Extracorporeal membrane oxygenation for severe acute respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a technique for providing life support, in case the natural lungs are failing and are not able to maintain a sufficient oxygenation of the body's organ systems. ECMO technique was an adaptation of conventional cardiopulmonary bypass technique and introduced into treatment of severe acute respiratory distress syndrome (ARDS) in the 1970s. The intial reports of the use of ECMO in ARDS patients were quite enthusiastic, however, in the following years it became clear that ECMO was only of benefit in newborns with acute respiratory failure. In neonates treated with ECMO, survival rates of 80% could be achieved. In adult patients with ARDS, two large randomized controlled trials (RCTs) published in 1979 and 1994 failed to show an advantage of ECMO over convential treatment, survival rates were only 10% and 33%, respectively, in the ECMO groups. Since then, ECMO technology as well as conventional treatment of adult ARDS have undergone further improvements. In conventional treatment lung-protective ventilation strategies were introduced and ECMO was made safer by applying heparin-coated equipment, membranes and tubings. Many ECMO centres now use these advanced ECMO technology and report survival rates in excess of 50% in uncontrolled data collections. The question, however, of whether the improved ECMO can really challenge the advanced conventional treatment of adult ARDS is unanswered and will need evaluation by a future RCT.     

Prone positioning in acute respiratory distress syndrome: a multicenter randomized clinical trial

OBJECTIVE: We examined the effect on survival of prone positioning as an early and continuous treatment in ARDS patients already treated with protective ventilation. DESIGN AND SETTING: Open randomized controlled trial in 17 medical-surgical ICUs. PATIENTS: Forty mechanically ventilated patients with early and refractory ARDS despite protective ventilation in the supine position. INTERVENTIONS: Patients were randomized to remain supine or be moved to early (within 48[Symbol: see text]h) and continuous (>/=[Symbol: see text]20[Symbol: see text]h/day) prone position until recovery or death. The trial was prematurely stopped due to a low patient recruitment rate. MEASUREMENTS AND RESULTS: Clinical characteristics, oxygenation, lung pressures, and hemodynamics were monitored. Need for sedation, complications, length of MV, ICU, and hospital stays, and outcome were recorded. PaO(2)/FIO(2) tended to be higher in prone than in supine patients after 6[Symbol: see text]h (202[Symbol: see text]+/-[Symbol: see text]78 vs. 165[Symbol: see text]+/-[Symbol: see text]70[Symbol: see text]mmHg); this difference reached statistical significance on day 3 (234[Symbol: see text]+/-[Symbol: see text]85 vs. 159[Symbol: see text]+/-[Symbol: see text]78). Prone-related side effects were minimal and reversible. Sixty-day survival reached the targeted 15% absolute increase in prone patients (62% vs. 47%) but failed to reach significance due to the small sample. CONCLUSIONS: Our study adds data that reinforce the suggestion of a beneficial effect of early continuous prone positioning on survival in ARDS patients.     

Extracorporeal life support devices and strategies for management of acute cardiorespiratory failure in adult patients: a comprehensive review

Evolution of extracorporeal life support (ECLS) technology has added a new dimension to the intensive care management of acute cardiac and/or respiratory failure in adult patients who fail conventional treatment. ECLS also complements cardiac surgical and cardiology procedures, implantation of long-term mechanical cardiac assist devices, heart and lung transplantation and cardiopulmonary resuscitation. Available ECLS therapies provide a range of options to the multidisciplinary teams who are involved in the time-critical care of these complex patients. While venovenous extracorporeal membrane oxygenation (ECMO) can provide complete respiratory support, extracorporeal carbon dioxide removal facilitates protective lung ventilation and provides only partial respiratory support. Mechanical circulatory support with venoarterial (VA) ECMO employed in a traditional central/peripheral fashion or in a temporary ventricular assist device configuration may stabilise patients with decompensated cardiac failure who have evidence of end-organ dysfunction, allowing time for recovery, decision-making, and bridging to implantation of a long-term mechanical circulatory support device and occasionally heart transplantation. In highly selected patients with combined severe cardiac and respiratory failure, advanced ECLS can be provided with central VA ECMO, peripheral VA ECMO with timely transition to venovenous ECMO or VA-venous ECMO upon myocardial recovery to avoid upper body hypoxia or by addition of an oxygenator to the temporary ventricular assist device circuit. This article summarises the available ECLS options and provides insights into the principles and practice of these techniques. One should emphasise that, as is common with many emerging therapies, their optimal use is currently not backed by quality evidence. This deficiency needs to be addressed to ensure that the full potential of ECLS can be achieved.     

