bluuebunny/crossref_metadata_2025 huggingface dataset:
The Course of D-Dimers as Fibrinolytic Products Generated During Cardiopulmonary Bypass
Authors: Moretz Tim L. , Riley Jeff B. , Jeter Elaine K. , Sutton Robin G. , Bishop David G. , Kratz John M. , Crawford Fred A.
Published: August 2023

D-Dimers are the expressed degradation products of the lysis of fibrin. Fibrin monomers may normally occur during routine cardiopulmonary bypass (CPB); therefore, fibrinolysis could play a protective role. Serum D-dimer levels were observed at six events associated with routine CPB. An expected patient D-dimer level while heparinized would be <0.5 mcg/ml showing that fibrin is not being formed.

The majority of elevated D-dimer levels came at the termination of CPB when only one of twenty patients investigated showed a minimal D-dimer level of <0.5. The other patients ranged from 0.5 to >8.0 ug/ml at termination of CPB.

Table A

Event samples with respective ACT and D-Dimer

Event
ACT
DD Level

Baseline
123 ± 15
1.0 ± 1.1

Post Sternotomy

1.6 ± 1.9

5 min. on CPB
497 ± 84
1.6 ± 2.3

Terminate CPB
432 ± 84
5.1 ± 2.8

Post Protamine
116 ± 11
5.1 ± 2.8

1 Hr. Post Op

4.9 ± 3.0

ACT = mean activated clotting time ± 1SD

The last three event D-dimer levels were significantly greater than the D-dimer from the first three events (p<0.01) demonstrating that fibrinolysis may be a normal occurrence during CPB. The weak correlation in the rise in D-dimers during CPB versus the minimal CPB ACT data (n=20, r=.114) although not statistically significant, suggests that ACTs should be maintained above 480 seconds throughout CPB to minimize fibrin formation and therefore minimize fibrinolysis.
Perioperative Autotransfusion and its Correlation to Hemostasis and Coagulopathies
Authors: Page Paul
Published: August 2023

The use of autologous blood techniques affords the reduction or elimination of homologous blood transfusions for most patients. In addition, for certain religious faiths such as Jehovah’s Witnesses or those patients with rare blood types, intraoperative salvage and retUrn of the patient’s own blood is the only source of available blood.

Autologous blood salvage in the perioperative period includes:

• Hemodilution

• Intraoperative salvage of lost blood

• Postoperative collection of shed blood

Perioperatively, autologous blood is salvaged and returned and the volumes involved do not create any hematological problems for the patient. In those cases involving large volumes of blood being processed and returned to the patient, the autotransfusionist must be aware of the possible alterations that may occur in the patient’s coagulation system. The collection and reinfusion of wound drainage fluids from operative sites has the potential to cause severe bleeding problems. This paper will present an overview of autologous blood salvage techniques in the perioperative period along with a review of the clinical effects of autotransfusion on hemostasis. Also discussed will be possible coagulopathies that can be caused by returning collected autologous blood.
The Effect of Extracorporeal Circulation Time and Patient Age on Platelet Retention During Cardiopulmonary Bypass: A Comparison of Roller and Centrifugal Pumps
Authors: Parault Beverly G. , Conrad Steven A
Published: August 2023

Preservation of platelet count during cardiopulmonary bypass (CPB) was retrospectively studied in 784 consecutive adult patients undergoing cardiac surgery, including high-risk “special case” patients. The extracorporeal circuit included a closed membrane oxygenator system for all patients. A roller pump (Co be Laboratories or Stockert-Shiley) was used for bypass in one group of 564 patients, while a centrifugal pump (BioPump, BioMedicus) was used in a second group of 220 patients. There was no difference between the roller and centrifugal pump groups with respect to age, sex, total bypass time, and pre-bypass platelet count. For purposes of this study, retention refers to the patient's last platelet count on CPB expressed as a fraction of the pre-CPB platelet count. The centrifugal pump group had a higher platelet retention than the roller pump group (.619 vs .595, p<.05). Patients with prolonged bypass times (> 120 min) had a lower platelet retention in the roller pump group (.568 vs .610, p<.05), but no significant decrease was seen in the centrifugal pump group (.617 vs .621, p>.05). Patients OVer the age of 70 had a lower retention than those under 70 in the roller pump group (.576 VS .604, p<.05), but there was no difference in the centrifugal pump group (.600 vs .628, p>.05). The special case patients had a lower retention when the roller pump was used (.563 vs .607, p<.05), while platelet retention was not affected in the centrifugal pump group (.603 vs .625, p>.05), however bypass time was also prolonged in the special case group. The centrifugal pump results in improved platelet retention on cardiopulmonary bypass. This improvement is most notable in prolonged cases(> 120 min), in older patients(> 70 yrs), and in special cases.
In Vitro Testing of the 0.6 M2 SciMed Membrane Oxygenator for Use in Neonatal Extracorporeal Membrane Oxygenation
Authors: Van Meurs Krisa P. , Mikesell Gerald T. , Hearty Joseph P. , Seale Winslow R. , Rivera Oswaldo , Short Billie L.
Published: August 2023

