bluuebunny/crossref_metadata_2025 huggingface dataset:
New synthetic pathways to theAnastrepha ludenshost marking pheromone: harnessing iridium-catalysis with novel P,N-ligand for enantioselective construction
Authors: Pawar Tushar Janardan , Barcelona-Cazanave Liliette , Bonilla-Landa Israel , Escobar Magdalena , Jimenez-Halla J. Oscar C. , Altúzar-Molina Alma , Romero-Arellano Patricia , Edmunds Andrew J. F. , Aluja Martín , Olivares-Romero José Luis
Published: August 2023

A highly efficient iridium-catalyzed asymmetric hydrogenation approach is described for the total synthesis of the biologically active (R,L)A. ludenshost marking pheromone (HMP).
Differences in the catalytic properties of Fe isotopes
Authors: Xiao Songtao , Xue Yubing , Zhao Jing , Liu Xiechun , Cong Haifeng , Lan Tian , Liu Xiaojuan , Pan Dashu , Wang Lingyu , Ye Guoan , Ouyang Yinggen
Published: August 2023

The differences in catalytic properties of α-Fe2O3 with natural abundance ratio and with separated Fe isotope in thermal decomposition of AP were firstly investigated mainly attributed to the different nuclear morphology and charge distribution.
Multi-resistant diarrheagenicEscherichia coliidentified by FTIR and machine learning: a feasible strategy to improve the group classification
Authors: Marangoni-Ghoreyshi Yasmin Garcia , Franca Thiago , Esteves José , Maranni Ana , Pereira Portes Karine Dorneles , Cena Cicero , Leal Cassia R. B.
Published: August 2023

A new method based on FTIR spectroscopy and machine learning is proposed to identify multidrug-resistant strains fromE. colispecies responsible for diarrhea in calves.
One-pot, three-component, iron-catalyzed synthesis of benzimidazolesviadomino C–N bond formation
Authors: Aboonajmi Jasem , Mohammadi Masoumeh , Panahi Farhad , Aberi Mahdi , Sharghi Hashem
Published: August 2023

A one-pot multicomponent procedure for the efficient synthesis of benzimidazole derivativesviacoupling of benzo-1,2-quinone, aldehydes, and ammonium acetate using an Fe(iii)-porphyrin catalyst system is presented.
Optically amended biosynthesized crystalline copper-doped ZnO for enhanced antibacterial activity
Authors: Mengistu Adam , Naimuddin Mohammed , Abebe Buzuayehu
Published: August 2023

Green synthesis approach-based synthesis of nanoscale-sized doped nanocomposites for enhanced antibacterial activity.
Advanced Guareschi–Thorpe synthesis of pyridines in green buffer, and pH-controlled aqueous medium with ammonium carbonate
Authors: Tamaddon Fatemeh , Maddah-Roodan Sajedeh
Published: August 2023

Hydroxy-cyanopyridines are easily synthesized via an advanced version of the Guareschi–Thorpe reaction by three-component condensation of alkyl cyanoacetate or cyanoacetamide with 1,3-dicarbonyls and ammonium carbonate in aqueous medium.
Automated sulfur-[18F]fluoride exchange radiolabelling of a prostate specific membrane antigen (PSMA) targeted ligand using the GE FASTlab™ cassette-based platform
Authors: Yang Zixuan , Barnes Chris , Domarkas Juozas , Koch-Paszkowski Joanna , Wright John , Amgheib Ala , Renard Isaline , Fu Ruisi , Archibald Stephen , Aboagye Eric O. , Allott Louis
Published: August 2023

The sulfur-[18F]fluoride exchange reaction is a facile 19F/18F isotopic exchange labelling chemistry which is simple to automated for the preparation of positron emission tomography (PET) radiopharmaceuticals.
Stiffening and dynamics of a two-dimensional active elastic solid
Authors: Sandoval Mario
Published: August 2023

This work deals with the mechanical properties and dynamics of an active elastic solid defined as a two-dimensional network of active stochastic particles interacting by nonlinear hard springs.
Towards durable Li-hybrid flow batteries: composite membrane development, cell performance, and perspective
Authors: Akhmetov Nikita , Waris Zainab , Ryazantsev Sergey , Lipovskikh Svetlana , Gvozdik Nataliya , Pogosova Mariam , Stevenson Keith
Published: August 2023

Fabrication temperature and filler distribution significantly impact the Li+ selectivity of polymer–ceramic membranes. Along with catholyte and design issues, overcoming membrane-related problems is essential for prototyping Li-hybrid flow batteries.
Stacking polytypes of 1T′ phase Se-rich transition metal diselenide and their electrocatalytic activity in the hydrogen evolution reaction
Authors: Kim Ju Yeon , Kwak In Hye , Kwon Ik Seon , Sial Qadeer Akbar , Ihsan Junaid , Zewdie Getasew Mulualem , Park Jeunghee , Kang Hong Seok
Published: August 2023

First-principles calculations predict that Se enrichment in MoSe2 and WSe2 induces a phase conversion into the 2M phase, which is also supported by experiments.
Bismuth-based two-dimensional nanomaterials for cancer diagnosis and treatment
Authors: Hong Chengyuan , Chen Tianxiang , Wu Manxiang , Lin Jie , Gao Changyong , Ma Xuehua , Liu Zhusheng , Yang Xiaogang , Wu Aiguo
Published: August 2023

We summarize the recent progress including controllable synthesis, defect engineering, surface modifications, applications, and prospects of Bi-based two-dimensional nanomaterials for cancer diagnosis and treatment.
An improved cascade RCNN detection method for key components and defects of transmission lines
Authors: Dong Chao , Zhang Ke , Xie Zhiyuan , Shi Chaojun
Published: August 2023

