bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of satellite trails on H.E.S.S. astronomical observations
Authors: Lang T. , Spencer S. T. , Mitchell A. M. W. 
Published: August 2023

Context. The number of satellites launched into Earth’s orbit has almost tripled in the last three years (to over 4000) due to the increasing commercialisation of space. Multiple satellite constellations, consisting of over 400 000 individual satellites, have either been partially launched or are proposed for launch in the near future. Many of these satellites are highly reflective, resulting in a high optical brightness that affects ground-based astronomical observations. Despite this caveat, the potential effect of these satellites on gamma-ray-observing Imaging Atmospheric Cherenkov Telescopes (IACTs) has largely been assumed to be negligible due to their nanosecond-scale integration times. However, this assumption has not been verified to date.
Aims. As IACTs are sensitive to optical wavelength light, we aim to identify satellite trails in data taken by the High Energy Stereoscopic System (H.E.S.S.) IACT array. In particular, this study is aimed at quantifying the potential effects on data quality and extensive air shower event classification and reconstruction.
Methods. Using night sky background measurements from H.E.S.S., we determined which observation times and pointing directions are affected most by these satellite trails. We then evaluated their impact on the standard Hillas parameter variables used for event analysis.
Results. Due to the brightest trails, false trigger events can occur, however, for most modern analyses, the effect on astronomical results will be minimal. We observe a mild increase in the rate of trail detections over time (approximately doubling in three years), which is partially correlated with the number of satellite launches. Overall, the fraction of H.E.S.S. data affected (~0.2% of dark time observations) is currently minimal. We note that these trails could still have a non-negligible effect on future Cherenkov Telescope Array observations if advanced analysis techniques designed to lower the energy threshold of the instrument are applied.
An In Vitro Model for Hemostasis Monitoring During Simulated Cardiopulmonary Bypass
Authors: Beck Daniel J. , Dickes Melinda S. , Jones Clinton C. , Pierce Michelle L. , Song Zuorui , Taft Kimberly J. , Stammers Alfred H. 
Published: August 2023

The optimum model for hemostasis monitoring during cardiopulmonary bypass (CPB) is the evaluation of physiologic changes in the intact organism. This is often logistically difficult and expensive. The purpose of this study was to design an in vitro model of blood coagulation for use in simulated CPB.
Human expired blood components within 4 days of outdating were reconstitituted as follows: 4 units of packed red blood cells, 4 units of platelets, and 3 units of fresh frozen plasma. The mixture was circulated in a simulated extracorporeal circuit. Blood samples were drawn every 30 minutes over a 2 hour period, recalcified, and analyzed for platelet count (PL T), fibrinogen concentration (FIB), prothrombin time (PT), activated partial thromboplastin time (aPTT), celite and kaolin activated clotting times (ACT), and thrombelastography (TEG).
In the four different coagulation monitors utilized, there were no significant changes in celite or kaolin ACTs. PT increased from 15.8 ± 1.1 sec to 25.2 ± 7.8 sec and aPTT from 62.1 ± 15.9 sec to 78.9 ± 36.5 sec (p = NS). There were no changes in either PL T count or FIB concentration. Both celite and tissue factor activated TEG values trended towards hypocoagulability.
In conclusion, the results show that the in vitro model is stable over 120 min of recirculation time within a simulated cardiopulmonary bypass circuit in regards to platelet count, hematocrit, total protein, PT, aPTT, and ACT. Further examination will be necessary to establish the effects of the model in regard to platelet function.
Bilateral Extracorporeal Circulation (“Drew Technique”) for Coronary Artery Bypass Surgery using Patient’s Lung as Oxygenator
Authors: Tassani P. , Pfauder M. , Richter J. A. , Meisner H. 
Published: August 2023

The aim of this study was to determine: 1) whether a bilateral perfusion circuit (Drew technique) using the patient's own lung as the oxygenator is feasible for multi-vessel coronary artery bypass grafting; and 2) if the systemic inflammatory response to extracorporeal circulation differs compared to conventional cardiopulmonary bypass procedures.
Twenty patients were enrolled in a randomized, controlled study. In the Drew group (n=10) bilateral perfusion was used. The other patients (n= 1 0) were operated on with conventional perfusion techniques and served as the control group. Pro- (interleukin-6) and anti-inflammatory (interleukin-10) mediators were measured before operation, during rewarming, 30 min, 2, 4, and 24 hours after extracorporeal circulation.
The results show that: 1) multi-vessel coronary artery bypass grafting could be performed during 90 ± 8 min of bilateral cardiopulmonary bypass; 2) the concentration of the interleukin-6 was significantly lower in the Drew group at 2 hours (449 ± 82 versus 914 ± 152 pg/ml, p = 0.02), and 24 hours (146 ± 38 versus 424 ± 98 pg/ml, p = 0.02), after cardiopulmonary bypass.
The Drew technique seems to be a promising method of extracorporeal circulation which: 1) can safely be used during routine coronary bypass grafting procedures; and 2) significantly reduces the systemic inflammatory response as compared to conventional extracorporeal circulation.
Systemic Inflammatory Response Syndrome (SIRS) Following Emergency Cardiopulmonary Bypass: A Case Report and Literature Review
Authors: Sistino Joseph J. , Acsell Jeffrey R. 
Published: August 2023

