Development of Prone Position Ventilation Device and Study on the Application Effect of Combined Life Support Technology in Critically Ill Patients.

Objective: This study aims to evaluate a novel prone position ventilation device designed to enhance patient safety, improve comfort, and reduce adverse events, facilitating prolonged tolerance in critically ill patients. Methods: A randomized controlled trial was conducted on 60 critically ill patients from January 2020 to June 2023. Of which, one self-discharged during treatment and another was terminated due to decreased oxygenation, leaving an effective sample of 58 patients. Patients were allocated to either a control group receiving traditional prone positioning aids (ordinary sponge pads and pillows) or an intervention group using a newly developed adjustable prone positioning device. A subset of patients in each group also received life support technologies such as extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT). We assessed prone position ventilation tolerance, oxygen saturation increments postintervention, duration of prone positioning, CRRT filter lifespan, and the incidence of adverse events. Results: The intervention group exhibited significantly longer average tolerance to prone positioning (16.6 hours vs. 8.3 hours, P < 0.001 with a difference of 8.3 (4.4, 12.2) hours), higher increases in oxygen saturation postventilation (9% vs. 6%, P < 0.001 with a difference of 3.0 (1.5, 4.5)), and reduced time required for medical staff to position patients (11.7 min vs. 21.8 min, P < 0.001 with a difference of -10.1 (-11.9, -8.3)). Adverse events, including catheter displacement or blockage, facial edema, pressure injuries, and vomiting or aspiration, were markedly lower in the intervention group, with statistical significance (P < 0.05). In patients receiving combined life support, the intervention group demonstrated improved catheter blood drainage and extended CRRT filter longevity. Conclusion: The newly developed adjustable prone ventilation device significantly improves tolerance to prone positioning, enhances oxygenation, and minimizes adverse events in critically ill patients, thereby also facilitating the effective application of life support technologies.

Haemodynamic support with percutaneous devices in patients with cardiogenic shock: the current evidence of mechanical circulatory support.

INTRODUCTION: Cardiogenic shock (CS) is a complex life-threatening condition that results from primary cardiac dysfunction, leading to persistent hypotension and systemic hypoperfusion. Among the therapeutic options for CS are various percutaneous mechanical circulatory support (MCS) devices that have emerged as an increasingly effective hemodynamic support option. Percutaneous therapies can act as short-term mechanical circulatory assistance and can be split into intra-aortic balloon pump (IABP) and non-IABP percutaneous mechanical devices. AREAS COVERED: This review will evaluate the MCS value while considering the mortality rate improvements. We also aim to outline the function of pharmacotherapies and percutaneous hemodynamic MCS devices in managing CS patients to avoid the onset of end-organ dysfunction and improve both early and late outcomes. EXPERT OPINION: Given the complexity, acuity and high mortality associated with CS, and despite the availability and efficacy of pharmacological management, MCS is required to achieve hemodynamic stability and improve survival. Various percutaneous MCS devices are available with varying indications and clinical outcomes. The rates of early mortality and complications were found to be comparable between the four devices, yet, IABP seemed to show the most optimal clinical profile whilst ECMO demonstrated its more long-term efficacy.

Usefulness of net retrieval devices for central airway obstruction caused by blood clots during extracorporeal membrane oxygenation: Case series.

RATIONALE: Extracorporeal membrane oxygenation (ECMO) is the last trump card for severe respiratory failure. The main complications of ECMO are bleeding and thrombosis, both of which can be life-threatening. Large blood clots can cause central airway obstruction (CAO) during ECMO, and CAO should be removed as soon as possible because of asphyxiation. However, there is no comprehensive reports on its frequency and management. The purpose of this study is to share therapeutic experiences for rare and serious conditions and provide valuable insights. PATIENT CONCERNS: We report 3 patients placed on ECMO for severe respiratory failure. DIAGNOSIS: CAO due to large blood clots occurred during ECMO in all 3 patients. INTERVENTIONS: Large blood clots were removed using flexible bronchoscopy, grasping forceps, and net retrieval devices in all 3 patients. OUTCOMES: In all 3 patients, large blood clots were removed multiple times during ECMO. The patients' respiratory conditions improved and they were eventually weaned off the ECMO. LESSONS: CAO due to large blood clots during ECMO is rare. The frequency of CAO requiring bronchoscopic removal was estimated to be approximately 1,5%. When this occurs, clots should be removed as soon as possible. Net retrieval devices are useful tools for the collection of large blood clots.