Overhead transmission line detection based on deep learning of aerial images taken by UAVs has been widely investigated. Despite its success, it is limited by several factors, including inappropriate evaluation criteria and dramatic scaling of components in the images. To mitigate these issues, a relative mean Average Precision evaluation index is proposed to accurately measure the model's detection performance for smaller objects. A data enhancement strategy including multi‐scale transformation is adopted to alleviate the problem of drastic scaling. The existing Cascade RCNN target detection technology is enhanced by incorporating Swin‐v2 and a balanced feature pyramid to improve feature characterization capabilities, while side‐aware boundary localization is utilized to improve the positioning accuracy of the model. Experimental results demonstrate that the proposed method outperforms state‐of‐the‐art methods on CPLID and achieves 7.8%, 11.8%, and 5.5% higher detection accuracy than the baseline for mAP50, relative small and medium mAP, respectively. Additionally, the paper discusses the influence of adopted data enhancement on the robustness of the model.
V2V‐enabled cooperative adaptive cruise control strategy for improving driving safety and travel efficiency of semi‐automated vehicle fleet
Authors: Peng Liqun , Huang Ju , Zhou Tuqiang , Xu Shucai
Published: August 2023

Although highly automated vehicle fleets have committed a safe and efficient traffic flow, the next few years are likely the human‐driven vehicles (HDV) and intelligent vehicles (IV) mixed in large‐scale traffic network, where the interaction of HDVs with IVs will become more frequent. In this study, the authors investigate the traffic flow performance in a widespread of V2V environment deployed for all types of HDVs and IVs, levelled from L0 to L5. Based on this assumption, the vehicle movements and operations are collected and assembled into a V2X BSM dataset, and to any vehicle in fleet, the sequential movements and driving behaviours of the vehicle ahead can be predicted in the short term and considered as the input to cooperative adaptive cruise control (CACC) model of the controlled vehicle. The predicted motion of the vehicle ahead is applied to rolling optimization process of a given MPC framework, which calculates appropriate longitudinal operation for each car‐following vehicle and keeps optimal equilibrium state of the vehicle fleets in heterogeneous traffic flow. The experimental results showed that when the front vehicle generates random acceleration/deceleration in saturated and over saturated traffic state, in the car‐following case, the improved CACC controller maintains average car‐following distance at 20–40 m, the acceleration variation in the range [−0.1, 0.25], the gap error changed within [−10, 13], and controls the relative speed variation from −0.25 to 0.3 m/s, compared to an average headway of 20–140 m, acceleration variation in the range [−1.6, 0.65], gap error changed within [−21, 30], and a relative speed variation from −1.75 to 4.1 m/s by the traditional CACC controller. In the car‐in and car‐out cases, the vehicle controlled by the improved CACC controller had a travel displacement of 4050 m, a speed fluctuation interval of [18.7, 27.7], and an acceleration variation range of [−0.15, 0.2], while the vehicle controlled by the traditional MPC controller had a travel displacement of 3800 m, a speed fluctuation interval of [13.8,27.7] and an acceleration variation range of [−2.9, 0.6]. The improved CACC model can adapt more accurately and quickly to the maneouvre of vehicle ahead in V2V environment, which can effectively improve the capacity of heterogeneous traffic flow and the safety and comfort of driving.
Study on a hybrid algorithm for accurate ripple detection in DC microgrids
Authors: Zhang Yongjun , Chen Mingli , Deng Wenyang , Zhong Kanghua
Published: August 2023

With the advantages of the low cost of transmission lines and high efficiency, the DC microgrid has become a rising star in the low‐voltage network. However, multi‐source and multi‐transformation characteristics in DC microgrids will lead to the existence of various forms of ripple generation sources in the system. The existence of a large amount of ripple not only directly cause the reduction of power quality of DC microgrids, but also decreases the accuracy of electricity billing. It is vital to achieving accurate ripple detection for the reliable power supply of the DC microgrid. A DC‐side ripple detection method, which combines the Whale Optimization Algorithm (WOA), Variational Modal Decomposition (VMD), and Hilbert Transform (HT), is therefore investigated and proposed here. Firstly, the sample entropy (SampEn) is used as the fitness function, applied the whale optimization algorithm, is to determine the optimal decomposition scale and penalty factor, of the variational modal decomposition; then, the ripple‐containing DC signal is decomposed into a series of eigenmodal components (imf) by the optimized variational modal decomposition algorithm. Finally, the Hilbert Transform is performed to obtain the amplitude and frequency of the ripple components. To prove the effectiveness, the proposed method is compared with the conventional Empirical Mode Decomposition (EMD) and the VMD algorithm, by testing simulated DC signals without and with noise. Results show that the proposed method has higher accuracy and noise robustness than the EMD and VMD algorithms.
Surgery for Wolff-Parkinson-White Syndrome and the Role of the Perfusionist
Authors: Brodie John E. , Edwards Fred H. , Danshaw Craig B.
Published: August 2023

Surgical treatment of Wolff-Parkinson-White (WPW) is increasing dramatically and perfusionists should be familiar with the methods used in this procedure. Cardiac surgeons are being trained in this procedure in increasing numbers and hospitals are rapidly starting programs of surgery for certain arrhythmias. The success of the operation over the past 20 years has ensured that the number of procedures will increase as results continue to improve. In view of the safety and gratifying long-term results achieved in patients with a variety of supraventricular dysrhythmias, it has become apparent that early surgical intervention is generally preferable to chronic pharmacological therapy (1).