Respiratory failure of two sp gastric bypass patients and subsequent rescue with extracorporeal membrane oxygenation

Severe obesity is a chronic condition that is difficult to treat through diet and exercise alone. Gastrointestinal surgery for obesity (bariatric surgery) alters the digestive process by either restrictive surgical alterations or malabsorptive operations. Some 10-20% of patients who have weight-loss surgery require follow-up operations to correct complications. Hypoxemia after gastric bypass surgery for morbid obesity, a reported complication, can occur as early as 24 h post surgery. Two patients presented with severe hypoxia and were placed on veno-venous extracorporeal membrane oxygenation (ECMO). Patient No. 1 had an obstruction of the alimentary limb of the gastric bypass due to suture adhesions, and patient No. 2 had an incarcerated diaphragmatic hernia. While on ECMO, ventilation using a protective strategy (60% FiO2, pressure-controlled ventilation inspiratory pressure (PCV) IP 25-27, positive end-expiratory pressure (PEEP) 10-14, permissive hypercapnia) was employed. An inflow cannula to the level of the right atrium served as arterial outflow from the circuit to the patient, while the femoral vein served as venous inflow to the ECMO circuit. Although ECMO in adult respiratory failure is often used as the last resort due to serious associated adverse events, we report two patients with life-threatening complications from gastric bypass who were rescued, resuscitated to day 7, and uneventfully discharged from the hospital to home.     

Extracorporeal membrane oxygenation for refractory, life-threatening, and herpes simplex virus 1-induced acute respiratory distress syndrome. Our experience and literature review

We report our first experience of treating an immunocompetent adult patient with acute respiratory distress syndrome (ARDS) due to type 1 herpes simplex (HSV1) pneumonitis, using extracorporeal membrane oxygenation (ECMO). Similar cases reported in literature are reviewed as well. The therapeutic options for this particular complication are discussed. Pneumonia caused by HSV1 is a rare finding in immunocompetent individuals; it occurs more often in immunosuppressed and ventilated patients. It is a severe illness; therefore, early diagnosis and initiation of treatment are imperative. Diagnosis is based on cytologic and histologic findings, viral cultures, or serologic methods. This condition can be reversible; however, often, it can progress into refractory ARDS with limited therapeutic options available. We demonstrate the causative role of HSV1 in refractory ARDS of a previously healthy 18-year-old man who presented to the intensive care unit with acute respiratory distress after a week of flulike syndrome. Due to severe hypoxemia and hypercarbia, the patient required mechanical ventilation and later emergent blood oxygenation with extracorporeal support. For the first time in this condition, we used venovenous ECMO management, to rest the lung, sustain blood oxygenation and end-organ oxygen delivery, and promote potential lung recovery. During ECMO and after our etiologic diagnosis, specific therapy was introduced. After viral negativization, corticosteroid therapy (Meduri protocol) was initiated. Extracorporeal membrane oxygenation allowed us to initiate therapy while maintaining end-organ oxygenation and support the patient until lung recovery. After 18 days of ECMO, our patient recovered completely. Near-normal lung structures and functions were documented on a chest x-ray/computed tomography, thoracic ultrasonography, and pulmonary functional tests at hospital discharge and at a 1-year follow-up. Data suggest that severe pulmonary involvement in HVS1 infection associated with septicemia/shock is a rare but often fatal in immunocompetent adult as well. We suggest that ECMO might be the selected treatment for severe refractory ARDS in this clinical scenario. It seems to be an effective and useful ultimate therapeutic strategy for preventing death and furthermore permitting near-full pulmonary function recovery.     

