Extracorporeal membrane oxygenation in adults with acute respiratory distress syndrome:

Quality of life and functional status of patients treated with venovenous extracorporeal membrane oxygenation at 6 months

PURPOSE

Quality of life (QoL) outcomes of patients treated with extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) have been conflicting. This study reports on QoL outcomes for a broad group of ARDS patients managed with up-to-date treatment modalities.

METHODS

We prospectively recruited patients at a quaternary hospital in the United Kingdom from 2013 to 2015 who were treated with ECMO for ARDS. We evaluated their pulmonary function and QoL at 6-months after admission using three QoL instruments: EuroQoL 5D (EQ-5), HADS, and PTSS-14.

RESULTS

Forty-three patients included in the analysis had near-normal pulmonary function at 6 months. HADS showed moderate-to-severe anxiety and depression in 32% and 11% of patients, respectively. PTSS-14 showed 29% had signs of post-traumatic stress disorder. EQ-5D showed that 67% of patients had difficulty returning to usual activities, 74% suffered some pain, none reported severe problems and 77% were able to return to work. No clinical or demographic variables were associated with poor 6-month QoL.

CONCLUSIONS

Patients with ARDS treated with ECMO generally had good QoL outcomes, similar to outcomes reported for patients managed without ECMO. With respect to QoL, VV-EMCO represents a valid treatment modality for patients with refractory ARDS.

Extracorporeal membrane oxygenation for near fatal asthma with sudden cardiac arrest

INTRODUCTION

Near fatal asthma is a life-threatening disorder that requires mechanical ventilation. Near fatal asthma and COPD with sudden cardiac arrest can worsen the outcomes. Previous studies demonstrated that ECMO is a live-saving measure for near fatal asthma that does not respond to traditional treatment.

CASE STUDY

A patient with near fatal asthma (NFA) and COPD presented with high airway resistance, life-threatening acidemia and severe hypoxemia that failed to respond to conventional therapy. His hospital course was complicated by sudden cardiac arrest when preparing to initiate V-V mode extracorporeal membrane oxygenation (ECMO). The mode immediately changed from V-V to V-A, then to V-AV and finally to V-V mode in order to improve cardiac function and promote recovery of lung function.

RESULTS

On the sixth day, ECMO was removed and on the ninth day, he was extubated and transferred to the ward. Finally, the patient was discharged home on the nineteenth day after admission to be followed up in the pulmonary clinic.

CONCLUSIONS

The early application of ECMO and mode changing plausibly resulted in dramatic improvement in gas exchange and restoration of cardiac function. This case illustrates the critical role of ECMO mode changing as salvage therapy in NFA and COPD with sudden cardiac arrest.

Changes in Oxygen Saturation and Mean Arterial Pressure With Inhaled Epoprostenol in Transport

OBJECTIVE

Patients with hypoxemic respiratory failure have traditionally been considered one of the riskiest patient populations to transport, given the potential for desaturation with movement. We performed a retrospective cohort study to analyze our experience using inhaled epoprostenol in transport, with a primary objective of assessing change in the oxygen saturation throughout the transport.

METHODS

The transport records of patients with severe hypoxemic respiratory failure or right heart failure, transported on inhaled epoprostenol, were reviewed. The primary outcome was the change in SpO₂ from the start of the inhaled epoprostenol transport to the time of handover of care at the receiving institution. The secondary outcome was the change in the mean arterial pressure (MAP).

RESULTS

Comparing the initial SpO₂ to the final, there was no significant difference in oxygenation between time 0 and the transfer of care at the receiving hospital at 91% versus 93% (interquartile range [IQR] 86.0-93.5 vs 87.5-96.0, P = .49). Comparing the SpO₂ for those who had inhaled epoprostenol started by the transport team showed a larger change at 86% compared to 93% (IQR: 83.0-91.0 vs 86.5-94.5, P = .04). There was no change in the median MAP from time 0 to the end of the transport (77 vs 75 mm Hg, IQR, 67.5-84.8 vs 68.5-85.8, P = .70).

CONCLUSIONS

In this study, patients with severe cardiopulmonary compromise transported on inhaled epoprostenol had no significant change in their median oxygen saturations, with the overall population increasing from 91% to 93%. When inhaled epoprostenol was initiated by the transport team, the improvement was clinically and statistically significant with an increase in SpO₂ from 86% to 93%, with a final oxygen saturation comparable to those who were on the medication at the time of the team's arrival.

