bluuebunny/crossref_metadata_2025 huggingface dataset:
P-doped hard carbon microspheres for sodium-ion battery anodes with superior rate and cyclic performance
Authors: Wu Sheng , Peng Handong , Huang Le , Liu Yongsi , Wu Yanxue , Liu Lei , Ai Wei , Sun Zhipeng
Published: August 2023

P-doping regulates the morphology and microscopic characteristics of hard carbon microspheres to obtain excellent rate and cyclic sodium storage performance. This study provides a method for preparing high-performance P-doped hard carbon.
Dynamic-dependent selectivity in a bisphosphine iron spin crossover C–H insertion/π-coordination reaction
Authors: Davenport Michael T. , Kirkland Justin K. , Ess Daniel H.
Published: August 2023

Organometallic reaction selectivity is governed by dynamic motion rather than transition states or spin crossover.
Reversible alkaline hydrogen evolution and oxidation reactions using Ni–Mo catalysts supported on carbon
Authors: Patil Rituja B. , Kaur Manjodh , House Stephen D. , Kavalsky Lance , Hu Keda , Zhong Shirley , Krishnamurthy Dilip , Viswanathan Venkatasubramanian , Yang Judith , Yan Yushan , Lattimer Judith , McKone James R.
Published: August 2023

Carbon-supported Ni–Mo composites catalyze alkaline hydrogen evolution and oxidation with negligible onset overpotential. Electrolyzers using Ni–Mo cathodes perform comparably to Pt–Ru cathodes, but oxidative instability limits fuel cell operation.
An assessment of H‐bridge less grid‐tied multilevel inverter with minimum device count and lesser total standing voltage
Authors: Debela Tamiru , Singh Jiwanjot , Sood Vijay K.
Published: August 2023

An innovative switched‐capacitor‐based inverter is proposed in this paper. The suggested converter can produce a five‐level output voltage by utilizing minimal components (single dc source, six switches, and one capacitor). The proposed topology does not require an H‐bridge setup at the load end to achieve the output voltage level. Furthermore, the proposed converter configuration and its operating principle are investigated in depth. A detailed power loss calculation of the suggested inverter and a comparison with another converter is presented. It demonstrates that the proposed inverter is more cost‐effective and requires fewer components than competing inverters. The effectiveness of the proposed multilevel inverter is verified by using hardware in loop OPAL‐RT OP4510 and further five‐level inverter prototype has been verified by experimentally using dSpace 1103 controller.
Research on spot market price forecasting method considering the electricity‐purchase gain for demand side
Authors: Ning Wang , Yuan Du , Haohao Wang , Tao Zhu , Mingxing Wu , Saite Yang
Published: August 2023

The clearing price in electricity spot market is an important reference guiding market participants to purchase energy. Current electricity price forecasting methods mainly focus on improving numerical accuracy, and the need to optimize economic benefits is ignored. However, higher numerical precision sometimes leads to lower electricity‐purchase gain. To deal with that, this paper proposes a price forecasting method that optimizes economic benefits together with numerical accuracies. A revenue‐optimizing term evaluating the relationship between the predicted price and the cost reference price is introduced to the loss function of the prosumers’ forecasting model. A sequence comparison neural network structure is proposed and added to consumers’ model, so the forecasting model is trained by also considering price trend. By co‐optimizing numerical precision and electricity‐purchase gain, the prediction is more conducive to reducing the cost of purchasing power. Price data in actual electricity market are used to verify the feasibility and improvement of the proposed method.
The JWST view of the barred galaxy population in the SMACS0723 galaxy cluster
Authors: Méndez-Abreu J. , Costantin L. , Kruk S.
Published: August 2023

Context.The cosmic evolution of the barred galaxy population provides key information about the secular evolution of galaxies and the settling of rotationally dominated discs.

Aims.We study the bar fraction in the SMACSJ0723.37323 (SMACS0723) cluster of galaxies atz = 0.39 using the Early Release Observations obtained with the NIRCam instrument mounted on the JWST telescope.

Methods.We visually inspected all cluster member galaxies using the images from the NIRCamF200Wfilter. We classified the galaxies into ellipticals and discs and determine the presence of a bar. The cluster member selection was based on a combined method using both the available spectroscopy and the color-magnitude relation.

Results.As has previously been found in nearby galaxy samples, we find that the bar fraction distribution of SMACS0723 is a strong function of the galaxy stellar luminosity (or stellar mass). The analogy with local clusters, such as Virgo and Coma, reveals a similar distribution among the three clusters for low-mass galaxies (log(M⋆/M⊙)≤9.5). The comparison with a sample of local galaxies in a field environment shows a remarkable lack of bars in this low-mass regime for the SMACS0723 cluster (and, therefore, in Virgo and Coma) with respect to the field. At high masses (log(M⋆/M⊙)≥10.25), galaxies in SMACS0723 show a slightly lower bar fraction than those in Coma. At these high masses, we find a much larger bar fraction in SMACS0723 than previous works on field galaxies atz ∼ 0.4. Nevertheless, the difference is only marginal when we compare with a sample of well-resolved local field galaxies. Thus, we suggest that the improved capabilities of JWST with respect to HST in terms of both spatial resolution and image depth are responsible for the higher bar fraction we obtained.

