Published: July 2023

Carbon monoxide (CO), a by-product of Heme metabolism, is a potent modulator of inflammation. Low dose inhaled CO has demonstrated reduced lung and kidney injury in animal models of cardiopulmonary bypass (CPB). We evaluated the impact of low dose inhaled CO on systemic, pulmonary, and myocardial inflammatory response to CPB in rats. Sixteen male Sprague-Dawley rats underwent CPB for 1 hour. The CO (n= 8) group received inhaled CO at 250 ppm for 3 hours before CPB. The Air (n= 8) group served as the control. Pulmonary mechanics were assessed pre and post CPB. The animals were recovered for 30 minutes post CPB and subsequently sacrificed. Pre CPB and post CPB serum Tumor Necrosis Factor-alpha (TNF-α) and Interleukin-10 (IL-10) were analyzed by enzyme-linked immunosorbent assay. Gene expression array and real time quantitative polymerase chain reaction (PCR) analysis was performed on the extracted heart tissue. Baseline characteristics were similar between the groups with the expected exception of carboxyhemoglobin levels (p≤.001) and oxyhemoglobin saturation (p≤.01) in Air versus CO treated groups, respectively. Serum TNF-α (363 ± 278 vs. 287 ± 195;p= .13) and IL-10 (237 ± 26 vs. 302 ± 137;p= Not Significant) in Air versus CO groups respectively were not statistically different after CPB, despite showing a trend of inflammatory attenuation. Gene expression array of the myocardial tissue suggested a pattern of inflammatory modulation, which was confirmed by real time quantitative PCR demonstrating IL-10 expression 3.13 times higher (p= .02) in the CO treated group com pared to the Air group. These data demonstrate that pretreatment with CO at 250 ppm may have a modulatory effect on the inflammatory response to CPB without compromising hemodynamics or oxygen delivery. Further investigation in a survival model of CPB is warranted.
Lissajous Figures: An Engineering Tool for Root Cause Analysis of Individual Cases—A Preliminary Concept
Authors: Palmer Kenneth , Ridgway Tim , Al-Rawi Omar , Johnson Ian , Poullis Michael
Published: July 2023

Some patients have short intensive care stay periods and little or no organ dysfunction after cardiac surgery and others do not despite seemingly faultless surgery, perfusion, and anesthesia. These “unknown” reasons for death and morbidity usually relate to organ ischemia and inflammation, but are obviously mutlifactorial. A Lissajous figure is a technique in electrical engineering to compare two different electrical signals. We utilize this basic concept in a very simple manner to potentially identify why some of these unknown deaths or morbidities occur. Utilizing an electronic perfusion database, we retrospectively analyzed 43 patients undergoing aortic surgery with regard to central venous saturations during cooling and rewarming. Isolated aortic valve replacement patients were excluded. Central venous saturation, time, and temperature were plotted to create a Lissajous figure for the whole operation, and during cooling and rewarming separately. Temperature and saturations were analyzed every 20 seconds. Perfusion related variables were registered and uploaded to www.perfsort.net. Lissajous figures during cooling add little to patient care due to their similarity. Isolated rewarming revealed startling differences. It is immediately visually obvious who had short and long periods of tissue ischemia and reperfusion during rewarming in a seemingly uneventful operation. The periods of ischemia can be semi quantified into: none, mild, moderate, and severe. Creation of simple Lissajous figures during rewarming for bypass runs may be an additional helpful tool in root cause analysis of patient death/ morbidity when surgery, perfusion, and anesthesia seemed faultless. Low central venous saturations at hypothermic temperatures mean significant metabolic activity, indicating tissue ischemia is occurring. Further work is needed to correlate this concept to outcomes.
The Addition of a Membrane Oxygenator to a Ventricular Assist Device in a Patient with Acute Respiratory Distress Syndrome
Authors: Betit Peter , Matte Gregory S. , Howe Robert , Iudiciani Peter , Barrett Cindy , Thiagarajan Ravi , Fynn-Thompson Francis
Published: July 2023