Direct Apical Cannulation With Protek Duo Rapid Deployment Cannula via Mini Thoracotomy for Ambulatory Venoarterial-Extracorporeal Membrane Oxygenation.

National trends show rapid increases in the use of mechanical circulatory support devices (MCSD) over the last 20 years. While current literature has not proven a mortality benefit in cardiogenic shock as a complication of acute myocardial infarction (AMI-CS) with percutaneous MCSD, these devices are vital to maximizing cardiopulmonary parameters for definitive therapy. To minimize complications, many different techniques have been described including a novel off-pump direct apical cannulation for venoarterial-extracorporeal membrane oxygenation (VA-ECMO). This technique allows early ambulation and avoids peripheral artery access complications but has only been described in small case series. Our case series represents the largest summary of patients (50) using this technique and contains the only comparison data to date. Fifty-four percentage of our patients were Society for Cardiovascular Angiography and Interventions (SCAI) stage D and 22% were arrested before cannulation. We achieved flows on average >5 L/min and most patients required biventricular drainage (86%) and an oxygenator (92%). Thirty day survival was 56% and most survivors were bridged to heart transplant (30%). Our most common complication was bleeding (16%). This technique showed significant improvement in ejection fraction (EF), cardiac output/index (CO/CI), and pulmonary artery pressures. This case series demonstrates the safety and efficacy of this novel technique for central cannulation in cardiogenic shock at large scale within a single institution.

Pathophysiology, diagnosis and management of right ventricular failure: A state of the art review of mechanical support devices.

The function of the right ventricle (RV) is to drive the forward flow of blood to the pulmonary system for oxygenation before returning to the left ventricle. Due to the thin myocardium of the RV, its function is easily affected by decreased preload, contractile motion abnormalities, or increased afterload. While various etiologies can lead to changes in RV structure and function, sudden changes in RV afterload can cause acute RV failure which is associated with high mortality. Early detection and diagnosis of RV failure is imperative for guiding initial medical management. Echocardiographic findings of reduced tricuspid annular plane systolic excursion (<1.7) and RV wall motion (RV S' <10 cm/s) are quantitatively supportive of RV systolic dysfunction. Medical management commonly involves utilizing diuretics or fluids to optimize RV preload, while correcting the underlying insult to RV function. When medical management alone is insufficient, mechanical circulatory support (MCS) may be necessary. However, the utility of MCS for isolated RV failure remains poorly understood. This review outlines the differences in flow rates, effects on hemodynamics, and advantages/disadvantages of MCS devices such as intra-aortic balloon pump, Impella, centrifugal-flow right ventricular assist devices, extracorporeal membrane oxygenation, and includes a detailed review of the latest clinical trials and studies analyzing the effects of MCS devices in acute RV failure.

Quantifying potential fluid transfused through pressure monitoring and circuit flushes in pediatric ECMO patients.

Pressure monitoring on pediatric Extracorporeal Membrane Oxygenation (ECMO) circuits is used to aid in the evaluation of patient hemodynamics and circuit health. Extracorporeal Life Support Organization (ELSO) recommends monitoring pressures on the venous line, pre-, and post-oxygenator. In order to keep pressure ports patent, crystalloid can be used as a flush. The fluid transfused to the patient through these lines can be challenging to quantify accurately due to variance in clinician practice. Currently, there is no published data or practice suggestions on this topic. In Vitro experiments using Edwards True Wave transducers and pressure bags were constructed, allowing for common negative and positive pressures to be simulated. Passive volume infused through the transducer as well as intermittent active flushing by pulling the snap tab were measured and the volumes were recorded. When the pressure transducer and associated tubing are kept patent by using a pressurized IV bag, per the instructions for use, the daily volume transfused was found to be 319.6 mL or close to a typical neonate's total blood volume. Rather than using passive or active flushing, the use of automated syringe pumps can reduce the transfused volume to 24 mL per day. Further study is recommended to develop and publish best practices.

