Extracorporeal membrane oxygenation for severe acute respiratory failure

Key performance indicators in extracorporeal membrane oxygenation (ECMO): protocol for a systematic review

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is an intervention used in critically ill patients with severe cardiopulmonary failure that is expensive and resource intensive and requires specialised care. There remains a significant practice variation in its application. This systematic review will assess the evidence for key performance indicators (KPIs) in ECMO.

METHODS AND ANALYSIS

We will search Ovid MEDLINE, Ovid EMBASE, Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library including the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials and databases from the National Information Center of Health Services Research and Health Care Technology, for studies involving KPIs in ECMO. We will rate methodological quality using the Newcastle-Ottawa Quality Assessment Scale. Randomized controlled trials (RCTs) will be evaluated with the Cochrane Risk of Bias tool, and qualitative studies will be evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN checklist). Grey literature sources will be searched for technical reports, practice guidelines and conference proceedings. We will identify relevant organisations, industry leaders and non-profit organisations that represent key opinion leads in the use of ECMO. We will search the Agency of Healthcare Research and Quality National Quality Measures Clearinghouse for ECMO-related KPIs. Studies will be included if they contain quality measures that occur in critically ill patients and are associated with ECMO. The analysis will be primarily descriptive. Each KPI will be evaluated for importance, scientific acceptability, utility and feasibility using the four criteria proposed by the US Strategic Framework Board for a National Quality Measurement and Reporting System. Finally, KPIs will be evaluated for their potential operational characteristics, their potential to be integrated into electronic medical records and their affordability, if applicable.

ETHICS AND DISSEMINATION

Ethical approval is not required as no primary data will be collected. Findings will be published in a peer-reviewed journal and presented at academic.

PROSPERO REGISTRATION NUMBER

9 August 2022. CRD42022349910.

Extracorporeal Membrane Oxygenation (ECMO): A Lifeline for Pregnant and Postpartum Women

Extracorporeal membrane oxygenation (ECMO) is a life-saving technology that temporarily supports the heart and lungs in critical care situations. This review article examines the role of ECMO as a lifeline for pregnant and postpartum women facing severe maternal and fetal conditions. The review begins with an overview of the physiology and pathophysiology of ECMO, including its procedure and how it supports cardiopulmonary function. Unique considerations specific to pregnant and postpartum women, such as physiological changes during pregnancy, risks and complications associated with ECMO, and the need to balance maternal and fetal considerations, are discussed. The indications for ECMO in this population are explored, including common maternal indications such as cardiogenic shock, acute respiratory distress syndrome (ARDS), pulmonary embolism, and eclampsia, as well as fetal indications such as fetal distress, hypoxic-ischemic encephalopathy (HIE), and twin-to-twin transfusion syndrome (TTTS). The challenges and considerations in ECMO for pregnant and postpartum women, including ethical considerations and the decision-making process, are highlighted. The review further explores the multidisciplinary care and collaborative approach required, emphasizing the importance of a specialized ECMO team and collaboration between obstetricians, neonatologists, cardiologists, and other specialists. Additionally, patient selection, pre-ECMO assessment, and planning strategies are discussed. The review evaluates existing literature and studies on ECMO in pregnant and postpartum women, analyzing survival rates and maternal and fetal outcomes and comparing different ECMO modalities and strategies. Future directions and research opportunities are presented, including emerging technologies, areas for further research and clinical trials, and improved patient selection and management strategies. The conclusion emphasizes the importance of ECMO as a lifeline for pregnant and postpartum women and the potential impact on maternal and fetal health. The review highlights the need for ongoing research and advancements in ECMO to optimize outcomes and improve care for this unique and vulnerable patient population.

A Systematic Review and Meta-Analysis of Extracorporeal Membrane Oxygenation in Patients with Burns

BACKGROUND

Severely burned patients are at high risk for cardiopulmonary failure. Promising studies have stimulated interest in using extracorporeal membrane oxygenation as a potential therapy for burn patients with refractory cardiac and/or respiratory failure. However, the findings from previous studies vary.

METHODS

In this study, the authors conducted a systematic review and meta-analysis using standardized mortality ratios to elucidate the benefits associated with the use of extracorporeal membrane oxygenation in patients with burn and/or inhalation injuries. A literature search was performed, and clinical outcomes in the selected studies were compared.

RESULTS

The meta-analysis found that the observed mortality was significantly higher than the predicted mortality in patients receiving extracorporeal membrane oxygenation (standardized mortality ratio, 2.07; 95 percent CI, 1.04 to 4.14). However, the subgroup of burn patients with inhalation injuries had lower mortality rates compared to their predicted mortality rates (standardized mortality ratio, 0.95; 95 percent CI, 0.52 to 1.73). Other subgroup analyses reported no benefits from extracorporeal membrane oxygenation; however, these results were not statistically significant. Interestingly, the pooled standardized mortality ratio values decreased as the selected patients' revised Baux scores increased (R = -0.92), indicating that the potential benefits from the treatment increased as the severity of patients with burns increased.

CONCLUSIONS

The authors' meta-analysis revealed that burn patients receiving extracorporeal membrane oxygenation treatment were at a higher risk of death. However, select patients, including those with inhalation injuries and those with revised Baux scores over 90, would benefit from the treatment. The authors suggest that burn patients with inhalation injuries or with revised Baux scores exceeding 90 should be considered for the treatment and early transfer to an extracorporeal membrane oxygenation center.

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.

A Dedicated Veno-Venous Extracorporeal Membrane Oxygenation Unit during a Respiratory Pandemic: Lessons Learned from COVID-19 Part II: Clinical Management

(1) Background: COVID-19 acute respiratory distress syndrome (CARDS) has several distinctions from traditional acute respiratory distress syndrome (ARDS); however, patients with refractory respiratory failure may still benefit from veno-venous extracorporeal membrane oxygenation (VV-ECMO) support. We report our challenges caring for CARDS patients on VV-ECMO and alterations to traditional management strategies. (2) Methods: We conducted a retrospective review of our institutional strategies for managing patients with COVID-19 who required VV-ECMO in a dedicated airlock biocontainment unit (BCU), from March to June 2020. The data collected included the time course of admission, VV-ECMO run, ventilator length, hospital length of stay, and major events related to bleeding, such as pneumothorax and tracheostomy. The dispensation of sedation agents and trial therapies were obtained from institutional pharmacy tracking. A descriptive statistical analysis was performed. (3) Results: Forty COVID-19 patients on VV-ECMO were managed in the BCU during this period, from which 21 survived to discharge and 19 died. The criteria for ECMO initiation was altered for age, body mass index, and neurologic status/cardiac arrest. All cannulations were performed with a bedside ultrasound-guided percutaneous technique. Ventilator and ECMO management were routed in an ultra-lung protective approach, though varied based on clinical setting and provider experience. There was a high incidence of pneumothorax (n = 19). Thirty patients had bedside percutaneous tracheostomy, with more procedural-related bleeding complications than expected. A higher use of sedation was noted. The timing of decannulation was also altered, given the system constraints. A variety of trial therapies were utilized, and their effectiveness is yet to be determined. (4) Conclusions: Even in a high-volume ECMO center, there are challenges in caring for an expanded capacity of patients during a viral respiratory pandemic. Though institutional resources and expertise may vary, it is paramount to proceed with insightful planning, the recognition of challenges, and the dynamic application of lessons learned when facing a surge of critically ill patients.

Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid

Over the last few years, microbubbles have found application in biomedicine. In this study, the characteristics of bubbles formed when air is introduced from a micro-tube (internal diameter 110 μm) in non-Newtonian shear thinning fluids are studied. The dependence of the release time and the size of the bubbles on the gas phase rate and liquid phase properties is investigated. The geometrical characteristics of the bubbles are also compared with those formed in Newtonian fluids with similar physical properties. It was found that the final diameter of the bubbles increases by increasing the gas flow rate and the liquid phase viscosity. It was observed that the bubbles formed in a non-Newtonian fluid have practically the same characteristics as those formed in a Newtonian fluid, whose viscosity equals the asymptotic viscosity of the non-Newtonian fluid, leading to the assumption that the shear rate around an under-formation bubble is high, and the viscosity tends to its asymptotic value. To verify this notion, bubble formation was simulated using Computational Fluid Dynamics (CFD). The simulation results revealed that around an under-formation bubble, the shear rate attains a value high enough to lead the viscosity of the non-Newtonian fluid to its asymptotic value.

Prognostic Factors of ICU Mortality in Pediatric Oncology Patients With Pulmonary Complications

OBJECTIVE

This study aimed to determine prognostic factors associated with mortality in pediatric oncology patients admitted to the intensive care unit (ICU) with pulmonary complications.

MATERIALS AND METHODS

This retrospective cohort study included patients 21 years of age with underlying oncologic diseases admitted to the ICU of a Korean Tertiary Referral Hospital with pulmonary complications from April 2009 to March 2017. Patients admitted for perioperative management or nonpulmonary complications were excluded. Demographic, laboratory, and clinical parameters (eg, Glasgow Coma Scale [GCS], pediatric Sequential Organ Failure Assessment [pSOFA], and Pediatric Logistic Organ Dysfunction [PELOD] scores) were reviewed.

RESULTS

Overall, 110 patients (62 male, 56.3%) with a median age of 13 years (interquartile range: 8 to 16 y) were studied. The median ICU stay was 8 days (interquartile range: 4.25 to 16 d). Forty-five (40.9%) patients required mechanical ventilation. The overall mortality rate was 59.1% (65/110 patients). A multivariate logistic regression identified a low GCS score, peripheral oxygen saturation/fraction of inspired oxygen ratio, and hematocrit and increased total bilirubin as significantly associated with increased mortality. The pSOFA and PELOD scores on days 1 and 3 postadmission predicted in-ICU mortality, with corresponding areas under the curve of 0.80/0.76 and 0.87/0.83, respectively.

CONCLUSION

Several clinical scores and factors may predict mortality in pediatric oncology patients with pulmonary complications.

Extracorporeal membrane oxygenation in pregnant and postpartum women: a ten-year case series

Objective

tExtracorporeal membrane oxygenation (ECMO) is a life-saving therapy for severe, reversible cardiopulmonary failure, but data regarding its use in pregnancy and the postpartum period are limited. We sought to quantify survival of pregnant and postpartum women necessitating ECMO in a contemporary cohort at a single tertiary institution.

Study Design

All women of reproductive age (14–44 years), who underwent ECMO at our institution between January 1, 2008, and December 31, 2017, were identified using a query of hospital encounters for ECMO-related CPT codes. We manually reviewed all charts of women of reproductive age; women who were pregnant or <6 weeks postpartum at the time of ECMO initiation were included. Clinical characteristics and maternal and fetal outcomes are described.

Results

In this study, 54 women of reproductive age underwent ECMO for cardiopulmonary failure. Of those, 9 (17%) were pregnant or <6 weeks postpartum at the time of ECMO initiation: 4 antepartum, 1 intraoperative at the time of cesarean delivery, and 4 postpartum (including 2 in whom ECMO was initiated on postpartum day 0 or 1). Overall, maternal survival was 33%. The median maternal age was 24 years (range 19–39 years); most women were nonsmokers without underlying medical comorbidities. The most common indication for ECMO use in pregnant and postpartum women was acute respiratory distress syndrome, which was present in 7 cases (78%), including 5 cases that were due to infectious etiologies and 2 cases that were attributed to preeclampsia. The median number of days on ECMO was 6 (range 1–14). There were no cases of obstetric hemorrhage. Venovenous ECMO was utilized in all but 1 case, in which emergent attempted venoarterial ECMO was unsuccessful in resuscitating a postpartum patient with cardiac arrest and a massive pulmonary embolism. A total of 4 women were initiated on ECMO during pregnancy: their gestational ages at ECMO initiation were 21, 22, 29, and 30 weeks; maternal survival was 50%, and fetal mortality was 50%. A case of ECMO initiated during cesarean section at 29 weeks’ gestation resulted in both maternal and fetal survival. Among 4 mothers with ECMO initiation after childbirth, none survived. Finally, we found a tendency toward survival in those patients for whom ECMO was initiated soon after mechanical ventilation, earlier in the disease process. In contrast, in this study, 23 of 45 women of reproductive age (51%) who were not pregnant but underwent ECMO survived.

Conclusion

When ECMO was initiated during pregnancy or during childbirth, 60% of mothers and fetuses survived, supporting current use of ECMO as a salvage therapy in pregnant and intrapartum women. In this generally young and healthy population, ECMO has the potential to increase the survival rates of both mother and fetus and should be considered a salvage therapy for peripartum women with reversible forms of cardiorespiratory failure.

Update on extracorporeal carbon dioxide removal: a comprehensive review on principles, indications, efficiency, and complications

TECHNOLOGY

Extracorporeal carbon dioxide removal means the removal of carbon dioxide from the blood across a gas exchange membrane without substantially improving oxygenation. Carbon dioxide removal is possible with substantially less extracorporeal blood flow than needed for oxygenation. Techniques for extracorporeal carbon dioxide removal include (1) pumpless arterio-venous circuits, (2) low-flow venovenous circuits based on the technology of continuous renal replacement therapy, and (3) venovenous circuits based on extracorporeal membrane oxygenation technology.

INDICATIONS

Extracorporeal carbon dioxide removal has been shown to enable more protective ventilation in acute respiratory distress syndrome patients, even beyond the so-called "protective" level. Although experimental data suggest a benefit on ventilator induced lung injury, no hard clinical evidence with respect to improved outcome exists. In addition, extracorporeal carbon dioxide removal is a tool to avoid intubation and mechanical ventilation in patients with acute exacerbated chronic obstructive pulmonary disease failing non-invasive ventilation. This concept has been shown to be effective in 56-90% of patients. Extracorporeal carbon dioxide removal has also been used in ventilated patients with hypercapnic respiratory failure to correct acidosis, unload respiratory muscle burden, and facilitate weaning. In patients suffering from terminal fibrosis awaiting lung transplantation, extracorporeal carbon dioxide removal is able to correct acidosis and enable spontaneous breathing during bridging. Keeping these patients awake, ambulatory, and breathing spontaneously is associated with favorable outcome.