Prior to the introduction of the 0.6 M2 SciMed membrane oxygenator, the 0.8 M2 membrane was the only oxygenator FDA-approved for long-term bypass. The performance of the 0.6 M2 SciMed membrane oxygenator was examined using a modified test protocol suggested by the Association for Advancement of Medical Instrumentation for testing gas exchange devices. Four 0.6 M2 SciMed membrane oxygenators were tested in vitro using filtered ovine blood and a customized test circuit designed to provide a continuous source of deoxygenated, CO2-laden blood. Venous blood delivered to the test membrane had an oxygen saturation of 65 ± 2%. Testing confirmed good oxygenation throughout the manufacturer’s specified blood flow range. Transfer rates of CO2 measured for the 0.6 M2 SciMed membrane oxygenator were comparable to those of the 0.8 M2 membrane up to a blood flow rate of 400 ml/minute. Further increases in blood flow did not augment CO2 transfer rates. Use of the 0.6 M2 SciMed membrane oxygenator for neonatal extracorporeal membrane oxygenation (ECMO) should be limited to the lower blood flow range and to infants not likely to experience significant hypercarbia, if such infants can be accurately identified.
Thrombelastography (TEG): A Graphic Profile for Analyzing Coagulation After Cardiopulmonary Bypass
Authors: Hoxmeier Kent , Goddard David , Morton Randall , Chapin James , Landers Dennis , Fleming William
Published: August 2023

Thrombelastography (TEG) was first introduced in 1948 by Hartert and is now used to examine coagulation in a wide range of clinical research settings. TEG measures the elastic properties of whole blood clots as they are formed. A graphic profile of the clot analysis is produced on a chart recorder. Manual evaluation of the graphic profile provides useful information regarding the status of coagulation. The basic theory and technology is demonstrated through this poster presentation.
Effects of Imidazole Buffered Cardioplegia on Isolated Guinea Pig Hearts
Authors: Jenkins Eric H. , Beckley Philip D.
Published: August 2023

The imidazole moiety of histidine is responsible for the alpha-stat theory of intracellular pH regulation, which conserves the function of essential enzymes at different temperatures. This study tests the hypothesis that the addition of imidazole to cardioplegia enhances myocardial protection.

Eighteen isolated guinea pig hearts were randomly divided into 3 groups and perfused with Krebs-Henseleit solution at 35°C using the Langendorff technique. Perfusion was discontinued after 25 minutes, and each group was arrested by the infusion of cold (4-6°C) oxygenated cardioplegic solution at 2.8 mL/min/ g. Group 1 acted as a control, while Groups 2 and 3 were infused with a cardioplegic solution containing 15 mmol/L and 30 mmol/L imidazole respectively. After 30 minutes of hypothermic (< 16°C) ischemia, perfusion was resumed for 15 minutes. Hemodynamic measurements and analysis of perfusate and effluent were made prior to arrest and after 15 minutes of reperfusion. Post-ischemic lactate levels were linearly related to cardioplegia pH (r = 0.7148) and non-bicarbonate buffer capacity (r = 0.8006). Cardiac edema was lower in Group 3 (P < 0.05). Persistent arrhythmic activity was exhibited by 83% of Group 1 throughout reperfusion, compared to 33% and 14% of Groups 2 and 3 respectively. These results suggest that the addition of imidazole enhanced anaerobic metabolism during ischemia, facilitating the preservation of membrane integrity and function.
Verapamil and Acebutolol Overdose Results in Asystole: Intra-Aortic Balloon Pump Provides Mechanical Support
Authors: Welch Carroll D. , Knoerzer Rob E. , Lewis Gregory S.
Published: August 2023

This is a case report of a 17-year-old woman who was in severe cardiogenic shock with intermittent consciousness due to an overdose of acebutolol and verapamil when paramedics arrived at her house. Two and one-half hours of CPR were required because she failed to respond to high doses of positive inotropes or to glucagon. A temporary pacemaker and intra-aortic balloon pump were used to provide hemodynamic support and hemoperfusion was used in an attempt to decrease serum levels of the cardiac-depressing drugs. This patient soon experienced complete recovery without sequelae.
Cephalic Jugular Venous Blood Gas Measurement during Neonatal Venoarterial Extracorporeal Membrane Oxygenation
Authors: O'Connor Timothy A. , Haney Barbara M. , Shaffer Stanley G. , Crist Cary E.
Published: August 2023

Cannulation of the cephalic portion of the right internal jugular vein during extracorporeal membrane oxygenation (ECMO) allows for increased venous return flow to the circuit.

This procedure also allows access to venous drainage from the brain. We reviewed data from simultaneous blood gases obtained from the cephalic jugular vein and the mixed venous return in 5 neonates during venoarterial ECMO. Cephalic venous pO2 values were significantly lower than mixed venous pO2 values (P < .001). The values for pH and pCO2 did not vary between the sites. Our experience with 34 infants using cephalic jugular drainage is reviewed. Since the institution of right jugular venous drainage, the intracranial hemorrhage rate in neonates undergoing ECMO at our center has decreased from 34% to 6% (p < .01).
Case Report: Monitoring the Adequacy of Anticoagulation During CPB in Factor XII Deficiency
Authors: Ecklund J.M. , Riley J.B. , Kratz J.M. , Kizer J.
Published: August 2023

Cardiopulmonary bypass was performed on a 57 year old white male with a known Factor XII deficiency. Preoperative laboratory screening revealed an abnormal activated prothrombin time of 75.8 seconds and a pre-heparinized activated clotting time (ACT) of 560 seconds. Since this ACT was prolonged, heparin administration was managed using heparin concentrations. Thrombin times, soluble fibrin monomer complexes, and D-dimers were monitored while on bypass. Additional heparin was given to maintain heparin concentration> 3.5 U/ml. Postoperatively the patient experienced no coagulopathy, no excess bleeding, and required no homologous blood product administration. The use of heparin levels by protamine titration to monitor the adequacy of anticoagulation, as monitored by D-dimers and soluble fibrin monomer complexes proved to be successful in this patient.
Improved Fluid Management By A Simple Extracorporeal Circuit Design Change
Authors: DeBell R. H.
Published: August 2023

Extracorporeal circulation (ECC) circuits vary in design in order to fulfill the needs and perfusion plans ofthe surgical team. There are as many variations in these configurations as there are perfusion techniques. This article describes a simple circuit modification that has diverse advantages in its application. The implementation of this modification may improve sterile technique, lower prime volume, sequester blood, and add versatility in fluid management.
Review of Deep Hypothermia and Circulatory Arrest Techniques For Surgical Repair of Giant Cerebral Aneurysms
Authors: Mongero Linda B. , Sistino Joseph J.
Published: August 2023

Early experience in the 1960s with the repair of giant cerebral aneurysms utilizing cardiopulmonary bypass (CPB) with deep hypothermia and circulatory arrest was reviewed. However, due to the complications associated with CPB, its use was abandoned in the early 1970's. Surface cooling alone with open chest cardiac massage was then employed successfully in a series of neurosurgical patients.