Extracorporeal membrane oxygenation for severe influenza A (H1N1) acute respiratory distress syndrome: a prospective observational comparative study

Purpose

To compare characteristics, clinical evolution and outcome in adult patients with influenza A (H1N1) acute respiratory distress syndrome (ARDS) treated with or without extracorporeal membrane oxygenation (ECMO).

Methods

A prospective observational study of patients treated in Marseille South Hospital from October 2009 to January 2010 for confirmed influenza A (H1N1)-related ARDS. Clinical features, pulmonary dysfunction and mortality were compared between patients treated with and without ECMO.

Results

Of 18 patients admitted, 6 were treated with veno-venous and 3 with veno-arterial ECMO after median (interquartile, IQR) duration of mechanical ventilation of 10 (6–96) h. Six ECMO were initiated in a referral hospital by a mobile team, a median (IQR) of 3 (2–4) h after phone contact. Before ECMO, patients had severe respiratory failure with median (IQR) PaO₂ to FiO₂ ratio of 52 (50–60) mmHg and PaCO₂ of 85 (69–91) mmHg. Patients treated with or without ECMO had the same hospital mortality rate (56%, 5/9). Duration of ECMO therapy was 9 (4–14) days in survivors and 5 (2–25) days in non-survivors. Early improvement of PaO₂ to FiO₂ ratio was greater in ECMO survivors than non-survivors after ECMO initiation [295 (151–439) versus 131 (106–144) mmHg, p < 0.05]. Haemorrhagic complications occurred in four patients under ECMO, but none required surgical treatment.

Conclusions

ECMO may be an effective salvage treatment for patients with influenza A (H1N1)-related ARDS presenting rapid refractory respiratory failure, particularly when provided by a mobile team allowing early cannulation prior to transfer to a reference centre.     

肺保护性通气对肺内外不同源性急性呼吸窘迫综合征犬外周血和肺泡灌洗液中炎性递质的影响

背景:肺保护性通气策略和呼气末正压作为近些年来治疗急性呼吸窘迫综合征(acuterespiratorydistresssyndrome,ARDS)有效通气方式在临床得到广泛的应用,但对其疗效一直有很大的争议。目的:观察在肺保护性通气条件下ARDS模型犬氧合指数以及外周血和肺不同部位(肺上区、肺下区腹侧和肺下区背侧)支气管肺泡灌洗液中炎性递质的变化。设计:随机对照动物实验。单位:解放军总医院呼吸科。材料:取健康成年雄性杂种犬24只,单纯随机分为肺内源性ARDS实验组、肺内源性ARDS对照组、肺外源性ARDS实验组和肺外源性ARDS对照组,每组6只。方法:采用静脉注射油酸0.1～0.15mg/kg形成肺外源性ARDS动物模型;应用十六烷磺基丁二酸钠盐气管内吸入形成肺内源性ARDS动物模型。实验组肺损伤后进行肺保护性通气(潮气量:8mL/kg,呼气末正压:0.981kPa)3h,对照组继续进行大潮气通气(潮气量:14～17mL/kg,呼气末正压:0kPa)3h。主要观察指标:①各组犬氧合指数的变化。②动态观察肺保护性通气条件下各组犬外周血和肺不同部位(肺尖叶、肺心叶和肺膈叶)支气管肺泡灌洗液中炎性递质(肿瘤坏死因子α,白细胞介素1β和白细胞介素6)的变化。结果:24只犬全部进入结果分析。①肺损伤后各组犬氧合指数均显著下降,应用肺保护性通气治疗后实验组氧合指数明显高于对照组(P<0.05);肺保护性通气后2h和3h肺外源性ARDS实验组氧合指数明显高于肺内源性ARDS实验组(P<0.05)。②肺损伤后各组外周血中炎性递质明显升高,应用肺保护性通气治疗后,炎性递质水平有不同度下降,但肺内源性ARDS实验组的治疗效果不如肺外源性ARDS实验组。③肺内源性ARDS模型犬肺尖叶和肺心叶支气管肺泡灌洗液中炎性递质水平明显高于肺外源性ARDS模型犬。结论:肺外源性和肺内源性急性呼吸窘迫综合征模型犬肺的不同部位炎性递质释放和氧合指数改善均具有明显的差异,而肺保护性通气模式对肺外源性急性呼吸窘迫综合征模型犬具有良好的效果,对肺内源性急性呼吸窘迫综合征模型犬疗效较差。     