A complication of emergency resuscitation is the development of the Systemic Inflammatory Response Syndrome (SIRS). In the past, this has been identified as multiple organ failure, with symptoms similar to sepsis. The hallmark of this syndrome is peripheral vasodilation, which is associated with a breakdown of capillary membranes and the accumulation of excess interstitial fluid.
This case report discusses the development of SIRS in a patient following emergency cardiopulmonary bypass (CPB). The patient was a 53 year old male with significant left main coronary artery disease who developed sudden bradycardia and hypotension in the operating room and was emergently placed on cardiopulmonary bypass. During CPB, the patient was peripherally vasodilated, and required continuous alpha-adrenergic support to maintain normal systemic vascular resistance. In addition, metabolic acidosis was present despite high flow rates, high hematocrit, addition of colloids, and hemoconcentration. Despite excellent neurological and myocardial recovery following surgery, the patient died one week later in renal and hepatic failure.
Several mechanisms for the development of this syndrome have been hypothesized. One of these theories is that the ischemic injury in the gastrointestinal tract disturbs the gut barrier function and allows enteric bacterial endotoxins to pass into the circulation producing sepsislike symptoms. Other theories relate to the release patterns of cytokines associated with CPB. These mechanisms and the treatment of SIRS with new pharmacological agents and perfusion techniques are reviewed.
In vivo Evaluation of a Phosphorylcholine Coated Cardiopulmonary Bypass Circuit
Authors: De Somer F. , Van Belleghem Y. , Foubert L. , François K. , Dubrulle F. , De Wolf D. , Van Nooten G. 
Published: August 2023

A complete phosphorylcholine coated cardiopulmonary bypass circuit, including the Dideco D901 oxygenator, was tested for gas transfer, blood path resistance, and biocompatibility in a standardized setting. Blood compatibility was tested by measuring complement and platelet activation.
Three dogs (mean body weight 28 ± 3 kg) were placed on cardiopulmonary bypass at a flow rate of 600 mL/min during 6 hours. The animals were weaned from cardiopulmonary bypass and sacrificed electively after 7 days.
Oxygen and carbon dioxide transfer were 26.6 ± 2.4 mL/min and 33.0 ± 1.9 mL/min, respectively. Mean pressure drop across the oxygenator was 52.6 ± 0.2 mmHg. The respective baseline values for thromboxane B2, prostaglandin E2 and platelet factor 4 were 1817 ± 283 pg/mL, 12783 ± 2109 pg/mL, and 0.35 ± 0.08 IU/mL. Thromboxane B2 and prostaglandin E2 increased slightly to 2881 ± 868 pg/mL and 18083 ± 3144 pg/mL at 30 minutes of bypass, whereas platelet factor 4 values remained stable curing the procedure. Concentrations of complement split products C5a were only mildly increased.
After use scanning electron microscopy was performed on the inner housing, heat exchanger, and outer surface of the hollow fibers. No thrombi nor organized cellular deposits were found on any of the components. Phosphorylcholine coating of CPB seems to be very promising regarding platelet activation and complement activation.
High Dose Thrombin Time versus the Activated Clotting Time during Cardiopulmonary Bypass
Authors: de Jong M.A. 
Published: August 2023