Reintroduction of bypass techniques for core cooling using peripheral cannulation combined with neurosurgical advances has decreased the morbidity associated with this technique in the 1980s. However, some centers continue to perform these procedures with open chest cardiopulmonary bypass. Although there are advantages to the open chest technique, it is no longer necessary in most patients. With a long thin-walled venous cannula advanced from the femoral vein to the right atrium, combined with a centrifugal pump in the venous line, adequate venous return and cardiac decompression can be achieved without the need for a sternotomy. Advances in perfusion techniques and anesthetic monitoring are the hallmarks of the successful outcome in neurosurgical repairs of giant cerebral aneurysms in the 1990s.
Extracorporeal Life Support of Neonates with Congenital Cardiac Defects: Techniques Used During Cardiac Catheterization and Surgery
Authors: Faulkner Sherry C. , Chipman Carl W. , Moss M. Michele , Frazier Elizabeth A. , Love John C. , Harrell James E. , Van Devanter Stephen H. , Fasules James W.
Published: August 2023

Neonatal patients with congenital cardiac defects require proper diagnosis often by cardiac catheterization before surgical repair. In our institution, patients whose echocardiograms reveal surgically correctable lesions, but who are severely decompensated, have been placed on Extracorporeal Life Support (ECLS) prior to catheterization or surgery. Subsequent management of ECLS and cardiopulmonary bypass (CPB) are dictated by the surgical procedure. Hypothermia can be utilized while on ECLS to facilitate low-flow CPB, or circulatory arrest. Total extracorporeal circulation may be performed with the ECLS circuit, or the patient may be transferred to a conventional CPB circuit during the procedure. If required, post surgical ECLS can be facilitated through prior cannulation. We have found pre-operative institution ofECLS, in the neonate with severe congenital cardiac defects, provides immediate control of hemodynamic and respiratory problems, lowers the risk of cardiac catheterization, and reduces the usage of blood products during surgery.
Gravity Venting of the Left Ventricle: A Useful Adjunct
Authors: Chellappan Subramanian , Prabhakar Ganga , Kumar Naresch , Duran Carlos M.G.
Published: August 2023

Venting of the left ventricle helps in decompressing the heart and improves visibility during surgery. Venting may be performed by direct cannulation of the left ventricle or the pulmonary veins. It may also be performed indirectly from the aortic root or pulmonary artery. We describe a method of left ventricular venting, by gravity, using the venous return of the heart.
Pulmonary Surfactant Protein B Deficiency: A Case Report
Authors: Nelson Verna E. , Raithel Steven C. , Glenn George F.
Published: August 2023

The first reported case of pulmonary alveolar proteinosis (PAP) was documented in 1958. Since then, more cases have become evident of this unusual disease. PAP is a disease characterized by positive periodic acid-Schiff, diastase-resistant granular eosinophilic material within the alveoli. Individuals with PAP have impaired gas exchange and progressive hypoxemia. In congenital PAP, newborn infants show severe and progressive pulmonary failure at birth which leads to death. In one family, a male sibling was born with severe respiratory distress syndrome and diagnosed with congenital alveolar proteinosis (CAP) by open lung biopsy. His female sibling died at one month of age nineteen years earlier with severe respiratory disease. Her autopsy slides were consistent with CAP. This case sibling followed the same clinical course as his brother and sister diagnosed with CAP by family history. Surfactant protein 'B' deficiency was identified as the cause of the congenital alveolar proteinosis. Aggressive therapy was initiated in the case sibling with exogenous surfactant replacements, extracorporeal membrane oxygenation (ECMO) as a bridge to transplant, lung lavage, and maximum ventilator settings via conventional mechanical ventilation. The child died on ECMO day 29 after 696 hours of support.
Gross Air Handling Characteristics of Membrane Oxygenators: An In Vitro Study
Authors: Courtney Pat H. , Qi Han You , Warren E. Taliaferro , Heath Bobby J.
Published: August 2023

The goal of this study was to quantitate gross air handling characteristics of membrane oxygenators. Three oxygenator designs were tested: 1) flat plate, 2) blood-inside hollow fiber, and 3) blood-outside hollow fiber. Neither filters nor bubble traps were utilized in the test circuit; however, the purge line remained open during testing. The priming solution was Plasmalyte and expired human blood. The total circuit volume was 1000 ml with a resulting hematocrit of 23-25%. Tested blood flow range was 1-5 L/min and tested temperatures were 25°, 30° and 37°C. Tests were performed with oxygenator gas flow either on or off. Air boluses were introduced and counted by a micro bubble detector. In this study, all six oxygenators allowed macro air bubbles to pass through at flow rates of 1, 2, 3, 4 and 5 L/min. The distribution of non-visual micro bubble numbers and sizes varied with the flow rates and size of introduced air boluses. High flow rates (3-5 L/min) and 10-30 ml air boluses produced larger (81-160 μm) micro bubbles and low flow rates (1-2 L/min) and 5 ml air boluses produced smaller (1-80 μm) micro bubbles. This study shows that while membrane oxygenators may moderate, they cannot eliminate micro bubbles. Therefore, membrane oxygenators do not eliminate the risks of air during during cardiopulmonary bypass. The results suggest that arterial filters/bubble traps should be used in cardiopulmonary bypass circuits with membrane oxygenators.
Estimation of Minimum Heparin Circulation Time for Activated Clotting Time Determination
Authors: Coleman E.T. , Hargrove M. , Singh H.P. , Aherne T.
Published: August 2023