Acute effects of tidal volume strategy on hemodynamics, fluid balance, and sedation in acute lung injury

OBJECTIVE: To examine the effects of mechanical ventilation with a tidal volume of 6 mL/kg compared with 12 mL/kg predicted body weight on hemodynamics, vasopressor use, fluid balance, diuretics, sedation, and neuromuscular blockade within 48 hrs in patients with acute lung injury and acute respiratory distress syndrome. DESIGN: Retrospective analysis of a previously conducted randomized, clinical trial. SETTING: Two adult intensive care units at a tertiary university medical center and a large county hospital. PATIENTS: One hundred eleven patients who were enrolled in the National Institutes of Health ARDS Network trial at the University of California, San Francisco. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Compared with 12 mL/kg predicted body weight, treatment with a tidal volume of 6 mL/kg predicted body weight had no adverse effects on hemodynamics. There were also no differences in the need for supportive therapies, including vasopressors, intravenous fluids, or diuretics. In addition, there were no differences in body weight, urine output, and fluid balance. Finally, there was no difference in the need for sedation or neuromuscular blockade between the two tidal volume protocols. CONCLUSIONS: When compared with ventilation with 12 mL/kg predicted body weight, patients treated with the lung-protective 6 mL/kg predicted body weight tidal volume protocol had no difference in their supportive care requirements. Therefore, concerns regarding potential adverse effects of this protocol should not preclude its use in patients with acute lung injury or the acute respiratory distress syndrome.     

ECMO used successfully in a near fatal case of opioid-induced acute respiratory distress syndrome

Acute Respiratory Distress Syndrome (ARDS) was first recognized during the 1960s. It is a distinct type of hypoxemic respiratory failure characterized by acute abnormality of both lungs. Extracorporeal membrane oxygenation (ECMO) is being increasingly used for patients with severe ARDS refractory to otherwise conventional management. A 29 year old male arrived with Emergency Medical Services (EMS) status post presumed heroin overdose. He was administered Naloxone 2 mg intravenously prior to arrival in the emergency department. The patient arrived in severe respiratory distress with a pulse oximetry level of 50% and was immediately intubated. The patient's pulse oximetry level remained in the seventies despite intubation and aggressive ventilator management. The Intensive Care Unit team in conjunction with cardiothoracic surgery initiated venovenous ECMO therapy in the emergency department itself. The patient was transferred to a tertiary center for venoarterial ECMO that was continued for 6 more days. After an extensive hospitalization, the patient was ultimately transferred to an acute medical rehabilitation center. With the current opioid crisis, emergency physicians and providers need to be aware that opioids can induce severe ARDS refractory to mechanical ventilation. ECMO as a treatment option can be used safely and successfully as described in this unique patient case report.     

Effectiveness of extracorporeal membrane oxygenation when conventional ventilation fails: Valuable option or vague remedy?

The mortality and morbidity of patients with severe acute respiratory distress syndrome (ARDS) remains high despite the advances in intensive care practice. The low-tidal-volume ventilation strategy (ARDS net protocol) has been shown to be effective in improving survival. Unfortunately, however, some patients have such severe ARDS that they cannot be managed with the ARDS net strategy. In these patients, rescue therapies such as high-frequency ventilation, prone ventilation, nitric oxide, and extracorporeal membrane oxygenation (ECMO) are considered. The CESAR trial has shown that an ECMO-based protocol improved survival without severe disability as compared with conventional ventilation. The recent increased incidence of severe respiratory failure due to H1N1 influenza pandemic has led to an increased use of ECMO. Although several reports showed ECMO use to be encouraging, some scepticism remains. In this article, we reviewed the usefulness of ECMO in patients with severe ARDS in the light of current evidence.     