Conclusions.Our results support a scenario where cluster environment affects the formation of bars in a mass-dependent way. At high masses, the mild increase in the bar fraction of local clusters (Coma) with respect to both SMACS0723 and local field galaxies suggests a weak effect coming from the cluster environment possibly triggering bar formation. On the other hand, low-mass galaxies show the same bar fraction in the three clusters (different redshifts) and a significant drop with respect to field galaxies atz = 0, thus suggesting that: (i) the bar fraction of low-mass galaxies in clusters is not evolving during the last 4 Gyr; and (ii) bar formation is severely inhibited in low-mass galaxies residing in clusters.
Hematologic Derangements of Cardiopulmonary Bypass: A
Comparison of Two Perfusion Systems
Authors: Zirbel Gretchen M. , Letson Mary Elizabeth , Kauffman Jeffrey N. , Walker C. Ty , Guyton Robert A.
Published: August 2023

A major goal of new perfusion equipment is minimal trauma to blood elements. This study compares two perfusion systems, quantifies the change in blood components and generation of microemboli, as well as compares the hospital courses of each perfusion system. Forty-four coronary patients were assigned to either Group S, a silicone rubber membrane (SciMed) and centrifugal pump (Bio-Medicus) (N=19) or Group C (our routine equipment), a microporous polypropylene membrane (COBE CML) and roller pump (COBE)(N=25). The rise in plasma hemoglobin (26±14mg* in Group S and 26±17mg* in Group C), the drop in hematocrit (-15.0±3.9* in GroupS and -14.7±3.8* in Group Cat the second post-op day), and the decrease in platelet count (-152,000±78,000* in Group S and -129,000±52,000* in Group C) were similar in both groups. There was no difference in rise in post-op alveolararterial oxygen gradients or debris generated by each system. 27.7% in Group S required red cell transfusions and only 8% required red cell transfusions in Group C. There was no significant difference in clinical endpoints such as ICU stay, hospital stay and complication rate. We found no advantage to more expensive perfusion devices and no improvement upon the extensive CPB damage to formed blood elements.
Dynamic Assessment of Mitral Valve Repair by Directing Pump Blood into the Left Ventricle
Authors: Balasundaram S. , Kassay M. , Duran CMG
Published: August 2023

Intraoperative testing has a major role in the evaluation of the results of mitral valve repair. Static evaluations are possible by inspecting the valve. Once the patient is weaned from cardiopulmonary bypass, dynamic assessment can be done by digital palpation through a partially closed left atriotomy or pressure monitoring or by transoesophageal or epicardial echocardiography. Before weaning off cardiopulmonary bypass, dynamic assessment is possible by injection of cold saline or cardioplegic solution into the left ventricle either by a catheter advanced through the aortic valve or through a left ventricular apical vent. Another method is by connecting the apical vent to the arterial line of the cardiopulmonary bypass by short side tubing. Repeated clamping and unclamping of this side tubing and the vent suction tubing will divert the arterial blood into the left ventricle under adequate pressure to test the dynamic function of the valve. This method leads to sudden partial diversion of the pump flow towards the left ventricle and absent vent flow. The perfusion technologist should be aware of this method and make appropriate adjustments in the pumping procedure.
Assessment of Alveolar Function in Neonates on ECMO Using the Measurement of Net CO2 Transfer by the Artificial Lung
Authors: Grist Gary , Kangas Bonnie , Haney Barbara , Thibeault Donald , Ashcraft Keith
Published: August 2023

The measurement of the net transfer of the CO2 by the artificial lung (Delta Cap) during ECMO indicates the rate at which the alveoli are becoming functional and allows the prediction of when weaning can best begin. Usually, an infant with lung disease placed on ECMO will need to excrete most of his CO2 production via the artificial lung. But as the alveoli heal, CO2 will be removed in increasing amounts by the infant’s own lungs. When the Delta Cap reaches zero, all of the infant’s CO2 production is being removed by his own lungs, an indication that he has adequate alveolar function to exchange O2· A capnagraph is used to measure the CO2 concentration of affluent and effluent sweep gas and the Delta Cap is determined by their difference.
The Total Artificial Heart - A Bridge to Transplantation
Authors: Broecker L. , Zombolas T. , Keon W.J. , Asselin M.
Published: August 2023

Many heart centers are utilizing the total artificial heart for a bridging technique to transplantation, particularly in patients with bi-ventricular failure or irreversible left ventricular failure, where a donor heart is not readily available. This discussion includes the training procedure, operation and management of Canada’s first total artificial heart performed on May 1, 1986.
Aortic Valve Replacement
Authors: Hollingsed Michael J.
Published: August 2023

Indications for aortic valve replacement can be summarized into two disease processes, moderate to severe aortic stenosis (with or without symptoms) and moderate to severe aortic insufficiency. Fortunately, standards of care differ with each physician and so indications for aortic valve replacement are not clearly defined. To understand how the surgeon or cardiologist decides when to recommend replacement of an aortic valve, a brief review is presented.
Continuous Warm Blood Cardioplegia: A New Technique for Myocardial Protection
Authors: Karim Jabr A. , Straus S. , Brewster R. , Rodriguez R. , Panos A. , Hieb B. , Perry J. , Daugharthy J.
Published: August 2023

Hypothermia is used to prolong the safe period of ischemic arrest by reducing the heart's oxygen demands. Due to this effect, hypothermia has been the fundamental component of most methods of myocardial protection during cardiac surgery. However, hypothermia has a number of unwanted side effects, such as detrimental effects on enzyme function, energy generation, and cell membranes. Since electromechanical arrest accounts for 90% of myocardial oxygen consumption, arresting the heart with chemical cardioplegia will reduce O2 consumption dramatically. Therefore, if the resting (arrested) heart is continuously perfused with oxygenated blood cardioplegia, one can easily provide the remaining 10% of O2 that it requires. Under these conditions, the need for hypothermia becomes questionable. In this paper, we describe the perfusionist's experience using the antegrade and retrograde technique of continuous warm blood cardioplegia.
On-Line Arterial PO2 Measurements During Cardiopulmonary Bypass
Authors: Demierre D. , Schmid E. R. , Walpoth B. , Maass D. , Garcia E. , Turina M.
Published: August 2023

A modified intra-arterial PO2 sensor (O.D. 0.55 mm) and associated automatic temperature correction module (Roche) were evaluated as on-line monitoring devices during extracorporal circulation (ECC) in six dogs as well as in four patients undergoing open-heart surgery.

