Extracorporeal membrane oxygenation for respiratory failure in adults:

Extracorporeal Life Support for Severely Burned Patients with Concurrent Inhalation Injury and Acute Respiratory Distress Syndrome: Experience from a Military Medical Burn Center

BACKGROUND

Both inhalation injury and acute respiratory distress syndrome (ARDS) are risk factors that predict mortality in severely burned patients. Extracorporeal life support (ECLS) is widely used to rescue these patients; however, its efficacy and safety in this critical population have not been well defined. We report our experience of using ECLS for the treatment of severely burned patients with concurrent inhalation injury and ARDS.

METHODS

This was a retrospective analysis of 14 patients collected from a single medical burn center from 2012 to 2019. All patients suffered from major burns with inhalation injury and ARDS, and were treated with ECLS.

RESULTS

The median total body surface area of deep dermal or full thickness burns was 94.5%, ranging 47.7-99.0 %. The median revised Baux score was 122.0, ranging 90.0-155.0. All patients developed ARDS with a median partial pressure of arterial oxygen to a fraction of inspired oxygen ratio of 61.5, ranging 49.0-99.0. Indications for ECLS included sustained hypoxemia and unstable hemodynamics. The median interval for initiating ECLS was 2.5 days, ranging 1.0-156.0 days. The median duration of ECLS was 2.9 days, ranging 0.3-16.7 days. The overall survival to discharge was 42.8%. Causes of death included sepsis and multiple organ failure. ECLS-related complications included cannulation bleeding, catheter-related infection, and hemolysis. The incidence of risk factors reported in literature were higher in non-survivors, including Baux>120, albumin < 3.0 g/dL, and lactate > 8 mmol/L.

CONCLUSIONS

For severely burned patients with concurrent inhalation injury and ARDS, ECLS could be a salvage treatment to improve sustained hypoxemia. However, the efficacy of hemodynamic support was limited. Identifying definite ECLS indications and rigorous patient selection would contribute to better clinical outcomes.

In Vivo Suction Pressures of Venous Cannulas During Veno-venous Extracorporeal Membrane Oxygenation

Extracorporeal lung support includes the risk of hemolysis due to suction pressures. Manufacturers measure the negative suction pressure across drainage cannulas for their products in vitro using water. Clinical experience suggests that hemolysis occurs in vivo already at much lower flow rates. The aim of this study was to analyze the in vivo suction pressure for veno-venous extracorporeal membrane oxygenation (VV-ECMO) cannulas. Prospective, observational study at a tertiary-care intensive care unit: 15 patients on VV-ECMO for severe ARDS were prospectively included. In vitro , the 25 Fr drainage cannula pressure drops below a critical level of around -100 mm Hg at a flow rate of 7.9 L/min, the 23 Fr drainage cannula at 6.6 L/min. In the clinical setting, critical suction pressures were reached at much lower flow rates (5.5 and 4.7 L/min; p < 0.0001, nonlinear regression). The in vitro data largely overestimate the safely achievable flow rates in daily clinical practice by 2.4 L/min (or 44%, 25 Fr) and 1.9 L/min (or 41%, 23 Fr). In vivo measurement of suction pressure of venous drainage cannulas differed significantly from in vitro derived measurements as the latter largely underestimate the resulting suction pressure.

Veno-venous Extracorporeal Membrane Oxygenation for pregnant women with Acute Respiratory Distress Syndrome: a narrative review

Acute respiratory distress syndrome remains an uncommon condition during pregnancy. In patients with severe acute respiratory distress syndrome, when oxygenation or ventilation cannot be supported sufficiently using best practice conventional mechanical ventilation and additional therapies, veno-venous extracorporeal membrane oxygenation may be considered. In the past two decades, there has been increasing adoption of this technique to support adult patients with refractory acute respiratory distress syndrome. However, its use for the management of pregnant women is rare and remains a challenge. This narrative review addresses acute respiratory distress syndrome and its management during pregnancy, and then focuses on indications, contraindications, challenges, potential complications, and outcomes of the use of veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome in the pregnant patient.

A Comparison of Anticoagulation Strategies in Veno-venous Extracorporeal Membrane Oxygenation

Bleeding remains a major source of morbidity associated with veno-venous extracorporeal membrane oxygenation (VV-ECMO). Moreover, there remains significant controversy, and a paucity of data regarding the ideal anticoagulation strategy for VV-ECMO patients. All patients undergoing isolated, peripheral VV-ECMO between January 2009 and December 2014 at our institution were retrospectively reviewed. Patients (n = 123) were stratified into one of three sequential eras of anticoagulation strategies: activated clotting time (ACT: 160-180 seconds, n = 53), high-partial thromboplastin time (H-PTT: 60-80 seconds, n = 25), and low-PTT (L-PTT: 45-55 seconds, n = 25) with high-flow (>4 L/min). Pre-ECMO APACHE II scores, SOFA scores, and Murray scores were not significantly different between the groups. Patients in the L-PTT group required less red blood cell units on ECMO than the ACT or H-PTT group (2.1 vs. 1.3 vs. 0.9; p < 0.001) and patients in the H-PTT and L-PTT group required less fresh frozen plasma than the ACT group (0.33 vs. 0 vs. 0; p = 0.006). Overall, major bleeding events were significantly lower in the L-PTT group than in the ACT and H-PTT groups. There was no difference in thrombotic events. In this single-institution experience, a L-PTT, high-flow strategy on VV-ECMO was associated with fewer bleeding and no difference in thrombotic events than an ACT or H-PTT strategy.