Surgery for WPW syndrome requires team work even more than other cardiac procedures. The surgical procedures used require either cardiopulmonary bypass (CPB) or immediate standby in case of complications. In addition, operation of the cryoablation machine used in some procedures is most appropriately delegated to the perfusion team. The perfusionist must be thoroughly familiar with the techniques used and the varying aspects of each procedure.
Effect of Oxygen Flow on pCO2 and pO2 During Cardiopulmonary Bypass in Man
Authors: Baraka Anis , Haroun Sania , Baroody Maurice , Nawfal Maud , Dabbous Aliya , Sibaii Abla , Jamal Salim , Shamli Sana
Published: August 2023

The effect of oxygen flow on arterial pO2 and pCO2 was investigated during cardiopulmonary bypass in three groups of patients undergoing open heart surgery. A Bentley-10 adult bubble oxygenator was used in all patients. The perfusion was maintained in the three groups at a constant flow of 2.31/m2/min throughout bypass. The oxygenator was bubbled in Group 1 by oxygen at an oxygen:perfusion ratio of 0.75:1.0 while 1.0:1.0 ratio was used in Group 2 and 1.5:1.0 ratio was used in Group 3. After going on bypass, moderate hypothermia was achieved, and the patients were rewarmed when surgery was completed.

The report shows that the arterial pCO2, and pO2 may be determined during cardiopulmonary bypass by the bubbled oxygen flow. Increasing the oxygen:perfusion ratio from 0.5:1.0 to 1.0: 1.0 is associated with a significant decrease of pCO2 and increase of pO2. Further increase of the oxygen:perfusion ratio to 1.5:1.0 resulted in further decrease of pCO2 without a significant increase of pO2. The results suggest that optimal oxygenation and carbon dioxide elimination can be achieved by using an oxygen:perfusion ratio 1.0:1.0 during hypothermia and following rewarming.
Evaluation of Extracorporeal Blood Heat Exchanger Devices
Authors: Barthelmy Robert , Chauveau Nicolas
Published: August 2023

An accurate and easy to use test circuit has been developed for the performance evaluation of the heat exchangers used in cardiac surgery during extracorporeal circulation. The water part of the heat exchanger is fixed at a flow rate of 15 Vmin and at a temperature of 40°C. In the blood side, the flow rate is varied from 1 to 6 1/min and the temperature is 30°C. The use of a precise thermometer (precision 0.01 °C) and of a microcomputer permits efficiency with a good reproducibility. The results obtained show a real improvement in the efficiency of the new extracorporeal blood heat exchangers devices.
A Comparative Evaluation of Pulmonary Artery Balloon Counterpulsation and a Centrifugal Flow Pump in an Experimental Model of Right Ventricular Infarction
Authors: Taylor Allen J. , Edwards Fred H. , Macon Michael G. , Worley Brian , Graeber Geoffrey M.
Published: August 2023

To compare the efficiency of pulmonary artery balloon counterpulsation and a centrifugal flow pump in reversing the hemodynamic consequences of acute right-sided heart failure, we employed both devices in 14 Yorkshire pigs in which right ventricular infarction was created via surgical ligation of branches of the right coronary artery. Pulmonary artery balloon counterpulsation improved some of the indicators of right heart failure, as manifested by significantly decreased right atrial pressure and increased mean systemic blood pressure. In contrast, the centrifugal flow pump consistently and significantly reversed all of the hemodynamic consequences of right ventricular infarction. In comparison to pulmonary artery balloon counterpulsation, the centrifugal flow pump resulted in lower right atrial pressures (p=0.020), lower mean pulmonary pressures (p<0.0001), increased left atrial pressures (p=0.026), increased cardiac output (p<0.0001), and increased mean systemic blood pressures (p<0.0001). Possible mechanisms to explain the superiority of the centrifugal flow pump include better hemodynamic unloading of the failing myocardium and independence from right ventricular output.
Clinical Accuracy of Continuous Hemoglobin Oxygen Saturation Monitoring Devices
Authors: Bolen Gregory Z. , Anderson Gary E. , Huddleson James R. , Riley Jeffrey B. , Sutton Robin G. , Bishop David G.
Published: August 2023

Three devices used to measure hemoglobin oxygen saturation in the extracorporeal circuit were studied and compared to a control. The Baxter Bentley OxySat, Oximetrix Accusat, and the Radiometer ABIA blood gas monitor were compared to a control, the IL 282 Co-Oximeter. Fifty-one sample points were obtained during all phases of cardiopulmonary bypass with results as follows:

Table 1

Comparison of oxygen saturation devices.

r

DIFF
SD
p

ACCUSAT
0.94
p<.0001
-0.6
3.2
0.1834
NS

ABL-4
0.93
p<.0001
-1.7
3.3
0.0008
S

OXYSAT
0.87
p<.0001
-6.8
4.4
0.0001
S

r = correlation coefficient with corresponding p value, DIFF = difference from IL282,

SD = Standard deviation of difference, p = p value for testing the hypothesis of no difference between test device and IL282, NS = no significant difference,

S = significant difference.

The Accusat was found to be a statistically more accurate means of monitoring hemoglobin oxygen saturations during cardiopulmonary bypass than the ABL4 and the OxySat. All devices had significant correlation with the control and with each other.
Predictable Spontaneous Beating in 96% of Coronary Bypass Operations
Authors: Brenner William I.
Published: August 2023

To determine the incidence of spontaneous beating in isolated coronary bypass operations, one cardiac surgeon's experience with 677 consecutive cases over an 8 1/2 year period (1980-1988) was studied. Myocardial protection included hypothermic (4°C) blood cardioplegia containing procaine and papaverine, topical cooling (4°C) and systemic hypothermia (25°C). During warming, 100 mg of lidocaine was administered when body temperature reached 30°C. Six hundred fifty-one patients (96%) had spontaneous beating after removal of the aortic cross-clamp following completion of distal anastamoses. Electrical cardioversion was required immediately in 26 of these 677 patients (4%) and in an additional 32 (5%) later in the operation, usually when ventricular fibrillation was induced by manipulation of the beating heart to inspect the distal anastamoses. Therefore, 619 of these 677 coronary bypass patients (91 %) were spared intraoperative electrical cardioversion and its potential for myocardial damage.
Alpha-Stat versus pH-Stat: Implications for the Brain During Cardiopulmonary Bypass
Authors: Murkin John M.
Published: August 2023

During cardiac surgery, systemic hypothermia is often utilized to augment cardioplegic myocardial preservation. The ensuing reduction in metabolic activity is directly related to the decrease in temperature as predicted by Vant Hoff's law. Lowered metabolic-activity decreases oxygen utilization, thus increasing tissue tolerance for reductions in oxygen delivery.

