A novel therapeutic strategy using extracorporeal membrane oxygenation in patients with anti-neutrophil cytoplasmic antibodies-associated vasculitis: a case report and literature review

Diffuse alveolar hemorrhage (DAH) secondary to anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) often results in severe respiratory failure which requires emergent management. In patients who are resistant to traditional mechanical respiratory support, extracorporeal membrane oxygenation (ECMO) can be used to maintain gas exchange, thereby providing time for the administration of immunosuppressive therapy to control the inflammation. Herein, we report the application of ECMO to support an adult patient with AAV complicated by severe respiratory failure due to DAH. Similar cases in the literature were identified and discussed. The patient in our case study was successfully treated with ECMO in the acute phase and relieved by immunosuppressive therapy after withdrawal of ECMO. A search in the PubMed database revealed 32 similar cases with DAH, of which 11 cases were microscopic polyangiitis (MPA), 2 cases were eosinophilic granulomatosis with polyangiitis (EGPA), and 19 cases were granulomatosis with polyangiitis (GPA). These patients were all treated with ECMO. Therefore, to date, we identified 33 patients who were effectively treated with ECMO, including 13 (39.4%) males and 20 (60.6%) females, with a ratio of 1:1.54. The average age was 32.4±17.5 and 36.0±16.1 years for males and females, respectively (t=0.610, P=0.547). Most patients received ECMO on the first day of admission to the intensive care unit (ICU) and it appeared that early initiation of ECMO was associated with a shorter duration of ECMO. In general, complications of ECMO in these patients were mild and were not often seen in the clinical setting. This study suggested that early recognition of respiratory failure and referral for ECMO are vital to achieve a satisfactory outcome in AAV patients with DAH.

The intersection of bronchoscopy and extracorporeal membrane oxygenation

Central airway obstruction (CAO), which results from malignant, benign or iatrogenic etiologies, causes significant morbidity and mortality and can be seen in both the pediatric and adult patient population. Patients frequently present to the hospital with dyspnea, stridor, and respiratory distress, indicating impending respiratory failure. Heliox is used to help alleviate symptoms while procedural planning takes place. A multidisciplinary approach to airway management is often needed. Interventional pulmonologists treat CAO with rigid of flexible bronchoscopy in order to deliver therapeutic interventions under general anesthesia. In severe CAO where there is concern for total loss of the airway creating a life-threatening situation for the patient during procedural intervention, short term extracorporeal membrane oxygenation or ECMO has been successfully reported in the literature to provide ventilation and oxygenation support throughout the procedure. Venoarterial ECMO can be used to augment cardiac output in cases of central tumors with cardiac involvement. ECMO can also be used for the removal of tracheal stents when there is a concern that ventilation will be interrupted for a prolonged period of time. ECMO has also been reported as a salvage measure for patients with life threatening hemoptysis until more definitive interventions can be performed. Short term ECMO cannulation can be used with limited associated morbidity and a heparin-free approach can be pursued when there is a concern for bleeding. We will briefly review the anesthetic considerations in CAO as well as review cases of CAO where ECMO was employed to safely alleviate the airway compromise.

Extracorporeal Membrane Oxygenation with rituximab-combined chemotherapy in AIDS-associated primary cardiac lymphoma: A case report

Although effective combination of antiretroviral medications is being developed, the incidence of non-Hodgkin lymphoma (NHL) with human immunodeficiency/acquired immunodeficiency syndrome (HIV/AIDS) still remains significantly higher than that in individuals without infection. Primary cardiac lymphoma (PCL) is an NHL that involves the heart and/or the pericardium. PCL is very rare and often causes serious complications, which can be a diagnostic challenge. To our knowledge, no study has reported the measurement of rituximab concentration under venoarterial extracorporeal membrane oxygenation (VA-ECMO). Herein, we report the case of a 54-year-old male patient with AIDS-associated primary cardiac NHL who developed right ventricular outflow tract obstruction. The patient experienced fatigue and dyspnea on exertion. Contrast-enhanced computed tomography showed a bulky tumor mass in his right atrium and ventricle, and an echocardiogram revealed severe hypokinesis of his heart and poor cardiac output. A biopsy was performed, and immunohistochemistry revealed diffuse large B-cell lymphoma. Therefore, he was treated with rituximab-combined chemotherapy under VA-ECMO. Blood levels of rituximab were measured during chemotherapy with VA-ECMO. Thereafter, he was temporarily discharged from the hospital. This clinical case suggests that VA-ECMO and rituximab-combined chemotherapy are useful in rescuing patients with severe cardiopulmonary failure due to AIDS-associated PCL.