Research Trends and Hotspots of Extracorporeal Membrane Oxygenation: A 10-Year Bibliometric Study and Visualization Analysis

Objective: To determine the research hotspots and trends in the field of extracorporeal membrane oxygenation (ECMO), and to provide a reference for further and wider research in the future. Methods: The literatures on ECMO from January 2011 to July 2021 in the Web of Science Core Collection (WOSCC) database were searched, and Citespace5.8.R1 software was used to conduct bibliographic and visual analysis on the literature by country, institution, author and keywords. Results: A total of 5,986 articles were enrolled. According to an observation, the number of articles published in the past decade has increased, especially from 2019 to 2020. The USA had the largest number of publications, while less ECMO related studies were conducted among non-developed countries. The University of Michigan (Univ Michigan) was the institution that had the largest number of publications and the highest centrality, and Daniel B was the author who had the largest number of publications. However, more inter-institutional cooperation among author teams was needed. The focus of existing ECMO research has primarily been on the treatment of patients suffering from severe cardiopulmonary failure, and the prevention and management of complications during the application ECMO. Conclusion: Inter-regional and inter-institutional cooperation and exchanges should be carried out among ECMO research teams and institutions. The suggested research direction is to further broaden the application scope of ECMO, while determining the ways to reduce the incidence of complications and the cost, cultivate specialized team talents, and promote the application thereof.

The Evolution of the Use of Extracorporeal Membrane Oxygenation in Respiratory Failure

Extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency to support patients with acute respiratory failure, most commonly, and severe forms of acute respiratory distress syndrome (ARDS). The marked increase in the global use of ECMO followed the publication of a large randomized trial in 2009 and the experience garnered during the 2009 influenza A (H1N1) pandemic, and has been further supported by the release of a large, randomized clinical trial in 2018, confirming a benefit from using ECMO in patients with severe ARDS. Despite a rapid expansion of ECMO-related publications, optimal management of patients receiving ECMO, in terms of patient selection, ventilator management, anticoagulation, and transfusion strategies, is evolving. Most recently, ECMO is being utilized for an expanding variety of conditions, including for cases of severe pulmonary or cardiac failure from coronavirus disease 2019 (COVID-19). This review evaluates modern evidence for ECMO for respiratory failure and the current challenges in the field.

Respiratory care for the critical patients with 2019 novel coronavirus

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through respiratory droplets, aerosols and close contact. Cross infections occur because viruses spread rapidly among humans. Nineteen percent (19%) of the infected patients developed severe pneumonia and acute respiratory distress syndrome (ARDS). Hypoxemia usually occurs and patients may require oxygen therapy or mechanical ventilation (MV) support. In this article, recently published clinical experience and observational studies were reviewed. Corresponding respiratory therapy regarding different stages of infection is proposed. Infection control principles and respiratory strategies including oxygen therapy, non-invasive respiratory support (NIRS), intubation evaluation, equipment preparation, ventilator settings, special maneuvers comprise of the prone position (PP), recruitment maneuver (RM), extracorporeal membrane oxygenation (ECMO), weaning and extubation are summarized. Respiratory equipment and device disinfection recommendations are worked up. We expect this review article could be used as a reference by healthcare workers in patient care while minimizing the risk of environmental contamination.

Impact of an Extracorporeal Membrane Oxygenation Intensivist-Led Multidisciplinary Team on Venovenous Extracorporeal Membrane Oxygenation Outcomes

Objectives:

Venovenous extracorporeal membrane oxygenation is increasingly being established as a treatment option for severe acute respiratory failure. We sought to evaluate the impact of a dedicated specialist team-based approach on patient outcomes.

Design:

Retrospective cohort study.

Setting:

Single-center medical ICU in an academic tertiary hospital.

Patients:

Adult patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure.

Interventions:

Initiation of an extracorporeal membrane oxygenation intensivist-led multidisciplinary team; critical decisions on extracorporeal membrane oxygenation management were jointly made by a dedicated team of extracorporeal membrane oxygenation intensivists, together with the multidisciplinary team.

Measurements and Main Results:

Eighty-one patients (75%) and 27 patients (35%) were initiated on venovenous extracorporeal membrane oxygenation in the preextracorporeal membrane oxygenation intensivist-led multidisciplinary team (before January 2018) and postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period (after January 2018), respectively. Inhospital (14.8% vs 44.4%, p = 0.006) and ICU mortality (11.1% vs 40.7%, p = 0.005) were significantly lower in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period. On multivariate analysis correcting for possible confounding factors (ICU severity and extracorporeal membrane oxygenation-specific mortality prediction scores, body mass index, preextracorporeal membrane oxygenation vasopressor support, preextracorporeal membrane oxygenation cardiac arrest, and days on mechanical ventilation before extracorporeal membrane oxygenation initiation), management by an extracorporeal membrane oxygenation intensivist-led multidisciplinary team remained associated with improved hospital survival (odds ratio, 5.06; 95% CI, 1.20–21.28). Patients in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period had less nosocomial infections (18.5% vs 46.9%, p = 0.009), a shorter ICU stay (12 days [interquartile range, 6–16 d] vs 15 days [interquartile range, 10–24 d]; p = 0.049), and none suffered an intracranial hemorrhage or nonhemorrhagic stroke.

Conclusions:

An extracorporeal membrane oxygenation intensivist-led multidisciplinary team approach is associated with improved outcomes in patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure.

Does Earlier Cannulation With Veno-Venous Extracorporeal Membrane Oxygenation in Adult Patients With Acute Respiratory Distress Syndrome Decrease Duration of Artificial Mechanical Ventilation?

BACKGROUND

Acute respiratory distress syndrome (ARDS) is characterized by an acute, diffuse, inflammatory lung injury, leading to increased alveolar capillary permeability, increased lung weight, and loss of aerated lung tissue (Fan, Brodie, & Slutsky, 2018). Primary treatment for ARDS is artificial mechanical ventilation (AMV) (Wu, Huang, Wu, Wang, & Lin, 2016). Given recent advances in technology, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) to treat severe ARDS is growing rapidly (Combes et al., 2014).