A 12-year-old boy with Marfan’s syndrome required a biventricular assist device (VAD) after an aortic root replacement. The patient developed acute respiratory distress syndrome and required escalating ventilator support. We hypothesized that the addition of a membrane oxygenator in series with the assist device would improve gas exchange and allow for a more lung-protective ventilator approach. A membrane oxygenator was placed in series with the right VAD resulting in a blood path of right atrium to VAD to oxygenator to pulmonary artery. Circuit function was gauged by monitoring flow and oxygenator pressures and periodic circuit inspections and oxygenator blood gases. Heparin was titrated to maintain unfractionated antifactor Xa levels of .3–.7 IU/mL and partial thromboplastin time of 60–80 seconds. The initial sweep gas supplying the oxygenator was 5 L/min at an FIO2 of 1.0, which achieved a pH >7.40 and a PF ratio >250. The pre- and post-oxygenator pressures were 55–60 mmHg and 45–50 mmHg, respectively, and the measured flow at the oxygenator outlet was 2.0–2.2 L/min. The patient was changed from high-frequency oscillatory ventilation to pressure-controlled synchronized intermittent ventilation with pH maintained at 7.35–7.40 and PF ratio >250. Paralytics were discontinued and the patient’s neurologic condition was deemed intact. The patient hemorrhaged after a sternal closure and required transfusions and antifibrinolytics that led to thrombus in the membrane and membrane circuitry, which were replaced without incident. The patient’s respiratory status remained stable; however, his overall condition worsened as a result of additional organ dysfunction and septicemia, and he did not survive. The addition of a membrane oxygenator to a VAD is feasible and supplements gas exchange permitting the use of more lung protective ventilation.
The Effect of Acute Sleep Deprivation and Fatigue in Cardiovascular Perfusion Students: A Mixed Methods Study
Authors: Hodge Ashley B. , Snyder Alexandra C. , Fernandez Adam L. , Boan Andrea D. , Malek Angela M. , Sistino Joseph J.
Published: July 2023

Sleep deprivation as a result of long working hours has been associated with an increased risk of adverse events in healthcare professions but not in cardiovascular perfusion. The purpose of this study is to investigate the impact of sleep deprivation on cardiovascular perfusion students. Testing with highfidelity simulation after 24 hours of sleep deprivation allowed investigators to assess user competency and the effect of fatigue on performance. After informed consent, seven senior perfusion students were enrolled in the study (three declined to participate). The qualitative portion of the study included a focus group session, whereas the quantitative portion included administration of questionnaires, including the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), as well as clinical skills assessment using high-fidelity simulation. Subjects were assessed at three different intervals of sleep deprivation over a 24-hour period: baseline (6:00am), 12 hours (6:00pm), 16 hours (10:00pm), and 24 hours (6:00am) of wakefulness. During each scenario, normally monitored bypass parameters, including mean arterial pressure, activated clotting times, partial pressures of oxygen, partial pressures of carbon dioxide, and venous flow, were manipulated, and the subjects were required to return the parameters to normal levels. In addition, the scenario required calculation of the final protamine dose (using a dose–response curve) and detection of electrocardiography changes. Each task was varied at the different simulation sessions to decrease the effect of learning. Despite any lack of sleep, we hypothesized that, because of repetition, the times to complete the task would decrease at each session. We also hypothesized that the ESS and SSS scores would increase over time. We expected that the students would anticipate which tasks were being evaluated and would react more quickly. The average ESS scores progressively increased at each time period: baseline, 12 hours, 16 hours, and 24 hours. At 24 hours, the ESS and SSS scores were the greatest and the standard deviation was low, suggesting that fatigue affected all participants. During the clinical task evaluations, a “flattening effect” on the learning curve over time was observed. Tasks that required a higher level of cognition had prolonged completion times. Sleep deprivation significantly affects clinical performance as assessed with high-fidelity simulation. To optimize patient and clinician safety, it is important that the question of length of working time be investigated further.
Ventricular Assist Device Malfunction: Sometimes It Is a Zebra
Authors: Reagor James A.
Published: July 2023