Among numerous other physiologic effects, hypothermia increases the solubility of O2 and CO2 in blood, producing a fall in gaseous partial pressures, while total gas content remains unchanged. When this occurs with CO2, the corresponding rise in pH may be perceived as a "respiratory alkalosis."
The Optimal Preservation of the Patient's Hematocrit When Cardiopulmonary Bypass Is Required
Authors: Schill David M.
Published: August 2023

The following study demonstrates a method of perfusion management by which a patient can be placed on cardiopulmonary bypass with a minimal drop in the individual's hematocrit while using any extracorporeal tubing pack or oxygenator. This method involves replacing the crystalloid solution used to prime the circuit with the patient's own blood. The process is performed after the patient is heparinized and cannulated, but just prior to initiating bypass. This study includes 100 patients who underwent cardiopulmonary bypass. The average change in the patient's hematocrit 15 minutes into bypass was 3.69, while the average change in the hematocrit at the end of bypass compared to that seen before bypass was 4.31. These patients did not require ultrafiltration techniques or blood donations of any type.
Optimal Perfusion Flow Rates for Cardiopulmonary Bypass
Authors: Mitchell Bennett A.
Published: August 2023

In addressing the subject of optimal perfusion flow rates for cardiopulmonary bypass, we must be reminded of a remark made by a pioneer in the physiology of cardiac surgery, Dr. Frank Gollan, who said “We cannot command nature except by obeying her” (1). During extracorporeal circulation (ECC), we try to closely approximate the physiologic state, “but we never duplicate.” During my travels as a perfusionist, both in the United States and abroad, I have noted that flow rates during cardiopulmonary bypass vary widely from a low flow of 1.61/m2/min in adults to a high flow of over 3.0 1/m2/min in infants and children; flow rates were not written in stone and handed down to us. Flow rates are “optimal,” thus the variations we see are appropriate to the time, place and circumstances that prevail.
Reperfusion Modification with a Simplified Blood Cardioplegia System Compared with Oxygenated Crystalloid Cardioplegia
Authors: Kauffman Jeffrey N. , Walker Tyrone , Lattout Omar , Letson Beth , Guyton Robert A.
Published: August 2023

A simplified system was developed for administration of blood cardioplegia with reperfusion modification. This system utilizes a single pass stainless steel coil to eliminate the need for a separate heat exchanger circuit. This system was compared with an oxygenated crystalloid cardioplegia system which was utilized in a manner which allowed warm blood perfusion of the heart for the last three minutes of the crossclamp interval. Both of these systems were compared with regard to mortality, spontaneous defibrillation, myocardial temperature, blood usage and peak CK-MB levels. In this series of patients, no significant advantage of either system could be identified.
Leukocyte and Platelet Depletion Can Alleviate Reperfusion Injury in Rabbits
Authors: Kutsumi Yasunori , Misawa Toshihiro , Yoshida Makoto , Nakai Tsuguhiko , Miyabo Susumu
Published: August 2023

To investigate the effect of leukocyte and platelet depletion on reperfusion injury using a leukocyte-platelet removal filter (LRF), several cardiovascular variables were examined in the rabbits during ischemia followed by reperfusion. The rabbits underwent cytoapheresis with LRF (n=S) and were compared with controls without LRF (n=S). LRF was composed of a nonwoven polyester fabric (1.8,um, 4.6 gm). Removal of leukocytes and platelets by LRF was 98% for both. A period of 30 min equilibration was allowed before any experimental intervention, at which time the diagonal artery was occluded for 20 min and then reperfused. All arrhythmias were defined and quantified in accordance with the Lambeth Convention. Regional wall thickening was examined by a pulsed Doppler dimension system. No significant differences were observed in hemodynamic variables between the two groups; however, rabbits treated with a LRF demonstrated greater regional wall thickening (LRF group: 17.0 ± 0.9%, control group: 11.0 ± 0.3%, p < 0.01), as well as significant improvement in the frequency of ventricular arrhythmias (LRF group: 12.5%, control group: 47.2%, p < 0.01). The data suggest that LRF may help prevent arrhythmias and preserve left ventricular contraction during and after intracoronary thrombolysis.
Percutaneous Cardiopulmonary Bypass
Authors: Whittaker S. , Rees M.R. , Hick D.C. , Browne T. , Tan L.B. , Nair U. , Davies G.A.
Published: August 2023

We have employed a percutaneous cardiopulmonary bypass (PCPB) system during high risk interventional procedures in the cardiac catheterization laboratory. Eight patients (group 1) were elective and six (group 2) were emergencies. Group 1 (ages 39 - 80 years, mean 56 years) includes seven patients who were high risk percutaneous transluminal coronary angioplasty (PTCA) and one patient who underwent balloon aortic valvuloplasty. Group 2 (ages 54 - 80 years, mean 66 years) were in cardiogenic shock, five of whom had arrested.

All patients were fully heparinized (300 iu•Kg1) prior to percutaneous insertion of 17 - 19F cannulae. Group 1 patients underwent ilio-femoral angiography prior to cannulae insertion.