OBJECTIVE

This 49-month quantitative, retrospective inpatient EMR chart review compared if cannulation with VV-ECMO up to and including 48 hours of admission and diagnosis in adult patients 30 to 65 years of age diagnosed with ARDS, decreased duration on AMV, as compared to participants who were cannulated after 48 hours of admission and diagnosis with ARDS.

METHODS

A total of 110 participants were identified as receiving VV-ECMO during the study timeframe. Of the 58 participants who met all inclusion criteria, 39 participants were cannulated for VV-ECMO within 48 hours of admission and diagnosis with ARDS, and 19 participants were cannulated with VV-ECMO after 48 hours of admission and diagnosis with ARDS.

RESULTS

Data collected identified no statistically significant (p < 0.579) difference in length of days on AMV between participant groups.

CONCLUSIONS

Further studies are needed to determine if earlier initiation of VV-ECMO in adult patients with ARDS decrease time on AMV.

IMPLICATIONS FOR NURSING

Although the results related to length of time on AMV did not produce statistical significance, the decreased duration of AMV in the participants who were cannulated within 48 hours (21 days vs. 27 days) may support several benefits associated with this participant population including increased knowledge of healthcare providers, decreased lung injury, earlier discharge which decreases hospital and patient cost, ability for patients to communicate sooner, decreased risk of pulmonary infection, decreased length of stay, decreased cost, and improved patient and family satisfaction.

Venovenous Extracorporeal Membrane Oxygenation in a Gravid Patient with Acute Respiratory Distress Syndrome: A Case Report

Patient: Female, 22

Final Diagnosis: Acute respiratory distress syndrome

Symptoms: Flank pain • urinary frequency

Medication: —

Clinical Procedure: ECMO

Specialty: Critical Care Medicine

Bridging to Lung Transplantation

Lung transplantation is the gold standard for treating patients with end-stage lung disease. Such patients can present with severe illness on the waitlist and may deteriorate before a lung donor is available. Bridging strategies with extracorporeal membrane oxygenation (ECMO) are valuable for getting patients to transplant and provide a chance at survival. The current article describes the indications, contraindications, and techniques involved in bridging to lung transplantation with ECMO.

Critical Care before Lung Transplantation

Lung transplantation is widely accepted as the only viable treatment option for patients with end-stage lung disease. However, the imbalance between the number of suitable donor lungs available and the number of possible candidates often results in intensive care unit (ICU) admission for the latter. In the ICU setting, critical care is essential to keep these patients alive and to successfully bridge to lung transplantation. Proper management in the ICU is also one of the key factors supporting long-term success following transplantation. Critical care includes the provision of respiratory support such as mechanical ventilation (MV) and extracorporeal life support (ECLS). Accordingly, a working knowledge of the common critical care issues related to these unique patients and the early recognition and management of problems that arise before and after transplantation in the ICU setting are crucial for long-term success. In this review, we discuss the management and selection of candidates for lung transplantation as well as existing respiratory support strategies that involve MV and ECLS in the ICU setting.

Acute Respiratory Failure Managed via Inter-Facility Transport for Extracorporeal Life Support: A 3-Year Experience

OBJECTIVES

The objectives of this study were as follows: (1) to describe a successful design for a mobile lung rescue program, focusing on challenges and resources required to support such a program, and (2) report short-term outcomes for patients placed on venovenous extracorporeal life support (VV-ECLS) by a transferring team before inter-facility transport to a specialized extracorporeal life support (ECLS) center.

DESIGN

This retrospective review and analysis used patient chart review to collect outcomes data and resource demand.

SETTING

A single institutional experience in an academic center in the United States.

PARTICIPANTS

Patient selection targeted the 75 patients who were placed on VV-ECLS for acute respiratory failure at an outside institution by the authors' team before transport from January 1, 2015, through December 31, 2017.

INTERVENTIONS

No intervention was made.

MEASUREMENTS AND MAIN RESULTS

Average time for dispatch and transfer was 4 hours and 10 minutes for ground and 3 hours and 30 minutes for air transport (p = 0.029). Demand was highest in winter, with 61% (46/75) of patients presenting from November through April, and daytime, with 73% (55/75) occurring from 8 am to 8 pm. Demand increased during the study period, with 21 patients in 2015, 24 in 2016, and 30 in 2017. Mortality was low, with 72% of patients surviving to discharge.

CONCLUSIONS

Herein a successful mobile lung rescue program for transfer to a regional ECLS center is described. These findings demonstrate bed availability during high census and presence of a physician for duration of transport. These challenges can be overcome and successful implementation can be made with low mortality, supporting the development of regional ECLS centers.

The Role of Echocardiography in Neonates and Pediatric Patients on Extracorporeal Membrane Oxygenation

Indications for extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR) are expanding, and echocardiography is a tool of utmost importance to assess safety, effectiveness and readiness for circuit initiation and separation. Echocardiography is key to anticipating complications and improving outcomes. Understanding the patient's as well as the ECMO circuit's anatomy and physiology is crucial prior to any ECMO echocardiographic evaluation. It is also vital to acknowledge that the utility of echocardiography in ECMO patients is not limited to the evaluation of cardiac function, and that clinical decisions should not be made exclusively upon echocardiographic findings. Though echocardiography has specific indications and applications, it also has limitations, characterized as: prior to and during cannulation, throughout the ECMO run, upon separation and after separation from the circuit. The use of specific and consistent echocardiographic protocols for patients on ECMO is recommended.