Humans and machines fail. It is a matter of fact. Preventing, recognizing, and troubleshooting problems with the many intricate systems used by perfusionists are key skills within the profession. Preventive measures are used in an attempt to fend off errors before they occur. Skills are taught during the educational process to enable clinicians to recover from, and mitigate the effects of, critical events when they do occur. Diagnostic procedures have been developed to step through the troubleshooting process for device and procedural failures. The most common cause of an event is at the top of the list along with its solution. Sometimes, however, the most common issue is not the cause of the problem. Sometimes the problem cannot be diagnosed within the clinical setting. This case is a report of such a situation.
Nanosecond Pulse Electric Field Activation of Platelet-Rich Plasma Reduces Myocardial Infarct Size and Improves Left Ventricular Mechanical Function in the Rabbit Heart
Authors: Hargrave Barbara , Li Francis
Published: July 2023

In the current study, we used the novel, nonchemical method of nanosecond pulsed electric fields (nsPEF) to investigate the efficiency of a protocol involving the in vivo treatment of the ischemic and reperfused heart and heart cells in culture with platelet-rich plasma (PRP). Associated with the restoration of blood flow to the ischemic tissue is a phenomenon referred to as “ischemic reperfusion injury.” Clinically a type of reperfusion injury occurs during coronary bypass surgery once blood perfusion to the heart is restarted. Although the restoration of oxygen to ischemic myocardial cells is critical for tissue survival, reperfusion causes myocardial oxidative stress, attributable in part to the increased production of reactive oxygen species (ROS). Enhanced ROS production is associated with mitochondrial damage. Adult female New Zealand white rabbits were anesthetized and a left thoracotomy performed to expose the heart. The distal segment of the left anterior descending coronary artery was occluded for 15 minutes and then released so reperfusion of the tissue could occur. PRP (.21 mg/heart) or saline was injected into the ischemic area of the myocardium. Mechanical function of the left ventricle was analyzed using a Millar catheter attached to a Micro-Med Analysis System. H9c2 cells in culture were treated with 1 mL of nsPEF activated PRP (1.05 mg/flask) for 24 hours before analysis for ROS production or mitochondrial depolarization damage). The left ventricle contracted and relaxed faster and infarct size was reduced in hearts treated with PRP compared with saline. ROS production and mitochondrial depolarization were reduced in H9c2 cells treated with PRP and stimulated with hydrogen peroxide. These results provide evidence that nsPEFs can successfully be used to prepare PRP and that the PRP is functional in heart protection possibly by reducing ROS generation and stabilizing the mitochondria of the ischemic/reperfused heart.
The Role of Extracorporeal Life Support in Acute Myocarditis: A Bridge to Recovery?
Authors: Sanders D. Bradford , Sowell Steven R. , Willis Brigham , Lane John , Pierce Christopher , Pophal Stephen , Arabia Francisco A. , Nigro John J.
Published: July 2023

Acute myocardial failure associated with myocarditis is highly lethal. Left ventricular assist device support for these patients has been advocated to decompress the left ventricle and facilitate myocardial remodeling and recovery. Concerns exist regarding the ability of venoarterial (VA) extracorporeal life support (ECLS) to decompress the left ventricle and allow effective myocardial recovery. ECLS has several advantages, including availability, rapid deployment, and flexibility, as compared with contemporary ventricular assist devices. The objective of this study was to provide a brief review of acute myocarditis and present our series of patients. After Institutional Review Board approval, we conducted a retrospective data analysis of patients on ECLS experiencing rapidly progressive myocardial failure from a normal baseline. Patients with a history of intrinsic heart disease were excluded. All patients were thought to have myocarditis and had failed medical therapy requiring emergent ECLS support. Five patients demographics are detailed in Table 1. Patients experienced life-threatening intractable dysrhythmias or cardiac arrest and were refractory to medical therapy with severe acidosis and impending multisystem organ failure. All patients were stabilized with VA ECLS, and the left ventricle and atrium were decompressed in four of five patients. A left atrial vent was placed in one patient. Myocardial recovery with successful weaning from ECLS was obtained in four of five patients and to a normal ejection fraction in three of the five. One patient failed ECLS weaning and required biventricular VAD support secondary to severe myocardial necrosis from giant cell myocarditis and was transplanted, one died, all others are alive at follow-up. ECLS is safe and effective to treat acute myocardial failure and may be used to obtain myocardial recovery in certain subsets. We devised a decision algorithm for ECLS deployment in this patient cohort and routinely use ECLS.
Extracorporeal Membrane Oxygenation: Beneficial Strategy for Lung Transplant Recipients
Authors: Cottini Silvia R. , Wenger Urs , Sailer Susanne , Stehberger Paul A. , Schuepbach Reto A. , Hasenclever Peter , Wilhelm Markus , Béchir Markus
Published: July 2023