Performance of the equipment was assessed by comparing the PO2 values determined by the sensor with those measured by a blood gas analyzer (AVL). In addition, the reliability of the PO2 sensor calibration factor and the accuracy of the automatic temperature correction module were determined.

The correlation coefficient between sensor and blood gas analyser was r = 0.97 (n=14) for laboratory and r = 0.98 (n=14) for clinical values with blood temperature ranging from 38°C to 22.5°C.

The calibration factor determined in vivo correlated with the value provided by the manufacturer (r=0.97, n=4).

The correlation factor between calculated and automatic temperature correction was r=0.97 (n=21). On line PO2 monitoring is feasible with this equipment and early clinical experience was satisfying.
Myocardial Recovery During Mechanical Circulatory Support After Acute Myocardia/Ischemia
Authors: von Segesser Ludwig K. , Hess Otto M. , Tjon-A-Meeuw Louis , Leskosek Boris , Turina Marko I.
Published: August 2023

Irreversible myocardial failure due to severe ischemia is a challenging problem in clinical practice. The present study was performed to evaluate the potential benefit of mechanical circulatory support in a bovine model with prolonged, acute myocardial ischemia. Seven calves (74+6 kg) underwent 6 hours of regional ischemia by temporary (6h) ligation of the left circumflex coronary artery. Ventricular assist was started 10 minutes after occlusion of left circumflex coronary artery. Ventricular fibrillation occurred in all animals after a mean interval of 4.0±2.4 hours. Defibrillation was attempted immediately and every hour thereafter. Successful defibrillation was achieved in 6/7 animals after 4.1±2.5 hours of ventricular fibrillation during mechanical circulatory support. Weaning from biventricular assist was attempted after 24 hours and was successful in 5 I 6 animals. Hence timely mechanical circulatory support in acute, prolonged ischemia with subsequent “irreversible” cardiac failure allows not only maintainence of acceptable hemodynamics for bridging to heart transplantation but also significant myocardial recovery if coronary artery blood flow is restored within 6 hours.
Continuous Blood Gas Monitoring Using the CDI System 300
Authors: Harloff Michael
Published: August 2023

The virtues and benefits of continuous on-line, realtime blood gas monitoring cannot be successfully denied, or its need be dismissed, on the basis of unavailable technology.

Not electing to monitor blood gases continuously is parallel in thought to not continuously monitoring arterial blood pressures or the electrocardiogram. Given the ever changing pH, and the fluctuation of the pCO2 and pO2, we are never really sure of the trending that occurs during periods of low flow, temperature, and the myriad of other factors which affect acid/base balance.

In order to be fully informed as to the total status of the patient, it is of the utmost importance to recognize continuous blood gas monitoring as an adjunct to cardiopulmonary bypass and not just a luxury option. The CDI System 300 continuously monitors arterial and venous pH, pCO, pO2 and calculates HC03/B.E., and SvO2 while storing the hematocrit. With virtually effortless calibration and insignificant set-up time, the perfusionist can create a wide margin of safety for himself and quality perfusion of the patient, as well as providing the minimum standard care.
A New Cardioplegia Reservoir for the Neonate, Infant and the Pediatric Patient
Authors: Molina Jorge , Gorney Ronald
Published: August 2023

The neonate, infant and pediatric patient requires significant modifications in equipment. A new low volume cardioplegia reservoir combined with an established recirculation line system was developed to satisfy both blood and crystalloid cardioplegia users. This system is designed for volumes under 300 ml with precise level increments allowing for specific ratios of blood to crystalloid. This product demonstrates excellent cooling, uniformity of mixing and blood flow capability for the small patient.
Computer Assisted Instruction and Simulation Programs in Perfusion Education: A Survey
Authors: Bartley Diane M. , Beckley Philip D.
Published: August 2023

This study was done to determine what computer assisted instruction (CAI) and/or simulation programs (SP) are available for use in perfusion education, whether they are being used, and what is desired in a CAI and SP. The 24 program directors in the U.S.A. and Canada were surveyed. Of the 24 surveys sent, 18 were returned. Of those returned, 5 use CAIs, 1 has access to CAIs, but does not use them, 11 do not have access to CAIs, but would use them if available, and 1 does not have access to CAIs and would not use them if access was available. Concerning the SPs, 5 of the respondents use SPs, 12 would use SPs if available, and 1 does not and would not use SPs. There is a large demand for CAIs and SPs by perfusion educators. The program directors surveyed responded that the CAIs and SPs can be used as aides in teaching students, evaluating students, giving them exposure to different situations that do not always occur in lab, and giving students a chance to observe how all the various factors affect one another. Suggestions were made regarding the achievement of these goals.
Biocompatible Circuits: An Adjunct to Non-Cardiac Extracorporeal Cardiopulmonary Support
Authors: Bennett John , Hill Jonathan , Long William , Parsons James , Bruhn Pamela , Starr Albert , Hovaguimian Hagop , Okies J. Edward
Published: August 2023

The utilization of cardiopulmonary bypass systems, for circulatory and/or pulmonary support of patients undergoing non-cardiac procedures, has been previously reported. There is, however, a sub-group of patients for whom total systemic anticoagulation for cardiopulmonary support is extremely undesirable or contraindicated altogether, due to the presenting pathology or procedure to be performed.