Mechanical ventilation and respiratory monitoring during extracorporeal membrane oxygenation for respiratory support

Over the past decade, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) for respiratory support has widely expanded as a treatment strategy for patients with acute respiratory distress syndrome (ARDS). Despite considerable attention has been given to the indications, the timing and the management of patients undergoing ECMO for refractory respiratory hypoxemic failure, little is known regarding the management of mechanical ventilation (MV) in this group of patients. ECMO enables to minimize ventilatory induced lung injury (VILI) and it has been successfully used as rescue therapy in patients with ARDS when conventional ventilator strategies have failed. However, literature is lacking regarding the best strategies and MV settings, including positive end expiratory pressure (PEEP), tidal volume (VT), respiratory rate (RR) and plateau pressure (PPLAT). The aim of this review is to summarize current evidence, the rationale and provide recommendations about the best ventilator strategy to adopt in patients with ARDS undergoing VV-ECMO support.

Incidence, Outcome, and Predictors of Intracranial Hemorrhage in Adult Patients on Extracorporeal Membrane Oxygenation: A Systematic and Narrative Review

Background: Intracranial hemorrhage (ICH) is a common complication in adults treated with extracorporeal membrane oxygenation (ECMO).

Objectives: The aim of this study was to conduct a systematic review of the literature on the incidence, outcome and predictors of ECMO-associated ICH in adult patients, supplemented by a narrative review of its pathophysiology, management and future perspectives.

Methods: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews and www.clinicaltrials.gov were systematically searched. Studies that reported incidence, outcome or predictors of ECMO-associated ICH in adults (≥18 years) were eligible for inclusion.

Results: Twenty five articles were included in the systematic review. The incidence of ECMO-associated ICH varied between 1.8 and 21 %. Mortality rates in ICH-cohorts varied between 32 and 100 %, with a relative risk of mortality of 1.27–4.43 compared to non-ICH cohorts. An increased risk of ICH was associated with ECMO-duration, antithrombotic therapy, altered intrinsic coagulation, renal failure, need of blood products, rapid hypercapnia at ECMO initiation, and even pre-ECMO morbidity.

Conclusions: ICH is a common complication in adults treated with ECMO and associated with increased mortality. Treating an ICH during ECMO represents a balance between pro- and anticoagulatory demands. Neurosurgical treatment is associated with severe morbidity, but has been successful in selected cases. Future studies should aim at investigating the validity and feasibility of non-invasive monitoring in early detection of ECMO-associated ICH.

Acute Respiratory Distress Syndrome: An Update and Review

Acute respiratory distress syndrome (ARDS) is a life threatening condition characterized by severe hypoxemia due to pulmonary gas exchange failure and was first recognized in 1960s.Since its first description, it has undergone intensive research in the past few decades to understand its pathogenesis and therapies. Despite this, the recommended therapies to decrease mortality in ARDS remain limited and include low-tidal volume mechanical ventilation, prone ventilation and recently, the ECMO rescue therapy in extreme cases. This review article will summarize the key features of ARDS with a brief overview of the therapeutic options in the management of ARDS.

Life span of different extracorporeal membrane systems for severe respiratory failure in the clinical practice

Over the past decade, veno-venous extracorporeal membrane oxygenation (vvECMO) has been increasingly utilized in respiratory failure in patients. This study presents our institution´s experience focusing on the life span of ECMO systems reflecting the performance of a particular system. A retrospective review of our ECMO database identified 461 adult patients undergoing vvECMO (2010-2017). Patients that required more than one system and survived the first exchange >24 hours (n = 139) were included. Life span until the first exchange and exchange criteria were analyzed for all systems (PLS, Cardiohelp HLS-set, both Maquet Cardiopulmonary, Rastatt, Germany; Deltastream/Hilite7000LT, iLA-activve, Xenios/NovaLung, Heilbronn, Germany; ECC.O5, LivaNova, Mirandola, Italy). At our ECMO center, the frequency of a system exchange was 30%. The median (IQR) life span was 9 (6-12) days. There was no difference regarding the different systems (p = 0.145 and p = 0.108, respectively). However, the Deltastream systems were exchanged more frequently due to elective technical complications (e. g. worsened gas transfer, development of coagulation disorder, increased bleedings complications) compared to the other exchanged systems (p = 0.013). In summary, the used ECMO systems are safe and effective for acute respiratory failure. There is no evidence for the usage of a specific system. Only the increased predictability of an imminent exchange preferred the usage of a Deltastream system. However, the decision to use a particular system should not depend solely on the possible criteria for an exchange.

Endotracheal tube clamping and extracorporeal membrane oxygenation to resuscitate massive pulmonary haemorrhage

Massive pulmonary haemorrhage is a life‐threatening and difficult‐to‐manage condition. In certain circumstances, traditional approaches for haemoptysis may not be effective. Here, we report a 64‐year‐old man presenting with dyspnoea and leg oedema. He was diagnosed with microscopic polyangiitis due to positive perinuclear anti‐neutrophil cytoplasmic antibody and other supportive evidence. His hospital course was complicated with massive pulmonary haemorrhage, which led to hypoxic respiratory failure, shock, and pulseless electrical activity. Extracorporeal membrane oxygenation (ECMO) was employed during cardiopulmonary resuscitation. To control blood loss from his lungs, we clamped the endotracheal tube for tamponade therapy. The tube was clamped for 15 h till the haemorrhage subsided. ECMO and ventilator support were successfully weaned off after 5 and 10 days, respectively. Our favourable experience suggests that endotracheal tube clamping with ECMO support is a viable management option for life‐threatening pulmonary haemorrhage.

Extracorporeal membrane oxygenation line-associated complications: in vitro testing of cyanoacrylate tissue adhesive and securement devices to prevent infection and dislodgement

Background

Extracorporeal membrane oxygenation (ECMO) delivers cardiac and/or respiratory support to critically ill patients who have failed conventional medical therapies. If the large-bore cannulas used to deliver ECMO become infected or dislodged, the patient consequences can be catastrophic. ECMO cannula-related infection has been reported to be double the rate of other vascular devices (7.1 vs 3.4 episodes/1000 ECMO days respectively). The aim of this study was to assess the ability of cyanoacrylate tissue adhesive (TA) to inhibit bacterial growth at the ECMO cannulation site, and the effectiveness of TA and securement devices in securing ECMO cannulas and tubing.