COMPLICATIONS

Complications of extracorporeal carbon dioxide removal are mostly associated with vascular access and deranged hemostasis leading to bleeding. Although the spectrum of complications may differ, no technology offers advantages with respect to rate and severity of complications. So called "high-extraction systems" working with higher blood flows and larger membranes may be more effective with respect to clinical goals.

Extra-Corporeal Membrane Oxygenation for Neonatal Respiratory Support

To review our experience with Extra-Corporeal Membrane Oxygenation (ECMO) for respiratory support in neonates. From 1989 to 2018 2114 patients underwent respiratory ECMO support, with 764 (36%) neonates. Veno-Venous (V-V) cannulation was used in 428 (56%) neonates and Veno-Arterial (V-A) in 336 (44%). Historically V-V ECMO was our preferred modality, but due to lack of suitable cannula in the last 7 years V-A was used in 209/228 (92%) neonates. Mean and inter-quartile range of ECMO duration was 117 hours (inter-quartile range 90 to 164 hours). Overall 724 (95%) neonates survived to ECMO decannulation, with 640 (84%) hospital discharge. Survival varied with underlying diagnosis: meconium aspiration 98% (354/362), persistent pulmonary hypertension 80% (120/151), congenital diaphragmatic hernia 66% (82/124), sepsis 59% (35/59), pneumonia 86% (6/7), other 71% (43/61). Survival was 86% with V-V and 80% with V-A cannulation, better than ELSO Registry with 77% V-V and 63% V-A. Major complications: cerebral infarction/hemorrhage in 4.7% (31.1% survival to discharge), renal replacement therapy in 17.6% (58.1% survival to discharge), new infection in 2.9%, with negative impact on survival (30%). Following a circuit design modification and subsequent reduction in heparin requirement, intracerebral hemorrhage decreased to 9/299 (3.0%) radiologically proven cerebral infarction/hemorrhage. We concluded (1) outcomes from neonatal ECMO in our large case series were excellent, with better survival and lower complication rate than reported in ELSO registry. (2) These results highlight the benefits of ECMO service in high volume units. (3) The similar survival rate seen in neonates with V-A and V-V cannulation differs from the ELSO register; this may reflect the change in cannulation enforced by lack of suitable V-V cannula and all neonates undergoing V-A cannulation.

Successful resuscitation by using extracorporeal membrane oxygenation in a patient with amniotic fluid embolism: a case report

Amniotic fluid embolism (AFE) is a rare disease, but it is a potentially fatal condition, as well as a leading cause of unpredictable maternal death in developed countries. The typical clinical symptoms of AFE include hypoxia, hypotension, and coagulopathy, and with rapid progression, it may cause cardiac arrest and death. We report a case of sudden hemodynamic instability due to amniotic fluid embolism, which was successfully treated with veno-arterial extracorporeal membrane oxygenation (ECMO). A 39-year-old woman was scheduled for delivery at 38 weeks and 2 days of gestation. During labor, sudden generalized tonic-clonic seizures developed, followed by dyspnea and cyanosis. Despite immediate cesarean section being performed, she became hypoxemic and experienced cardiovascular collapse. ECMO was promptly applied, and the patient became stable 8 days after cesarean section. ECMO appears to be an appropriate treatment option for catastrophic amniotic fluid embolism.

Outcomes of pediatric oncology and hematopoietic cell transplant patients receiving extracorporeal membrane oxygenation

BACKGROUND/OBJECTIVES

There is controversy regarding the utilization of extracorporeal membrane oxygenation in pediatric patients with an underlying oncologic diagnosis or who have undergone hematopoietic cell transplant. We hypothesized that these patients have higher mortality, more bleeding complications, more blood product utilization, and a higher rate of new infections than the general pediatric intensive care unit population supported with extracorporeal membrane oxygenation.

DESIGN/METHODS

This is a retrospective chart review at a single center quaternary care pediatric hospital including all pediatric intensive care unit extracorporeal membrane oxygenation patients from 2011 to 2016. Patients were categorized as either oncology/hematopoietic cell transplant or general pediatric intensive care unit. Patients from the cardiovascular intensive care unit or the neonatal intensive care unit were excluded.

RESULTS

A total of 38 patients met inclusion criteria of which 7 were oncology/hematopoietic cell transplant patients. The oncology/hematopoietic cell transplant group had lower platelets at the start of extracorporeal membrane oxygenation (p = 0.02) but other pre-extracorporeal membrane oxygenation characteristics were similar. Extracorporeal membrane oxygenation survival was lower in the oncology/hematopoietic cell transplant group (29% vs 77%, p = 0.02). The incidence of bleeding complications and new infections did not differ. The oncology/hematopoietic cell transplant group received more platelets (median of 15.9 mL/kg/day (interquartile range 8.4, 36.6) vs 7.9 mL/kg/day (3.3, 21.9), p = 0.04) and fresh frozen plasma (14.0 mL/kg/day (3, 15.7) vs 1.8 mL/kg/day (0.5, 5.9), p = 0.04).

CONCLUSION

Oncology and hematopoietic cell transplant patients had a higher mortality and received more blood products while on extracorporeal membrane oxygenation than the general pediatric intensive care unit patients despite similar pre-extracorporeal membrane oxygenation characteristics. Physicians should use caution when deciding whether or not to utilize extracorporeal membrane oxygenation in this population.

Clinical complications during veno-arterial extracorporeal membrane oxigenation in post-cardiotomy and non post-cardiotomy shock: still the achille's heel

Extracorporeal membrane oxygenation (ECMO) is life-saving for potentially reversible heart failure and respiratory injuries not responsive to conventional therapies. Technological innovations have produced over the years significant improvements in ECMO devices (pump, cannula design and oxygenator) and have allowed a better risk/benefit profile. Alongside with recognized advantages in the treatment of very sick patients, ECMO remains an invasive procedure for mechanical circulatory support (MCS) and it is associated with complications that strongly influence the prognosis. Current review was designed to provide a comprehensive outline on ECMO complications, analyzing risk factors and strategies of management, focusing on adult population undergoing veno-arterial ECMO (VA-ECMO) therapy.