Mean bypass time was 103 minutes (range 37 - 231 minutes) in group 1 and 406 minutes (range 40 -1781 minutes) in group 2. Bypass was instituted at a flow of 0.5 1•min-1 in group 1, flow was increased if chest pain, ECG changes or hypotension occurred, (maximum flow 0.5-2.5 1•min-1 mean flow 1.7 1•min-1) Maximum bypass flow in group 2 was 4 - 5.5 1•min-1 (mean 4.5 1•min-1). Mean fluid infusion during PCPB was 200 ml•hour-1 in group 1 and 385 ml•hour-1 in group 2.

The mortality was four patients, all in group 2. Three patients were unable to support their circulation when weaned from PCPB and one patient had a massive intrathoracic bleed such that PCPB could not be maintained. There were no procedural complications associated with cannulae insertion or perfusion management. Of the survivors two had an unexplained haematuria (normal plasma haemoglobin). Two patients bled from the cannulation site following cannulae removal, haemostasis was achieved without surgical intervention.
Comparing Ultrafiltration and Centrifugation During and After Pediatric Cardiopulmonary Bypass
Authors: Traynor L , Sutton R , Riley J , Crawford FA , Sade RM
Published: August 2023

Blood processing techniques related to pediatric cases have previously been generalized from adult experiences.

Twenty-two pediatric patients (<25 kilograms) undergoing cardiopulmonary bypass (CPB) for various congenital defects were prospectively randomized into an ultrafiltration or centrifugation group. Sixty-one variables were compared.

The blood infused from the ultrafiltration technique contained significantly more heparin (p=0.0001) and more plasma-free hemoglobin (PFH) (p=0.0001) levels than the centrifugation blood. Centrifugation patients had a significantly higher hematocrit (p=0.0066) than the ultrafiltration group twenty minutes postoperatively. The ultrafiltration patients (mean=431.82cc±116.8) received less total packed red blood cell volume before and during bypass than the centrifugation group (mean=534.091cc±113.07). In the centrifugation group, wash volumes showed positive correlation to postoperative blood sodium levels (r= +0.4006, p< 0.05). No significant difference was found between postoperative and preoperative sodium levels (p> 0.05). PFH levels for both groups showed a significant positive correlation to postoperative creatinine levels (r= +.4029, p< 0.05) suggesting decreased postoperative renal function, but a significant negative correlation to post-bypass hematocrit (r= -.4548, p< 0.05). Post-bypass heparin levels in the circuit showed a significant positive correlation to heparin levels in the reinfusion blood for the ultrafiltration group (r= +.8025, p<0.05). Post-bypass PFH level in the circuit showed a significant positive correlation to PFH levels in the reinfusion blood for both groups (r= +.5339, p<0.05). No significant difference existed between the ultrafiltration and centrifugation groups for postoperative prothrombin and partial thromboplastin times.

For pediatric cases, the centrifugation technique was found to be superior for post-bypass blood processing based on a higher postoperative patient hematocrit and the presence of less heparin and less PFH in the reinfused blood. The ultrafiltration technique was found to be superior for intraoperative blood processing due to a lower total packed red cell volume addition before and during bypass.
Percutaneous Cardiopulmonary Support System for the Treatment of Fulminant Myocarditis
Authors: Koyama Tomio , Itoh Takeshi , Takasu Akihiko , Yamazaki Yoshihisa , Tsuboi Hideyuki , Sone Takahito , Tauchi Nobuo , Minakuchi Kazue , Sassa Hiromi , Murase Mitsuya
Published: August 2023

We have developed a simple percutaneous cardiopulmonary support (PCPS) system. The circuit of the system is set up and sterilized beforehand and can be used promptly in an emergency situation. We used the PCPS on three patients with fulminant myocarditis and treated them successfully.

Case 1 was a 53-yr-old man and Case 2 was a 12-yr-old girl. They had failed to respond to treatment of their circulatory states with conventional therapy. Their circulatory states improved dramatically after application of PCPS with 2 L/min blood flow. They were weaned from PCPS after 107 and 227 hours use, respectively. Case 3 was a 37-yr-old woman who developed ventricular fibrillation which was resistant to drug therapy and cardioversion. After starting PCPSwith4 L/min blood flow, arrhythmia disappeared and her circulatory state improved. She was successfully weaned after 39-hour of PCPS.

Patients with fulminant myocarditis fall into circulatory collapse which is resistant to conventional therapy, but there is a possibility that cardiac function will recover after the acute phase of myocarditis. Therefore, PCPS can be the only treatment of the circulatory collapse of fulminant myocarditis, which is refractory to conventional therapy.
Comparison Study of the Hepcon System Four and the Hemostasis Management System
Authors: Harloff Michael , Taraskiewicz John , Fotouhi Carol
Published: August 2023

Milwaukee Heart Surgery Associates in affiliation with St. Mary's Medical Center was asked to be clinical investigators for a comparison study of the current Hepcon System Four (HSF) and the next generation Hemostasis Management System (HMS) manufactured by HemoTec Inc. The Hepcon System Four has been in place at St. Mary's Medical Center for the past three years in a program that performs approximately 900-1100 cardiac procedures a year. Heparin Assays and High Range Activated Clotting Times (HR-ACTs) are performed routinely on all patients placed on cardiopulmonary bypass (CPB). This comparison study will evaluate the results based upon the two systems run in tandem on a series of patients undergoing cardiac surgery with no exclusions i.e. valve repair or replacement and myocardial revascularization. The results will determine whether or not the new generation Hemostasis Management System has any distinct advantages over the Hepcon System Four and is or is not suitable for this clinical setting.
Does Cardioplegic Protection of the Pediatric Patient Heart Vary According to the Cardiac Defect?
Authors: Stammers Alfred H. , Riley Jeffrey B.
Published: August 2023

The technique of myocardial protection utilized during pediatric cardiac surgery may be influenced by the congenital lesion, and be related to the pathophysiological changes associated with myocardial dysfunction and altered systemic and pulmonary circulations. The present study is a retrospective examination of the cardioplegic and cardiopulmonary bypass parameters utilized during pediatric cardiac surgery.