Electron Microscopic Confirmation of Anisotropic Pore Characteristics for ECMO Membranes Theoretically Validating the Risk of SARS-CoV-2 Permeation

The objective of this study is to clarify the pore structure of ECMO membranes by using our approach and theoretically validate the risk of SARS-CoV-2 permeation. There has not been any direct evidence for SARS-CoV-2 leakage through the membrane in ECMO support for critically ill COVID-19 patients. The precise pore structure of recent membranes was elucidated by direct microscopic observation for the first time. The three types of membranes, polypropylene, polypropylene coated with thin silicone layer, and polymethylpentene (PMP), have unique pore structures, and the pore structures on the inner and outer surfaces of the membranes are completely different anisotropic structures. From these data, the partition coefficients and intramembrane diffusion coefficients of SARS-CoV-2 were quantified using the membrane transport model. Therefore, SARS-CoV-2 may permeate the membrane wall with the plasma filtration flow or wet lung. The risk of SARS-CoV-2 permeation is completely different due to each anisotropic pore structure. We theoretically demonstrate that SARS-CoV-2 is highly likely to permeate the membrane transporting from the patient’s blood to the gas side, and may diffuse from the gas side outlet port of ECMO leading to the extra-circulatory spread of the SARS-CoV-2 (ECMO infection). Development of a new generation of nanoscale membrane confirmation is proposed for next-generation extracorporeal membrane oxygenator and system with long-term durability is envisaged.

Advanced Thermochromic Ink System for Medical Blood Simulation

Simulators for extracorporeal membrane oxygenation (ECMO) have problems of bulky devices and low-fidelity methodologies. Hence, ongoing efforts for optimizing modern solutions focus on minimizing expenses and blending training with the intensive care unit. This is particularly evident following the coronavirus pandemic, where economic resources have been extensively cut. In this paper, as a part of an ECMO simulator for training management, an advance thermochromic ink system for medical blood simulation is presented. The system was developed and enhanced as a prototype with successful and reversible transitions between dark and bright red blood color to simulate blood oxygenation and deoxygenation in ECMO training sessions.

Transportation of patients with severe respiratory failure on ECMO support. Four-year experience of a single ECMO center

BACKGROUND

Acute respiratory distress syndrome (ARDS) is associated with high mortality despite advances in the field of critical care, including growing implementation of veno-venous extracorporeal membrane oxygenation (V-V ECMO) support. The primary aim of this study was to present complications during transport on V-V ECMO support from regional hospitals to a tertiary center. The secondary goal was to identify initial laboratory and demographic data differentiating survivors and non-survivors.

METHODS

This was a retrospective, single-center, case-series study. We extracted data from the hospital's ECMO database from March 2016 to June 2019. Patients' diagnosis at admission, baseline demographics, the Sequential Organ Failure Assessment (SOFA) and the Respiratory ECMO Survival Prediction (RESP) scoring systems, laboratory parameters at admission, duration of ECMO therapy and mechanical ventilation time, and the patient survival rate until the ICU discharge were analyzed.

RESULTS

We assessed 31 patients retrieved from regional intensive care units. All analyzed transports on V-V ECMO were performed by an ambulance and median distance and transport time were 100 kilometers and 70 minutes, respectively. Minor complications during the transport were reported in 10 cases (32.25%). The mean V-V ECMO support time was 6.56 days and survival rate until the patient discharge was 64.51%. We found higher body mass index (33.5 vs. 26.5, P = 0.00251) and lower serum lactate level (1.25 vs. 1.6, P = 0.0058) at V-V ECMO initiation to correlate with higher survival rates.

CONCLUSIONS

The transport of patients on V-V ECMO support appears to be safe and feasible. Further studies are needed to identify the specific clinical conditions which might affect the final outcomes.