In this study we compared the High Dose Thrombin Time (HiTT) with the Activated Clotting Time (ACT) during cardiopulmonary bypass (CPB) in non-aprotinin treated patients. On the advice of the HiTT test manufacturer each institution should perform comparative ACT/HiTT assays in the cardiac surgery population. In previous tests our target ACT value of 480 seconds corresponds with a mean HiTT value of 190 seconds.
Our results showed that after heparinization (300–400 IU/kg body weight) 8 out of 20 patients did not reach the target ACT of 480 seconds, while the HiTT results in those 8 patients were higher than our target time of 190 seconds. Four heparin pretreated patients who received 400 IU/kg heparin, had relatively low ACT values (467 ± 14 sec.) and high HiTT values (324 ± 47 sec.). Before and during CPB there was a poor correlation between the HiTT and ACT (r = 0.38).
The results of this study show that for the individual patient the target HiTT of 190 seconds is no guarantee for reaching an adequate ACT of 480 seconds. Although the HiTT may be a very useful assay for monitoring heparin effects during CPB, the determination of the target time can be a point of discussion. In contrast of the advice of the manufacturer we therefore suggest that comparative ACT/HiTT assay should be done in every individual patient to determine a safe target HiTT time, instead of the whole group of patients.
Staffing Issues at Open-Heart Centers Offering both Pediatric and Adult Perfusion Service: 1998 Survey Results
Authors: Scott Lawson D. , Darling Edward M. , Collins Kevin , Smigla Gregory R. , Shearer Ian R. 
Published: August 2023

A survey directed to centers offering both pediatric and adult perfusion services was conducted to determine how pediatric cases were distributed among individual perfusionists in their departments. These centers were also asked what they believed the clinical activity level should be for a perfusionist each year to remain proficient in pediatric cardiopulmonary bypass. The questions were asked via e-mail and then followed up with telephone interviews as necessary.
Out of the 100 centers contacted, 45 responded to the survey (43 North American, 2 European). Of the forty-five centers, forty-one provided both pediatric and adult perfusion services. Thirty-two centers (78%) offering adult as well as pediatric perfusion services distributed the pediatric caseload to a select group of perfusionists. Nine centers (22%) distributed the pediatric open-heart caseload to the entire staff. From the respondents, the average minimum number of pediatric cases believed necessary to remain proficient in pediatric perfusion was 42.8 cases annually. Centers having dedicated pediatric perfusionists had a slightly higher annual caseload than did those at non-specialized centers, despite practicing at institutions averaging fewer pediatric open-heart cases annually.
Avoiding Hyperoxemia at the Start of Cardiopulmonary Bypass While Optimizing Gas Flow and Temperature
Authors: Myers Gerard J. , Légaré Jean-François 
Published: August 2023

There seems to be a wide range of practice in relation to the optimum oxygen setting before, and at the start of, cardiopulmonary bypass. Even manufacturers of blood oxygenators vary in their suggestions for this phase of extracorporeal circulation. Most of these suggestions are based on peak performance, Association for the Advancement of Medical Instrumentation (AAMI) standards, experience, and legal considerations. Therefore, suggested gas:blood flow ratios will vary from no gas flow at the start of bypass, to a ratio setting of 1:1. On the other hand, suggested inspired oxygen concentrations will generally vary between 0.80 to 1.0 at the start of cardiopulmonary bypass. In regard to perfusate temperatures before going on bypass, there are no clearly defined standards other than those of clinical preference. The manufacturer of the oxygenator used in this study clearly states in the operating instructions that gas flow should be proportional to blood flow at the start of bypass, and gas flow should be turned off when there is no fluid flow through the oxygenator.
The presence of hyperoxic perfusates and wide patient/perfusate temperature gradients at the start of bypass has been suspected in the appearance of gaseous microemboli during this critical period. Hyperoxemia during the bypass period is also implicated in the introduction of oxygen free radicals and nitric oxide into the hypoxic myocardium during cardioplegia delivery.
Presented here are the results of a randomized clinical study involving 39 adult patients undergoing cardiopulmonary bypass for the surgical treatment of coronary artery disease. All patients were randomly selected into five groupings. The first group had 1 L of gas flow through the perfusate before bypass, and bypass was then started with an FIO2 of 0.80. The second two groups had no gas flow through the perfusate prior to bypass and a starting FIO2 of 0.21. Groups 4 and 5 had 1 L of gas flowing through the perfusate and a starting FIO2 of 0.21.
Results indicate that gas flow through Normosol R/Albumin perfusates will prevent the acidosis that is found in this solution when the system is previously flushed with carbon dioxide. Also, suggested high FIO2 settings will produce hyperoxic perfusates at the start of cardiopulmonary bypass. However, the use of an FIO2 of 0.21 at the start of bypass will produce normoxemic conditions that are both safe and reliable for the conduct of initiating cardiopulmonary bypass.
Effects on C3 and CH50 Levels During and Following Extracorporeal Whole Body Hyperthermia
Authors: Shecterle L.M. , Wetherall N. , St. Cyr J.A. 
Published: August 2023