Methods

This in vitro study tested the (1) antimicrobial qualities of TA against standard transparent dressing with ECMO cannula; (2) chemical compatibility between cannula, TA and removal agent; (3) pull-out strength of transparent dressing and TA at the cannula insertion site; and (4) pull-out strength of adhesive bandage and commercial sutureless securement devices (SSDs) on circuit tubing. Fisher’s exact test was used to evaluate differences in bacterial growth observed between the transparent dressing and TA groups. Data from mechanical testing were analysed using one-way ANOVA, followed by Tukey’s multiple comparison test or t test as appropriate. Statistical significance was defined as p < 0.05.

Results

No bacterial growth occurred under TA-covered cannulas compared with transparent dressing-covered cannulas (p = 0.002). Compared to plates lacking TA or transparent dressing, growth was observed at the insertion point and under the dressing in the transparent dressing group; however, no growth was observed in the TA group (p = 0.019). TA did not weaken the cannulas; however, the TA removal agent did after 60 min of exposure, compared with control (p < 0.01). Compared with transparent dressing, TA increased the pull-out force required for cannula dislodgement from the insertion point (p < 0.0001). SSDs significantly increased the force required to remove the tubing from the fixation points compared with adhesive bandage (p < 0.01).

Conclusions

Our findings suggest that the combined use of TA at the cannula insertion site with a commercial device for tubing securement could provide an effective bedside strategy to prevent or minimise infection and line dislodgement.

Histopathologic Findings in Lungs of Patients Treated With Extracorporeal Membrane Oxygenation

BACKGROUND

The outcome of extracorporeal membrane oxygenation (ECMO) might be influenced by its complications. Only limited information is available regarding the pathologic consequences of ECMO, especially in the era of modern ECMO technology.

METHODS

We studied the histopathologic findings in autopsy lungs of patients treated with ECMO compared with those without ECMO. Autopsy files were queried for cases with ECMO. An age- and sex-matched control group comprised of patients who died in the ICU without acute respiratory distress syndrome, pneumonia, or ECMO was compared with patients with ECMO for cardiac reason. Histopathology and medical records were reviewed.

RESULTS

Seventy-six patients treated with ECMO (38 men; median age, 40 years) and 47 control patients (23 men; median age, 45 years) were included. Common histologic pulmonary findings in the ECMO group were pulmonary hemorrhage (63.2%), acute lung injury (60.5%), thromboembolic disease (47.4%), calcifications (28.9%), vascular changes (21.1%), and hemorrhagic infarct (21.1%). Pulmonary hemorrhage was associated with longer ECMO duration (median, 7.0 vs 3.5 months; P = .014), acute lung injury with venovenous ECMO (91.7% vs 54.7%; P = .039) and longer ECMO (6.0 vs 4.0 months; P = .044), and pulmonary calcifications with infants (50.0% vs 22.4%; P = .024). Patients with ECMO for cardiac reasons (n = 60) more frequently showed pulmonary hemorrhage (P < .001), diffuse alveolar damage (P = .044), thromboembolic disease (P = .004), hemorrhagic infarct (P = .002), pulmonary calcifications (P = .002), and vascular changes (P = .001) than patients in the non-ECMO group.

CONCLUSIONS

Some findings are suspected to be associated with the patient's underlying disease, whereas others might be related to ECMO. Our results provide a better understanding of ECMO-related lung disease and might help to prevent it.

Bleeding during veno-venous ECMO cannot reliably be predicted by rotational thrombelastometry (ROTEM™)

Introduction:

Veno-venous extracorporeal membrane oxygenation (vvECMO) used for respiratory support is associated with clinical bleeding in at least one third of patients. Mechanisms promoting bleeding, like acquired von Willebrand syndrome, cannot be identified by routine coagulation tests. This study was performed to evaluate rotational Thrombelastography (ROTEM™) for specific results predicting bleeding events during vvECMO.

Methods:

Five hundred and thirty-four ROTEM™ analyses of 57 patients over 574 days have been evaluated. Patients were graded into three groups according to the severity of bleeding, following the Freiburg ECMO bleeding assessment. ROTEM™ results and basic as well as comprehensive laboratory coagulation tests have been compared among the three groups and overall between defined time points.

Results:

Fourteen patients (25 %) presented without bleeding, 22 patients (39 %) showed mild bleeding and 21 patients (36 %) became evident with relevant clinical bleeding. No bleeding shock and no fatal bleeding event occurred. No case of hyperfibrinolysis was observed. Neither a statistical difference for ECMO blood flow nor duration of therapy among the groups could be shown. The only significant difference was clotting time (CT) in the InTEM analysis, with a median (IQR) of 175 (37.5) seconds in Group 1, 190 (54.5) seconds in Group 2 and 204 (90) seconds in Group 3. When comparing overall ROTEM™ analyses between defined time points, continuous worsening of CT can be found in ExTEM, FibTEM and ApTEM. Reduced A10, A20 and congruently maximum clot firmness, especially, developed in ExTEM and ApTEM and with a minor characteristic in InTEM, but not in FibTEM. ROTEM™ and coagulation-parameter results before 19 clinical relevant bleeding episodes compared to all other results only showed differences in FibTEM.

Conclusion:

ROTEM™ as a functional viscoelastic analysis does not provide additional information to basic and comprehensive laboratory tests during vvECMO. Bleeding events cannot be predicted by the means of specific ROTEM™ results.