A Modular Approach for a Patient Unit for Extracorporeal Membrane Oxygenation Simulator

Despite many advancements in extracorporeal membrane oxygenation (ECMO), the procedure is still correlated with a high risk of patient complications. Simulation-based training provides the opportunity for ECMO staff to practice on real-life scenarios without exposing ECMO patients to medical errors while practicing. At Hamad Medical Corporation (HMC) in Qatar, there is a critical need of expert ECMO staff. Thus, a modular ECMO simulator is being developed to enhance the training process in a cost-effective manner. This ECMO simulator gives the instructor the ability to control the simulation modules and run common simulation scenarios through a tablet application. The core modules of the simulation system are placed in the patient unit. The unit is designed modularly such that more modules can be added throughout the simulation sessions to increase the realism of the simulation sessions. The new approach is to enclose the patient unit in a trolley, which is custom-designed and made to include all the components in a modular fashion. Each module is enclosed in a separate box and then mounted to the main blood simulation loop box using screws, quick connect/disconnect liquid fittings, and electrical plugs. This method allows fast upgrade and maintenance for each module separately as well as upgrading modules easily without modifying the trolley’s design. The prototype patient unit has been developed for portability, maintenance, and extensibility. After implementation and testing, the prototype has proven to successfully simulate the main visual and audio cues of the real emergency scenarios, while keeping costs to a minimum.

Zinc Poisoning - Symptoms, Causes, Treatments

Zinc poisoning has been reported from many parts of the world. It is one of the global health problems that affect many organs, if exposed by inhalation of zinc vapors or by consumption of contaminated food and water. Long term exposure to zinc compounds from different sources such as air, water, soil, and food, lead to toxic effects on body systems, especially digestive, respiratory, and nerve systems, and also causes cancer. Zinc levels can be determined in blood, urine, hair, and nails. Patients with zinc toxicity need chelating agents, other pharmacological treatment, protective lung ventilation, extracorporeal membrane oxygenation (ECMO), and supportive care.

Development of an artificial placenta for support of premature infants: narrative review of the history, recent milestones, and future innovation

Over 50 years ago, visionary researchers began work on an extracorporeal artificial placenta to support premature infants. Despite rudimentary technology and incomplete understanding of fetal physiology, these pioneering scientists laid the foundation for future work. The research was episodic, as medical advances improved outcomes of premature infants and extracorporeal life support (ECLS) was introduced for the treatment of term and near-term infants with respiratory or cardiac failure. Despite ongoing medical advances, extremely premature infants continue to suffer a disproportionate burden of mortality and morbidity due to organ immaturity and unintended iatrogenic consequences of medical treatment. With advancing technology and innovative approaches, there has been a resurgence of interest in developing an artificial placenta to further diminish the mortality and morbidity of prematurity. Two related but distinct platforms have emerged to support premature infants by recreating fetal physiology: a system based on arteriovenous (AV) ECLS and one based on veno-venous (VV) ECLS. The AV-ECLS approach utilizes only the umbilical vessels for cannulation. It requires immediate transition of the infant at the time of birth to a fluid-filled artificial womb to prevent umbilical vessel spasm and avoid gas ventilation. In contradistinction, the VV-ECLS approach utilizes the umbilical vein and the internal jugular vein. It would be applied after birth to infants failing maximal medical therapy or preemptively if risk stratified for high mortality and morbidity. Animal studies are promising, demonstrating prolonged support and ongoing organ development in both systems. The milestones for clinical translation are currently being evaluated.

Spanish experience with heart transplants from controlled donation after the circulatory determination of death using thoraco-abdominal normothermic regional perfusion and cold storage

Heart transplantation from controlled donation after the circulatory determination of death (cDCDD) may help to increase the availability of hearts for transplantation. During 2020, four heart transplants were performed at three different Spanish hospitals based on the use of thoraco-abdominal normothermic regional perfusion (TA-NRP) followed by cold storage (CS). All donors were young adults <45 years. The functional warms ischemic time ranged from 8 to 16 minutes. In all cases, the heart recovered sinus rhythm within 1 minute of TA-NRP. TA-NRP was weaned off or decreased <1L within 25 minutes. No recipient required mechanical support after transplantation and all were immediately extubated and discharged home (median hospital stay: 21 days) with an excellent outcome. Four livers, eight kidneys, and two pancreata were also recovered and transplanted. All abdominal grafts recipients experienced an excellent outcome. The use of TA-NRP makes heart transplantation feasible and allows assessing heart function before organ procurement without any negative impact on the preservation of abdominal organs. The use of TA-NRP in cDCDD heart donors in conjunction with cold storage following retrieval can eliminate the need to use ex situ machine perfusion devices, making cDCDD heart transplantation economically possible in other countries.