The role of extra-corporeal membrane oxygenation (ECMO) in the treatment of diffuse alveolar haemorrhage secondary to ANCA-associated vasculitis: report of two cases and review of the literature

Diffuse alveolar haemorrhage (DAH) secondary to anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a rare life-threatening condition presenting with severe respiratory failure. The management of AAV-related DAH consists of remission induction immunosuppressive therapy, which requires time to be effective, with significant fatality rates despite appropriate treatment. Extracorporeal membrane oxygenation (ECMO) can support gas exchanges providing the time necessary for immunosuppressive treatment to control the underlying disease in cases refractory to the conventional ventilation techniques. Despite severe preexisting bleeding has been considered a relative contraindication, ECMO has proven to be life-saving in several cases of respiratory failure associated with pulmonary haemorrhage due to various causes, including AAV. We reviewed the clinical presentation and course of two patients affected by AAV-related DAH treated at our Institution between 2012 and 2017, whose management required the use of veno-venous ECMO. We reviewed the current literature on the role of ECMO in the support of these patients. In both patients, ECMO provided life support and allowed disease control, in combination with immunosuppressive treatment. Despite systemic anticoagulation, clinical improvement was achieved without exacerbation of the pulmonary bleeding. We performed a literature review, and summarized available data confirming the effectiveness and safety of ECMO in AAV-related DAH. ECMO has a life-saving role in the management of patients with severe respiratory failure due to ANCA-associated pulmonary capillaritis.

Management of vascular complications of extra-corporeal membrane oxygenation

Extra-corporeal membrane oxygenation (ECMO) is a well-established treatment for cardiopulmonary failure. Based on the requirement for cardiac and or respiratory support different configurations of ECMO circuits are utilized. Vascular complication of ECMO constitutes the most important determinant of treatment outcomes. The complications are primarily related to limb ischemia, vascular injury, hemorrhage, and infection. Endovascular and surgical treatment options are the cornerstone for managing vascular complications of ECMO.

[Topical respiratory strategies in neurocritical care]

Management of the respiratory tract and maintenance of adequate gas exchange are the basic goals of critical care. Injury to the nervous system is often accompanied by development of respiratory disorders. On the other hand, changes in the gas composition of arterial blood can cause brain damage. In addition, approaches to the patient with respiratory failure, which are used in general critical care and neurocritical care, may differ. The presented literature review is devoted to modern respiratory strategies used in neurocritical care.

Clinical risk factors of extracorporeal membrane oxygenation support in older adults

Background

The ageing population and the expected increase in the number of elderly patients make an evidence-based assessment of Extracorporeal Membrane Oxygenation (ECMO) therapy in old patients progressively more important. Veno-arterial (VA) ECMO results for patient aged <65 years is well known. However, the risk profile and in-hospital prognosis of advanced age patients with ECMO still need more investigation. The aim of this study was to identify risk factors that predicted the outcomes for elderly patients who received VA-ECMO.

Methods

In this retrospective study, medical records for patients with ECMO aged 65 years and over were collected between 2009 and 2012 at a tertiary hospital.

Results

A total of 99 patients (mean age: 76.4±6.4 years) were included. The most common condition requiring VA-ECMO support was cardiogenic shock. Among survivors on VA-ECMO, 28 (28.3%) patients were successfully weaned from support. Thirteen (13.1%) patients were successfully discharged. We found that cardiogenic shock (OR = 3.158, P = 0.013), acute physiology and chronic health evaluation II (APACHE II) score (OR = 1.147, P<0.001), and simplified acute physiology score II (SAPS II) score (OR = 1.054, P = 0.001) were risk factors associated with survival on VA-ECMO. By using the areas under the receiver operating characteristic (AUC) curve, the APACHE II score and SAPS II score displayed acceptable discriminative power (AUC 0.722; 0.715, respectively).

Conclusion

Our findings indicate that the risk of mortality increases with cardiogenic shock, higher APACHE II score, and higher SAPS II score. These risk factors can be utilized as potential predictors to identify the potential candidates for ECMO support.

Use of neuromuscular blocking agents in acute respiratory distress syndrome

Acute respiratory distress syndrome is the result of an acute inflammatory response of the lungs, causing severe hypoxemia. A variety of therapeutic modalities have been extensively studied, with only a few demonstrating improvement in survival. Specifically, mechanical ventilation with use of low tidal volumes, prone positioning, and treatment with neuromuscular blocking agents have proven beneficial. This article focuses on the utilization of neuromuscular blocking agents in this entity. In particular, we briefly review the mechanism of action of neuromuscular blockades, the latest published evidence supporting their use in acute respiratory distress syndrome, and current recommendations for their utilization in clinical practice.

Pediatric ECMO Research: The Case for Collaboration

The use of extracorporeal membrane oxygenation (ECMO) in the pediatric age has increased considerably in the last decade, as has the complexity of cases and the variety of indications outside of the neonatal age. However, no randomized controlled trials have been attempted to date to test ECMO as an intervention in non-neonatal pediatric patients with critical illness. In this review, we provide a brief overview of the history of clinical research in pediatric ECMO and discuss methodological challenges including heterogeneity of ages and diagnoses in the pediatric ECMO population, rapid advances in technology and clinical practice related to ECMO, feasibility of enrolling critically ill children on ECMO in clinical research studies, and variability in ECMO management across institutions and countries. Lastly, we discuss opportunities and existing infrastructure for future multicenter, multi-network research collaborations for pediatric ECMO studies.

Pathophysiology and Management of Acute Respiratory Distress Syndrome in Children

Acute respiratory distress syndrome (ARDS) is a syndrome of noncardiogenic pulmonary edema and hypoxia that accompanies up to 30% of deaths in pediatric intensive care units. Pediatric ARDS (PARDS) is diagnosed by the presence of hypoxia, defined by oxygenation index or Pao₂/Fio₂ ratio cutoffs, and new chest infiltrate occurring within 7 days of a known insult. Hallmarks of ARDS include hypoxemia and decreased lung compliance, increased work of breathing, and impaired gas exchange. Mortality is often accompanied by multiple organ failure. Although many modalities to treat PARDS have been investigated, supportive therapies and lung protective ventilator support remain the mainstay.

Changes in the levels of beta-thromboglobulin and inflammatory mediators during extracorporeal membrane oxygenation support

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been associated with platelet dysfunction, but no markers of platelet dysfunction during ECMO have been identified.

METHODS

We investigated the potential uses of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) as markers of platelet activation induced by ECMO in vivo.

RESULTS

13 patients who received ECMO for acute respiratory failure were included. Generalized estimating equations were used to examine the associations between days on ECMO and the plasma levels of beta-TG and PF4 and of proinflammatory markers. Analyses were performed before ECMO (baseline) and 24, 48, 72 and 168 hours after the commencement of ECMO. The plasma levels of biomolecules were measured by ELISA and Luminex assay.Percentages of platelets varied widely without statistical significance (p = 0.17). Beta-TG levels significantly decreased over the first 72 hours (p<0.001), but PF4 levels decreased nonsignificantly (p = 0.17). Inflammatory markers, that is, plasma IL-6 (p = 0.03), IL-18 (p<0.001), and MMP-8 (p<0.01) levels stabilized during an early period of ECMO support.

CONCLUSIONS

Our data suggest that ECMO use may not affect platelet activation during the first 3 days of ECMO. Plasma beta-TG levels may allow assessment of the time-dependent extent of ECMO-induced platelet dysfunction in patients with acute respiratory failure.

Anticoagulation and Transfusions Management in Veno-Venous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: Assessment of Factors Associated With Transfusion Requirements and Mortality

Purpose:

We describe an approach for anticoagulation and transfusions in veno-venous–extracorporeal membrane oxygenation (VV-ECMO), evaluating factors associated with higher transfusion requirements, and their impact on mortality.