Pitfalls of cannulation for extracorporeal life support: review of the literature and illustrative case presentation

Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) are an increasingly established advanced therapy for emerging severe lung and/or cardiocirculatory dysfunction or failure. Several reports have provided evidence for a potential benefit in prognosis by ECLS in cases of cardiogenic shock including cardiopulmonary resuscitation. Routine use in specialized centers reduces the incidence of negative side effects (e.g., vascular/ischemic, embolic, hemorrhagic, hemolytic and, furthermore, septic). Vascular complications like not only limb ischemia but also hypoxia proximal to the cannulation site up to complete sectorial hypoxia called "harlequin phenomenon" could refer to be a major adverse event in ECLS which, therefore, should be limited primarily to cardiocirculatory indications. Here we report on a case with "harlequin phenomenon" after ECLS implementation as a relevant complication of the mode of cannulation and review benefits and risks of commonly used variants of vascular access.

Bridging to lung transplantation with extracorporeal circulatory support: when or when not?

Patients with end-stage lung disease who are candidates for lung transplantation may acutely decompensate before a donor organ becomes available. In this scenario, extracorporeal life support (ECLS) may be considered as a bridge to transplant or as a bridge to decision. In the current chapter, we review the indications, techniques, and outcomes for bridging to lung transplantation with ECLS.

Bleeding Complications Associated With Percutaneous Tracheostomy Insertion in Patients Supported With Venovenous Extracorporeal Membrane Oxygen Support: A 10-Year Institutional Experience

OBJECTIVES

To evaluate the bleeding complications associated with percutaneous tracheostomy while a patient is receiving venovenous extracorporeal membrane oxygen (VV ECMO) support.

DESIGN

Retrospective, observational analysis.

SETTING

Single-center, tertiary, academic institution.

PARTICIPANTS

All consecutive patients on VV ECMO over a 10 year-period undergoing percutaneous tracheostomy.

INTERVENTIONS

Percutaneous tracheostomy.

MEASUREMENTS AND MAIN RESULTS

Fifty percutaneous tracheostomies were performed in patients requiring VV ECMO support over the 10-year period. The authors observed a 40% incidence of bleeding, with 32% of these incidences characterized as minor (self-limiting, localized stomal ooze) and 8% characterized as significant (necessitating surgical control and frequent packing or accompanied by a decrease in hemoglobin >20%).

CONCLUSIONS

Bleeding is associated with percutaneous tracheostomy and is self-limiting in the majority of patients.

Fifty Years of Research in ARDS. Is Extracorporeal Circulation the Future of Acute Respiratory Distress Syndrome Management?

Mechanical ventilation (MV) remains the cornerstone of acute respiratory distress syndrome (ARDS) management. It guarantees sufficient alveolar ventilation, high Fi_O2 concentration, and high positive end-expiratory pressure levels. However, experimental and clinical studies have accumulated, demonstrating that MV also contributes to the high mortality observed in patients with ARDS by creating ventilator-induced lung injury. Under these circumstances, extracorporeal lung support (ECLS) may be beneficial in two distinct clinical settings: to rescue patients from the high risk for death associated with severe hypoxemia, hypercapnia, or both not responding to maximized conventional MV, and to replace MV and minimize/abolish the harmful effects of ventilator-induced lung injury. High extracorporeal blood flow venovenous extracorporeal membrane oxygenation (ECMO) may therefore rescue the sickest patients with ARDS from the high risk for death associated with severe hypoxemia, hypercapnia, or both not responding to maximized conventional MV. Successful venovenous ECMO treatment in patients with extremely severe H1N1-associated ARDS and positive results of the CESAR trial have led to an exponential use of the technology in recent years. Alternatively, lower-flow extracorporeal CO₂ removal devices may be used to reduce the intensity of MV (by reducing Vt from 6 to 3-4 ml/kg) and to minimize or even abolish the harmful effects of ventilator-induced lung injury if used as an alternative to conventional MV in nonintubated, nonsedated, and spontaneously breathing patients. Although conceptually very attractive, the use of ECLS in patients with ARDS remains controversial, and high-quality research is needed to further advance our knowledge in the field.

One-Year Experience With a Mobile Extracorporeal Life Support Service

BACKGROUND

Severe acute respiratory distress syndrome is associated with a high mortality rate. The International Extracorporeal Membrane Oxygenation Network recommends regionalization of extracorporeal life support (ECLS) to high-volume centers and development of mobile ECLS teams to rescue patients with severe acute respiratory disease.

METHODS

A tertiary medical center developed a mobile team and the infrastructure to support a ECLS transport service available 24 hours a day, 7 days a week. We conducted a retrospective study of all consecutive patients presenting for ECLS for severe acute respiratory distress syndrome from outside hospitals through our mobile ECLS program associated with hemodynamic instability from January 1, 2015, until December 31, 2015.

RESULTS

During the study period, 106 consultations for ECLS were received, and 36 patients were placed on ECLS. Of these 36 ECLS patients, 11 were deemed stable enough for transport before ECLS, and 21 required mobile ECLS by the mobile ECLS, with a survival of 67% (14 of 21). The other 4 ECLS patients were inhouse patients and therefore received ECLS in a nonmobile fashion. In addition, 28 patients were transferred to our hospital who did not receive ECLS. Patient survival increased significantly with increased experience with the program, as the highest mortality rates were early in the program (p = 0.006), and in conjunction with stricter adherence to our exclusion criteria.

CONCLUSIONS

The formation of a mobile ECLS program is a complex undertaking that took 2 years of planning to develop. Development of criteria for ECLS implementation can guide appropriate resources utilization and may prevent their use in patients with little to no chance of survival.