Inhaled Epoprostenol to Facilitate Safe Transport in Legionnaires' Disease

Hypoxemic patients often desaturate further with movement and transport. While inhaled epoprostenol does not improve mortality, improving oxygenation allows for transport of severely hypoxemic patients to tertiary care centers with a related improvement in mortality rates. Extracorporeal membrane oxygenation (ECMO) use is increasing in frequency for patients with refractory hypoxemia, and with increasing regionalization of care, safe transport of hypoxemic patients only becomes more important. In this series, four cases are presented of young patients with severe hypoxemic respiratory failure from Legionnaires' disease transported on inhaled epoprostenol to ECMO centers for consideration of cannulation. With continued climate changes, Legionella and other pathogens are likely to be a continued threat. As such, optimizing oxygenation to allow for transport should continue to be a priority for critical care transport (CCT) services.

Invasive pulmonary aspergillosis is associated with adverse clinical outcomes in critically ill patients receiving veno-venous extracorporeal membrane oxygenation

To identify the incidence, risk factors and impact on long-term survival of invasive pulmonary aspergillosis (IPA) and Aspergillus colonisation in patients receiving vv-extracorporeal membrane oxygenation (ECMO). A retrospective evaluation was performed of patients receiving vv-ECMO at a tertiary hospital in Manchester (UK) between January 2012 and December 2016. Data collected included epidemiological data, microbiological cultures, radiographic findings and outcomes. Cases were classified as proven IPA, putative IPA or Aspergillus colonisation according to a validated clinical algorithm. One hundred thirty-four patients were supported with vv-ECMO, median age of 45.5 years (range 16.4-73.4). Ten (7%) patients had putative IPA and nine (7%) had Aspergillus colonisation. Half of the patients with putative IPA lacked classical host risk factors for IPA. The median number of days on ECMO prior to Aspergillus isolation was 5 days. Immunosuppression and influenza A infection were significantly associated with developing IPA in a logistic regression model. Cox regression model demonstrates a three times greater hazard of death associated with IPA. Overall 6-month mortality rate was 38%. Patients with putative IPA and colonised patients had a 6-month mortality rate of 80 and 11%, respectively. Immunosuppression and influenza A infection are independent risk factors for IPA. IPA, but not Aspergillus colonisation, is associated with high long-term mortality in patients supported with vv-ECMO.

Microfluidic cell sorting: Towards improved biocompatibility of extracorporeal lung assist devices

Extracorporeal lung assist technology is one of the last options in critical care medicine to treat patients suffering from severe oxygenation and decarboxylation disorders. Platelet activation along with the consequent thrombus formation is a potentially life-threatening complication of this technique. To avoid platelet-dependent clot formation, this study aims at developing a microfluidic cell sorting chip that can bypass platelets prior to the membrane oxygenator of the extracorporeal lung assist device. The cell sorting chips were produced by maskless dip-in laser lithography, followed by soft lithography replication using PDMS. Citrated porcine whole blood with a clinically relevant haematocrit of 17% was used for the cell sorting experiments involving three different blood flow rates. The joint effects of flow focusing and hydrodynamic lifting forces within the cell sorting chip resulted in a reduction of up to 57% of the baseline platelet count. This cell sorting strategy is suitable for the continuous and label-free separation of red blood cells and platelets and is potentially applicable for increasing the biocompatibility and lifetime of current extracorporeal lung assist devices.

Mechanically Ventilating the Severe Asthmatic

The management of the critically ill patients with asthma can be rather challenging. Potentially devastating complications relating to this presentation include hypoxemia, worsening bronchospasm, pulmonary aspiration, tension pneumothorax, dynamic hyperinflation, hypotension, dysrhythmias, and seizures. In contrast to various other pathologies requiring mechanical ventilation, acute asthma is generally associated with better outcomes. This review serves as a practical guide to the physician managing patients with severe acute asthma requiring mechanical ventilation. In addition to specifics relating to endotracheal intubation, we also discuss the interpretation of ventilator graphics, the recommended mode of ventilation, dynamic hyperinflation, permissive hypercapnia, as well as the role of extracorporeal membrane oxygenation and noninvasive mechanical ventilation.

Extracorporeal membrane oxygenation (ECMO) as a treatment strategy for severe acute respiratory distress syndrome (ARDS) in the low tidal volume era: A systematic review

OBJECTIVE

To evaluate the hospital survival in patients with severe ARDS managed with ECMO and low tidal volume ventilation as compared to patients managed with low tidal volume ventilation alone.

METHODS

Electronic databases were searched for studies of at least 10 adult patients with severe ARDS comparing the use of ECMO with low tidal volume ventilation to mechanical ventilation with a low tidal volume alone. Only studies reporting hospital or ICU survival were included. All identified studies were assessed independently by two reviewers.