A comparison of cardiopulmonary bypass versus extracorporeal membrane oxygenation: Does intraoperative circulatory support strategy affect outcomes in pediatric lung transplantation?

OBJECTIVE

Data on adult lung transplantation suggest perioperative benefits of intraoperative extracorporeal membrane oxygenation (ECMO) compared to cardiopulmonary bypass (CPB). Information regarding their pediatric counterparts, however, is limited. This study compares outcomes of intraoperative ECMO versus CPB in pediatric lung transplantation.

METHODS

We reviewed all pediatric lung transplants at our institution from 2014 to 2019 and compared those supported intraoperatively on ECMO (n = 13) versus CPB (n = 22), plus a conditional analysis excluding re-transplantations (ECMO [n = 13] versus CPB [n = 20]). We evaluated survival, surgical times, intraoperative transfusions, postoperative support, complications, and duration of hospitalization.

RESULTS

Total time on ECMO support was significantly less than that of CPB support (P = .018). Intraoperatively, the ECMO group required fewer transfusions of fresh-frozen plasma (8.9 [5.8-22.3] vs 16.6 [11.4-39.0] mL/kg, P = .049) and platelets (4.2 [0.0-6.7] vs 8.0 [3.5-14.0] mL/kg, P = .049). When excluding re-transplantations, patients on ECMO required fewer packed red blood cells intraoperatively (12.6 [2.1-30.7] vs 28.2 [14.0-54.0] mL/kg, P = .048). There were no differences in postoperative support requirements, complications, or mortality at one, six, and twelve months.

CONCLUSIONS

Intraoperative ECMO support during pediatric lung transplantation appears to decrease intraoperative transfusion requirements when compared to CPB. Data from additional institutions may strengthen these observations.

Physiological Basis of Extracorporeal Membrane Oxygenation and Extracorporeal Carbon Dioxide Removal in Respiratory Failure

Extracorporeal life support (ECLS) for severe respiratory failure has seen an exponential growth in recent years. Extracorporeal membrane oxygenation (ECMO) and extracorporeal CO2 removal (ECCO2R) represent two modalities that can provide full or partial support of the native lung function, when mechanical ventilation is either unable to achieve sufficient gas exchange to meet metabolic demands, or when its intensity is considered injurious. While the use of ECMO has defined indications in clinical practice, ECCO2R remains a promising technique, whose safety and efficacy are still being investigated. Understanding the physiological principles of gas exchange during respiratory ECLS and the interactions with native gas exchange and haemodynamics are essential for the safe applications of these techniques in clinical practice. In this review, we will present the physiological basis of gas exchange in ECMO and ECCO2R, and the implications of their interaction with native lung function. We will also discuss the rationale for their use in clinical practice, their current advances, and future directions.

ECMO combined with prone positioning strategies in COVID-19 respiratory distress syndrome

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become a global pandemic as a public health emergency of international concern. Previous evidence from similar patient populations proved that carefully selected patients with severe ARDS who did not benefit from conventional treatment might be successfully supported with Veno-Venous extracorporeal membrane oxygenation (V-V ECMO). We now share the case reports of COVID-19 patients with ECMO combined prone position strategies.

Right ventricular failure after left ventricular assist device implantation: a review of the literature

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.

Application of extracorporeal cardiopulmonary resuscitation in adult patients with refractory cardiac arrest

Background

The aim of this study was to summarize the clinical experience of extracorporeal cardiopulmonary resuscitation (ECPR) in the treatment of adult patients with refractory cardiac arrest.

Methods

The clinical data of 12 cases of adult patients with cardiac arrest hospitalized between June 2015 and September 2019 who were unable to achieve return of spontaneous circulation effectively with conventional cardiopulmonary resuscitation (CCPR) and were treated with ECPR technology were retrospectively analyzed. The group included six males and six females aged between 18 and 69 years. All the patients underwent veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support with the adoption of femoral artery and vein catheterization.