Results of the treatment of cardiac surgery patients with postoperative acute respiratory distress syndrome by prone-position pulmonary ventilation

Prone position ventilation (PPV) became an effective method of management of ARDS since 1974. Its positive effects on arterial oxygenation have been amply described, but its impact on the results of treatment and hospital mortality remains a disputable point. We observed 2 groups of patients, 36 pts. each, with ARDS after cardiovascular surgery. The main causes of ARDS were shock syndrome, massive blood loss and transfusion, previous COPD, and postcardiopulmonary bypass ALI. Because of impaired lung function (PaO2/FiO2 < 200), all patients were supported by special methods of ventilation including PEEP, high FiO2, and PCV with inverse I:E ratio. In the main group, PPV was started on days 3.6 +/- 1.2 postoperation. Daily duration of PPV was 4-12 h, after which the patients were turned into a supine position. Controls were treated in a supine position. The groups were identical by age, sex, types of surgery, severity of ARF, and manifestations of MOSF. PPV improved lung function and arterial oxygenation. Clinical outcomes were better in the PPV group than in the controls: a lower frequency of threatening arrhythmia, better results of MOSF treatment, and lower mortality (69 and 33.4%, respectively). Prone position is an effective measure improving arterial oxygenation in patients with ARDS after cardiovascular surgery. The main results of PPV are decrease in complications induced by hypoxia and higher survival rate.     

超声在急性呼吸窘迫综合征围静脉-静脉体外膜氧合期中的应用价值

目的探讨经胸超声心动图、血管超声及腹部超声在急性呼吸窘迫综合征(ARDS)患者围静脉-静脉体外膜氧合(V-V ECMO)期的临床应用价值。方法选取我院拟行V-V ECMO支持治疗的ARDS患者13例,分析超声在插管前对患者基本情况的评估结果,以及在插管过程中、V-V ECMO支持治疗期间和脱机后对心脏及血管相关并发症监测情况。结果行V-V ECMO支持治疗的13例ARDS患者中,12例存活至脱机,8例存活至康复出院。V-V ECMO插管过程中,7例在超声引导下调整套管末端位置;V-V ECMO支持治疗期间,2例在超声引导下调整套管末端位置。并发症发生情况:V-V ECMO支持治疗期间血管超声提示2例套管周围血栓形成,腹部超声提示1例腹腔出血;脱机后超声心动图提示1例下腔静脉附壁血栓形成,血管超声提示1例插管同侧下肢深静脉血栓形成。围V-V ECMO期无严重不良事件发生。结论超声在V-V ECMO插管过程中、支持治疗期间及监测并发症方面均具有重要价值。     

Extending the limits of extracorporeal membrane oxygenation: lung rest for a child with non-specific interstitial pneumonia

Objective Veno-venous extracorporeal membrane oxygenation (ECMO) is an established therapy for the treatment of respiratory failure. Traditionally ECMO has been used to support patients with an acute, reversible disease process, with a predictable outcome. We report the successful use of veno-venous ECMO for an unusual indication.Patient A 10-year old girl was admitted to intensive care with severe, hypoxic respiratory failure on the background of a 2-month history of worsening respiratory symptoms. She required high levels of conventional positive pressure ventilation, and high frequency oscillation. Lung biopsy confirmed a non-specific interstitial pneumonia, and the patient was commenced on immune suppressive therapy. Her clinical course was further complicated by pulmonary haemorrhage and severe air leak.Interventions On day 20 after admission the patient was placed on veno-venous ECMO for lung rest while awaiting a response to continued medical treatment. She required ECMO for 20 days, during which time sedation was reduced, and she was able to interact with those around her. The patients ventilatory requirements after decannulation were minimal, and she subsequently made a steady clinical recovery.Conclusions ECMO was safely and successfully used to provide a period of lung rest and time for medical therapy to take effect in a child with an unusual indication for support: a rare disease with an uncertain outcome on the background of prolonged mechanical ventilation.     