RESULTS

Of 1782 citations, 27 studies (n=1674) met inclusion criteria. Hospital survival for ECMO patients ranged from 33.3 to 86%, while survival with conventional therapy ranged from 36.3 to 71.2%. Five studies were identified with appropriate control groups allowing comparison, but due to the high degree of variability between studies (I²=63%), their results could not be pooled. Two of these studies demonstrated a significant difference, both favouring ECMO over conventional therapy.

CONCLUSION

Given the lack of studies with appropriate control groups, our confidence in a difference in outcome between the two therapies remains weak. Future studies on the use of ECMO for severe ARDS are needed to clarify the role of ECMO in this disease.

Improved Oxygenation After Transport in Patients With Hypoxemic Respiratory Failure

OBJECTIVE

The purpose of this study is to measure the rate and magnitude of changes in oxygenation that occur in patients with hypoxemic respiratory failure after transport by a critical care transport team.

METHODS

We performed a retrospective review of 239 transports of patients with hypoxemic respiratory failure requiring a fraction of inspired oxygen (Fio2) > 50% transported from October 2009 to December 2012 from referring hospitals to 3 tertiary care hospitals. We analyzed the change the ratio of the partial pressure of oxygen in the blood to FiO2 from the sending to the receiving hospital as well as the percentage saturation of oxygen (Spo2) before, after, and en route.

RESULTS

The mean change in the Pao2/Fio2 ratio from the sending to the receiving hospital was an increase of 27.62 (95% confidence interval [CI], 15.84-39.40; P = .0003). The mean change in Pao2 was an increase of 27.85 mm Hg (CI, 17.49-38.22; P < .0001). The mean Spo2 was not significantly changed at -0.12 (CI, - 1.69 to 1.45, P = .9). Despite improvement in the Pao2/Fio2 ratio and a stable Spo2 on arrival, 28.1% of patients desaturated to Spo2 < 90% in transport.

CONCLUSION

In patients with hypoxemic respiratory failure, Pao2/Fio2 and Pao2 increased after transport by a critical care transport team despite 28.1% of patients desaturating with hypoxemia in transit.

Severe ARDS caused by adenovirus: early initiation of ECMO plus continuous renal replacement therapy

The reported survival rates of patients with acute respiratory distress syndrome (ARDS) caused by human adenovirus (HAdV) pneumonia are poor. The results do not differ much in immunocompetent patients supported by extracorporeal membrane oxygenation (ECMO). We report two immunocompetent patients with severe ARDS complicating HAdV pneumonia who were treated successfully and survived to discharge. Compared with previous cases, our cases might have benefited from several factors. First, the time interval between mechanical ventilator support and ECMO implantation was shorter. Second, we implemented conservative fluid management as recommended by the ARDS network using continuous renal replacement therapy (CRRT). Third, we administered an antiviral agent as early as possible. A clinical trial of early ECMO with CRRT and the administration of cidofovir in patients with severe ARDS complicating HAdV pneumonia are needed to confirm our results.

Extracorporeal membrane oxygenation support for life-threatening acute severe status asthmaticus

INTRODUCTION

Status asthmaticus is a life-threatening condition characterized by progressive respiratory failure due to asthma that is unresponsive to standard therapeutic measures. We used extracorporeal membrane oxygenation (ECMO) to treat patients with near-fatal status asthamticus who did not respond to aggressive medical therapies and mechanical ventilation under controlled permissive hypercapnia.

MATERIALS AND METHODS

Between January 2011 and October 2015, we treated 16 adult patients with status asthmaticus (8 women, 8 men, mean age: 50.5±10.6years) with veno-venous ECMO (13 patients) or veno-arterial (3 patients). Patients failed to respond to conventional therapies despite receiving the most aggressive therapies, including maximal medical treatments, mechanical ventilation under controlled permissive hypercapnia and general anesthetics.

RESULTS

Mean time spent on ECMO was 300±11.8 hours (range 36-384 hours). PaO₂, PaCO₂ and pH showed significant improvement promptly after ECMO initiation p=0.014, 0.001 and <0.001, respectively, and such values remained significantly improved after ECMO, p=0.004 and 0.001 and <0.001, respectively. The mean time of ventilation after decannulation until extubation was 175±145.66 hours and the median time to intensive care unit discharge after decannulation was 234±110.30 hours. All 16 patients survived without neurological sequelae.

CONCLUSIONS

ECMO could provide adjunctive pulmonary support for intubated asthmatic patients who remain severely acidotic and hypercarbic despite aggressive conventional therapy. ECMO should be considered as an early treatment in patients with status asthmaticus whose gas exchange cannot be satisfactorily maintained by conventional therapy for providing adequate gas change and preventing lung injury from the ventilation.