The role of extracorporeal membrane oxygenation (ECMO) as a therapeutic strategy has been very well documented for over a decade now with consistently positive remarks. The aim of the present study was analyzing the outcome of ECMO application in our lung transplant program, especially the feasibility and safety of our ECMO approach. Therefore, we retrospectively analyzed the data of 15 patients recipients requiring ECMO support. We analyzed clinical data, complications, and survival of the lung-transplanted population that needed ECMO support at our institution from 2006–2009. During that period, 19 applications of ECMO were done on 15 adult patients with the following indications: primary graft dysfunction (10 patients), “bridge to transplantation” (five), pulmonary hypertension (three), and severe acute respiratory distress syndrome (one). At 28 days, the overall survival was 93% (14 of 15 patients) and 12 of these patients (80%) survived at least 6 months. Complications included acute renal insufficiency with temporary need of renal replacement therapy (53%), bleeding (33%), critical illness polyneuropathy (66%), and reversible thrombocytopenia (73%). Based on the evaluation of the patients in this analysis, ECMO seems to be a safe therapeutic approach in lung transplant recipients with severe respiratory failure directly after transplantation.
Plasma-Free Hemoglobin Levels in Advanced vs. Conventional Infant and Pediatric Extracorporeal Life Support Circuits
Authors: Cornelius Amanda M. , Riley Jeffrey B. , Schears Gregory J. , Burkhart Harold M.
Published: July 2023

Extracorporeal life support (ECLS) is a reliable method to support pediatric patients with reversible cardiorespiratory failure associated with congenital heart disease, respiratory insufficiency, or after cardiac surgery. In 2010, our institution adopted an infant/pediatric extracorporeal membrane oxygenation (ECMO) circuit that contains a magnetically levitated centrifugal pump, polymethylpentene oxygenator, and shorter tubing length (ECMO II circuit). Our prior circuit contained a nonocclusive roller pump, polypropylene oxygenator, venous compliance chamber, and hemoconcentrator (ECMO I circuit). A retrospective chart review comparing ECMO I and ECMO II daily plasma-free hemoglobin (PFH) values was conducted. We hypothesized that the PFH is similar between the two ECMO circuit groups. We reviewed medical records of children 3 years of age or younger weighing less than 13 kg who required ECLS between January 2008 and February 2012. PFH levels from 18 ECMO II patients were compared with levels in a retrospective group of an equal number of well-matched ECMO I circuit patients. There was no significant difference between ECMO I and ECMO II circuit groups regarding mean time on ECMO, age in days, and weight. There was also no significant difference in the group mean levels of PFH between ECMO I and ECMO II circuits. There was a significant increase in PFH with hours on ECMO (p < .01) within and between both circuit groups (p < .01) and a significantly greater increase in PFH with ECMO hours (p = .0091) in the ECMO I circuit group. Although there was no significant difference in average PFH with the change in ECMO II circuit technology, advancements such as the magnetically levitated blood pump and polymethylpentene gas exchange device has been associated with significantly fewer mechanical component change-outs (p = .0156) and less clots and fibrin build-up in the circuits (p = .0548).
Improved Environmental Impact with Diversion of Perfusion Bypass Circuit to Municipal Solid Waste
Authors: DeBois William , Prata Jessica , Elmer Barbara , Liu Junli , Fominyam Edward , Salemi Arash
Published: July 2023