Clinical and experimental reports have suggested that with the use of heparin-bonded bypass circuits, the amount of heparin required for anticoagulation of the patient may be substantially reduced, or eliminated, safely. This allows the resuscitation and/or support of patients in whom bypass would otherwise be contraindicated.

We present our clinical experience with heparin-bonded, biocompatible circuits, for support of patients undergoing non-cardiac procedures. In each case, low-dose or no heparin was administered. The group includes patients with trauma related pulmonary insufficiency, pulmonary embolism, hypothermia, neurosurgery, aortic aneurysm, aortic transection, respiratory distress syndrome, pericardiectomy, and cardiogenic shock.
Performance Characteristics of Hemofilters with Heparin Surface Coating: An Experimental Study
Authors: von Segesser L. K. , Pasic M. , Olah A. , Tonz M. , Keusch G. , Hanseler A. , Leskosek B. , Turina M.
Published: August 2023

Heparin surface coated hemofilters and tubing sets were evaluated in comparison to identical but uncoated controls in 8 bovine experiments (74±6 kg). No heparin was given (neither systemically nor in the priming fluid). The hemofilters were primed with one liter of Ringer's lactate in both groups and the maximal filter performance (arterial line pressure 300 mmHg; transmembrane pressure (TMP) 500 mmHg) was measured over 6 hours or until filter occlusion. All coated and one control filter remained functional during the scheduled 6 hours. The mean filter patency was 360±0 minutes for coated versus 21 0±99 minutes for uncoated (p<0.01). Mean blood flow at 1 hourand6hours was 675±114and580±96ml/minfor coated versus 432±183 and 25±43 for uncoated (NS; p<0.0l). Mean filter output during the 6th hour and total filter output over 6 hours was 4225±998 ml and 21779±4273 for coated versus 400±692 and 7717±9757 for uncoated (p<0.01; p<0.0l). Mean lactatedehydrogenase (LDH) levels before and 30 minutes after hemofiltration were 1855±413 IU and 2007±635 for coated versus 2160±411 and 1945±500 for uncoated (NS; NS). The heparin coated hemofilters demonstrated improved thromboresistance resulting in superior filter performance. There was no evidence of increased blood trauma.
Prediction of Post-Cardiopulmonary Bypass Cardiac Output by Venous Oximetry
Authors: Baraka Anis , Baroody Maurice , Haroun Sania , Nawfal Maud , Dabbous Aliya , El-Khatib Rania , Taha Samar , Meshefedjian Garbis , Baraka Hoda
Published: August 2023

The present study evaluates two equations for predicting the post-cardiopulmonary bypass cardiac output (CO) in 10 patients undergoing coronary artery bypass grafting. One equation is based on the relationship of CO with mixed venous oxygen saturation (SVO2), while the second equation is based on the relationship with oxygen extraction (1 - SVO2). Each patient served as his own control. During bypass, when the patients were normothermic and perfused with a pump flow of 2.4 L/min/m2, the SVO2 was monitored by an in-line Bentley oxystat Meter. Just before termination of bypass, the pump flow was decreased to 0.4 L/min/m2 and the left atrial pressure was increased to 10-15 mmHg; the resulting SVO2 was recorded. The post-bypass CO was predicted in every patient by the two equations. Immediately after weaning from bypass, the cardiac output was measured by thermodilution. The thermodilutional CO measurement was correlated with the CO predicted by the two equations. Correlation analysis suggests that CO prediction is more accurate and approaches the 1:1 ratio when the calculation of predicted CO is based on the relationship between cardiac output and oxygen extraction.
Hematological Assessment of Patients Undergoing Plasmapheresis During Cardiac Surgery
Authors: Stammers Alfred H. , Kratz John , Johnson Timothy , Crumbley Jack , Merrill Jon
Published: August 2023

Methods of reducing patient exposure to homologous blood transfusions include the technique of intraoperative plasmapheresis for the production of platelet rich plasma (PRP). The present study was designed to determine the patient benefits of PRP by examining hemostatic changes in coagulation screens and viscoelastic whole blood monitoring (Thrombelastography, [TEG]). One hundred fifteen patients undergoing elective cardiac surgery were prospectively randomized into a blinded study. Sixty-three patients had 20 percent of the circulating plasma volume sequestered prior to heparinization and pheresed into PRP, which was reinfused 10 minurtes following heparin reversal with protamine. The control (CTR) group of 52 patients were exposed to no sequestration procedure. Patients were followed to discharge and 112 parameters, including anthropometric, operative, and postoperative factors, were measured.

There were no significant differences between patient groups in preoperative, cardiopulmonary bypass (CPB), or surgical parameters. Average PRP volume was 660± 100 ml with a total platelet yield of 1.1 billion platelets per patient. TEG indices were determined at four distinct times during the surgical procedure. The CTR group had significantly higher preCPB TEG indices of2.3±1.2 and 2.1±1.2 (mean±SD), vs. 1.8±1.5 and 1.4±1.7 in the PRP group (p<.04). Following heparin reversal, pre-PRP reinfusion TEG values were similar between groups, although both groups had significantly decreased indices when compared to pre-CPB values. Thirty minutes post-PRP infusion the treatment group had significantly improved TEG recovery when compared to the CTR group, 1.0±1.2 vs. 0.3±1.7 (p<.05). Fibrinolysis increased significantly in both groups post-CPB, but following PRP reinfusion, the treatment group returned to baseline values, while the CTR patients remained significantly elevated. There were no differences between groups in postoperative routine coagulation screens, nor significant changes in postoperative chest tube drainage. Packed red blood cell, fresh frozen plasma, and platelet transfusions in the CTR group were approximately twice as great as the PRP group (p=ns). CTR total homologous blood exposure rate was 3.06±6.6 units compared to 1.41±3.2 units in the PRP group (p<.0007). Discharge hematocrit was 31.5±5.2 percent in the PRP group, and 29.8±4.8 in the CTR group (p<.07). Total length of stay in the hospital was 1 0.8±4.2 days in the PRP patients, compared to 13.4±4.8 days in non-treated patients (p<.03).