1016 pediatric patients were subdivided according to cardiac lesion, with the following parameters recorded: Age at operation, weight, body surface area, cardioplegia (CP) volume administered, cardioplegia dose schedule, cardiopulmonary bypass and cross clamp times, and low perfusate temperature. Cardioplegia volume administration was indexed according to weight and body surface area and patients were categorized as being either acyanotic or cyanotic The following results (Mean ±SEM) were obtained between groups not significantly different in respect to weight and body surface area:

Defect
CP/Unit Weight (ml/Kg)
P Value

ASD vs Pulmonary Stenosis
26.7+0.8 vs 38.0±2.6
.001

ASD vs Pulmonary Atresia
26.7+0.8 vs 34.1+3.4
.001

A/VSD vs Truncus Arteriosus
30.5+2.1 vs 48.1+4.5
.009

VSD vs Tetralogy of Fallot
36.3+4.2 vs 35.2+1.1
.79

LV Outflow vs RV Outflow Lesions
32.3+2.8 vs 35.5+0.9
.27

Patients with pulmonary obstructive lesions had significantly more cardioplegic volume administered than certain acyanotic lesions. This may reflect a greater susceptibility to ischemic and reperfusion related phenomena in cyanotic compared to acyanotic patients. Cardioplegic protection of the pediatric heart may be influenced by multiple factors related to the cardiac lesion, necessitating preferential preservation strategies.
Coagulation Patterns in Perfusion with Low Systemic Heparinization
Authors: von Segesser L. K. , Weiss B. M. , Garcia E. , von Felten E. , Turina M. I.
Published: August 2023

Cardiopulmonary bypass (CPB) with heparin coated perfusion equipment was realized in 13 patients undergoing myocardial revascularization with either low (ACT> 180) or full systemic heparinization (ACT>480). Blood samples for coagulation and other studies were drawn before, after heparin, and at regular intervals during and after CPB.

Heparinization
low
full
p<
 

Preop
ACT s
118±6
112±13
NS

 
PTT s
38±4
35±2
NS

 
TT s
14±1
14±1
NS

 
D-dimers mg/L
<05
<0.5
NS

Heparin
IU 103
8±2
51±9
.01

CPB 60 min
ACT s
230±19
594±287
.05

 
PTT s
56±9
94±63
.10

 
TT s
>200
>200
NS

 
D-dimers mg/L
<0.5
<0.5
NS

Protamin
IU 103
7±1
30±4
.01

60 min
ACT s
110±11
109±9
NS

 
PTT s
47±6
48±10
NS

 
TT s
19±6
19±8
NS

 
D-dimers mg/L
0.6±0.5
1.1±0.6
NS

Blood loss day 1 L/m2
0.4±0.1
1.0±1.0
.05

We conclude, that low dose systemic heparinization (16% of full) resulted in adequate anticoagulation during perfusion with heparin coated equipment and in reduced blood loss.
Fatal Retrograde Aortic Dissection During Cardiopulmonary Bypass for Reoperative Mitral Valve Replacement
Authors: Komorowski Benjamin
Published: August 2023

In September 1991 a 62-year-old female presented to our institute for replacement of a prosthetic mitral valve. She was cannulated for cardiopulmonary bypass via the right femoral artery with venous drainage through the inferior and superior vena cava. During rewarming there was a sudden drop in arterial blood pressure. After the cross clamp was removed the heart remained flaccid with no apparent perfusion of the coronary arteries. As a result of this, the diagnosis of retrograde aortic dissection was made and the ascending aorta was immediately cannulated. In spite of this action, severe metabolic acidosis, hyperkalemia and oliguria had developed. After two attempts to wean the patient off bypass and when maximal pharmacological support had failed, bypass was discontinued and the patient was pronounced dead.
Plasmapheresis Techniques During Cardiac Surgery
Authors: Rasmussen Caroline R. , Stammers Alfred H. , Kratz John M. , Southworth Rhonda S. , Crumbley Arthur J. , Riggs Thomas R. , Crawford Fred A.
Published: August 2023

Plasmapheresis is an aggressive autologous blood conservation method utilized in cardiac surgery to reduce patient exposure to homologous blood transfusion. Presently the three perioperative techniques which have been used clinically incorporate varying methodology in producing platelet rich plasma (PRP). However, no prospective randomized study has been made to concurrently examine the benefits of individual devices.

Fifty-two consenting adult cardiac patients who met selection criteria were randomly assigned to one of three plasmapheresis devices: Plasma Saver (PS), Cell Saver (CS), and Autotrans 1000 (AT 1000). Following induction of anesthesia, 20% of each patient's estimated plasma volume was removed, stored and then reinfused following the reversal of heparin with protamine. One hundred and twenty-two parameters were measured for each patient. These included anthropomorphic, operative, cardiopulmonary bypass, and postoperative follow-up parameters. Indices of hemostasis were measured which included coagulation screens and thrombelastographic data.

There were no differences between groups in all preoperative parameters including the volume of PRP removed. Fibrinogen levels in the PRP were 213.9 +/- 63, 219.4+/-73, and 188.9+/- 69mg/dl in groups PS,CS, and AT 1000 (p=NS), while platelet counts were 178.4 +/- 73, 121.6 +/- 85, and 210.6 +/- 77 109/L, respectively (p<.05 CS vs. AT). There were no differences in chest tube drainage, time on ventilator, or length of ICU stay between groups. However, patients in PS group had significantly lower discharge platelet counts than groups CS and AT 1000. Total homologous blood exposure rate (donor blood exposure per patient) was 8.2 units in group PS, 4.5 in CS, and 5.4 in AT 1000, (p=NS).