Results

The duration of cardiopulmonary resuscitation (CPR) for the 12 patients was 32-125 min, and the ECMO duration was 2-190 h. Four patients were successfully weaned from ECMO and survived until hospital discharge. The other eight patients died in hospital; hemodynamic collapse (four patients) in the early stage of ECMO and severe neurological complications (three patients) were the main causes of death.

Conclusions

Single-center data showed that ECPR provided a new rescue alternative for some patients with reversible refractory cardiac arrest. We have demonstrated that the success rate of treatment could be improved by selecting suitable patients and reducing the CPR duration as much as possible.

Platelet count reduction during in vitro membrane oxygenation affects platelet activation, neutrophil extracellular trap formation and clot stability, but does not prevent clotting

Introduction:

Due to improved technology and increased application the mortality during extracorporeal membrane oxygenation (ECMO) is constantly declining. Nevertheless, complications including haemorrhage or thrombus formation remain frequent. Local mitigation of coagulation within an ECMO system to prevent thrombus formation on ECMO components and optimizing systemic anticoagulation is an approach to reduce clotting and bleeding complications at once. Foreign surfaces of ECMO systems, activate platelets (PLTs), which besides their major role in coagulation, can trigger the formation of neutrophil extracellular traps (NETs) contributing to robust thrombus formation. The impact of a reduced PLT count on PLT activation and NET formation is of paramount importance and worth investigating.

Methods:

In this study platelet poor (PLT^–) and native (PLT⁺) heparinized human blood was circulated in two identical in vitro test circuits for ECMO devices for 6 hours. PLT reduction was achieved by a centrifugation protocol prior to the experiments. To achieve native coagulation characteristics within the test circuits, the initial heparin dose was antagonized by continuous protamine administration.

Results:

The PLT^– group showed significantly lower platelet activation, basal NET formation and limited clot stability measured via thromboelastometry. Fluorescent and scanning electron microscope imaging showed differences in clot composition. Both groups showed equal clot formation within the circuit.

Conclusions:

This study demonstrated that the reduction of PLTs within an ECMO system is associated with limited PLT activation and NET formation, which reduces clot stability but is not sufficient to inhibit clot formation per se.

Use of Venovenous Extracorporeal Membrane Oxygenation in Critically-Ill Patients With COVID-19

Acute respiratory distress syndrome (ARDS) related to Coronavirus disease (COVID-19) is associated with high mortality. It has been suggested that venovenous extracorporeal membrane oxygenation (ECMO) was suitable in this indication, albeit the effects of ECMO on the mechanical respiratory parameters have been scarcely described. In this case-series, we prospectively described the use of venovenous ECMO and its effects on mechanical respiratory parameters in eleven COVID-19 patients with severe ARDS. Implantation of ECMO occurred 6 [3–11] days after the onset of mechanical ventilation. At the time of ECMO implantation, all patients received neuromuscular blocking agents, three (27%) received inhaled nitric oxide and prone positioning was performed in all patients with 4 [3−5] sessions of PP per patient. Under ECMO, the tidal volume was significantly decreased from 6.1 [4.0–6.3] to 3.4 [2.5–3.6] mL/kg of predicted body weight and the positive end-expiratory pressure level was increased by 25 ± 27% whereas the driving pressure and the mechanical power decreased by 33 ± 25% and 71 ± 27%, respectively. The PaO₂/FiO₂ ratio significantly increased from 68 [58–89] to 168 [137–218] and the oxygenation index significantly decreased from 28 [26–35] to 13 [10–15]. The duration of ECMO was 12 [8–25] days. Nine (82%) patients experienced ECMO-related complications and the main complication was major bleeding requiring blood transfusions. Intensive care unit mortality rate was 55% but no patient died from ECMO-related complications. In COVID-19 patients with severe ARDS, venovenous ECMO allowed ultra-protective ventilation, improved oxygenation and should be considered in highly selected patients with the most severe ARDS.

Use of Extracorporeal Membrane Oxygenation After Congenital Heart Disease Repair: A Systematic Review and Meta-Analysis

Introduction: Extracorporeal membrane oxygenation (ECMO) has been widely used to treat cardiopulmonary failure in patients with congenital heart defects (CHD) postoperatively. A meta-analysis is performed for outcomes of postoperative CHD patients on ECMO.