Systematic review and meta-analysis of complications and mortality of veno-venous extracorporeal membrane oxygenation for refractory acute respiratory distress syndrome

Veno-venous extracorporeal membrane oxygenation (ECMO) for refractory acute respiratory distress syndrome (ARDS) is a rapidly expanding technique. We performed a systematic review and meta-analysis of the most recent literature to analyse complications and hospital mortality associated with this technique. Using the PRISMA guidelines for systematic reviews and meta-analysis, MEDLINE and EMBASE were systematically searched for studies reporting complications and hospital mortality of adult patients receiving veno-venous ECMO for severe and refractory ARDS. Studies were screened for low bias risk and assessed for study size effect. Meta-analytic pooled estimation of study variables was performed using a weighted random effects model for study size. Models with potential moderators were explored using random effects meta-regression. Twelve studies fulfilled inclusion criteria, representing a population of 1042 patients with refractory ARDS. Pooled mortality at hospital discharge was 37.7% (CI 95% = 31.8–44.1; I² = 74.2%). Adjusted mortality including one imputable missing study was 39.3% (CI 95% = 33.1–45.9). Meta-regression model combining patient age, year of study realization, mechanical ventilation (MV) days and prone positioning before veno-venous ECMO was associated with hospital mortality (p < 0.001; R² = 0.80). Patient age (b = 0.053; p = 0.01) and maximum cannula size during treatment (b = −0.075; p = 0.008) were also independently associated with mortality. Studies reporting H1N1 patients presented inferior hospital mortality (24.8 vs 40.6%; p = 0.027). Complication rate was 40.2% (CI 95% = 25.8–56.5), being bleeding the most frequent 29.3% (CI 95% = 20.8–39.6). Mortality due to complications was 6.9% (CI 95% = 4.1–11.2). Mechanical complications were present in 10.9% of cases (CI 95% = 4.7–23.5), being oxygenator failure the most prevalent (12.8%; CI 95% = 7.1–21.7). Despite initial severity, significant portion of patients treated with veno-venous ECMO survive hospital discharge. Patient age, H1N1-ARDS and cannula size are independently associated with hospital mortality. Combined effect of patient age, year of study realization, MV days and prone positioning before veno-venous ECMO influence patient outcome, and although medical complications are frequent, their impact on mortality is limited.

[Apnea test for assessment of brain death under extracorporeal life support]

BACKGROUND

The fourth edition of the German guideline for the assessment of brain death, published in 2015 by the German Medical Council (Bundesärztekammer), emphasizes the importance of an apnea test. It is also now required under all circumstances of extracorporeal life support.

OBJECTIVES

This article is an instruction for the guideline-conforming performance of an apnea test in general and also in cases of extracorporeal life support in different configurations.

MATERIALS AND METHODS

A literature review was performed.

CONCLUSIONS

The apnea test is an essential part of the bedside examination for the clinical diagnosis of brain death. It is required for all kinds of extracorporeal life support and can be easily performed without endangering the patient. More accurate recommendations for its performance should be considered for the next version of the German guideline for brain death assessment.

Extracorporeal Life Support: Four Decades and Counting

Extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS) is a form of heart lung bypass that is used to support neonates, pediatrics, and adult patients with cardiorespiratory failure for days or weeks till organ recovery or transplantation. Venoarterial (VA) and venovenous (VV) ECLS are the most common modes of support. ECLS circuit components and monitoring have been evolving over the last 40 years. The technology is safer, simpler, and more durable with fewer complications. The use of neonatal respiratory ECLS use has been declining over the last two decades, while adult respiratory ECLS is growing especially since the H1N1 influenza pandemic in 2009. This review provides an overview of ECLS evolution over the last four decades, its use in neonatal, pediatric and adults, description of basic principles, circuit components, complications, and outcomes as well as a quick look into the future.

Extracorporeal Membrane Oxygenation Outcomes in Acute Respiratory Distress Treatment: Case Study in a Chinese Referral Center

Background

No definitive conclusions have been drawn from the available data about the utilization of extracorporeal membrane oxygenation (ECMO) to treat severe acute respiratory distress syndrome (ARDS). The aim of this study was to review our center’s experience with ECMO and determine predictors of outcome from our Chinese center.

Material/Methods

We retrospectively analyzed a total of 23 consecutive candidates who fulfilled the study entry criteria between January 2009 and December 2015. Detailed clinical data, ECMO flow, and respiratory parameters before and after the introduction of ECMO were compared among in-hospital survivors and nonsurvivors; factors associated with mortality were investigated.

Results

Hemodynamics and oxygenation parameters were significantly improved after ECMO initiation. Thirteen patients survived to hospital discharge. Univariate correlation analysis demonstrated that APACHE II score (r=−0.463, p=0.03), acute kidney injury (r=−0.574, p=0.005), membrane oxygenator replacement (r=−0.516, p=0.014) and total length of hospital stay (r=0.526, p=0.012) were significantly correlated with survival to hospital discharge, and that the evolution of the levels of urea nitrogen, platelet, and fibrinogen may help to determine patient prognosis. Sixteen patients referred for ECMO from an outside hospital were successfully transported to our institution by ambulance, including seven transported under ECMO support. The survival rate of the ECMO-transport group was comparable to the conventional transport or the non-transport group (both p=1.000).

Conclusions

ECMO is an effective alternative option for severe ARDS. APACHE II score on admission, onset of acute kidney injury, and membrane oxygenator replacement, and the evolution of levels of urea nitrogen, platelet, and fibrinogen during hospitalization may help to determine the in-hospital patient prognosis. By establishing a well-trained mobile ECMO team, a long-distance, inter-hospital transport can be administered safely.

Remote cannulation and extracorporeal membrane oxygenation transport is safe in a newly established program

Extracorporeal membrane oxygenation (ECMO) has become an increasingly utilized modality for the support of patients with severe cardiac or pulmonary dysfunction. Unfortunately, the costs and expertise required to maintain a formal ECMO program preclude the vast majority of hospitals from employing such technology routinely. These barriers to implementation of an effective ECMO program highlight the importance of the safe transport of patients in need of extracorporeal support. While many centers with extensive expertise in the management of patients on extracorporeal support have demonstrated their ability to transport those same patients, the ability of new ECMO programs to provide such transportation remains poorly studied. We established an ECMO program at our institution and immediately provided equipment and personnel to transport patients in need of or receiving extracorporeal support to our institution. Overall, we found that 13 out of 28 patients transported to our institution on ECMO or for consideration of ECMO support during the first 15 months of the program survived to hospital discharge. During that period, four incidents associated with patient transport occurred but none were related to ECMO support or adversely affected patient outcome. These observations demonstrate that new ECMO programs can safely and reliably transport patients on or in need of extracorporeal support.