Transferring patients with refractory hypoxemia to a regional extracorporeal membrane oxygenation center: key considerations for clinicians

Because of technological advancements and encouraging experiences during the 2009 influenza A (H1N1) epidemic, many critical care clinicians consider extracorporeal membrane oxygenation (ECMO) a reasonable strategy for managing patients with refractory hypoxemia when standardized therapies have failed. Although the literature remains unclear as to whether it should be considered a routine or a rescue strategy in the management of patients with severe acute respiratory distress syndrome, experts agree that ECMO therapy is most likely to result in positive outcomes and fewer complications when provided at regional ECMO centers. Some institutions have developed the expertise and resources required to provide this sophisticated therapy, but significantly more facilities may choose to send their patients to a tertiary ECMO center when they do not respond to usual care. This article provides information essential for health care teams who refer their patients to such centers. The clinical indications for, and the use of, ECMO therapy in the management of refractory hypoxemia is briefly reviewed, followed by a description of how ECMO works to provide gas exchange and tissue perfusion. The primary considerations for circuit management, hemodynamic support, and pulmonary care are described, and significant complications of the therapy are identified. The remainder of the article focuses on the patient care and preparatory activities that occur before and during ECMO initiation, so that health care teams, patients, and their families can be confident of an efficient, safe, and highly skilled transfer of care between institutions.

Survival Predictors for Severe ARDS Patients Treated with Extracorporeal Membrane Oxygenation: A Retrospective Study in China

Extracorporeal membrane oxygenation (ECMO) is increasingly being applied as life support for acute respiratory distress syndrome (ARDS) patients. However, the outcomes of this procedure have not yet been characterized in severe ARDS patients. The aim of this study was to evaluate the outcomes of severe ARDS patients supported with ECMO and to identify potential predictors of mortality in these patients. A total of 38 severe ARDS patients (aged 51.39±13.27 years, 32 males) who were treated with ECMO in the specialized medical intensive care unit of Guangzhou Institute of Respiratory Diseases from July 2009 to December 2014 were retrospectively reviewed. The clinical data of the patients on the day before ECMO initiation, on the first day of ECMO treatment and on the day of ECMO removal were collected and analyzed. All patients were treated with veno-venous ECMO after a median mechanical ventilation duration of 6.4±7.6 days. Among the 20 patients (52.6%) who were successfully weaned from ECMO, 16 patients (42.1%) survived to hospital discharge. Of the identified pre-ECMO factors, advanced age, a long duration of ventilation before ECMO, a higher Acute Physiology and Chronic Health Evaluation II (APACHE II) score, underlying lung disease, and pulmonary barotrauma prior to ECMO were associated with unsuccessful weaning from ECMO. Furthermore, multiple logistic regression analysis indicated that both barotrauma pre-ECMO and underlying lung disease were independent predictors of hospital mortality. In conclusion, for severe ARDS patients treated with ECMO, barotrauma prior to ECMO and underlying lung disease may be major predictors of ARDS prognosis based on multivariate analysis.

Extracorporeal life support for severe acute respiratory distress syndrome

PURPOSE OF REVIEW

To provide a summary of the recent literature on extracorporeal membrane oxygenation (ECMO) in adults with severe acute respiratory distress syndrome (ARDS), focusing on advances in equipment, current conventional and unconventional indications, complications, and future applications.

RECENT FINDINGS

ECMO use has increased during the past 5 years. Advances in cannulation, circuit design, and patient selection have made it a safer therapeutic option in severe ARDS, and its use has become more widespread for nonconventional indications.

SUMMARY

High-quality evidence for the routine use of ECMO for management of adult patients with severe ARDS is still lacking. An ongoing randomized controlled trial (ECMO to rescue lung injury in severe ARDS) will contribute valuable data to guide clinical decisions to opt for this supportive therapy.

[Veno-arterial extracorporeal membrane oxygenation. Indications, limitations and practical implementation]