The project goal was to reduce waste disposal volume, costs and minimize the negative impact that regulated waste treatment and disposal has on the environment. This was accomplished by diverting bypass circuits from the traditional regulated medical waste (RMW) to clear bag waste, or municipal solid waste (MSW). To qualify circuits to be disposed of through MSW stream, the circuits needed to be void of any free-flowing blood and be “responsibly clear.” Traditionally the perfusion bypass circuit was emptied through the cardioplegia pump starting shortly after decannulation and heparin reversal. Up to 2000 mL of additional prime solution was added until the bypass circuit was rinsed clear. Three hundred sixty of 400 procedures (90%) had a complete circuit rinse and successful diversion to MSW. An additional 240 mL of processed cell salvage blood was available for transfusion. No additional time was spent in the operating room as a result of this procedure. Based on our procedure case volume and circuit weight of 15 pounds, almost 15,000 pounds (7.5 tons) of trash will be diverted from RMW. This technique represents another way for perfusionists to participate in sustainability efforts. Diverting the bypass circuit to clear bag waste results in a reduced environmental impact and annual cost savings. The treatment of RMW is associated with various environmental implications. MSW, or clear bag waste, on the other hand can now be disposed of in waste-to-energy facilities. This process not only releases a significantly less amount of carbon dioxide into the environment, but also helps generate renewable energy. Therefore, the bypass circuit diversion pilot project effectively demonstrates decreases in the carbon footprint of our organization and overall operating costs.
Membrane Oxygenator Heat Exchanger Failure Detected by Unique Blood Gas Findings
Authors: Hawkins Justin L.
Published: July 2023

Failure of components integrated into the cardiopulmonary bypass circuit, although rare, can bring about catastrophic results. One of these components is the heat exchanger of the membrane oxygenator. In this compartment, unsterile water from the heater cooler device is separated from the sterile blood by stainless steel, aluminum, or by polyurethane. These areas are glued or welded to keep the two compartments separate, maintaining sterility of the blood. Although quality control testing is performed by the manufacturer at the factory level, transport presents the real possibility for damage. Because of this, each manufacturer has included in the instructions for use a testing procedure for testing the integrity of the heat exchanger component. Water is circulated through the heat exchanger before priming and a visible check is made of the oxygenator bundle to check for leaks. If none are apparent, then priming of the oxygenator is performed. In this particular case, this procedure was not useful in detecting communication between the water and blood chambers of the oxygenator.
Successful Implantation of a Left Ventricular Assist Device in a Patient with Heparin-Induced Thrombocytopenia and Thrombosis
Authors: Garland Cassandra , Somogyi David
Published: July 2023

We report the case of a 27-year-old woman with signs of heparin-induced thrombocytopenia and thrombosis (HITT) and left heart failure presenting for urgent implantation of a left ventricular assist device (LVAD). HITT can occur in 4.2–6.1% of patients with LVADs. If the patient remains hemodynamically stable, implantation can be delayed for several months until the heparin/PF-4 antibodies decline allowing the use of heparin on cardiopulmonary bypass, However, in most cases related to cardiogenic shock, surgery cannot be delayed. We present the case of a patient who underwent implantation of a HeartMate II LVAD and discuss management strategy using bivalirudin during cardiopulmonary bypass.
Understanding Off-Label Use and Reference Blood Flows in Modern Membrane Oxygenators
Authors: Myers Gerard J.
Published: July 2023

This editorial will address two issues that are still a source of global controversy and confusion in present day perfusion practice. Membrane oxygenators are designed and tested to a set of stringent flow standards prior to their release from every manufacturer. But how well do we know the iatrogenic consequences of pushing these devices beyond their maximum rated limits? In addition, how well do we know the meaning of the term ‘AAMI Reference Flow’ as it relates to the Manufacturers Maximum Rated Flow?
Air Transmission Comparison of the Affinity Fusion Oxygenator with an Integrated Arterial Filter to the Affinity NT Oxygenator with a Separate Arterial Filter
Authors: Potger Kieron C. , McMillan Darryl , Ambrose Mark
Published: July 2023