This study has shown demonstrable hematological benefits of preoperative plasmapheresis during cardiac surgery, with the major reduction of bleeding occurring immediately following the administration of PRP.
Case Report: Cardiopulmonary Bypass with a Nonhemic Prime for an Infant of Less Than Four Kilograms
Authors: Woolhouse K. , Reitz B. , Hanson K.
Published: August 2023

Cardiopulmonary bypass in infants without the use of blood or blood products poses serious challenges for the cardiac surgical team. Excessive hemodilution may compromise how an infant will tolerate the procedure. We describe the methods used to provide cardiopulmonary bypass without blood for a 3.97 kg infant of Jehovah’s Witness parents. The surgical repair was successful and the child was discharged without receiving any blood or blood products.
Cardiopulmonary Bypass and the Pregnant Patient: A Review
Authors: Josephs John , Hindman Roger
Published: August 2023

Increasing maternal age within the general population in conjunction with cardiac disease during pregnancy, increases the probability that perfusionists will be called upon to provide extracorporeal support to the gravid patient.

Reviewing the available literature regarding cardiopulmonary bypass (CPB) during pregnancy produces some satisfying, isolated single-case reports. However, in the majority of reports, fetal compromise resulted from maternal cardio-surgical intervention.

Given the occurrence of CPB during pregnancy with resultant fetal loss, a need has been identified to provide perfusionists with a guide to patient management. Toward this effort, insights into normal physiologic and hemodynamic changes of pregnancy and their relationship to technical management of perfusion is presented. Concise information is provided regarding fetal responses to CPB and fetal distress. Situations most associated with intrauterine fetal loss and premature labor are identified. Constant monitoring of fetal heart rate is emphasized and optimal pharmacological management to achieve desired maternal effect while minimizing fetal response is also presented.
Intermittent Failure of a Stockert/Shiley Multiflow Roller Pump Module
Authors: Leahy W.R. , Massimino R.J. , Wohlfert W.J.
Published: August 2023

Pump failures are an inherent problem associated with the operation of a heart lung machine. This report details the observation and identification of an unusual modular pump failure. Pump stoppage occurred intermittently over a period of two months with two separate Stockert/Shiley Computer Aided Perfusion System (CAPS) consoles. The mechanism was identified as a static discharge transferred to the module by a perfusion record clipboard. Electrical testing revealed that all modules could be stopped with a simulated static charge between 2 kilovolts (kV) and 25 kV. A sub-normal relative humidity in the operating room was a contributing factor but did not eliminate the problem when levels were returned to normal. Clinical engineering test results were forwarded to the manufacturer with recommendations. Preventive measures by this institution were adopted to reduce static discharge failure.
Sterility of Previously Assembled Cardiopulmonary Bypass Circuits
Authors: Homishak Michael , Widmer Steven , Klementovich Michael , Cunningham John , Oblack Donna
Published: August 2023

The sterility of previously assembled cardiopulmonary bypass circuits was investigated for 17 extracorporeal circuits. The closed circuits were assembled using aseptic technique and remained in the operating room until the time of use. The mean time from point of setup to point of priming for the 17 randomly chosen circuits was 21.47 hours, with a range of 13.50 to 60.50 hours. Circuits were primed with three liters of sterile Plasma-Lyte A Injection, circulated for 5 minutes and tested for microbial contamination by withdrawing one liter of the priming solution through an Addi-Chek Quality Control System. The Addi-Chek canister, which contains a 0.45 μm cellulose membrane filter, was then filled with tryptic soy broth and incubated for 14 days. All were found to be free of microbial contamination as indicated by no growth in culture.

The results of this investigation demonstrate that the sterility of the extracorporeal circuit, pre-assembled in advance of actual priming, can be maintained over an extended interval when standard aseptic technique is used. This allows the utilization of a pre-assembled circuit for emergency cardiopulmonary bypass support.
Master's Education for Perfusion: Is It Needed? Is It Important to Future Sub-specialization?
Authors: Syracuse Phillip L. , Beckley Philip D.
Published: August 2023

This survey research measured the opinions of practicing perfusionists on the perceived need for a master's level perfusion degree, specialization within the field, attractors and barriers to education, and employer support for a master's degree. Descriptive and correlational analyses (including ANOVA) were performed upon 224 questionnaires received from the membership of The American Society of Extra-Corporeal Technology (AmSECT). A majority of the AmSECT population (58%) feels there is a need to recognize areas of specialization within perfusion. The top five choices for specialties are: pediatrics, support devices-pacemakers, perfusion education, physiology-hematology, and advanced perfusion study. The AmSECT practicing perfusionist membership's opinion on new entries into the perfusion field strongly favors baccalaureate level education (79%). This conclusion is supported by a majority of perfusionists regardless of their perfusion training. Of the respondents, 35% agreed there is a need for a master's degree, while 58% agreed there is a need to recognize areas of specialization within perfusion. This mixed support exists across demographic categories without respect to age, gender, years of practice, education, job title, number of cases a facility performs per year, or employment. Support for the degree arises from the belief it will: provide continuing education, benefit one's career, help establish specialty recognition, and provide personal and professional knowledge.
Extracorporeal Support with a Cadaver Liver as a Bridge to Transplantation
Authors: Fristoe Lance W. , Merrill Jonathan H. , Kangas Jeff A. , Vogel James E. , Stammers Alfred H. , Langnas Alan N. , Fox Ira J. , Shaw Byers W.
Published: August 2023