Methods:

Observational study on consecutive adults supported with VV-ECMO for acute respiratory distress syndrome (ARDS). We targeted an activated partial thromboplastin time of 40 to 50 seconds and a hematocrit of 24% to 30%. Univariate and multiple analyses were done to evaluate factors associated with transfusion requirements and the influence of increasing transfusions on mortality during ECMO.

Results:

In a cohort of 82 VV-ECMO patients (PRedicting dEath for SEvere ARDS on VV-ECMO [PRESERVE] score: 4, Interquartile range [IQR]: 3-5, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction [RESP] score: 2, IQR: 2-4), 76 (92.7%) patients received at least 1 unit of packed red blood cells (PRBCs) during the intensive care unit stay related to ECMO (median PRBC/d 156 mL, IQR: 93-218; median ECMO duration 14 days, IQR: 8-22). A higher requirement of PRBC transfusions was associated with pre-ECMO hematocrit, and with the following conditions during ECMO: platelet nadir, antithrombin III (ATIII), and stage 3 of acute kidney injury (all P < .05). Sixty-two (75.6%) patients survived ECMO. Pre-ECMO hospital stay, PRBC transfusion, and septic shock were associated with mortality (all P < .05). The adjusted odds ratio for each 100mL/d increase in PRBC transfusion was 1.9 (95% confidence interval [CI]: 1.1-3.2, P = .01); for the development of septic shock it was 15.4 (95% CI: 1.7-136.8, P = .01), and for each day of pre-ECMO stay it was 1.1 (95% CI: 1-1.2, P = .04).

Conclusion:

Implementation of a comprehensive protocol for anticoagulation and transfusions in VV-ECMO for ARDS resulted in a low PRBC requirement, and an ECMO survival comparable to data in the literature. Lower ATIII emerged as a factor associated with increased need for transfusions. Higher PRBC transfusions were associated with ECMO mortality. Further investigations are needed to better understand the right level of anticoagulation in ECMO, and the factors to take into account in order to manage personalized transfusion practice in this select setting.

Early measurement of IL-10 predicts the outcomes of patients with acute respiratory distress syndrome receiving extracorporeal membrane oxygenation

Patients diagnosed with acute respiratory distress syndrome are generally severely distressed and associated with high morbidity and mortality despite aggressive treatments such as extracorporeal membrane oxygenation (ECMO) support. To identify potential biomarker of predicting value for appropriate use of this intensive care resource, plasma interleukin-10 along with relevant inflammatory cytokines and immune cell populations were examined during the early and subsequent disease courses of 51 critically ill patients who received ECMO support. High interleukin-10 levels at the time of ECMO installation and during the first 6 hours after ECMO support of these patients stand as a promising biomarker associated with grave prognosis. The initial interleukin-10 level is correlated to other conventional risk evaluation scores as a predictive factor for survival, and furthermore, elevated interleukin-10 levels are also related to a delayed recovery of certain immune cell populations such as CD14⁺CD16⁺, CD14⁺TLR4⁺ monocytes, and T regulator cells. Genetically, high interleukin-10 is associated to two polymorphic nucleotides (−592 C and −819 C) at the interleukin-10 gene promoter area. Our finding provides prognostic and mechanistic information on the outcome of severely respiratory distressed patients, and potentially paves the strategy to develop new therapeutic modality based on the principles of precision medicine.

Extracorporeal membrane oxygenation for acute respiratory distress syndrome in adults: an analysis of differences between survivors and non-survivors

OBJECTIVES

Over the last decade, extracorporeal membrane oxygenation (ECMO) has become a promising option for patients with severe acute respiratory distress syndrome (ARDS). In this single-center observational cohort study, data from a patient group with severe ARDS treated with ECMO was analyzed.

METHODS

Data from 46 patients [median age 54 years (18 to 72), male: 65.2%] were evaluated retrospectively between January 2009 and September 2015.

RESULTS

Diagnosis leading to ARDS was pneumonia in 63.1% of the patients. The median SOFA Score was 13 (10 to 19) and the median LIS was 3.5 (2.67 to 4). The median duration of ECMO support was 12 days (1 to 86). Twenty-eight patients (60.9%) were successfully weaned from ECMO and 22 patients survived (47.8%). Non-survivors needed significantly more frequent renal replacement therapy (37.5% vs. 18.2%; p<0.01) and transfusion of red blood cell concentrates [0.4 units (0.3 to 1.2) vs. 0.9 units (0.5 to 1.6); p<0.01] during ECMO support compared to patients who survived.

CONCLUSION

This report suggests that ECMO currently allows treatment of severe ARDS with presumed improved survival. The incidence rate of acute kidney injury and transfusion are associated with adverse outcomes.

Physiological closed-loop control of mechanical ventilation and extracorporeal membrane oxygenation

A new concept is presented for cooperative automation of mechanical ventilation and extracorporeal membrane oxygenation (ECMO) therapy for treatment of acute respiratory distress syndrome (ARDS). While mechanical ventilation is continuously optimized to promote lung protection, extracorporeal gas transfer rates are simultaneously adjusted to control oxygen supply and carbon dioxide removal using a robust patient-in-the-loop control system. In addition, the cooperative therapy management uses higher-level algorithms to adjust both therapeutic approaches. The controller synthesis is derived based on the introduced objectives, the experimental setup and the uncertain models. Finally, the autonomous ARDS therapy system capabilities are demonstrated and discussed based on

Intravenous oxygen: a novel method of oxygen delivery in hypoxemic respiratory failure?

INTRODUCTION

Hypoxemic respiratory failure is a common problem in critical care. Current management strategies, including mechanical ventilation and extracorporeal membranous oxygenation, can be efficacious but these therapies put patients at risk for toxicities associated with invasive forms of support. Areas covered: In this manuscript, we discuss intravenous oxygen (IVO₂), a novel method to improve oxygen delivery that involves intravenous administration of a physiologic solution containing dissolved oxygen at hyperbaric concentrations. After a brief review of the physiology behind supersaturated fluids, we summarize the current evidence surrounding IVO₂. Expert commentary: Although not yet at the stage of clinical testing in the United States and Europe, IVO₂ has been used safely in Asia. Furthermore, preliminary laboratory data have been encouraging, suggesting that IVO₂ may play a role in the management of patients with hypoxemic respiratory failure in years to come. However, significantly more work needs to be done, including definitive evidence that such a therapy is safe, before it can be included in an intensivist's arsenal for hypoxemic respiratory failure.