Cardiopulmonary bypass can affect inflammatory reactions and evoke the “postperfusion syndrome,” manifested as multiple organ dysfunction in the recovery period. This syndrome is generated by the activation of complement, macrophages, neutrophils, and inflammatory cytokines. Following the use of hypothermia during cardiac procedures, active hyperthermic rewarming is used to reestablish body temperature. Complement levels and their interactions have been investigated during and following hypothermia. Hyperthermia is being used clinically; however, the effect of markedly elevated temperatures on complement is unknown and, therefore, needs to be investigated.
A pilot canine study was designed to begin to explore what role hyperthermia may play on complement levels during and following extracorporeal whole body hyperthermia. Five dogs were heated to a core temperature of approximately 42°C, held at this elevated temperature for 90 minutes, then cooled to normothermia. A decline in C3 levels at the end of warming with further declines through day 4 post treatment was observed. CH50 levels mimicked the C3 level decline; however, there was a trend for rebounding by day 4. The findings involving complement factors following hyperthermia signify that this increase in temperature causes a decrease in both C3 and CH50 levels.
Hematological Effects of a Low-Prime Neonatal Cardiopulmonary Bypass Circuit Utilizing Vacuum-Assisted Venous Return in the Porcine Model
Authors: Ahlberg Kevin , Sistino Joseph J. , Nemoto Shintaro 
Published: August 2023

Limiting hemodilution in neonates is difficult when extracorporeal circuits require priming volumes that are 2 to 3 times the blood volume of the newborn patient. This extreme hemodilution contributes to the development of significant postbypass coagulation disturbances. The purpose of this project was to design a low-prime neonatal bypass circuit and evaluate the coagulation status after reduced hemodilution. The null hypothesis stated there is no significant difference in the measured coagulation parameters between the low-prime circuit and the standard high-prime circuit.
Four neonatal piglets (2–4 kg) were divided into two groups and placed on cardiopulmonary bypass using either a low- (200 ml) or high-prime (500 ml) circuit. Both groups were cooled to 20°C, and, following cardioplegic arrest, underwent circulatory arrest for 20 minutes. The low-prime circuit used vacuum-assisted venous drainage, which permitted the circuit to be at the patient level. The high-prime circuit required fresh washed donor red blood cells to maintain the hematocrit in the desired range of 15–20%.
The platelet count on bypass decreased by 60 ± 1.0% in the low-prime group versus 79.6 ± 0.1% in the high-prime group. Following bypass, the platelet count was reduced by 38.3 ± 14.3% in the low-prime versus 60.2 ± 2.6% in the high-prime group. During rewarming, the mean heparinase activated clotting time (ACT) increased 5.1% above baseline in the lowprime group and 53.5% above baseline in the high-prime group. Mean plasma-free hemoglobin levels increased 40.4 mg/dl in the low-prime group versus 62.1 mg/dl in the high-prime group during bypass. This laboratory evaluation of a low-prime neonatal circuit demonstrates that coagulation disturbances often present in neonates can be reduced with the use of a low-prime circuit.
Modified Ultrafiltration After Congenital Heart Surgery: A Veno–Venous Method Using a Dual-Lumen Hemodialysis Catheter
Authors: LaLone Brian J. , Turrentine Mark W. , Bando Ko , Frederick Chris C. , Horner Michael T. , Richmond Lon H. , Bezruczko Alex P. , Morris Susan M. , Frankenberg Deborah L. , Brown John W. 
Published: August 2023