Extracorporealliver perfusion (ECLP) has been used for detoxifying blood in patients in class IV hepatic encephalopathy. Palliation of the moribund patient utilizing extracorporeal devices with cross-circulation of a cadaver liver has been documented for over three decades. Common problems associated with this procedure which appear in the literature include cadaver liver distention, increased resistance to blood flow, and limited time of extracorporeal support due to cadaver liver failure. This report summarizes the experiences of the perfusion team in utilizing an extracorporeal circuit with an otherwise non-transplantable cadaveric liver, to support the decompensating hepatic patient as a bridge to transplantation.

Between January and July 1992, three patients were supported for hepatic failure with ECLP. Two patients were placed on ECLP with a modified circuit containing two positive displacement pumps and one centrifugal pump. The third patient was placed on ECLP with a circuit that contained two centrifugal pumps and one positive displacement pump. Patient age ranged from 6 to 38 years and length of support ranged from 24 to 72 hours. In all three patients, a centrifugal pump was placed in the suprahepatic inferior vena cava line to facilitate cadaver liver drainage and decompression. Intensive monitoring of both patient and cadaver liver hemodynamics, hepatic function, and hematological status was performed. All three patients were successfully weaned from ECLP. Two patients received successful orthotopic liver transplantation. The third died of complications unrelated to ECLP after support was discontinued. At present, the technique of ECLP has been shown to be an effective treatment for supporting the comatose patient with fulminant hepatic failure prior to transplantation.
Oxygen Pressure field Theory, The Krogh Cylinder and Long-Term Extra corporeal Perfusion: An Old Concept Provides New Insight
Authors: Grist Gary E. , Meiling Greg
Published: August 2023

This article describes oxygen pressure field theory and its relevance to the application of long-term perfusion support. Prolonged applications of extracorporeal support for cardiac or pulmonary failure require a more perceptive understanding of perfusion and how it works over a period of days or weeks. The key to this understanding lies in the concepts of the Krogh tissue cylinder, the lethal corner and perfused capillary density. The interrelationships of these concepts define the microvascular redistribution system and its need to remain in balance in order to maintain homeostasis. An imbalance in any of the aspects described could result in tissue damage and eventual death.

Perfusionists attempting to perform long-term extracorporeal support can improve the odds for patient survival with a clear understanding of oxygen pressure field theory and its associated concepts. By maintaining a balance in the microvascular redistribution system, the perfusionist not only keeps the patient alive, but creates an environment where healing can occur over a period of days or weeks.
An Evaluation of Three Methods for Determining Colloid Osmotic Pressure
Authors: Blackwell Mindy M. , Riley Jeffrey , McCall Mary , Ecklund Jodie , Southworth Rhonda
Published: August 2023

Plasma colloid osmotic pressure (COP) is an important determinant in edema formation. Three methods for assessing the COP were evaluated. Direct measurement of COP using the 4420 Wescor Colloid Osmometer was compared to the estimation of COP from both serum total protein and total serum solids (TSS) determinations. Blood samples from twenty adult patients (mean age = 64 years) undergoing cardiopulmonary bypass surgery were collected for COP assessment. Sample collection was performed prior to heparinization/hemodilution, during hypothermic bypass and at the conclusion of bypass following protamine administration. The results obtained from each method were analyzed by a two-way analysis of variance. The Bonferroni technique was used for comparison of sample means when the difference was significant (p<0.05). Correlations were reported by linear regression analysis. A statistically significant difference (p<0.01) was found between the three methods. A regression equation for the estimation of COP from total serum solids is offered:

COP = (3.02 * TSS) + 0.65.

Prospective clinical testing between the direct COP measurement and the estimation of COP from TSS using the equation (n=38) revealed a significant correlation (R2 = .932) and no significant difference between the two (p > 0.05).
Thrombelastograph Analysis After Heparin Neutralization with Protamine and Heparinase During Cardiopulmonary Bypass
Authors: Forst Curtis , Chapin James , Forst Stephanie , Stammers Alfred , Galbraith Timothy
Published: August 2023

Hemostatic disorders generated during cardiopulmonary bypass (CPB) result in postsurgical hemorrhage, a major cause of morbidity in cardiac patients. Thrombelastography (TEG) monitors elastokinetic whole blood coagulation but is sensitive to low quantities of circulating heparin, obviating its use during CPB. Heparinase is an enzyme that degrades heparin without affecting coagulation proteins that may aid in identifying coagulopathies during CPB.