Extracorporeal Membrane Oxygenation (ECMO) for Lung Injury in Severe Acute Respiratory Distress Syndrome (ARDS): Review of the Literature

Despite advances in mechanical ventilation, severe acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality rates ranging from 26% to 58%. Extracorporeal membrane oxygenation (ECMO) is a modified cardiopulmonary bypass circuit that serves as an artificial membrane lung and blood pump to provide gas exchange and systemic perfusion for patients when their own heart and lungs are unable to function adequately. ECMO is a complex network that provides oxygenation and ventilation and allows the lungs to rest and recover from respiratory failure while minimizing iatrogenic ventilator-induced lung injury. In critical care settings, ECMO is proven to improve survival rates and outcomes in patients with severe ARDS. This review defines severe ARDS; describes the ECMO circuit; and discusses recent research, optimal use of the ECMO circuit, limitations of therapy including potential complications, economic impact, and logistical factors; and discusses future research considerations.

Extracorporeal Life Support: Physiological Concepts and Clinical Outcomes

Extracorporeal life support (ECLS) describes a system that involves drainage from the venous circulation and return via an oxygenator into the arterial circulation (veno-arterial extracorporeal membrane oxygenation). ECLS provides effective cardiopulmonary support, but the parallel circulation has complex effects on the systemic and pulmonary circulatory physiology. An understanding of the physiological changes is fundamental to the management of ECLS. In this review, the key physiological concepts and the implications on the clinical management of ECLS are discussed. In addition, the clinical outcomes associated with ECLS in cardiogenic shock are systematically reviewed. The paucity of clinical trials on ECLS highlights the need for randomized trials to guide the selection of patients.

Adult venovenous extracorporeal membrane oxygenation for severe respiratory failure: Current status and future perspectives

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure was proposed more than 40 years ago. Despite the publication of the ARDSNet study and adoption of lung protective ventilation, the mortality for acute respiratory failure due to acute respiratory distress syndrome has continued to remain high. This technology has evolved over the past couple of decades and has been noted to be safe and successful, especially during the worldwide H1N1 influenza pandemic with good survival rates. The primary indications for ECMO in acute respiratory failure include severe refractory hypoxemic and hypercarbic respiratory failure in spite of maximum lung protective ventilatory support. Various triage criteria have been described and published. Contraindications exist when application of ECMO may be futile or technically impossible. Knowledge and appreciation of the circuit, cannulae, and the physiology of gas exchange with ECMO are necessary to ensure lung rest, efficiency of oxygenation, and ventilation as well as troubleshooting problems. Anticoagulation is a major concern with ECMO, and the evidence is evolving with respect to diagnostic testing and use of anticoagulants. Clinical management of the patient includes comprehensive critical care addressing sedation and neurologic issues, ensuring lung recruitment, diuresis, early enteral nutrition, treatment and surveillance of infections, and multisystem organ support. Newer technology that delinks oxygenation and ventilation by extracorporeal carbon dioxide removal may lead to ultra-lung protective ventilation, avoidance of endotracheal intubation in some situations, and ambulatory therapies as a bridge to lung transplantation. Risks, complications, and long-term outcomes and resources need to be considered and weighed in before widespread application. Ethical challenges are a reality and a multidisciplinary approach that should be adopted for every case in consideration.

Extracorporeal membrane oxygenation treatment of a H7N9-caused respiratory failure patient with mechanical valves replacement history: A case report

BACKGROUND

Patients with respiratory failure caused by H7N9 may benefit from veno-venous, veno-arterial, and veno-veno-arterial extracorporeal membrane oxygenation (ECMO) support.

CASE SUMMARY

A 55-year-old male patient was suffering from H7N9-caused acute respiratory distress syndrome (ARDS). He had a mechanical mitral and aortic valve replacement surgery and was using warfarin for anticoagulation. After prolonged mechanical ventilation, oxygen saturation was not improved. Veno-veno ECMO was then applied. After 16 days of extracorporeal life support, the patient successfully weaned from ECMO, with relatively good pulmonary recovery.

CONCLUSION

This report demonstrates that ECMO support can help treating life-threatening diseases such as H7N9-associated ARDS. Because of his special mitral and aortic valve replacement surgery history and long duration of mechanical ventilation before ECMO, we report it as a separate case, hoping to provide some reference for ECMO treatment.

Hospital Management of Acute Decompensated Heart Failure

Heart failure (HF) is one of the leading causes of hospitalizations for elderly adults in the United States. One in 5 Americans will be >65 years of age by 2050. Because of the high prevalence of HF in this group, the number of Americans requiring hospitalization for this disorder is expected to rise significantly. We reviewed the most recent and ongoing studies and recommendations for the management of patients hospitalized due to decompensated HF. The Acute Decompensated Heart Failure National Registry, together with the 2013 American College of Cardiology Foundation and American Heart Association heart failure guidelines, earlier retrospective and prospective studies including the Diuretic Optimization Strategies Evaluation (DOSE), the Trial of Intensified vs Standard Medical Therapy in the Elderly Patients With Congestive Heart Failure (TIME-CHF), the Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF), the Rapid Emergency Department Heart Failure Outpatient Trial (REDHOT) and the Comparison of Medical, Pacing and Defibrillation Therapies in Heart Failure (COMPANION) trial were reviewed for current practices pertaining to these patients. Gaps in our knowledge of optimal use of patient-specific information (biomarkers and comorbid conditions) still exist.