Methods: Electronic databases, including PubMed, EMbase, and Cochrane Library CENTRAL were searched systematically from January 1990 to June 2020 for literature which reported the outcomes of postoperative CHD cases on ECMO. The scope of this search was restricted to articles published in English.

Results: Forty-three studies were included in this study, involving 3,585 subjects. Postoperative ventricular failure with low cardiac output was the most common indication of ECMO initiation. The pooled estimated incidence of in-hospital mortality was 56.8% (95% CI, 52.5–61.0%). Bleeding was the most common complication with ECMO with an incidence of 47.1% (95% CI, 38.5–55.8%). Multivariate meta-regression analysis revealed that single ventricular physiology (coefficient 0.213, 95% CI 0.099–0.327, P = 0.001) and renal failure (coefficient 0.315, 95% CI 0.091–0.540, P = 0.008) were two independent risk factors for in-hospital mortality.

Conclusions: There is an overall high in-hospital mortality of 56.8% in postoperative CHD patients on ECMO. Bleeding is the most common complication during ECMO running with an incidence of 47.1%. Single ventricular physiology and renal failure, as two independent risk factors, may potentially increase in-hospital mortality. Further studies exploring the differences in outcomes between ECMO and other extracorporeal life support strategies are warranted.

Venovenous extracorporeal membrane oxygenation for patients with refractory coronavirus disease 2019 (COVID-19): Multicenter experience of referral hospitals in a large health care system

BACKGROUND

The benefit of extracorporeal membrane oxygenation (ECMO) for patients with severe acute respiratory distress from coronavirus disease 2019 refractory to medical management and lung-protective mechanical ventilation has not been adequately determined.

METHODS

We reviewed the clinical course of 37 patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection supported by venovenous ECMO at 4 ECMO referral centers within a large health care system. Patient characteristics, progression of hemodynamics and inflammatory markers, and clinical outcomes were evaluated.

RESULTS

The patients had median age of 51 years (interquartile range, 40-59), and 73% were male. Peak plateau pressures, vasopressor requirements, and arterial partial pressure of carbon dioxide all improved with ECMO support. In our patient population, 24 of 37 patients (64.8%) survived to decannulation and 21 of 37 patients (56.8%) survived to discharge. Among patients discharged alive from the ECMO facility, 12 patients were discharged to a long-term acute care or rehabilitation facility, 2 were transferred back to the referring hospital for ventilatory weaning, and 7 were discharged directly home. For patients who were successfully decannulated, median length of time on ECMO was 17 days (interquartile range, 10-33.5).

CONCLUSIONS

Venovenous ECMO represents a useful therapy for patients with refractory severe acute respiratory distress syndrome from coronavirus disease 2019.

Newly Developed Pediatric Membrane Oxygenator that Suppresses Excessive Pressure Drop in Cardiopulmonary Bypass and Extracorporeal Membrane Oxygenation (ECMO)

This article developes a pediatric membrane oxygenator that is compact, high performance, and highly safe. This novel experimental approach, which imaging the inside of a membrane oxygenator during fluid perfusion using high-power X-ray CT, identifies air and blood retention in the local part of a membrane oxygenator. The cause of excessive pressure drop in a membrane oxygenator, which has been the most serious dysfunction in cardiovascular surgery and extracorporeal membrane oxygenation (ECMO), is the local retention of blood and air inside the oxygenator. Our designed blood flow channel for a membrane oxygenator has a circular channel and minimizes the boundary between laminated parts. The pressure drop in the blood flow channel is reduced, and the maximum gas transfer rates are increased by using this pediatric membrane oxygenator, as compared with the conventional oxygenator. Furthermore, it would be possible to reduce the incidents, which have occurred clinically, due to excessive pressure drop in the blood flow channel of the membrane oxygenator. The membrane oxygenator is said to be the “last stronghold” for patients with COVID-19 receiving ECMO treatment. Accordingly, the specification of our prototype is promising for low weight and pediatric patients.

The use of extracorporeal membrane oxygenation in human immunodeficiency virus-positive patients: a review of a multicenter database

AIM

We chose to evaluate the survival of extracorporeal membrane oxygenation among patients with human immunodeficiency virus in a multicenter registry.

METHODS

Retrospective case review of the Extracorporeal Life Support Organization Registry respiratory failure of all patients with human immunodeficiency virus supported with extracorporeal membrane oxygenation.