Prior to commencing cardiopulmonary bypass (CPB) anticoagulation is generally monitored by the activated clotting time (ACT). Serial ACT estimations at one minute time intervals were performed on 50 CPB patients following heparinization to establish the time required for heparin circulation and for elevation of the ACT to a preset target value of 400 seconds. The results showed that adequate anticoagulation for cannulation to proceed was achieved in 86% of samples taken one minute following heparinization. Confirmation of adequate anticoagulation at one minute would allow earlier cannulation in an emergency situation and alert the cardiac team if the heparin failed to enter the systemic circulation. Patients in whom ACT values failed to reach the target value at one minute subsequently required additional heparin, immediately, or at a later stage.
Alpha-Stat Capnography for the Sorin Monolyth Oxygenator
Authors: McCloskey David B. , Strickler R. Franklin , Reusch Gerald W.
Published: August 2023

Monitoring the carbon dioxide exhaust of an oxygenator is an inexpensive method to accurately predict and control the arterial carbon dioxide tension during cardiopulmonary bypass (CPB). The partial pressure of carbon dioxide in the exhaust ventilating gas (PexCO2) was continuously monitored from the capnograph port of the Sorin Monolyth oxygenator during CPB. At the time of routine arterial blood gas sampling, the arterial blood temperature (ABT) was recorded along with the pexCO2 from the capnograph monitor. The arterial carbon dioxide tension (paCO2) from the arterial blood sample analysis was then statistically analyzed and related to the PexCO2 and ABT. The statistical relationship of PexCO2 and ABT while employing alpha stat ventilation resulted in an exponential regression with a correlation coefficient of 0.98. The exponential regression is unique to each manufacturer's oxygenator; we have titled this the "regression signature." This regression signature can be easily learned and employed by the perfusionist during CPB as an aid in controlling oxygenator ventilation.

The mean paCO2 value obtained during the study period was 39.0 ± 2.5 mmHg. There was no statistical difference between the paCO2 values when separated into four different blood temperature groups, (<28, 28-32,32-37, and >37°C).
Low Flow Veno-Venous ECMO: An Experimental Study
Authors: Calderón M. , Verdín R. , Galván J. , Gonzalez M. , Cárdenas H. , Campos R. , Vidrio H. , Amezcua J.
Published: August 2023

Clinical use of extracorporeal membrane oxygenation (ECMO) and carbon dioxide removal (ECCO2R) have become well established techniques for the treatment of severe respiratory failure; however they require full cardiopulmonary bypass, representing major procedures with high morbidity. We theorized the possibility of an efficient low flow venavenous extracorporeal membrane gas exchange method. Four mongrel 12kg dogs were submitted to vena-venous extracorporeal membrane gas exchange via a jugular dialysis catheter using a low flow (10 ml/min) roller pump and a membrane oxygenator for a period of four hours. Respiratory rate was set at 4 breaths/min with a FiO2 of 21% and ventilatory dead space was increased. Adequate gas exchange was obtained (pO2 139, pCO2 24, Sat 99.4%), without major hemodynamic changes or hematuria. Our results demonstrate the feasibility of a low flow, less aggressive system. Further research should be considered.
Nafamostat Mesilate Reduces Blood Cell Adhesion to Cardiopulmonary Bypass Circuits: An In-Vitro Study
Authors: Hiroura Manabu , Usui Akihiko , Kawamura Mitsuo , Hibi Michiaki , Iwase Jinichi
Published: August 2023

Nafamostat mesilate (FUT-175) is a protease inhibitor, working as an inactivator of coagulation, fibrinolysis and platelet aggregation. Although FUT-175 directly blocks contact factors in coagulation, it also may decrease activation of humoral cascade systems when used in cardiopulmonary bypass circuits. We performed an in vitro study using fresh human blood in the following cardiopulmonary bypass circuits: standard circuit (C), biosurfaced circuit (B) and standard circuit containing FUT-175 (F). Each circuit was primed with 500 ml of electrolyte solution and 500 ml of fresh blood. Cardiopulmonary bypass was performed using a roller pump for four hours in two sets of each circuit configuration. Platelet factors (platelet count and beta-thromboglobulin), coagulation factors (thrombin-antithrombin III complex and fibrinopeptide A), fibrinolysis factors (alpha 2-plasmin inhibitor complex and alpha 2-plasmin inhibitor), complement factors (C3a, C4a), free hemoglobin, and granulocyte elastase were measured at the beginning and end of the study. Hemocytograms were measured concurrently. The FUT-175 group showed significantly lower levels ofthe measured indices than the biosurfaced group in thrombin-antithrombin III complex (7.4±2.1 vs. 54.9±38.1 ng/ml), fibrinopeptide A (7.2±2.0 vs. 20.2±14.6 ng/ml), beta-thromboglobulin ( 1940±250 vs. 2438±314 ng/ml) and free hemoglobin (25.2±14.3 vs. 73.8±18.4 mg/dl). There were no significant differences between Group F and Group B in platelet count, C3a, C4a and granulocyte elastase, although these indices were significantly lower in Groups F and B when compared to Group C. Therefore, FUT-17 5 appears to reduce blood-foreign surface reaction and diminishes cellular adhesion to the inner surface of the cardiopulmonary bypass circuit.
Innovations in Intra-Aortic Balloon Pump Management: Computer Modem Technology
Authors: Ingram John M.
Published: August 2023