The currently available techniques for perioperative PRP production differ in both methodology and platelet yield, although the difference did not result in significantly different patient postoperative outcome indices.
Thrombus Formation in Centrifugal Pumps
Authors: Morin Bruce J. , Riley Jeff B.
Published: August 2023

Three centrifugal flow pumps; the Biomedicus BP80, the Sarns Delphin and the Aries Lifestream 2100, were evaluated in vitro to determine each pump's individual tendencies for thrombus formation. Thrombogenic surfaces in the circuit were minimized by using heparin coated tubing and connectors. The centrifugal pumps, which were not heparin bonded, were placed in line in a circuit which consisted of a venous reservoir, a heat exchanger and a centrifugal pump.

One trial was performed for each of the three pumps by priming the circuits with approximately 500 ml of fresh heparinized bovine plasma. Protamine sulfate was titrated in slowly to decrease the activated clotting time (ACT) from an initial level of >600 seconds back to baseline. The thrombus formation was documented on videotape using a strobe lamp flashed at a frequency compatible with the pump's rpm.

Thrombus formation was observed in each of the centrifugal pumps we evaluated. We have determined that the centrifugal pump is a potential source of thrombus formation and it may result in an increased morbidity or mortality for the patient when used for cardiopulmonary bypass or ventricular assist without adequate systemic heparinization.
Oxygenator Failure Due to Contact With Bathing Alcohol: A Case Report
Authors: Niles Scott D. , Ploessl Jay , Sutton Robin G. , Steinberg John B.
Published: August 2023

Polycarbonate plastics are used in the construction of cardiopulmonary bypass oxygenator shells. Oxygenator failure due to contact with organic and anesthetic solvents can occur. An incident in which bathing alcohol was spilled onto a hollow fiber oxygenator, necessitating its replacement during cardiopulmonary bypass, prompted this case report. We recommend additional safety precautions and urge manufacturers to label components constructed of such material to prevent this potentially catastrophic event.
Perfusing the Bleeding Diathesis Patient An Example of Protocol Flexibility
Authors: DeBell R.H. , Kyger E.R. , Blakestad B.R. , Stephens M.D.
Published: August 2023

A patient who clearly fell within the parameters that define those who are likely to bleed excessively postoperatively presented for coronary artery bypass grafting. As this patient refused donor blood or blood products, the risk of excessive post-operative bleeding was a serious concern. This article elucidates the protocol modifications in equipment, blood management, heparin dosing, flow regulation, pressure control, and in the basic surgical approach that resulted in a successful operation and recovery with minimal blood loss.
Laboratory Evaluation of a Low Prime ClosedCircuit Cardiopulmonary Bypass System
Authors: Sistino Joseph J. , Michler Robert E. , Mongero Linda B.
Published: August 2023

We have explored the potential advantages of a low prime closed-circuit cardiopulmonary bypass (CPB) system using a non-human primate model. Although manufacturers have reduced priming volumes in individual CPB components, the standard circuit volume remains high because of the tubing diameter and length necessary for gravity drainage. By replacing gravity drainage with the negative pressure generated by a centrifugal pump, we can realize significant tubing volume reduction.

Closed-circuit bypass was conducted on 13 baboons ranging from 5-15 kg. The circuit consisted of a centrifugal pump, a hollow fiber oxygenator, and l/4" arterial and venous tubing. The design of the circuit included the capacity to remove a limited amount of venous air. Circulatory arrest during deep hypothermia with volume displacement into a reservoir was also accomplished with this circuit.

The potential benefits of this low prime closed-circuit bypass system include blood conservation and reduction in blood surface area contact. The future safe clinical use of this type of closed-circuit bypass for routine open heart surgery will depend upon the incorporation of a device in the venous line to remove air. This is the greatest threat to patient safety in a closed circuit system and its use for open chest surgery must wait until an efficient venous air elimination device is available.
The Temperature-Corrected Versus the Uncorrected PO2 During Hypothermic Cardiopulmonary Bypass-Correlation with Oxyhemoglobin Saturation
Authors: Baraka Anis S. , Musa K. Muallem , Baroody Maurice A. , Haroun Sania T. , Sibai Abla A.
Published: August 2023

In 8 adult patients undergoing cardiopulmonary bypass, the perfusion flow was altered from 2.4 to 1.8 and 1.2 L/min/m2 during hypothermia (26.5 ± 2.3°C). Following rewarming of the patients to 37°C, the perfusion flow was also altered from 2.4 to 1.8 and 1.2 L/min/m2. The resulting mixed venous oxyhemoglobin saturation (SvO2) was measured in vivo by in-line oximetry at the actual body temperature, and was correlated with the corresponding temperature-corrected and uncorrected mixed venous oxygen tension (PvO2) as measured in the lab at 37°C. Venous blood at the entrance of the oxygenator was used for continuous in-line oximetry, blood gas sampling, and for measuring body temperature.

Correlation of SvO2 at the different perfusion flows with the corresponding temperature-corrected PvO2 during hypothermia is shifted to the leftofthecorrelation following rewarming ofthe patients to 37°C. In contrast, correlation of SvO2 with the uncorrected PvO2 is not significantly different from the normothermic relationship. Also, the uncorrected PvO2 and SvO2 during hypothermia at a perfusion flow of 1.2 L/min/m2 were not significantly different from that achieved during normothermia at a flow of 2.4 L/min/m2 Thus, maintenance of the temperature-uncorrected PO2 during hypothermia at the normal normothermic value facilitates clinical interpretation and reflects a normal oxyhemoglobin saturation, irrespective of changing the body temperature.
Safe, Compact and Portable System for Regional Chemotherapeutic Hyperthermic Perfusion Procedures
Authors: Fried Steven J. , Miller Randy , Weaver Fred A. , Faddis David
Published: August 2023

Perfusion techniques utilizing hyperthermic chemotherapy have been established as a successful modality of therapy for isolated metastatic malignant melanoma. The combination of chemotherapeutic agents (Dactinomycin, thiotepa and Mechlorethamine HCl) given in high doses, not possible systemically, combined with hyperthermia ( 40-42°C) in an isolated extremity has shown greater tumor regression compared with systemic medication only.