Scaled-up Microfluidic Lung Assist Device for Artificial Placenta Application with High Gas Exchange Capacity.

Premature neonates with underdeveloped lungs experience respiratory issues and need respiratory support, such as mechanical ventilation or extracorporeal membrane oxygenation (ECMO). The "artificial placenta" (AP) is a noninvasive approach that supports their lungs and reduces respiratory distress, using a pumpless oxygenator connected to the systemic circulation, and can address some of the morbidity issues associated with ECMO. Over the past decade, microfluidic blood oxygenators have garnered significant interest for their ability to mimic physiological conditions and incorporate innovative biomimetic designs. Achieving sufficient gas transfer at a low enough pressure drop for a pumpless operation without requiring a large volume of blood to prime such an oxygenator has been the main challenge with microfluidic lung assist devices (LAD). In this study, we improved the gas exchange capacity of our microfluidic-based artificial placenta-type LAD while reducing its priming volume by using a modified fabrication process that can accommodate large-area thin film microfluidic blood oxygenator (MBO) fabrication with a very high gas exchange surface. Additionally, we demonstrate the effectiveness of a LAD assembled by using these scaled-up MBOs. The LAD based on our artificial placenta concept effectively increases oxygen saturation levels by 30% at a flow rate of 40 mL/min and a pressure drop of 23 mmHg in room air, which is sufficient to support partial oxygenation for 1 kg preterm neonates in respiratory distress. When the gas ambient environment was changed to pure oxygen at atmospheric pressure, the LAD would be able to support premature neonates weighing up to 2 kg. Furthermore, our experiments reveal that the LAD can handle high blood flow rates of up to 150 mL/min and increase oxygen saturation levels by ∼20%, which is equal to an oxygen transfer of 7.48 mL/min in an enriched oxygen environment and among the highest for microfluidic AP type devices. Such performance makes this LAD suitable for providing essential support to 1-2 kg neonates in respiratory distress.

Platelet Adhesion and Activation in an ECMO Thrombosis-on-a-Chip Model.

Use of extracorporeal membrane oxygenation (ECMO) for cardiorespiratory failure remains complicated by blood clot formation (thrombosis), triggered by biomaterial surfaces and flow conditions. Thrombosis may result in ECMO circuit changes, cause red blood cell hemolysis, and thromboembolic events. Medical device thrombosis is potentiated by the interplay between biomaterial properties, hemodynamic flow conditions and patient pathology, however, the contribution and importance of these factors are poorly understood because many in vitro models lack the capability to customize material and flow conditions to investigate thrombosis under clinically relevant medical device conditions. Therefore, an ECMO thrombosis-on-a-chip model is developed that enables highly customizable biomaterial and flow combinations to evaluate ECMO thrombosis in real-time with low blood volume. It is observed that low flow rates, decelerating conditions, and flow stasis significantly increased platelet adhesion, correlating with clinical thrombus formation. For the first time, it is found that tubing material, polyvinyl chloride, caused increased platelet P-selectin activation compared to connector material, polycarbonate. This ECMO thrombosis-on-a-chip model can be used to guide ECMO operation, inform medical device design, investigate embolism, occlusion and platelet activation mechanisms, and develop anti-thrombotic biomaterials to ultimately reduce medical device thrombosis, anti-thrombotic drug use and therefore bleeding complications, leading to safer blood-contacting medical devices.

Point-of-Care Bedside Brain Magnetic Resonance Imaging Is Safe in Extracorporeal Membrane Oxygenation Patients With Swan Ganz Catheters: A Phantom Experiment and Single Center Experience.