The computer modem technology being developed by Datascope Corporation for the purpose of off-site intra-aortic balloon pump (IABP) monitoring was clinically evaluated in 30 patients requiring IABP support. The Datascope System 95 model IABP with built-in modem was used on all patients. Remote communications via a personal computer with modem were conducted under both routine and emergency settings. The Datascope PC IABP software was evaluated for its user compatibility, efficiency, diagnostic capability and overall usefulness as a clinical tool. During the eight month evaluation period, 87 remote communications were conducted for both routine and emergency IABP evaluation checks. Adjustments were recommended on 22 occasions relevant to balloon timing, trigger mode selection and augmentation volume settings. Eight communications were initiated in emergency settings due to a variety of patient conditions. Emergency intervention was successful in diagnosing and resolving critical situations including atrial arrhythmias, pacemaker timing, low cardiac output syndrome, loss of trigger source, catheter malpositioning and poor augmentation. The diagnostic capabilities and efficient means of data collection by the computer software provide the clinician with a valuable tool for routine IABP clinical monitoring, as well as emergency problem resolution.
In Vitro Evaluation of Continuous Mixed Venous Oxygen Saturation and Hematocrit Monitors
Authors: Brown Michael E. , Rawleigh Judith D. , Gallagher John M.
Published: August 2023

Four venous hemoglobin oxygen saturation monitors, two of which provide hemoglobin monitoring, were evaluated and compared to a performance standard (control) during cardiopulmonary bypass (CPB). The CDI 100 Hematocrit/Saturation Monitor, CDI 400, Cobe Hematocrit/Saturation Monitor, and the Baxter Bentley OxySat values were compared to the Radiometer Copenhagen OSM3 Hemoximeter and the Damon International Equipment Company Microbore Centrifuge Hematocrit. The Bentley OxySat meter was found to be the most accurate venous oxygen saturation monitor, with the CDI 100 and the Cobe Hct/Sat monitors correlating closely with the control. Only the CDI 400 failed to correlate with the control. The hematocrit monitors, although useful as trending devices, demonstrated inaccuracies in measurements requiring further refinement.
Conversion of Percutaneous Cardiopulmonary Bypass to Total Cardiopulmonary Bypass to Repair an Acute Ventricular Septal Defect
Authors: Jenkins Eric H. , Holt David W.
Published: August 2023

This case report describes techniques involved in the conversion of femoral-femoral percutaneous cardiopulmonary bypass to femoral/superior vena cava-femoral cardiopulmonary bypass with integrated cardiotomy suckers and cardioplegia delivery system. The conversion was instituted in order to repair an acute ventricular septal defect secondary to a myocardial infarction without switching to a traditional heart-lung machine set-up.
Modified Microsample ACT Test for Heparin Monitoring
Authors: Pan Chi-Miau , Jobes David , Riper Dan Van , Ogilby John David , Lin Chung-Yuan , Harrow Jan , Blumenthal Roger , Mendoza Marsha , LaDuca Frank
Published: August 2023

The activated clotting time (ACT) is a standard method of heparin monitoring during cardiac angioplasty and cardiac surgery. A modified ACT (ACT+) which employs a microsample blood volume (0.05 ml) and yields faster clotting time results than a conventional Hemochron ACT was evaluated and compared to the standard ACT.

The ACT+, determined using a single channel general purpose analyzer (Hemochron Jr.), employs a plastic cuvette containing dried ACT reagents (kaolin-silica-phospholipid). In vitro evaluation of heparinized normal donor blood demonstrated the test insensitivity to aprotinin. Using split blood specimens, duplicate ACT and ACT+ were performed (n=92) and a correlation between the two was established.

In evaluation of 79 cardiac surgery and 53 angioplasty patients, good correlation was observed between ACT+ and Hemochron ACT (r=0.93, n=574). Mean versus difference plots demonstrated an improved reproducibility of the ACT+ (Mean SD=35 seconds) compared to the ACT (Mean SD=53 seconds), presumably due to automation of the blood sample sizing and blood/reagent mixing. These studies indicate that the microsample ACT+ is an alternative to the conventional ACT with an advantage of small sample requirement and rapid reproducible results.
Moderate Hypothermia with Low Flow Rate Cardiopulmonary Bypass in Congenital Heart Defect Surgery
Authors: Huang Huiming , Cheng Hong , Zhu Deming , Chao Dinfang , Ding Wenxiang , Su Zhaokang
Published: August 2023