Successful treatment of acute respiratory distress syndrome and severe pulmonary hypertension in a child with Bordetella pertussis infection

Infection with Bordetella pertussis can cause severe illness with neurological and pulmonary complications in children. Pulmonary hypertension is an early sign of potentially fatal disease and can cause failure of conventional respiratory therapy in severe acute respiratory distress syndrome (ARDS). We report a 4 1/2-year-old boy with B. pertussis infection who developed severe ARDS and pulmonary hypertension. Because of severe neurological signs the patient did not qualify for extracorporal membrane oxygenation (ECMO). After conventional ventilation, surfactant and high frequency oscillation ventilation (HFOV) failed, treatment with nitric oxide (NO) improved oxygenation, allowing recovery without the need for ECMO. The patient survived with few sequelae. Thus, this treatment may be an option in high-risk children who meet the criteria for ECMO but are excluded because of poor neurological status, as in our patient.     

Extracorporeal membrane oxygenation and inhaled sedation in coronavirus disease 2019-related acute respiratory distress syndrome

Coronavirus disease 2019 (COVID-19) related acute respiratory distress syndrome (ARDS) is a severe complication of infection with severe acute respiratory syndrome coronavirus 2, and the primary cause of death in the current pandemic. Critically ill patients often undergo extracorporeal membrane oxygenation (ECMO) therapy as the last resort over an extended period. ECMO therapy requires sedation of the patient, which is usually achieved by intravenous administration of sedatives. The shortage of intravenous sedative drugs due to the ongoing pandemic, and attempts to improve treatment outcome for COVID-19 patients, drove the application of inhaled sedation as a promising alternative for sedation during ECMO therapy. Administration of volatile anesthetics requires an appropriate delivery. Commercially available ones are the anesthetic gas reflection systems AnaConDa^® and MIRUS^TM, and each should be combined with a gas scavenging system. In this review, we describe respiratory management in COVID-19 patients and the procedures for inhaled sedation during ECMO therapy of COVID-19 related ARDS. We focus particularly on the technical details of administration of volatile anesthetics. Furthermore, we describe the advantages of inhaled sedation and volatile anesthetics, and we discuss the limitations as well as the requirements for safe application in the clinical setting.     

Conduite et complications de l’oxygénation extracorporelle veinoveineuse

This article reviews the management of patients treated with venovenous extracorporeal membrane oxygenation (ECMO) for acute respiratory failure refractory to the conventional therapies. The period of extracorporeal respiratory support can be divided in three successive periods: the period of ECMO initiation, the period of treatment with ECMO, and the period of ECMO weaning. We will describe the main technical aspects of ECMO as well as the monitoring of the extracorporeal circuit and the ECMO-treated patient. The most frequent complications in each period of the management of ECMO-treated patients will be described and the possible adequate solutions will be considered.     

Venovenous versus venoarterial extracorporeal life support for pediatric respiratory failure: are there differences in survival and acute complications?