INTRODUCTION: More than 1.2 million pulmonary artery catheters (PACs) are used in cardiac patients per annum within the United States. However, it is contraindicated in traditional 1.5 and 3T magnetic resonance imaging (MRI) scans. We aimed to test preclinical and clinical safety of using this imaging modality given the potential utility of needing it in the clinical setting. METHODS: We conducted two phantom experiments to ensure that the electromagnetic field power deposition associated with bare and jacketed PACs was safe and within the acceptable limit established by the Food and Drug Administration. The primary end points were the safety and feasibility of performing Point-of-Care (POC) MRI without imaging-related adverse events. We performed a preclinical computational electromagnetic simulation and evaluated these findings in nine patients with PACs on veno-arterial extracorporeal membrane oxygenation. RESULTS: The phantom experiments showed that the baseline point specific absorption rate through the head averaged 0.4 W/kg. In both the bare and jacketed catheters, the highest net specific absorption rates were at the neck entry point and tip but were negligible and unlikely to cause any heat-related tissue or catheter damage. In nine patients (median age 66, interquartile range 42-72 y) with veno-arterial extracorporeal membrane oxygenation due to cardiogenic shock and PACs placed for close hemodynamic monitoring, POC MRI was safe and feasible with good diagnostic imaging quality. CONCLUSIONS: Adult ECMO patients with PACs can safely undergo point-of-care low-field (64 mT) brain MRI within a reasonable timeframe in an intensive care unit setting to assess for acute brain injury that might otherwise be missed with conventional head computed tomography.

Novel tubing connectors reduce ECMO circuit thrombosis.

BACKGROUND: Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions. METHODS: A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots. RESULTS: In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p < 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p < 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p < 0.001). CONCLUSION: Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.

Early thrombus detection in the extracorporeal membrane oxygenation circuit by noninvasive real-time ultrasonic sensors.

Thrombus formation in extracorporeal membrane oxygenation (ECMO) remains a major concern as it can lead to fatal outcomes. To the best of our knowledge, there is no standard non-invasive method for quantitatively measuring thrombi. This study's purpose was to verify thrombus detection in an ECMO circuit using novel, non-invasive ultrasonic sensors in real-time, utilizing the fact that the ultrasonic velocity in a thrombus is known to be higher than that in the blood. Ultrasonic sensors with a customized chamber, an ultrasonic pulse-receiver, and a digital storage oscilloscope (DSO) were used to set up the measuring unit. The customized chamber was connected to an ECMO circuit primed with porcine blood. Thrombi formed from static porcine blood were placed in the circuit and ultrasonic signals were extracted from the oscilloscope at various ECMO flow rates of 1-4 L/min. The ultrasonic signal changes were successfully detected at each flow rate on the DSO. The ultrasonic pulse signal shifted leftward when a thrombus passed between the two ultrasonic sensors and was easily detected on the DSO screen. This novel real-time non-invasive thrombus detection method may enable the early detection of floating thrombi in the ECMO system and early management of ECMO thrombi.

The impact of small movements with dual lumen cannulae during venovenous extracorporeal membrane oxygenation: A computational fluid dynamics analysis.

BACKGROUND AND OBJECTIVES: Venovenous Extracorporeal Membrane Oxygenation (VV ECMO) provides respiratory support to patients with severe lung disease failing conventional medical therapy. An essential component of the ECMO circuit are the cannulas, which drain and return blood into the body. Despite being anchored to the patient to prevent accidental removal, minor cannula movements are common during ECMO. The clinical and haemodynamic consequences of these small movements are currently unclear. This study investigated the risk of thrombosis and recirculation caused by small movements of a dual lumen cannula (DLC) in an adult using computational fluid dynamics. METHODS: The 3D model of an AVALON Elite DLC (27 Fr) and a patient-specific vena cava and right atrium were generated for an adult patient on ECMO. The baseline cannula position was generated where the return jet enters the tricuspid valve. Alternative cannula positions were obtained by shifting the cannula 5 and 15 mm towards inferior (IVC) and superior (SVC) vena cava, respectively. ECMO settings of 4 L/min blood flow and pulsatile flow at SVC and IVC were applied. Recirculation was defined as a scalar value indicating the infused oxygenated blood inside the drainage lumen, while thrombosis risk was evaluated by shear stress, stagnation volume, washout, and turbulent kinetic energy. RESULTS: Recirculation for all models was less than 3.1 %. DLC movements between -5 to 15 mm increased shear stress and turbulence kinetic energy up to 24.7 % and 11.8 %, respectively, compared to the baseline cannula position leading to a higher predicted thrombosis risk. All models obtained a complete washout after nine seconds except for when the cannula migrated 15 mm into the SVC, indicating persisting stasis and circulating zones. CONCLUSION: In conclusion, small DLC movements were not associated with an increased risk of recirculation. However, they may increase the risk of thrombosis due to increased shear rate, turbulence, and slower washout of blood. Developing effective cannula securement devices may reduce this risk.