Clinical Pharmacology Studies in Critically Ill Children

Developmental and physiological changes in children contribute to variation in drug disposition with age. Additionally, critically ill children suffer from various life-threatening conditions that can lead to pathophysiological alterations that further affect pharmacokinetics (PK). Some factors that can alter PK in this patient population include variability in tissue distribution caused by protein binding changes and fluid shifts, altered drug elimination due to organ dysfunction, and use of medical interventions that can affect drug disposition (e.g., extracorporeal membrane oxygenation and continuous renal replacement therapy). Performing clinical studies in critically ill children is challenging because there is large inter-subject variability in the severity and time course of organ dysfunction; some critical illnesses are rare, which can affect subject enrollment; and critically ill children usually have multiple organ failure, necessitating careful selection of a study design. As a result, drug dosing in critically ill children is often based on extrapolations from adults or non-critically ill children. Dedicated clinical studies in critically ill children are urgently needed to identify optimal dosing of drugs in this vulnerable population. This review will summarize the effect of critical illness on pediatric PK, the challenges associated with performing studies in this vulnerable subpopulation, and the clinical PK studies performed to date for commonly used drugs.

Extracorporeal Life Support in Pediatric and Neonatal Critical Care: A Review

Extracorporeal life support (ECLS) is a modified form of cardiopulmonary bypass used to provide prolonged tissue oxygen delivery in patients with respiratory and/or cardiac failure. The first large-scale success of ECLS was achieved in the management of term newborns with respiratory failure. ECLS has become an accepted therapeutic modality for neonates, children, and adults who have failed conventional therapy and in whom cardiac and/or respiratory insufficiency is potentially reversible. The use of ECLS allows one to reduce other cardiopulmonary supports and apply a gentle ventilation strategy in a population of severely compromised critical care patients. ECLS has now been employed in more than 26,000 neonatal and pediatric patients with an overall survival rate of 68%. ECLS has evolved significantly over 25 years of clinical practice; patient selection for this complex and highly invasive therapy, as well as how ECLS is employed in different patient groups, is constantly changing. Generally, ECLS is used more liberally now than in the past. The number of patients requiring this support, however, is declining yearly, and those patients who receive ECLS compose a more severe subset of an intensive care population. This review provides an overview of the development of ECLS and the equipment and techniques employed. The use of ECLS for neonatal respiratory failure, pediatric respiratory failure, and cardiac support are outlined. Management of the ECLS patient is discussed in detail, and outcome of these patients is reviewed. Finally, current trends and future implications of ECLS in neonatal and pediatric critical care are addressed.

Extracorporeal Respiratory Support With a Miniature Integrated Pediatric Pump-Lung Device in an Acute Ovine Respiratory Failure Model

Respiratory failure is one of the major causes of mortality and morbidity all over the world. Therapeutic options to treat respiratory failure remain limited. The objective of this study was to evaluate the gas transfer performance of a newly developed miniature portable integrated pediatric pump-lung device (PediPL) with small membrane surface for respiratory support in an acute ovine respiratory failure model. The respiratory failure was created in six adult sheep using intravenous anesthesia and reduced mechanical ventilation at 2 breaths/min. The PediPL device was surgically implanted and evaluated for respiratory support in a venovenous configuration between the right atrium and pulmonary artery. The hemodynamics and respiratory status of the animals during support with the device gas transfer performance of the PediPL were studied for 4 h. The animals exhibited respiratory failure 30 min after mechanical ventilation was reduced to 2 breaths/min, indicated by low oxygen partial pressure, low oxygen saturation, and elevated carbon dioxide in arterial blood. The failure was reversed by establishing respiratory support with the PediPL after 30 min. The rates of O₂ transfer and CO₂ removal of the PediPL were 86.8 and 139.1 mL/min, respectively. The results demonstrated that the PediPL (miniature integrated pump-oxygenator) has the potential to provide respiratory support as a novel treatment for both hypoxia and hypercarbia. The compact size of the PediPL could allow portability and potentially be used in many emergency settings to rescue patients suffering acute lung injury.

Venovenous Extracorporeal Life Support in Single-Ventricle Patients with Acute Respiratory Distress Syndrome

There is new and growing experience with venovenous extracorporeal life support (VV ECLS) for neonatal and pediatric patients with single-ventricle physiology and acute respiratory distress syndrome (ARDS). Outcomes in this population have been defined but could be improved; survival rates in single-ventricle patients on VV ECLS for respiratory failure are slightly higher than those in single-ventricle patients on venoarterial ECLS for cardiac failure (48 vs. 32-43%), but are lower than in patients with biventricular anatomy (58-74%). To that end, special consideration is necessary for patients with single-ventricle physiology who require VV ECLS for ARDS. Specifically, ARDS disrupts the balance between pulmonary and systemic blood flow through dynamic alterations in cardiopulmonary mechanics. This complexity impacts how to run the VV ECLS circuit and the transition back to conventional support. Furthermore, these patients have a complicated coagulation profile. Both venous and arterial thrombi carry marked risk in single-ventricle patients due to the vulnerability of the pulmonary, coronary, and cerebral circulations. Finally, single-ventricle palliation requires the preservation of low resistance across the pulmonary circulation, unobstructed venous return, and optimal cardiac performance including valve function. As such, the proper timing as well as the particular conduct of ECLS might differ between this population and patients without single-ventricle physiology. The goal of this review is to summarize the current state of knowledge of VV ECLS in the single-ventricle population in the context of these special considerations.

Trends in U.S. Extracorporeal Membrane Oxygenation Use and Outcomes: 2002-2012

This study evaluates contemporary trends in the use and outcomes of adult patients undergoing extracorporeal membrane oxygenation (ECMO) in U.S. hospitals. All adult discharges in the Nationwide Inpatient Sample database during the years 2002-2012 that included ECMO were used to estimate the total number of U.S. ECMO hospitalizations (n = 12,407). Diagnostic codes were used to group patients by indication for ECMO use into postcardiotomy, heart transplant, lung transplant, cardiogenic shock, respiratory failure, and cardiopulmonary failure. A Mann-Kendall test was used to examine trends over time using standard statistical techniques for survey data. We found that ECMO use increased significantly from 2002-2012 (P = 0.003), whereas in-hospital mortality rate fluctuated without a significant difference in trend over time. No significant trend was observed in overall ECMO use from 2002-2007, but the use did demonstrate a statistically significant increase from 2007-2012 (P = 0.0028). The highest in-hospital mortality rates were found in the postcardiotomy (57.2%) and respiratory failure (59.2%) groups. Lung and heart transplant groups had the lowest in-hospital mortality rates (44.10% and 45.31%, respectively). The proportion of ECMO use for postcardiotomy decreased from 56.9% in 2002 to 37.9% in 2012 (P = 0.026) and increased for cardiopulmonary failure from 3.9% to 11.1% (P = 0.026). We concluded that ECMO use in the United States increased between 2002 and 2012, driven primarily by increase in national ECMO use beginning in 2007. Mortality rates remained high but stable during this time period. Though there were shifts in relative ECMO use among patient groups, absolute ECMO use increased for all indications over the study period.