OBJECTIVES: To examine the Extracorporeal Life Support Organization (ELSO) registry database of infants and children with acute respiratory failure to compare outcome and complications of venovenous (VV) vs. venoarterial (VA) Extracorporeal Life Support (ECLS). DESIGN: Retrospective cohort study. SETTING: ELSO registry for pediatric pulmonary support. PATIENTS: All nonneonatal pediatric pulmonary support ECLS cases treated at U.S. centers and reported to the ELSO registry as of July 1997. Patients were excluded if they had one or more of the following diagnoses: hematologic-oncologic, cardiac, abdominal surgical, burn, metabolic, airway, or immunodeficiency disorder. INTERVENTIONS: Venoarterial or venovenous extracorporeal life support for severe pulmonary failure. MEASUREMENTS AND MAIN RESULTS: From 1986 to June of 1997, 763 pediatric patients met the inclusion criteria. Overall, 595 were initially managed with VA bypass, and 168 with VV bypass. The VA group was younger (mean +/- SD, 26.1+/-42.2 months for VA vs. 63.5+/-68.7 months for VV) and smaller (11.8+/-15.1 kg vs. 22.9+/-23.8 kg) (p<.001). There were no differences between groups in number of days on mechanical ventilation before ECLS, number of hours on ECLS, or number of hours on mechanical ventilation post-ECLS in survivors. Mean pH and Paco2 values, positive end-expiratory pressure, and mean airway pressure just before placing the patient on ECLS were also similar. VA-treated patients had higher Fio2 requirements (p = .034), lower Pao2 (p = .047), and lower Pao2/Fio2 ratio (p = .014) just before cannulation. There was a trend of higher peak inspiratory pressure in VA-treated patients (p = .053). Overall, survival rate was not different for the two groups (55.8% for VA vs. 60.1% for VV; p = .33). Central nervous system complications were not different between the two groups. Examination of the same variables was then conducted after dividing the patients into four subgroups. There were no significant differences in survival or complications during bypass between VV and VA modes of ECLS in any subgroup. Stepwise logistic regression modeling was performed to control for variables associated with the outcome survival for VV and VA-treated groups, and variables measured before bypass were identified as being associated with improved survival. There was a trend of improved survival in the VV-treated patients (p = .12). CONCLUSIONS: Overall survival of pediatric patients with acute respiratory failure supported by VA or VV ECLS was comparable. A randomized clinical trial may be useful in clarifying these observations.     

Extracorporeal membrane oxygenation

PURPOSE OF REVIEW: Extracorporeal membrane oxygenation (ECMO) has become a more or less accepted standard in the algorithm of advanced acute respiratory distress syndrome therapy in adult patients when all other treatment options have failed. This article reviews the current status of ECMO therapy with particular focus on new technical developments and their potential implications for performance and indications for ECMO therapy. RECENT FINDINGS: A recently published review on a single-center experience in 255 adult ECMO patients identified using multivariate logistic regression analysis age, sex, initial pH 7.10 or lower and PaO2/FiO2 ratio, and days of mechanical ventilation before ECMO as a significant predictors of survival. Additionally, a careful cost-effectiveness study for neonatal ECMO relating a 4-year base to the UK neonatal ECMO trial has clearly demonstrated cost-effectiveness. SUMMARY: Over the years, the technique for ECMO therapy underwent substantial changes in indications and the materials used. Impressive technical progress has been made in pumps, oxygenators, and coating of artificial surfaces, leading to a higher biocompatibility and to a lower rate of procedure-related complications. The potential of new inline pumps in combination with a decreasing rate of procedure-related complications might lead to a re-evaluation of the role of extracorporeal lung support in acute respiratory distress syndrome therapy. A very recent development is the use of spontaneous arteriovenous devices for carbon dioxide removal, allowing significant reduction of ventilator settings at decreased carbon dioxide partial pressures and at increased pH values. Ongoing studies are looking at the potential of this approach to reduce side effects of mechanical ventilation further.     

The role of echocardiography in the management of patients supported by extracorporeal membrane oxygenation

Extracorporeal life support can be viewed as a spectrum of modalities based on modifications of a cardiopulmonary bypass circuit to provide cardiac and respiratory support, which can be used for extended periods, from hours to several weeks. Extracorporeal membrane oxygenation (ECMO) is among the most frequently used forms of extracorporeal life support. It can be configured for venovenous blood flow, to provide adequate oxygenation and carbon dioxide removal in isolated refractory respiratory failure, or in a venoarterial configuration, when support is required for cardiac and/or respiratory failure. Echocardiography plays a fundamental role throughout the entire journey of a patient supported on ECMO. It provides information that assists in patient selection, guides the insertion and placement of cannulas, monitors progress, detects complications, and helps in determining cardiac recovery and the weaning of ECMO support. Although there are extensive published data regarding ECMO, particularly in the pediatric population, there is a paucity of data outlining the role of echocardiography in guiding the management of adult patients supported by ECMO. ECMO is likely to become an increasingly used form of cardiorespiratory support within the critical care setting. Hence, clinicians and sonographers who work within echocardiography departments at institutions with ECMO programs require specific skills to image these patients.