Clinical Effects of Nitric Oxide Added to the Oxygenator of Children on Extracorporeal Membrane Oxygenation: Pre-Post Cohort Study.

Nitric oxide (NO) can be safely delivered through the sweep gas to the oxygenator of an extracorporeal membrane oxygenation (ECMO) circuit. It has theoretical benefits such as preventing platelet adhesion to surfaces, mitigating inflammatory response and protection against ischemia-reperfusion injury. In this uncontrolled before-after study of children on ECMO, the outcomes of those who received NO were compared with those who did not. Among 393 ECMO runs (from 337 patients), 192 of 393 (49%) received NO and 201 of 393 (51%) did not. The use of NO was associated with a 37% reduction in circuit change (adjusted risk ratio [aRR]: 0.63, 95% confidence interval [CI]: 0.42-0.93). The aRR (95% CI) for risk of neurologic injury was 0.72 (0.47-1.11). We observed potential heterogeneity of treatment effect for the risk of neurologic injury in children who had cardiac surgery: the risk with NO was lower in those who had cardiac surgery (aRR: 0.50, 95% CI: 0.26-0.96). There was no difference in survival between the study groups. In children managed with NO delivered through the ECMO circuit, we report a reduction in observed rate of circuit change and lower risk of neurologic injury in children who underwent cardiac surgery. Nitric oxide therapy on ECMO warrants prospective evaluation in children.

ECMOve: A Mobilization Device for Extracorporeal Membrane Oxygenation Patients.

Extracorporeal membrane oxygenation (ECMO) is a temporary lifesaving treatment for critically ill patients with severe respiratory or cardiac failure. Studies demonstrated the feasibility of in-hospital mobilizing during and after ECMO treatment preventing neuromuscular weakness and impaired physical functioning. Despite more compact mobile ECMO devices, implementation of ambulatory ECMO remains labor-intensive, complex, and challenging. It requires a large multidisciplinary team to carry equipment, monitor and physically support the patient, and to provide a back-up wheelchair in case of fatigue. Moreover, there is no adequate solution to ensure the stability of the patient's cannula and circuit management during ambulation. We developed a system contributing to improvement and innovation of current ambulatory ECMO patient programs. Our modular cart-in-cart system carries necessary ECMO equipment, features an extendable walking frame, and contains a folding seat for patient transport. An adjustable shoulder brace with lockable tubing-connectors enables safe fixation of the blood tubing. ECMOve provides safety, support, and accessibility while performing ambulatory ECMO for both patient and caregiver. Prototype evaluation in a simulated intensive care unit showed feasibility of our design, but needs to be evaluated in clinical care.

ECPELLA: Beyond a Left Ventricular Venting Strategy When to Unload the Left Ventricle and How to Decide.

Left ventricular (LV) unloading has been shown to improve survival for patients requiring veno-arterial extracorporeal membrane oxygenation (VA ECMO) support for cardiogenic shock. A mortality benefit has been shown for ECMO and concomitant placement of a transcatheter unloading LV pump such as an Impella device (colloquially referred to as ECPELLA or ECMELLA) for patients resuscitated with VA ECMO after a short period of cardiac arrest. Despite the described benefit of LV unloading with VA ECMO for cardiopulmonary resuscitation, it remains unclear as to what criteria should be used and what other diagnostic and therapeutic adjuncts may be useful. We describe here the successful utilization of concomitant VA ECMO and Impella in a 43 year old male with acute heart failure and cardiac arrest. Distinguishing itself from the currently reported methods, our methodology incorporates transesophageal echocardiography (TEE) in the emergency department for rapid decision-making in addition to an automatic chest compression device, the Lund University Cardiac Assist System (LUCAS) device (Stryker, Portage, MI) as a bridge to LV unloading in a hybrid operating suite.

First 24-Hour-Long Intensive Care Unit Testing of a Clinical-Scale Microfluidic Oxygenator in Swine: A Safety and Feasibility Study.