Arterial filters used in the extracorporeal circuit (ECC) have been shown to minimize cerebral injury by capturing particulate matter and microbubbles. We clinically use the Affinity NT oxygenator with an Affinity arterial filter attached (“Affinity system”). The new Affinity Fusion oxygenator (“Fusion”) incorporates integrated arterial filtering. Our aim was to determine if the Fusion oxygenator was as safe as the Affinity system in terms of relative microbubble transmission of introduced air. A recirculating in vitro circuit primed with blood was used to compare the Fusion with the Affinity system. Microbubbles were detected using a GAMPT BC100 Doppler in the oxygenator–arterial filter outflow line. Measurements were taken 1 minute before and 3 minutes after bolusing 30 mL air proximal to the venous reservoir while altering pump flow rates (3 L/min; 5 L/min). Both the Fusion and Affinity system transmitted microbubbles during air injection. Microbubble volume transmitted at 5 L/min pump flow was significantly greater than at 3 L/min in both systems. The Fusion tended to transmit fewer bubbles, less bubble volume, and smaller sized bubbles than the Affinity system. Under the parameters of this in vitro study, the Affinity Fusion oxygenator with an integrated arterial filter is as safe as the Affinity NT oxygenator with a separate arterial filter in terms of microbubble transmission. However, more research is needed to confirm this study’s findings and generalizability to the clinical environment. As both oxygenator–arterial filter systems transmitted microbubbles during air introduction, it is important to develop strategies to minimize microbubble entry into the ECC.
Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype
Authors: Herbst Daniel P.
Published: July 2023

Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient’s systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependentttests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set atp< .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26–33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique.
Using Zero Balance Ultrafiltration with Dialysate as a Replacement Fluid for Hyperkalemia during Cardiopulmonary Bypass
Authors: Heath Michele , Raghunathan Karthik , Welsby Ian , Maxwell Cory
Published: July 2023

Avoiding or managing hyperkalemia during cardiac surgery, especially in a patient with chronic renal insufficiency, can be challenging. Hyperkalemic cardioplegia solution is usually administered to achieve and maintain an electrical arrest of the heart. This solution eventually mixes in with the systemic circulation, contributing to elevated systemic potassium levels. Administration of packed red blood cells, hemolysis, tissue damage, and acidosis are also common causes of hyperkalemia. Current strategies to avoid or manage hyperkalemia include minimizing the volume of cardioplegia administered, shifting potassium from the extracellular into the intracellular space (by the administration of sodium bicarbonate when the pH is low and/or dextrose–insulin when effects relatively independent of serum pH are desired), using zero-balanced ultrafiltration (Z-BUF) with normal saline as the replacement fluid (to remove potassium from the body rather than simply shift the electrolyte across cellular membranes), and, occasionally, hemodialysis (1). We report the application of Z-BUF using an electrolyte-balanced, low potassium dialysate solution rather than isotonic saline to avoid a high chloride load and the potential for hyperchloremic acidosis to successfully treat hyperkalemia while on cardiopulmonary bypass.
An Unusual Case of Cannula Obstruction Resulting from Venous Thromboembolism
Authors: Ozdirik Jessica E. , Grant Peter W. , Cheruvu Chaitu , Bassin Levi , Lahanas Andrew
Published: July 2023

Cerebral strokes of unknown origin frequently present with a patent foramen ovale (PFO), a common atrial septal defect occurring in approximately 25% of the adult population. Deep vein thrombosis (DVT) or pulmonary embolism (PE) in the presence of a PFO can produce paradoxical systemic embolization subsequent to an increase in pulmonary pressure, permitting entry of thrombi into the arterial circulation. Diagnosis of an impending paradoxical embolism (IPDE) involves the detection of DVT or PE in the presence of an abnormal communication between left and right circulations and may include a right-to-left shunt. Treatment includes oral anticoagulation, antiplatelet agents, thrombolysis, transcatheter closure of the defect, or surgical embolectomy and PFO closure. As a result of risks of intracranial hemorrhage with fibrinolysis, pulmonary embolectomy using cardiopulmonary bypass (CPB) and deep hypothermia is a primary treatment with a surgical mortality rate at approximately 5%. Despite optimal management, IPDE is associated with a mortality rate of 18%. Prompt diagnosis and treatment is critical in avoiding systemic thromboembolization and strokes in these patients. We report a case of superior vena cava cannula obstruction resulting from a paradoxical embolus traversing a PFO during surgery. Warning signs and management during CPB are discussed.
A 2013 Survey on Pressure Monitoring in Adult Cardiopulmonary Bypass Circuits: Modes and Applications
Authors: Rigg Laura , Searles Bruce , Darling Edward Morse
Published: July 2023