In the present study two methods of neutralizing heparin were used to generate TEG profiles during CPB. These profiles were generated by adding 0.03 ml protamine (0.0134 mg) or heparinase (6 U) 0.33 ml samples of heparinized blood. Samples were drawn pre-CPB, 10 and 30 minutes after initiation of CPB, 5 minutes after administration of protamine and 10 minutes after administration of platelet-rich-plasma, from 11 patients undergoing cardiac surgery. The results indicate a significantly higher baseline reaction time between pre-CPB in both groups when compared to all other time points (p < 0.007). During CPB, both protamine and heparinase reversed the anticoagulant effect of heparin, permitting the generation of useful TEG data. We therefore conclude that intraoperative TEG profiles can be produced during CPB for the purpose of identifying hemostatic conditions prior to termination of extracorporeal circulation.
Comparative Study of Five Blood Cardioplegia Systems
Authors: Byrne Christopher J. , Bednarski Allison J. , Beckley Philip D.
Published: August 2023

Five blood cardioplegia delivery systems (Gish Straight Shot, Sorin BCD Advanced, A vecor MYOtherm, Baxter-Bentley HE-30, and Baxter-Bentley HE-30 Gold) were evaluated with respect to ease of rapid priming, coefficient of heat exchange, pressure drop, bubble trap capacity, and priming volume. Each system was placed in a roller pump circuit consisting of source and collection reservoirs, cardioplegia solution, and pre-post system pressure and temperature monitoring sites. A trial was performed on four units of each brand by first priming the circuit with 0.9% NaCI at 200 ml/min. Bovine blood (hematocrit 22%) was then introduced simulating use during bypass. Pressure drops across the heat exchanger were measured at flows of 200, 300, and 400 ml/min and at temperatures of 37°, 19°, and 4°C. Coefficient of heat exchange was determined at 300 ml/min flow. Air was infused into the system to quantify the bubble trap capacity of the heat exchanger module. Priming volume of the entire system and of the heat exchanger module were determined by draining each into a graduated cylinder.

The Sorin system had significantly less priming volume when compared to all others. The HE-30 units had significantly higher heat exchange coefficients compared to all other systems. Variability was noted in pressure drop at the highest flows and lowest temperatures.
Evaluation of a Rapid Infusion System
Authors: Cronbaugh Robert , Ploessl James , Sutton Robin , Martin Maureen
Published: August 2023

Operative cases where there is a potential for massive blood loss necessitates a system to rapidly warm and transfuse large volumes of blood over short periods of time. An in-house system in which both crystalloid solutions and blood products can be quickly added, warmed and available for infusion was developed to meet this need. The purpose of this study was to evaluate how blood products are affected when warmed and recirculated for an extended period of time. A recirculating rapid infusion system was assembled utilizing two filtered cardiotomy reservoirs, a centrifugal pump, a stainless steel blood heat exchanger, and 1/4 inch tubing, and applied in six adult orthotopic liver transplantations. The system was primed with 2 to 4 units each of fresh frozen plasma and packed red blood cells. The prime was recirculated and warmed to 37°C. Samples for blood gases, oxygen saturation, hematocrit, plasma free hemoglobin, sodium and potassium levels were drawn after initial priming and then every 30 minutes until additional blood products were added. Results show no significant change in pH (6.57 ± 0.21), pO2 (56 mmHg ± 23 mmHg), pCO2 (173 mmHg ± 138 mmHg), hematocrit (27% ± 8.7%) and plasma free hemoglobin values (125 mg/dl ± 9.4 mg/dl), following 3 hours of recirculation. However, potassium levels significantly decreased from 11.6 meq/L ± 2.6 meq/L to 10.0 meq/L ± 2.3 meq/L (p<0.05), sodium levels significantly increased from 144 meq/L ± 5.9 meq/L to 147 meq/L ± 5.3 meq/L (p<0.05) and oxygen saturations significantly increased from 59%± 9.1% to 70% ± 16% (p<0.05). The results demonstrate that this system can maintain banked blood warm and available for immediate infusion without significant deterioration for up to 3 hours.
Use of the Abiomed BVS 5000 for Temporary Right Ventricular Assist Following Implantation of the TCI HeartMate for Left Ventricular Assist: A Case Report
Authors: Sistino Joseph J. , Mongero Linda B. , Levin Howard R. , Rose Eric A.
Published: August 2023

Until recently, right ventricular failure following implantation of a left ventricular assist device carried a 100% mortality. Unsuccessful use of centrifugal pumps for right ventricular assist in this patient population has been attributed to bleeding complications. In this patient, an Abiomed BVS 5000 was used for 5 days until the right ventricular function recovered and the patient was successfully weaned. Following transplantation and removal of the TCI HeartMate device, the patient's right ventricular function again deteriorated and required 8 days of right heart assist with the Abiomed BVS 5000. The patient was again weaned and has fully recovered. The benefits of the Abiomed BVS 5000 for ventricular assist include the automatic control of pump flow and the minimal system pressures which reduce blood trauma and bleeding complications.
Gesundheitsökonomie: Eine Rückbesinnung auf
Ordnungsökonomie bleibt auf der Tagesordnung
Authors: Rebscher Herbert
Published: August 2023

Die Gesundheitsökonomie (nicht nur in Deutschland) hat sich in den
vergangenen 30–40 Jahren in einer spektakulären Art und Weise in
analytisch, methodisch und technisch höchst anspruchsvolle
Subspezialitäten differenziert. Das gilt für die Wissenschaft im
engeren Sinne, wie auch für die Translation von wissenschaftlich-basierten
Erkenntnissen in den gesundheitspolitischen Diskurs, beispielsweise zur
Weiterentwicklung der Honorierungssysteme oder von Steuerungsinstrumenten
für die Versorgungspraxis (Care- und Case-Management).
AI First in der Medizin
Authors: Stoffers Christian
Published: August 2023