Microfluidic membrane oxygenators are designed to mimic branching vasculature of the native lung during extracorporeal lung support. To date, scaling of such devices to achieve clinically relevant blood flow and lung support has been a limitation. We evaluated a novel multilayer microfluidic blood oxygenator (BLOx) capable of supporting 750-800 ml/min blood flow versus a standard hollow fiber membrane oxygenator (HFMO) in vivo during veno-venous extracorporeal life support for 24 hours in anesthetized, mechanically ventilated uninjured swine (n = 3/group). The objective was to assess feasibility, safety, and biocompatibility. Circuits remained patent and operated with stable pressures throughout 24 hours. No group differences in vital signs or evidence of end-organ damage occurred. No change in plasma free hemoglobin and von Willebrand factor multimer size distribution were observed. Platelet count decreased in BLOx at 6 hours (37% dec, P = 0.03), but not in HFMO; however, thrombin generation potential was elevated in HFMO (596 ± 81 nM·min) versus BLOx (323 ± 39 nM·min) at 24 hours ( P = 0.04). Other coagulation and inflammatory mediator results were unremarkable. BLOx required higher mechanical ventilator settings and showed lower gas transfer efficiency versus HFMO, but the stable device performance indicates that this technology is ready for further performance scaling and testing in lung injury models and during longer use conditions.

Efficacy and safety of post-closure technique using Perclose ProGlide/ProStyle device for large-bore mechanical circulatory support access sites.

PURPOSE: Mechanical circulatory support (MCS) using a venoarterial extracorporeal membrane oxygenation (VA-ECMO) device or a catheter-type heart pump (Impella) is critical for the rescue of patients with severe cardiogenic shock. However, these MCS devices require large-bore cannula access (14-Fr and larger) at the femoral artery or vein, which often requires surgical decannulation. METHODS: In this retrospective study, we evaluated post-closure method using a percutaneous suture-mediated vascular closure system, Perclose ProGlide/ProStyle (Abbott Vascular, Lake Bluff, IL, Perclose), as an alternative procedure for MCS decannulation. Closure of 83 Impella access sites and 68 VA-ECMO access sites performed using Perclose or surgical method between January 2018 and March 2023 were evaluated. RESULTS: MCS decannulation using Perclose was successfully completed in all access sites without surgical hemostasis. The procedure time of ProGlide was shorter than surgical decannulation for both Impella and VA-ECMO (13 min vs. 50 min; p < 0.001, 21 min vs. 65 min; p < 0.001, respectively). There were no significant differences in the 30-day survival rate and major adverse events by decannulation including arterial dissection requiring endovascular treatment, hemorrhage requiring a large amount of red blood cell transfusion, and access site infection. CONCLUSION: Our results suggest that the post-closure technique using the percutaneous suture-mediated closure system appears to be a safe and effective method for large-bore MCS decannulation.

Extracorporeal Cardiopulmonary Resuscitation for Cardiac Arrest.

This JAMA Insights Clinical Update discusses the newer treatment option of extracorporeal cardiopulmonary resuscitation, particularly for patients with cardiac arrest who are not responsive to initial treatment.

Comparison of hemodynamic features and thrombosis risk of membrane oxygenators with different structures: A numerical study.