Many of the isolated limb perfusion procedures are performed in non-cardiac centers, especially at specialized cancer institutions. This often presents new obstacles for the perfusionist including lack of adequate perfusion equipment and disposables. Other obstacles include unfamiliarity of the operating room staff with the heart-lung machine and inappropriate and/or unsafe handling of the perfusion circuit. In order to overcome these obstacles and enhance safety, portability and effectiveness, the authors have developed an isolated limb perfusion system.

The purpose of this study was to compare the parameters of treatment and long term outcomes demonstrated by our system and method, to previously published data. The qualitative comparative analysis was performed between eight treatments with this type of perfusion system and outcome data previously published. It is the authors’ conclusion that the portable isolated limb perfusion system achieved all of the required parameters to provide safe and effective treatment for this type of melanoma. No demonstrated variation of the long term clinical results in our patient population was seen when compared to previously published data.
Comparison of Blood Gas and Electrolyte Test Results From the Gem-Stat and CDI-300 Versus a Conventional Laboratory Analyzer
Authors: Walton Howard G. , Duvall Thomas B. , Van den Hout Julie , Boucher David M.
Published: August 2023

Continuous blood gas monitoring devices have been an aid to the perfusionist since the introduction of the oxygen saturation meters of the early 1980s. Since that time, the perfusionist has had to decide between continuous versus intermittent sampling, and on-line (an analyzer that can automatically sample either at prescribed intervals and/or on demand) versus in-line devices (monitors that continuously sample and display results). This report compares the continuous, inline CDI-300 blood gas monitor and the Mallinckrodt Gem-Stat blood gas analyzer using intermittent sampling with the Coming 278 blood gas analyzer and 2500 Co-Oximeter. Thirty samples were taken, one per 30 patients, for comparison. Five samples were disqualified from the study. When comparing the remaining 25, the Gem-Stat results to the Coming 278 blood gas analyzer results, all measured values (arterial pH, pCO2, pO2, venous pO2, Na, K and Hct) correlated >0.5000 with a p value of <0.001. The exception was the ionized calcium value which had a correlation of0.2473 with a p value of <0.232. When comparing the CDI-300 results to the Coming 278 blood gas machine results, all measured values (pH, pO2, pCO2 and venous pO2) correlated >0.5000 with a p value of <0.003 or better. When comparing the Gem-Stat results to the CDI results, all measured values (pH, pCO2, pO2 and venous pO2) correlated >0.5000 with a p value of <0.002 or better.
Damaged Erythrocytes Following Cell Washing with a Hypotonic Solution: A Case Report
Authors: Hunt Allen , Stammers Alfred H. , Kangas Jeff , Fristoe Lance , Merrill Jonathan H. , Vogel James , Galbraith Timothy
Published: August 2023

This case report deals with the incidence of high levels of plasma free hemoglobin secondary to the infusion of erythrocytes washed with sterile water during an autotransfusion procedure. The danger of high levels of plasma free hemoglobin is acute renal failure due to precipitation of free hemoglobin in the form of acid hematin. Treatment attempts to prevent the precipitation by maintaining high urine output (75 - 100 ml/hr or 1-2 ml/kg/min) and alkalizing the urine (pH of8). Preventative treatment is outlined and includes: fluid and colloid replacement; diuretics and sodium bicarbonate. In this case, acute renal failure was prevented and the patient was discharged on post operative day five.
Combined Hypothermic Circulatory Arrest and Warm Blood Cardioplegia for Aortic Surgery
Authors: DiMarco David B. , Jurado Roy A. , Gomez Roberto , Rivera Anselmo
Published: August 2023

This is a case of an 87-year-old male who underwent successful repair of an acute ascending aortic dissection (Stanford Type A). Hypothermic circulatory arrest was used to provide cerebral protection during the performance of the "open" distal anastomosis. Continuous normothermic retrograde blood cardioplegia was used as a means for myocardial protection. To our knowledge, this is the first report of combining warm (aerobic) cardiac preservation with hypothermic circulatory arrest. We describe the perfusion management and discuss the rationale for the use of normothermic blood cardioplegia. We advocate the use of warm aerobic myocardial arrest for all procedures requiring myocardial protection regardless of systemic temperature.
A Comparison of Estimation of Blood Volume by Hematocrit Dilution with Prediction of Blood Volume by Patient Morphology
Authors: Acsell Jeffrey R. , Riley Jeffrey B. , Ecklund Jodie M.
Published: August 2023

Determination of circulating blood volume (CBV) is useful for quantifying and managing several physiologic parameters in patients undergoing cardiopulmonary bypass (CPB). Blood was drawn and the hematocrit (HCT) measured immediately pre and five minutes post initiation of CPB, in adult cardiac surgery patients (n=67). The CBV was estimated by HCT dilution, and compared utilizing regression analysis and Student's t-test, with eight formulas for predicting CBV from patient morphology.

CBV by HCT dilution vs Patient Morphology (T-Test) P value

1) ml/kg 65ml/kg <.0001

2) Allen-men Height3* Body mass (H*TBM) .0001

3) Allen-wmn Height3* Body mass (H*TBM) <.0001

4) Baker 2.68L/m2 <.0001

5) Nadler1-men Regression of Baker <.0001

6) Nadler1-wmn Regression of Baker .0001

7) Nadler2-men Regression of Allen-men <.0001

8) Nadler2-wmn Regression of Allen-wmn .0002

There is a significant statistical difference between CBV estimated by HCT dilution and CBV predicted by patient morphology. None of the equations investigated are adequate predictors of CBV estimated by HCT dilution in patients undergoing CPB.