Low flow rate perfusion has been recommended in profound hypothemric cardiopulmonary bypass (CPB) in recent years, but has not been used in moderate hypothermic CPB. In this report, 30 patients with congenital heart defects, from 2 to 11 years old and weighing 11.5 to 25 kg. were selected to be the subjects of moderate hypothermia with low flow rate perfusion. Once on CPB, a high flow rate of 2.27 ± 0.36 L/min/m2 was used to cool the patient to 25.6 ± 0.84°C rectal, 24.1 ± 1.32°C esophageal, and 23.8 ± 1.4°C tympanic temperature, followed by a low flow rate of 1.23 ± 0.09 Llmin/m2 until the main intracardiac repair was completed. Rewarming to a rectal temperature of 34.5–35.0°C was accomplished with a high flow rate of 2.70 ± 0.22 L/min/m2 until weaning. The total CPB, cross clamp, and low flow rate perfusion times were 95.4 ± 34.6 min, 51.4 ± 20.2 min, and 45.7 ± 22.4 min respectively. A second group of five patients from 1.5 to 4 years old and from 6 to 11 kg were operated on with profound hypothermic circulatory arrest. A high flow rate of 2.35 ± 0.43 L/min/m2 was used to cool the temperature to 19.3 ± 0.8°C rectal, 17.5 ± 2.2°C esophageal, and 17.8 ± 1.5°C tympanic, and then the circulation was temporarily arrested. The CPB and arrest time were 55.0 ± 10.7 min and 44.7 ± 3.8 min respectively. Among the patients under moderate hyperthermia with low flow rate perfusion, only one showed metabolic acidosis during cardiopulmonary bypass and received an extra 12 mEq sodium bicarbonate. After 27 to 99 min low flow rate perfusion. the venous oxygen saturation was still greater than 80% for each patient and lactate concentration did not increase. In contrast, among those cases using profound hypothermic circulatory arrest, the blood gas analysis after two min of rewarming demonstrated an obvious metabolic acidosis and increase in lactate concentration. An extra 9 to 24 mEq sodium bicarbonate was needed in each of five patients for acidosis correction. After the sodium bicarbonate administration, the blood gases returned to normal while the lactate concentration still increased progressively. The data from this study suggest that low flow rate perfusion may safely be used in moderate hyperthermic CPB as long as we monitor the oxygen saturation of returned venous blood, keeping it above 80%.
Wettbewerb in der Krankenversicherung – sinnvoll und
möglich? Gedanken zur wettbewerblichen Versorgungssteuerung
dreißig Jahre nach Lahnstein
Authors: Vauth Christoph , Zerth Jürgen
Published: August 2023

Mit dem sogenannten Lahnstein-Kompromiss wurde Anfang der 1990er Jahre die Idee
einer wettbewerblichen Steuerung im Gesundheitswesen eröffnet. Die Frage
nach den Begründungsebenen einer derartigen Wettbewerbssteuerung,
insbesondere die Erwartungen an die Effizienzhypothesen im statischen und
dynamischen Wettbewerb, sind auch nach 30 Jahren in nicht klar umrissen bzw.
stehen auch politisch in der Diskussion. Eine grundlegende Rahmung für
die Möglichkeiten und auch Grenzen wettbewerblicher Steuerung
aufzuzeigen, dabei das Spannungsverhältnis zur normativen
Begründung einer Regelleistungsdefinition zu berücksichtigen,
steht im Mittelpunkt des Beitrages, der gleichzeitig Ausgangspunkt für
weitere Beiträge zur Wettbewerbsrolle sein soll.
Posterior fossa choroidplexus papilloma in the pediatric population: case series and literature review
Authors: Pongeluppi Rodrigo Inácio , Ballestero Matheus Fernando Manzolli , Santos Marcelo Volpon , Oliveira Ricardo Santos de
Published: August 2023

Choroid plexus papillomas (CPPs) are rare benign neoplasms which are particularly uncommon in the posterior fossa in children. We herein present a case series of five patients treated at a tertiary care hospital. A comprehensive literature review was also carried out. The patients treated at the tertiary care hospital were aged between 4 and 16 years. Gross total resection (GTR) was initially achieved in two patients. All patients showed clinical improvement. Moreover, 27 articles published between 1975 and 2021 were selected for the literature review, totaling 46 patients; with the 5 patients previously described, the total sample was composed of 51 cases, With a mean age was 8.2 years. The lesions were located either in the fourth ventricle (65.3%) or the cerebellopontine angle (34.7%). Hydrocephalus was present preoperatively in 66.7% of the patients, and a permanent shunt was required in 31.6% of the cases. The GTR procedure was feasible in 64.5%, and 93.8% showed clinical improvement. For CPPs, GTR is the gold standard treatment and should be attempted whenever feasible, especially because the role of the adjuvant treatment remains controversial. Neuromonitoring is a valuable tool to achieve maximal safe resection. Hydrocephalus is common and must be recognized and promptly treated. Most patients will need a permanent shunt. Though there is still controversy on its efficacy, endoscopic third ventriculostomy is a safe procedure, and was the authors' first choice to treat hydrocephalus.
Robotic Transanal Minimally Invasive Surgery for Rectal Polyps
Authors: Friedman Garrett , Rodriguez Miguel
Published: August 2023

Transanal minimally invasive surgery (TAMIS) can be utilized to manage a wide variety of rectal lesions but can be technically demanding with traditional laparoscopic equipment. Robotic platforms such as the da Vinci Single Port system can reduce the technical barriers of TAMIS and allow more complicated lesions to be addressed. Robotic TAMIS with the SP system follows similar indications for local excision of benign and malignant lesions as conventional TAMIS or even transanal endoscopic microsurgery. We describe our initial experience using the SP system and provide technical suggestions for how to incorporate this technology. We also address innovations in flexible endoscopic robotic surgery that we anticipate will allow for increased use of organ preservation of the colon and rectum, as well as possibly expand the use of natural orifice surgery.
Brazilian headache registry: methods and preliminary data of the pilot study
Authors: Grassi Vanise , Jurno Mauro Eduardo , Fröhlich Alan Christmann , Rieder Carlos Roberto de Mello , Sarmento Elder Machado , Pereira Júlia Kássia , Silva Leonardo Lima , Barea Liselotte Menke , Poli Luiz Ernesto Besen , Queiroz Luiz Paulo , Ciciarelli Marcelo Cedrinho , Peres Mario Fernando Prieto , Rocha Filho Pedro Augusto Sampaio , Vieira Rebeca Veras de Andrade , Londero Renata Gomes , Kowacs Fernando
Published: August 2023

Background Evaluation and treatment of primary and secondary headaches is a global public health challenge. Recognizing the epidemiological impact of headaches, a group of researchers linked to the Brazilian Headache Society proposed the Brazilian Headache Registry and drew up its initial protocol.