Seit ein paar Monaten ist ChatGPT in aller Munde. Es wird befürchtet, dass
Schüler/-innen und Studierende den Bot als einfach zu bedienende
Hausaufgabenhilfe oder für ihre Abschlussarbeiten benutzen könnten;
sogar (Sonntags-)Reden könnte man sich mittels Künstlicher
Intelligenz schreiben lassen. Doch steht der Hype um das digitale Sprachmodell der
kalifornischen Firma „OpenAI“ für eine neue Zeit. ChatGPT
(in seiner Langfassung: Chatbot Generative Pre-trained Transformer) ist dabei kein
Einzelgänger. Denn auch Alphabet mit dem Technologieunternehmen
„Google“ agiert selbst massiv in diesem Forschungsfeld und hat
ähnliche Tools über die Jahre mehrfach präsentiert; anders
als OpenAI jedoch nie für die breite Öffentlichkeit freigegeben.
Zwanzig neue Produkte aus dem Bereich „Künstliche
Intelligenz“ (KI) befinden sich in deren Entwicklungs-Pipeline, darunter
auch ein Pendant zu ChatGPT. Mit Med-PaLM2 wird es in diesem Zusammenhang sogar eine
spezifische Variante für einen Einsatz in einem medizinischen Umfeld
geben.
ÖGD-Expertise in die Forschung bringen: eine Workshop-Reihe
zu vektorübertragenen und weiteren zoonotischen
Erkrankungen
Authors: Schmitz Saskia Rebecca , Klier Christiane , Princk Christina , Meyer-Schlinkmann Kristin , Mylius Maren , Dressel Kerstin , Kleele Sebastian , Winter Fenja , Campe Amely , Rissland Jürgen , Sternjakob Anna , Dobler Gerhard , Oehme Rainer , Ulrich Rainer Günter , Dreesman Johannes
Published: August 2023

Forschungsverbünde müssen die Bedürfnisse und
Anforderungen des Öffentlichen Gesundheitsdienstes (ÖGD)
verstehen, um geeignete Werkzeuge und Strategien zu entwickeln, die ihn bei der
Risikoidentifikation und - kommunikation unterstützen können.
Die Forschungsverbünde für zoonotische Infektionen RoBoPub,
Q-GAPS, TBENAGER und ZooBoCo haben ein Workshop-Format genutzt, um die Expertise
des ÖGD in ihre Arbeit einzubinden. Wir stellen die Ergebnisse der drei
Workshops dar, die im Rahmen des Jahreskongresses des Bundesverbandes der
Ärzt:innen des ÖGD in den Jahren 2018, 2019 und 2022 mit
Vertreter:innen des ÖGD durchgeführt wurden. Jeder Workshop
dauerte 90 Minuten und wurde im World-Café-Format mit jeweils
unterschiedlichen Themenschwerpunkten abgehalten. Im ersten Workshop wurden
Probleme, Ziele, Lösungen und Anforderungen an die
Forschungsverbünde bezüglich der beruflichen und privaten
Exposition gegenüber Nagetier-übertragenen Infektionen, sowie
dem Einsatz von Risikokarten zusammengetragen. Im zweiten und dritten Workshop
wurden Risikokommunikationsstrategien anhand von Ausbruchsszenarien oder
Szenarien mit neu identifizierten Risikogebieten erarbeitet. An jedem Workshop
nahmen mehr als 20 Personen teil, von denen je mindestens die Hälfte in
kommunalen Gesundheitsämtern tätig war. Die Workshops ergaben,
dass von den Forschungsverbünden vor allem praxisbezogenes,
zielgruppenspezifisches Material für die Risikokommunikation erwartet
wurde. In der Erfahrung der Teilnehmenden ist der direkte Kontakt zu Betroffenen
in der Risikokommunikation essentiell. Um Aufmerksamkeit für die
Risikolage zu erzeugen und Kontakt zu den Zielgruppen herzustellen,
können soziale Medien traditionelle Medien ergänzen, vor allem
bei schwer erreichbaren Zielgruppen. Ihr Einsatz sollte jedoch vorab
sorgfältig abgewogen und geplant werden. Das Workshop-Format erwies sich
als geeignet, um den ÖGD in die Forschungsvorhaben einzubinden. Die
Anforderungen des ÖGD konnten in den Verbünden in Form eines
Leitfadens, eines Risikomanagementplans und Erregersteckbriefen umgesetzt
werden. Bei der Integration des ÖGD sollte bedacht werden, wie die
Arbeitsbelastung für ÖGD-Vertreter:innen gering gehalten und wie
ein passendes Kollektiv erreicht werden kann.
Wettbewerb im Zusammenspiel mit alternativen Steuerungsstrukturen
– Ein konsistenter Steuerungsmix als gesundheitspolitische
Gestaltungsaufgabe
Authors: Greiner Wolfgang
Published: August 2023

Wettbewerbliche Systeme sind im Grundsatz ergebnisoffen, d. h. die
Wirkungen zeigen sich oft erst nach einer gewissen Weile, weshalb sie
regelmäßig unabhängig evaluiert und ggf. angepasst
werden sollten. Am Beispiel der sektorübergreifenden Akutversorgung und
des Arzneimittelmarktes wird deutlich, dass die derzeit feststellbaren Defizite
im Gesundheitswesen ihre Ursache vielfach nicht in einem Zuviel an
marktwirtschaftlicher Steuerung haben, sondern (im Gegenteil) in einem
fehlerhaften Ordnungsrahmen mit einem inkonsistenten Steuerungsmix, der zu
Fehlallokationen und damit zu Verschwendung knapper Ressourcen, hohen Kosten und
Überlastung der Beteiligten führt. Wesentliche Anteile von
bestehender Unter-. Über- und Fehlversorgung wären durch eine
adaptive Regulierung in vielen Bereichen wesentlich zu reduzieren.