PURPOSE: The geometric structure of the membrane oxygenator can exert an impact on its hemodynamic features, which contribute to the development of thrombosis, thereby affecting the clinical efficacy of ECMO treatment. The purpose of this study is to investigate the impact of varying geometric structures on hemodynamic features and thrombosis risk of membrane oxygenators with different designs. METHODS: Five oxygenator models with different structures, including different number and location of blood inlet and outlet, as well as variations in blood flow path, were established for investigation. These models are referred to as Model 1 (Quadrox-i Adult Oxygenator), Model 2 (HLS Module Advanced 7.0 Oxygenator), Model 3 (Nautilus ECMO Oxygenator), Model 4 (OxiaACF Oxygenator) and Model 5 (New design oxygenator). The hemodynamic features of these models were numerically analyzed using the Euler method combined with computational fluid dynamics (CFD). The accumulated residence time (ART) and coagulation factor concentrations (C[i], where i represents different coagulation factors) were calculated by solving the convection diffusion equation. The resulting relationships between these factors and the development of thrombosis in the oxygenator were then investigated. RESULTS: Our results show that the geometric structure of the membrane oxygenator, including the location of the blood inlet and outlet as well as the design of the flow path, has a significant impact on the hemodynamic surroundings within the oxygenator. In comparison to Model 4, which had the inlet and outlet located in the center position, Model 1 and Model 3, which had the inlet and outlet at the edge of the blood flow field, exhibited a more uneven distribution of blood flow within the oxygenator, particularly in areas distant from the inlet and outlet, which was accompanied with lower flow velocity and higher values of ART and C[i], leading to the formation of flow dead zones and an elevated risk of thrombosis. The oxygenator of Model 5 is designed with a structure that features multiple inlets and outlets, which greatly improves the hemodynamic environment inside the oxygenator. This results in a more even distribution of blood flow within the oxygenator, reducing areas with high values of ART and C[i], and ultimately lowering the risk of thrombosis. The oxygenator of Model 3 with circular flow path section shows better hemodynamic performance compared to the oxygenator of Model 1 with square circular flow path. The overall ranking of hemodynamic performance for all five oxygenators is as follows: Model 5 > Model 4 > Model 2 > Model 3 > Model 1, indicating that Model 1 has the highest thrombosis risk while Model 5 has the lowest. CONCLUSION: The study reveals that the different structures can affect the hemodynamic characteristics inside membrane oxygenators. The design of multiple inlets and outlets can improve the hemodynamic performance and reduce the thrombosis risk in membrane oxygenators. These findings of this study can be used to guide the optimization design of membrane oxygenators for improving hemodynamic surroundings and reducing thrombosis risk.

Insuficiencia cardíaca secundaria a cardiopatías congénitas y adquiridas en edades pediátricas / Heart Failure Secondary to Congenital and Acquired Heart Disease in the Pediatric Age Group

Introducción: Las cardiopatías congénitas son causa frecuente de insuficiencia cardíaca mientras las cardiopatías adquiridas resultan menos frecuentes. La expresión clínica difiere en gran manera de la población adulta y representa la emergencia cardiovascular más frecuente en pediatría. El diagnóstico es completamente clínico, y el tratamiento está encaminado a corregir la causa que la origina. Objetivo: Actualizar conceptos, fisiopatología, manifestaciones clínicas, y tratamiento de la insuficiencia cardíaca en pediatría. Métodos: Se revisaron las bases de datos Medline, PubMed, SciELO y plataforma Springerlink, disponibles desde Infomed; desde el año 2000 hasta 2020, en idioma español e inglés. Análisis y síntesis de la información: La insuficiencia cardíaca es un síndrome clínico resultado de disfunción ventricular, sobrecarga de presión o volumen, independiente o en combinación, que conlleva a signos y síntomas característicos. La identificación de su causa, el diagnóstico precoz y el tratamiento oportuno mejoraran el pronóstico de los pacientes aquejados. Conclusiones: La insuficiencia cardíaca en edad pediátrica representa una compleja afección de causas multifactoriales. El diagnóstico puede hacerse con el método clínico, complementándose con los diferentes exámenes. El tratamiento médico farmacológico o no, se encamina a tratar la causa, además de nuevas terapias en desarrollo prometedoras en el futuro(AU)

Introduction: Congenital heart disease is a frequent cause of heart failure while acquired heart disease is less frequent. The clinical expression differs greatly from the adult population and represents the most frequent cardiovascular emergency in pediatrics. Diagnosis is completely clinical and treatment is aimed at correcting the cause. Objective: To update concepts, pathophysiology, clinical manifestations and treatment of heart failure in pediatrics. Methods: The databases Medline, PubMed, SciELO and Springerlink platform, available from Infomed, were reviewed from 2000 to 2020, in Spanish and English. Analysis and synthesis of the information: Heart failure is a clinical syndrome resulting from ventricular dysfunction, pressure or volume overload, independently or in combination, leading to characteristic signs and symptoms. Identification of its cause, early diagnosis and timely treatment improve the prognosis of afflicted patients. Conclusions: Heart failure in pediatric age represented a complex condition with multifactorial causes. The diagnosis can be made with the clinical method, complemented with different examinations. Pharmacological or non-pharmacological medical treatment is aimed at treating the cause, in addition to promising new therapies under development in the future(AU)