Objective Here we describe the methods and preliminary data obtained from the pilot study.

Methods This was a multicenter longitudinal observational study conducted between September 2020 and August 2021. Prospective data were collected in three specialist centers for headache care in states in southern and southeastern Brazil. Patients aged 18 years or older who sought care for headache in tertiary centers and who agreed to participate in the study, were considered eligible.

Results Sixty-six patients were included in the pilot study: 43 (65%) from Rio Grande do Sul state and 23 (35%) from Minas Gerais state. Overall, 90% were female, and the subjects' mean age was 38.2 ± 11.2 years. Primary headaches accounted for 85.3% of the diagnoses made. Among secondary headaches, medication overuse headache was the most frequent type (7.1%).

Conclusions The pilot study showed the feasibility of the research protocol developed for tertiary centers. The Brazilian Headache Registry will form a source of longitudinal data with the aim of contributing to better characterization of the various phenotypes of patients with primary and secondary headaches, and to detailing the use of health resources and identifying predictors of better clinical outcomes.
Clinical Performance and Outcomes of an Injectable Bone Graft Substitute Following Core Decompression during the Treatment of Osteonecrosis of the Femoral Head
Authors: McConaghy Kara , Louiselle Erika L. , Knight Ashley D. , Rullán Pedro J. , Hortensius Rebecca A. , Fitch David A. , Piuzzi Nicolas S.
Published: August 2023

Osteonecrosis of the femoral head (ONFH) can be challenging to manage, as it primarily affects younger adult patients. Hip preservation is preferred in this population, and there is a heightened focus on treatment strategies such as biologic adjuvants and bone grafting. Therefore, the objective of this systematic literature review was to evaluate the clinical performance of a commercially available injectable bone graft substitute (calcium sulfate [CaSO4]/calcium phosphate [CaPO4]; Pro-Dense, Wright Medical Technology Inc., Memphis, TN) following core decompression for the management of ONFH. Specifically, we aimed to examine (1) patient-reported outcomes, (2) progression of disease, (3) rate of revision, and (4) complications. A systematic literature review was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses, using PubMed, Google Scholar, and Cochrane Library in July 2020 (gap search conducted in March 2022). The review included all clinical studies, published in English, on the use of an injectable bone graft substitute in ONFH-related procedures since 2007. Meta-analysis was conducted on Harris Hip Score (HHS), Visual Analog Scale (VAS), progression of disease, rate of revision, and complications. Nine studies were identified, with a total of 390 subjects ranging in age from 15 to 70 (weighted mean = 40.4) years old, with a weighted mean follow-up time of 37.1 months. Weighted mean improvement in HHS was +17.5 points (n = 296 procedures), while weighted mean improvement in VAS score was –3.0 points (n = 188 procedures). Overall weighted progression of disease for all patients was 6.1% (n = 17.9), including studies reporting precollapse (5.9%; n = 9.1/155) and/or postcollapse (9.91%; n = 16/162) lesions. Overall weighted revision rate was 2.9% (n = 11.5/390), including studies reporting precollapse (3.2%; n = 7.7/239) and/or postcollapse (4.3%; n = 8.2/191) lesions. The minor complication rate was 1.02% (n = 3/293), with no major complications reported. Clinical evidence on injectable CaSO4/CaPO4 bone graft substitute supports an acceptable benefit–risk profile, including safe real-world use since 2007, following core decompression for the treatment of ONFH.
In Search of the Holy Grail of Artificial Hearts: Are We There Yet?
Authors: Volod Oksana , Colon Modesto J. , Arabía Francisco A.
Published: August 2023

The total artificial heart (TAH) has a long and rich history, being the product of decades of innovation, hard work, and dedication. This review examines the history of the TAH, a device that has revolutionized the treatment of end-stage biventricular heart failure. It reviews the development of the device from early concepts to the current state-of-the-art device, the SynCardia TAH, which has been implanted in over 2,000 patients worldwide. The article also discusses the challenges and successes experienced by researchers, clinicians, and patients throughout the development of TAH devices. Our focus will also be on discussing the hemostatic alterations in patients implanted with TAH and anticoagulation strategies to decrease associated thromboembolic risks. The article concludes with a look at other novel TAH devices and the future of TAH as an increasingly viable treatment for end-stage heart failure.
Median: Reha-Gigant wird Umsatzmilliardär
Authors: Schmidt Hartmut
Published: August 2023

2021 lief für Median coronabedingt schlechter als geplant. Dennoch wird das Unternehmen zum neuen Umsatzmilliardär im Bereich Kliniken aufsteigen.
Rechtskolumne: Hirnschädigung nach Medikamentengabe: Die Compliance ist entscheidend
Authors: Weimer Tobias
Published: August 2023

Medikamentengabe im Krankenhaus ist Routine, aber gerade bei personellen Engpässen können kritische Situationen auftreten. Ein Fall vor dem Oberlandesgericht (OLG) Frankfurt verdeutlicht dies.
Krankenhäuser im ländlichen Raum: Zwischen Kliniksterben und Existenzgarantie
Authors: Hohnstein Aileen
Published: August 2023

Lange Distanzen, weniger Einwohnerzahlen – der ländliche Raum hat mit speziellen Herausforderungen zu kämpfen, die vor Ort die Gesundheitsversorgung erschweren. Neue Versorgungmodelle, die mehr Verzahnung von Ambulant und Stationär ermöglichen, sollen einen Ausweg bieten. Doch die gesetzlichen Grundlagen dafür stehen noch nicht fest. Die Deutsche Krankenhausgesellschaft drängt daher auf schnelle Entscheidungen, um kleinen Klinikstandorten eine Perspektive zu geben.
Digitales Bettenmanagement: Kleiner Eingriff, großes Aha
Authors: Dirks Claudia
Published: August 2023