Postperfusion lung syndrome: physiopathology and therapeutic options

Postperfusion lung syndrome is rare but can be lethal. The underlying mechanism remains uncertain but triggering inflammatory cascades have become an accepted etiology. A better understanding of the pathophysiology and the roles of inflammatory mediators in the development of the syndrome is imperative in the determination of therapeutic options and promotion of patients' prognosis and survival. Postperfusion lung syndrome is similar to adult respiratory distress syndrome in clinical features, diagnostic approaches and management strategies. However, the etiologies and predisposing risk factors may differ between each other. The prognosis of the postperfusion lung syndrome can be poorer in comparison to acute respiratory distress syndrome due to the secondary multiple organ failure and triple acid-base imbalance. Current management strategies are focusing on attenuating inflammatory responses and preventing from pulmonary ischemia-reperfusion injury. Choices of cardiopulmonary bypass circuit and apparatus, innovative cardiopulmonary bypass techniques, modified surgical maneuvers and several pharmaceutical agents can be potential preventive strategies for acute lung injury during cardiopulmonary bypass.

Pediatric Extracorporeal Membrane Oxygenation: An Introduction for Emergency Medicine Physicians

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) therapy has supported critically ill pediatric patients in the intensive care unit setting with cardiac and respiratory failure. This therapy is beginning to transition to the emergency department setting.

OBJECTIVE OF REVIEW

This article describes the fundamentals of ECMO and familiarizes the emergency medicine physician with its use in critically ill pediatric patients.

DISCUSSION

ECMO can be utilized as either venoarterial (VA) or venovenous (VV), to support oxygenation and perfusion in respiratory failure, sepsis, cardiac arrest, and environmental hypothermia.

The use of double lumen cannula for veno-venous ECMO in trauma patients with ARDS

Background

The use of a double lumen cannula for veno-venous extracorporeal membrane oxygenation (v.v. ECMO) offers several advantages such as cannulation with only one cannula, patient comfort and the earlier mobilization and physiotherapy. The cannulation should be performed under visual wire and cannula placement into the right atrium, which is associated with risks of malposition and right ventricular perforation. The aim of this patient series is to describe the use of double lumen cannula in trauma patients with posttraumatic ARDS.

Material and methods

Criteria for the v.v ECMO treatment were defined as hypoxaemia (pO2/FiO2 < 200 mmHg, FiO2 0.8-1,0); tidal volume >4-6 ml/kg ideal body weight; mean inspiratory pressure (Pinsp) >32-34 mmHg; respiratory acidosis pH <7.25; and arterial saturation (SaO2) <90%. The analysis included the Injury Severity Score (ISS), the types of injury, time of treatment, complications and outcomes.

Results

A total of 24 patients with major trauma were treated for posttraumatic ARDS with v.v. ECMO. The double lumen cannula (Avalon®, Fa. Maquet, Rastatt, Germany) was used in six male patients. The mean ISS was 31 (20–48). The ECMO therapy was started in an average on the third day after trauma. The mean ECMO run time was 7 days ± 5 (6–18), and the hospital stay was in mean of 60 days ± 34 (21–105).

Conclusion

The use of double lumen cannula for v.v ECMO therapy in trauma patients is a feasible treatment option. No higher risk of bleeding could be found in this case series. A PTT-controlled heparinization is recommended using double lumen cannula. Therefore the use of this cannula type in trauma patients with high risk of bleeding is to discuss controversially.

Extracorporeal membrane oxygenation for Life-threatening ANCA-positive pulmonary capillaritis. A review of UK experience

INTRODUCTION

Anti-neutrophil cytoplasmic antibody positive pulmonary capillaritis complicated by diffuse alveolar hemorrhage is a potentially fatal condition for which extracorporeal membrane oxygenation can facilitate improved outcomes and potential cure. Diffuse alveolar hemorrhage can be the initial presentation of an autoimmune disorder. The management is centered on the use of immunosuppressive therapy, which requires time, with fatality often occurring for these patients. We showed two very young patients with no previous history of vasculitis presenting with life threatening pulmonary hemorrhage due to anti-neutrophil cytoplasmic antibody positive vasculitis, whose management was facilitated with extracorporeal membrane oxygenation.

METHODS

We reviewed the clinical presentation and course of the first two patients with diffuse alveolar hemorrhage for anti-neutrophil cytoplasmic antibody positive vasculitis managed with veno-venous extracorporeal membrane oxygenation. We highlighted and analysed the unique challenges encountered in managing these patients.

RESULTS

The two patients were referred for extracorporeal membrane oxygenation since conventional ventilation was inadequate to provide physiologic support for respiratory failure. Clinical improvement was achieved without exacerbation of the pulmonary hemorrhage despite the use of anticoagulants. This provided time for the immunosuppressants to take effect. Both patients were discharged and were cured of the underlying condition.

CONCLUSIONS

Extracorporeal membrane oxygenation has a role in the management of patients with severe respiratory failure due to anti-neutrophil cytoplasmic antibody positive capillaritis. Early recognition and referral for extracorporeal membrane oxygenation are vital to achieve a favourable outcome.

Extracorporeal CO2 removal as bridge to lung transplantation in life-threatening hypercapnia

In patients awaiting lung transplantation (LTX), adequate gas exchange may not be sufficiently achieved by mechanical ventilation alone if acute respiratory decompensation arises. We report on 20 patients with life-threatening hypercapnia who received extracorporeal CO2 removal (ECCO2-R) by means of the interventional lung assist (ILA®, Novalung) as bridge to LTX. The most common underlying diagnoses were bronchiolitis obliterans syndrome, cystic fibrosis, and idiopathic pulmonary fibrosis, respectively. The type of ILA was pumpless arteriovenous or pump-driven venovenous (ILA activve®, Novalung) in 10 patients each. ILA bridging was initiated in 15 invasively ventilated and five noninvasively ventilated patients, of whom one had to be intubated prior to LTX. Hypercapnia and acidosis were effectively corrected in all patients within the first 12 h of ILA therapy: PaCO2 declined from 109 (70-146) to 57 (45-64) mmHg, P < 0.0001; pH increased from 7.20 (7.06-7.28) to 7.39 (7.35-7.49), P < 0.0001. Four patients were switched to extracorporeal membrane oxygenation due to progressive hypoxia or circulatory failure. Nineteen patients (95%) were successfully transplanted. Hospital and 1-year survival was 75 and 72%, respectively. Bridging to LTX with ECCO2-R delivered by arteriovenous pumpless or venovenous pump-driven ILA is feasible and associated with high transplantation and survival rates.

Influence of different oxygenator types on changing frequency, infection incidence, and mortality in ARDS patients on veno-venous ECMO

PURPOSE

Veno-venous extracorporeal membrane oxygenation (vv-ECMO) is pivotal in the treatment of patients suffering from acute respiratory distress syndrome (ARDS). Comparative data with different oxygenator models have not yet been reported. The aim of this retrospective investigation was therefore to assess whether different oxygenator types might influence changing frequency, infection incidence, and mortality in patients on vv-ECMO.

METHODS

42 patients undergoing vv-ECMO between 1998 and 2009 were identified. In 20 out of these patients, a polypropylene (PP) microporous hollow fiber membrane oxygenator, and in 22 patients a nonmicroporous polymethylpentene (PMP) diffusion membrane oxygenator was used. Infection incidence, changing frequency, and mortality were documented.