Pressure data acquired from multiple sites of extracorporeal circuits can be an important parameter to monitor for the safe conduct of cardiopulmonary bypass (CPB). Although previous surveys demonstrate that CPB circuit pressure monitoring is widely used, there are very little data cataloging specific applications of this practice. Therefore, the purpose of this study is to survey the perfusion community to catalog 1) primary CPB circuit site pressure monitoring locations; 2) type of manometers used; 3) pressure monitoring interface and servoregulation with pump console; and 4) the rationale and documentation associated with pressure monitoring during CPB. In June 2013, a validated 27-question online survey was sent directly through an e-mail link to the chief perfusionists in the northeast United States. Completed surveys were received from 75 of 117 surveys deployed yielding a 64% response rate. Arterial line pressure monitoring during CPB is reported by 99% with six distinct circuit site locations identified. Cardioplegia system pressure was monitored by 95% of the centers. For vacuum-assisted venous drainage (VAVD) users, the venous pressure was measured by 72% of the responding centers. Arterial line pressure servoregulation of the arterial pump was indicated by 61% of respondents and 75% of centers record arterial line pressure in their perfusion record. Most centers (77%) report the use of a transducer that is integrated into the pump console providing a digital pressure display, whereas 20% combine an aneroid gauge manometer with the integrated digital transducer. This study demonstrates that the practice of arterial line pressure monitoring during CPB is nearly universal. However, the selection of the pressure monitoring site on the circuit, modes of monitoring pressure, and their applications are highly variable across the perfusion community.
Interdisciplinary Simulation Using the Cardiopulmonary Bypass Simulator (CPBS)©
Authors: Mendel Shaun
Published: July 2023

Interdisciplinary education offerings between students of cardiovascular science and nurse anesthesia are uncommon despite the collaborative nature of these disciplines. The dual purpose of this article is to describe a method for interdisciplinary simulation and to report survey responses provided by participants. An interdisciplinary simulation session using concurrent use of the cardiopulmonary bypass simulator and the emergency care simulator is described. Interdisciplinary perceptions before and after the event were surveyed using the revised Interdisciplinary Education Perception Scale. Statistically significant differences between baseline and final survey responses were observed in the total score and within the areas of competency and perception of cooperation. Emerging simulation technologies and novel combinations of existing devices can facilitate meaningful interdisciplinary educational opportunities for health science students.
The Need to Develop Standardized Protocols for the Timing of Extracorporeal Membrane Oxygenation Initiation among Adult Patients in Cardiac Arrest: A Case Study
Authors: Mosca Matthew , Weinberg Allison
Published: July 2023

The duration of time between cardiac arrest, cardiopulmonary resuscitation (CPR), and initiation of extracorporeal membrane oxygenation (ECMO) among refractory patients is correlated with mortality. The duration of conventional CPR (CCPR) beyond which ECMO support should not be offered due to poor outcomes is not established. This case study describes a patient with heart failure with recurrent episodes of ventricular tachycardia who had a witnessed cardiac arrest in a coronary care unit. The patient received approximately 45 minutes of CCPR. Venoarterial ECMO was then initiated for extracorporeal CPR (ECPR) support. The total recorded ischemic time between CCPR and ECPR was 60 minutes. Despite aggressive medical therapy, ECMO support was discontinued 48 hours later following absence of electroencephalographic activity and no evidence of cardiac function ultimately leading to the patient’s death. This case study illustrates the possibility that prolonged ischemia resulting from duration of CCPR and time to initiate ECPR may contribute to adverse clinical outcomes. Systems of care that might reduce delays in ECMO initiation and improve patient outcomes are discussed including: 1) development of standardized protocols to allow for rapid initiation of ECMO support; 2) systematic evaluation of parameters such as biomarkers that might identify patients at risk for cardiac arrest in settings where ECMO is readily available; and 3) assessment of patient criteria to define subsets of individuals among whom late institution of ECMO, an expensive and labor-intensive mode of circulatory support, might be futile.
20 Years On: Is It Time to Redefine the Systemic Inflammatory Response to Cardiothoracic Surgery?
Authors: Landis R. Clive
Published: July 2023