Es ist ein scheinbar kleines Rädchen in der Maschinerie Krankenhaus, aber das Bettenmanagement entscheidet mit über die Produktivität eines Standortes. Digitale Lösungen sind hier nicht nur wirtschaftliche Schlüsselfaktoren, sie können darüber hinaus die Mitarbeitenden relevant entlasten.
Careocracy or isocracy? A feminist alternative to the neoliberal meritocratic discourse
Authors: Santori Paolo
Published: August 2023

The message of neoliberal meritocratic discourse, prevalent today and spreading throughout Western societies, is simple: free, unregulated markets are meritocratic. This is a way of placing a veil of social justice (i.e., markets reward merit) over neoliberal ideas. The worrisome consequences attached to it are the moral legitimation of inequalities and the reduction of social value to market value. The dimension of care is among the many values sacrificed to the altar of neoliberal meritocratic discourse. While feminist scholarship has criticized neoliberalism for its marginalization of care (primarily unpaid household activity performed by women) and care work (poorly rewarded to attract intrinsically motivated care providers), little has been done to address neoliberal meritocracy. This paper aims to fill this gap by sustaining three theses: (1) free markets are not meritocratic domains; (2) a counter-narrative advocating for a society grounded on careocracy (meritocracy of care) fails to address problems of neoliberal meritocratic discourse; and (3) a fruitful counter-discourse is the isocratic one, with an isocratic society being one where the sources of social value are plural and discussed by citizens.
How solar panels work, in theory and in practice
Authors: Krisciunas Kevin
Published: August 2023

We present an analysis of the functionality of an array of monocrystalline silicon solar panels over a 22 month period. For simple geometrical reasons, one expects the solar power produced to be linearly proportional to the cosine of the incidence angle of the Sun’s light on the panels. This can be demonstrated with high accuracy (root-mean-square scatter of less than one percent), but one must first correct the measured solar power for the dimming effect of the Earth’s atmosphere as a function of the atmospheric path length that the Sun’s light traverses. We elaborate a simple and robust method for determining the atmospheric extinction term on days with clear sky conditions. There are two situations under which the extinction-corrected data deviate from the linear relation. One is due to the heating of the panels during daylight hours, resulting in their being less efficient. The other is manifested as an increase of power that occurs when the sky is partially filled with reflective clouds. This is the phenomenon of cloud enhancement.
Analysis of the numerical scheme of the one-dimensional fractional Rayleigh–Stokes model arising in a heated generalized problem
Authors: Mesgarani H. , Aghdam Y. Esmaeelzade , Khoshkhahtinat M. , Farnam B.
Published: August 2023

In this paper, we present a well-organized method to estimate the one-dimensional fractional Rayleigh–Stokes model using the construction of orthogonal Gegenbauer polynomials (GBPs) and Lagrange square interpolation to estimate the time derivative. Therefore, we design an authentic and fast numerical calculation approach based on the elaborated convergence rate recovery method. The matrix of the derivative operation of an orthogonal GBP is gained by employing the characteristic of this type of polynomial. The privilege of the numerical method is the orthogonality of the GBP and operational matrices, which reduces time computation and increases speed. Eventually, we propose three numerical examples to check the validity and numerical studies to illustrate the precision and efficiency of the new approach.
Signal transmission analysis in implantable human body communication for abdominal medical devices
Authors: Muramatsu Dairoku , Kodama Miyu
Published: August 2023

Implantable medical devices, such as neurostimulators, need to be wirelessly controlled from outside the body. Many of these devices use high-frequency signals in the 400 MHz, 900 MHz, and 2.45 GHz bands to communicate with external devices. However, high-frequency bands can suffer from signal attenuation in biological tissues and from electromagnetic interference with surrounding devices. In contrast, human body communication (HBC) uses relatively low frequencies in the 3–30 MHz band, which can alleviate signal attenuation and prevent emissions outside the body during communication. In this study, we investigated the use of HBC for implantable medical devices in the abdomen using electromagnetic field simulations. The results showed that the transmission between the transmitter inside the body and the receiver outside the body was adequate for stable communication. However, when the receiver was detached from the skin surface, the transmission characteristics rapidly decreased. Moreover, when the receiver and skin were separated by 1 mm, the transmission degraded by 34 dB, indicating that electromagnetic interference between the implanted transmitter and surrounding devices (including other medical devices) is rare. Finally, we evaluated the proposed system from the perspective of medical electromagnetic compatibility and human safety. The simulation results demonstrated that the radiated emissions and human exposure of the HBC system meet international standards.
Superconductivity in hyperdoped Ge by molecular beam epitaxy
Authors: Strohbeen Patrick J. , Brook Aurelia M. , Sarney Wendy L. , Shabani Javad
Published: August 2023

Superconducting germanium films are an intriguing material for possible applications in fields such as cryogenic electronics and quantum bits. Recently, there has been a great deal of progress in hyperdoping of Ga doped Ge using ion implantation. Thin film growth of such a material would be advantageous, allowing homoepitaxy of doped and undoped Ge films and opening possibilities for vertical Josephson junctions. Here, we present our studies on the growth of one layer of hyperdoped superconducting germanium thin film via molecular beam epitaxy. We observe a fragile superconducting phase, which is extremely sensitive to processing conditions and can easily phase-segregate, forming a percolated network of pure gallium metal. By suppressing phase segregation through temperature control, we find a superconducting phase that is unique and appears coherent to the underlying Ge substrate.