RESULTS

A total of 126 patients were included. Survival to discharge was 36%. Eight infants were supported with extracorporeal membrane oxygenation and three (37.5%) survived to discharge. Respiratory extracorporeal membrane oxygenation was the primary indication (78%) with a 39% survival, while cardiac and extracorporeal cardiopulmonary resuscitation indications accounted for 16% and 6% of patients with survivals of 30% and 12.5%, respectively. These differences did not reach significance. There were no significant differences between survivors and non-survivors in demographic data, but non-survivors had significantly more non-human immunodeficiency virus pre-extracorporeal membrane oxygenation infections than survivors. There were no differences in other pre-extracorporeal membrane oxygenation supportive therapies, mechanical ventilator settings, or arterial blood gas results between survivors and non-survivors. The median duration of mechanical ventilation prior to cannulation was 52 (interquartile range: 13-140) hours, while the median duration of the extracorporeal membrane oxygenation exposure was 237 (interquartile range: 125-622) hours. Ventilator settings were significantly lower after 24 hours compared to pre-extracorporeal membrane oxygenation settings. Complications during extracorporeal membrane oxygenation exposure including receipt of renal replacement therapy, inotropic infusions, and cardiopulmonary resuscitation were more common among non-survivors compared to survivors. Central nervous system complications were rare.

CONCLUSION

Survival among patients with human immunodeficiency virus infection who receive extracorporeal membrane oxygenation was less than 40%. Infections before extracorporeal membrane oxygenation cannulation occurred more often in non-survivors. The receipt of renal replacement therapy, inotropic infusions, or cardiopulmonary resuscitation during extracorporeal membrane oxygenation was associated with worse outcome.

Critical Care Demand and Intensive Care Supply for Patients in Japan with COVID-19 at the Time of the State of Emergency Declaration in April 2020: A Descriptive Analysis

Background and objectives: The coronavirus disease 2019 (COVID-19) pandemic is overwhelming Japan's intensive care capacity. This study aimed to determine the number of patients with COVID-19 who required intensive care and to compare the numbers with Japan's intensive care capacity. Materials and Methods: Publicly available datasets were used to obtain the number of confirmed patients with COVID-19 undergoing mechanical ventilation and extracorporeal membrane oxygenation (ECMO) between 15 February and 19 July 2020 to determine and compare intensive care unit (ICU) and attending bed needs for patients with COVID-19, and to estimate peak ICU demands in Japan. Results: During the epidemic peak in late April, 11,443 patients (1.03/10,000 adults) had been infected, 373 patients (0.034/10,000 adults) were in ICU, 312 patients (0.028/10,000 adults) were receiving mechanical ventilation, and 62 patients (0.0056/10,000 adults) were under ECMO per day. At the peak of the epidemic, the number of infected patients was 651% of designated beds, and the number of patients requiring intensive care was 6.0% of ICU beds, 19.1% of board-certified intensivists, and 106% of designated medical institutions in Japan. Conclusions: The number of critically ill patients with COVID-19 continued to rise during the pandemic, exceeding the number of designated beds but not exceeding ICU capacity.

Diffuse Alveolar Hemorrhage After Pediatric Hematopoietic Stem Cell Transplantation

Pulmonary complications are common following hematopoietic cell transplantation (HCT) and contribute significantly to its morbidity and mortality. Diffuse alveolar hemorrhage is a devastating non-infectious complication that occurs in up to 5% of patients post-HCT. Historically, it carries a high mortality burden of 60–100%. The etiology remains ill-defined but is thought to be due to lung injury from conditioning regimens, total body irradiation, occult infections, and other comorbidities such as graft vs. host disease, thrombotic microangiopathy, and subsequent cytokine release and inflammation. Clinically, patients present with hypoxemia, dyspnea, and diffuse opacities consistent with an alveolar disease process on chest radiography. Diagnosis is most commonly confirmed with bronchoscopy findings of progressively bloodier bronchoalveolar lavage or the presence of hemosiderin-laden macrophages on microscopy. Treatment with glucocorticoids is common though dosing and duration of therapy remains variable. Other agents, such as aminocaproic acid, tranexamic acid, and activated recombinant factor VIIa have also been tried with mixed results. We present a review of diffuse alveolar hemorrhage with a focus on its pathogenesis and treatment options.