The “systemic inflammatory response” has never been defined from a cardiothoracic surgery perspective, but borrowed its definition from the critical care field at a landmark 1992 definition conference on sepsis. It is unclear why the diagnostic criteria for the Systemic Inflammatory Response Syndrome (SIRS) were adopted in isolation, ignoring other potentially more useful definitions for Severe Septic Shock or Secondary Multiple Organ Dysfunction Syndrome. The 1992 SIRS definition for sepsis has since been updated at a conference in 2001 advocating PIRO (Predisposition, Infection, host Response, Organ dysfunction) as a hypothetical model to better link sepsis with clinical outcome. PIRO is readily adaptable to cardiothoracic surgery and provides the precedent and road map for how to update a definition. The need is obvious since the current definition of SIRS is widely disregarded in heart surgery: a dwindling proportion (14%) of articles on the systemic inflammatory response even mention SIRS and 0% monitored SIRS criteria in the past decade in an evidence-based review of anti-inflammatory interventions. The name “inflammatory response” is also problematic; it is too narrow and might be replaced with host response (the R in PIRO) to better convey the wide spectrum of host defensive pathways activated during heart surgery (i.e., complement, coagulation, fibrinolysis, kinins, cytokines, proteases, hemolysis, oxidative stress). A variant on PIRO could allow these elements of the host Response (R) to be anchored within the context of Premorbid conditions (P) and the inevitable Insult (I) from surgery, to better link risk exposures to Organ dysfunction (O) in heart surgery. The precedent of PIRO suggests the following steps will be required to redefine the systemic inflammatory response: 1) buy-in from the leading societies for cardiothoracic surgery, anesthesia, and perfusion on the need for a re-definition conference, 2) assigning relative risk scores to different premorbid exposures, operative insults, and host response factors on clinical outcome, 3) validation of the risk model in a prospective cohort, and 4) development of algorithms or “apps” to facilitate rapid diagnosis and staging of care at bedside.
Perspective on Cerebral Microemboli in Cardiac Surgery: Significant Problem or Much Ado About Nothing?
Authors: Mitchell Simon J. , Merry Alan F.
Published: July 2023

From the time an association was perceived between cardiac surgery and post-operative cognitive dysfunction (POCD), there has been interest in arterial microemboli as one explanation. A succession of studies in the mid-1990s reported a correlation between microemboli exposure and POCD and there followed a focus on microemboli reduction (along with other strategies) in pursuit of peri-operative neuroprotection. There is some evidence that the initiatives developed during this period were successful in reducing neurologic morbidity in cardiac surgery. More recently, however, there is increasing awareness of similar rates of POCD following on and off pump cardiac operations, and following many other types of surgery in elderly patients. This has led some to suggest that cardiopulmonary bypass (CPB) and microemboli exposure by implication are non-contributory. Although the risk factors for POCD may be more patient-centered and multifactorial than previously appreciated, it would be unwise to assume that CPB and exposure to microemboli are unimportant. Improvements in CPB safety (including emboli reduction) achieved over the last 20 years may be partly responsible for difficulty demonstrating higher rates of POCD after cardiac surgery involving CPB in contemporary comparisons with other operations. Moreover, microemboli (including bubbles) have been proven harmful in experimental and clinical situations uncontaminated by other confounding factors. It remains important to continue to minimize patient exposure to microemboli as far as is practicable.