RESULTS

In the PMP group, an oxygenator change was necessary less often than in the PP group (p<0.001). The incidence of bacterial, viral, or fungal growth was similar in the groups, thus independent of the frequency of oxygenator change. Irrespective of the groups, the occurrence of Candida sp. tended to correlate with death (p = 0.06). In general, there was a trend towards a higher infection incidence in the subgroup with pulmonary ARDS (p = 0.07). Moreover, infection incidence was associated with a longer ICU stay (p = 0.03) and longer ECMO therapy (p = 0.03). ICU mortality was lower in the PMP group than in the PP group, although not statistically significant (p = 0.10).

CONCLUSIONS

The PMP oxygenator membranes showed benefits with regards to changing frequency, but not infection incidence, length of ICU stay, and length of ECMO therapy. There was a trend towards a lower ICU mortality in patients with PMP oxygenators.

Design and validation of a diaphragm pump for pediatric CRRT during ECMO

Purpose

Children requiring artificial heart-lung support through extracorporeal membrane oxygenation (ECMO) are at increased risk of developing acute kidney injury (AKI). Continuous renal replacement therapy (CRRT) is the preferred method of treatment in pediatric AKI patients. CRRT devices are noted to provide inaccurate fluid balance (FB) when operated under low flow rates seen in children. We present the design and validation of a novel pump concept to provide accurate pediatric CRRT during ECMO.

Methods

A diaphragm pump was prototyped with a working stroke volume (SV) of 7 mL. Fluid transport occurs by periodic expansion and contraction of a flexible membrane due to pressure fluctuations of hydraulic fluid contained below its surface. Comparison of intravenous (IV) pumps to the diaphragm pump was conducted in vitro across the range of pressures observed during CRRT in ECMO. The pump was integrated into a CRRT circuit parallel with ECMO and FB accuracy was evaluated.

Results

The pump design improved efficiency of fluid transport, with flow rate errors as low as 1-5 ml/hr as compared to IV pumps (15-50 ml/hr). The SV of IV pumps increased with source pressure in a nearly linear manner compared to the minimal variation produced by the diaphragm pump. Inclusion of the diaphragm pump in a conventional CRRT circuit with ECMO improved the FB accuracy.

Conclusions

A novel diaphragm pump concept has been presented for providing CRRT during ECMO in the pediatric population. Improvement of the pump accuracy compared to currently used CRRT pumps was demonstrated via in vitro testing.

Anesthetic management including extracorporeal membrane oxygenation therapy of liver transplant recipient with life-threatening hypoxemia -a case report-

We present a rare case of successful anesthetic management for a patient who had refractory hypoxia during liver transplantation (LT) with intraoperative veno-venous (VV) extracorporeal membrane oxygenation (ECMO) support. A 49 year-old female patient underwent living donor LT. After reperfusion of the grafted liver, graft congestion and massive oozing developed. Thus it was decided to reoperate with a temporary gauze packing. However, the patient's condition deteriorated with azotemia and severe hypoxemia. VV ECMO with continuous renal replacement therapy was started 24 hours before secondary LT and maintained during secondary LT. VV ECMO was weaned 32 hours after secondary LT. This case indicates that not only after the LT but also before and during LT, VV ECMO can be a treatment option for the patient with end-stage liver disease combined with respiratory failure when there is the possibility of lung recovery.

Approach to acute exacerbation of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia with a median survival of 3 years after diagnosis. Acute exacerbation of IPF (AE-IPF) is now identified as a life-threatening complication. It presents as worsening dyspnea with new ground glass opacities superimposed upon a radiographic usual interstitial pneumonia (UIP) pattern. It is a diagnosis of exclusion. The prognosis of AE-IPF is poor and treatment strategies lack standardization. In order to rule out any reversible etiology for an acute decompensation of a previously stable IPF patient diagnostic modalities include computerized tomographic angiogram (CTA) coupled with high-resolution computerized tomography (HRCT) imaging of the chest, bronchoalveolar lavage (BAL) and echocardiogram with bubble study. Avoiding risk factors, identifying underlying causes and supportive care are the mainstays of treatment. Anti-inflammatory and immunosuppressant medications have not shown to improve survival in AE-IPF. Most of the patients are managed in a critical care setting with mechanical ventilation. Lung transplantation is a promising option but most institutions are not equipped and not every patient is a candidate.

Rianimazione e influenza grave: pandemia influenzale A (H1N1)

Durante la pandemia influenzale A (H1N1) nel 2009-2010, il 20% dei pazienti ospedalizzati ha presentato delle forme gravi con trasferimento in rianimazione. L’età mediana di questi pazienti era di circa 30 anni, con una percentuale leggermente inferiore al 10% di donne gravide. Si riscontrava circa un 80% di comorbilità, essenzialmente malattie cardiorespiratorie e obesità. Il tempo mediano tra la comparsa della sindrome influenzale e il trasferimento in rianimazione era di un giorno. I test di diagnosi rapida sono realizzabili a partire da semplici campioni respiratori, ma la loro sensibilità rimane bassa. La durata mediana del ricovero in rianimazione era dell’ordine di 11 giorni. Circa il 70% dei pazienti ha richiesto una ventilazione meccanica (durata mediana di dieci giorni). Oltre il 95% di questi pazienti ha ricevuto un trattamento antivirale e oltre il 95% degli antibiotici, a fronte di un 20% soltanto di infezioni batteriche documentate, soprattutto da Streptococcus pneumoniae e Staphylococcus aureus. La mortalità globale a 28 giorni era del 17%. Il tempo mediano tra la comparsa della sindrome influenzale e il decesso era di 14 giorni. Fra questi decessi, la maggior parte dei pazienti aveva ricevuto un trattamento antivirale, ma non sempre nelle prime 48 ore, il che appare un fattore prognostico infausto. Così, il trattamento antivirale è consigliato nelle forme gravi; il virus pandemico A (H1N1) era sensibile ai due inibitori della neuraminidasi. Sono stati riscontrati dei casi sporadici di resistenza, il che spinge a sviluppare altre molecole attive sui virus influenzali.

Successful management of life-threatening respiratory failure from H1N1 influenza

We report the outcome of a pregnant woman with a life-threatening acute respiratory distress syndrome from a novel influenza A (H1N1) virus infection 3 d postpartum successfully managed by veno-arterial extracorporeal membrane oxygenation. The patient was successfully weaned from extracorporeal membrane oxygenation (ECMO) on day 10. Novel H1N1 virus infection was identified by real-time reverse transcription-polymerase chain reaction. Veno-arterial ECMO in this patient carried a number of specific advantages namely maintaining haemodynamic stability obviating the need for inotrope support and improving oxygenation compared to alternative approaches such as veno-venous ECMO and pumpless devices. Femoral arterial and venous cannulae were inserted in a pure percutaneous method allowing rapid establishment of extracorporeal circulation. Given the high mortality of acute respiratory distress syndrome following novel H1N1 virus infection, we advocate the use of ECMO when conventional mechanical ventilation fails.