Perfusion practice surveys on modified ultrafiltration show most clinicians reporting the use of arterial to venous cannulation. With an arterial–venous (A–V) approach, the patient’s blood is accessed in a retrograde direction from the cardiopulmonary bypass aortic cannula, and the hemoconcentrated blood is returned to a catheter placed at a systemic venous return site. To avoid possible hazards of these arterial–venous techniques, we developed a veno–venous (V–V) modified ultrafiltration circuit and method that: (1) uses an 11.5 F dual-lumen hemodialysis catheter placed at a right atrial cannulation site for concomitant pickup and return of the patient’s blood; (2) places the ultrafiltration circuit within the cardioplegia delivery system, enabling the use of the heat exchanger/bubble trap features and also allowing hemoconcentration during cardiopulmonary bypass; and (3) uses an elevated, collapsible transfusion bag within the circuit as a holding reservoir for crystalloid-chased blood from the CPB circuit.
The product literature and our lab testing of the hemodialysis catheter indicates adequate hemodynamics for modified ultrafiltration in children, and our clinical experience shows routine completion of the process in about 10–15 min (12.67 ± 1.73 mins; mean ± 1 SD, N = 9). Advantages of this V–V approach compared to A–V access include: (1) no potential aortic air entrainment at the aortic cannula purse-string suture; (2) modified ultrafiltration in patients regardless of aortic size or anatomy; and (3) avoidance of significant arterial to venous shunts during the performance of modified ultrafiltration. The elevated reservoir within the modified ultrafiltration circuit allows: (1) efficient pre- and/or postultrafiltration fluid chasing of blood from the main cardiopulmonary bypass circuit, thereby keeping it safely primed and allowing for the concentration of all circuit contents before and/or following the ultrafiltration method; (2) maintenance of desired patient filling pressures, temperature, and blood oxygen saturation within the ultrafiltration circuit by intermittent addition of warmed, oxygenated blood to the V–V modified ultrafiltration circuit.
Use of a Low-Prime Circuit for Bloodless Heart Transplantation in Xenotransplant of 5—7 Kilogram Primates
Authors: Gomez Daniel , Olshove Vincent F. , Weinstein Samuel , Davis J. Terrance , Michler Robert E. 
Published: August 2023

There is a great effort to decrease blood product use during open-heart surgery in pediatrics. We were presented with a research challenge to accomplish heart xenotransplantation from donor cynomologous monkey (Macaca fascicularis) to recipient olive baboon (Papio anubis) of 5–7 kilograms without benefit of donor or banked blood products. The purpose of this study was to design and implement a practical, low-volume circuit to minimize hemodilution and avoid the use of blood products.
A simple circuit was assembled using a low-volume oxygenator with hardshell venous reservoir, an 1/8-inch arterial line, an 1/4-inch venous line, and gravity drainage. Three xenotransplants were performed and evaluated. The mean recipient weights were 6.3 ± 0.7 kg. Circuit prime volume was 228 ± 5.8 mL, and bypass time was 85 ± 6.7 min. Blood flow rates were 585 ± 113 mL/min with postmembrane arterial line pressures of 344 ± 81 mmHg, and patient mean arterial pressures (MAP) of 51.4 ± 16.7 mmHg. Venous saturations were 63.7 ± 8.0%. The hematocrit prebypass was 37.4 ± 3.2, bypass 20.7 ± 0.9, post-MUF 27.8 ± 3.3, and 7 days postoperative 24.5 ± 7.5%. Platelet count was 289 ± 1.1 K/µL, 147 ± 37.1 K/µL, and 322 ± 292.7 K/µL prebypass, postbypass, and 7 days postoperative, respectively. Plasma-free hemoglobin prebypass was 7.5 ± 4.4 mg/dL and postbypass 22.2 ± 16.5 mg/dL with no noted hematuria during and after the procedure. All patients survived and were successfully weaned from cardiopulmonary bypass (CPB) with same day extubation.
A low-prime circuit for bloodless heart surgery is possible. To achieve low reservoir levels, especially without the use of an arterial line filter (ALF), it is necessary to have a full armament of monitoring and alarm devices.
Clinical Experience of a Vacuum-Assisted Nonroller Extra-Corporeal Circulation System
Authors: Hiroura M. , Furusawa T. , Amino M. , Moriya T. , Goto H. , Fukaya Y. , Amano J. 
Published: August 2023

We designed a nonroller extra-corporeal circulation system (NRECC) to minimize space requirements and to improve the safety and ease of cardiopulmonary bypass. The NRECC includes a circuit, a centrifugal pump, and a vacuum regulator. The vacuum regulator has five channels, each of which can control negative pressure independently. Negative pressure is applied to suctions, a vent, and a venous reservoir. Auto Vent-SV and one-way valves were placed between the suctions/vent and the reservoir. The total space required for the NRECC with a heat exchanger was 0.49 m2, which is much smaller than that of our current roller pump system.
The maximum volume through the suction/vent was 2.5 L/min at −100 mmHg measured in a simulated system. We used the NRECC for six CABG cases and compared results with those of five CABG cases managed by traditional roller pump extra-corporeal circulation (RECC). The two systems were compared in terms of set-up time and stability/accuracy of the suction/vent. The set-up time of the NRECC (5.3 ± 1.9 min) was significantly shorter than that of RECC (29 ± 3.4 min) (p < .01). Stable and accurate blood flow were achieved with the NRECC operating between −15 mmHg and −25 mmHg. In conclusion, NRECC can run a bypass easily and safely and has the benefit of reducing space requirements and shortening set-up time.