Due to the technical advances in pumps, oxygenators and cannulas, veno-arterial extracorporeal membrane oxygenation (va-ECMO) or extracorporeal life support (ECLS) has been widely used in emergency medicine and intensive care medicine for several years. An accepted indication is peri-interventional cardiac failure in cardiac surgery (postcardiotomy low cardiac output syndrome). Furthermore, especially the use of va-ECMO for other indications in critical care medicine, such as in patients with severe sepsis with septic cardiomyopathy or in cardiopulmonary resuscitation has tremendously increased. The basic indications for va-ECMO are therapy refractory cardiac or cardiopulmonary failure. The fundamental purpose of va-ECMO is bridging the function of the lungs and/or the heart. Consequently, this support system does not represent a causal therapy by itself; however, it provides enough time for the affected organ to recover (bridge to recovery) or for the decision for a long-lasting organ substitution by a ventricular assist device or by transplantation (bridge to decision). Although the outcome for bridged patients seems to be favorable, it should not be forgotten that the support system represents an invasive procedure with potentially far-reaching complications. Therefore, the initiation of these systems needs a professional and experienced (interdisciplinary) team, sufficient resources and an individual approach balancing the risks and benefits. This review gives an overview of the indications, complications and contraindications for va-ECMO. It discusses its advantages in organ transplantation and transport of critically ill patients. The reader will learn the differences between peripheral and central cannulation and how to monitor and manage va-ECMO.

A case of near fatal asthma: The role of ECMO as rescue therapy

We report a case of an adolescent with near fatal asthma (NFA). He presented with severe hypoxemia and lifethreatening acidemia, who failed to respond to conventional therapy. His hospital course was complicated by barotrauma and hemodynamic instability. Early introduction of extracorporeal membrane oxygenation (ECMO) led to dramatic improvement in gas exchange and lung mechanics. This case illustrates the important role of ECMO as salvage therapy in NFA.

Extracorporeal membrane oxygenation for critically ill adults

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a form of life support that targets the heart and lungs. Extracorporeal membrane oxygenation for severe respiratory failure accesses and returns blood from the venous system and provides non-pulmonary gas exchange. Extracorporeal membrane oxygenation for severe cardiac failure or for refractory cardiac arrest (extracorporeal cardiopulmonary resuscitation (ECPR)) provides gas exchange and systemic circulation. The configuration of ECMO is variable, and several pump-driven and pump-free systems are in use. Use of ECMO is associated with several risks. Patient-related adverse events include haemorrhage or extremity ischaemia; circuit-related adverse effects may include pump failure, oxygenator failure and thrombus formation. Use of ECMO in newborns and infants is well established, yet its clinical effectiveness in adults remains uncertain.

OBJECTIVES

The primary objective of this systematic review was to determine whether use of veno-venous (VV) or venous-arterial (VA) ECMO in adults is more effective in improving survival compared with conventional respiratory and cardiac support.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) on 18 August 2014. We searched conference proceedings, meeting abstracts, reference lists of retrieved articles and databases of ongoing trials and contacted experts in the field. We imposed no restrictions on language or location of publications.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), quasi-RCTs and cluster-RCTs that compared adult ECMO versus conventional support.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of all retrieved citations against the inclusion criteria. We independently reviewed full-text copies of studies that met the inclusion criteria. We entered all data extracted from the included studies into Review Manager. Two review authors independently performed risk of bias assessment. All included studies were appraised with respect to random sequence generation, concealment of allocation, blinding of outcome assessment, incomplete outcome data, selective reporting and other bias.

MAIN RESULTS

We included four RCTs that randomly assigned 389 participants with acute respiratory failure. Risk of bias was low in three RCTs and high in one RCT. We found no statistically significant differences in all-cause mortality at six months (two RCTs) or before six months (during 30 days of randomization in one trial and during hospital stay in another RCT). The quality of the evidence was low to moderate, and further research is very likely to impact our confidence in the estimate of effects because significant changes have been noted in ECMO applications and treatment modalities over study periods to the present.Two RCTs supplied data on disability. In one RCT survival was low in both groups but none of the survivors had limitations in their daily activities six months after discharge. The other RCT reported improved survival without severe disability in the intervention group (transfer to an ECMO centre ± ECMO) six months after study randomization but no statistically significant differences in health-related quality of life.In three RCTs, participants in the ECMO group received greater numbers of blood transfusions. One RCT recorded significantly more non-brain haemorrhage in the ECMO group. Another RCT reported two serious adverse events in the ECMO group, and another reported three adverse events in the ECMO group.Clinical heterogeneity between studies prevented meta-analyses across outcomes. We found no completed RCT that had investigated ECMO in the context of cardiac failure or arrest. We found one ongoing RCT that examined patients with acute respiratory failure and two ongoing RCTs that included patients with acute cardiac failure (arrest).

AUTHORS' CONCLUSIONS

Extracorporeal membrane oxygenation remains a rescue therapy. Since the year 2000, patient treatment and practice with ECMO have considerably changed as the result of research findings and technological advancements over time. Over the past four decades, only four RCTs have been published that compared the intervention versus conventional treatment at the time of the study. Clinical heterogeneity across these published studies prevented pooling of data for a meta-analysis.We recommend combining results of ongoing RCTs with results of trials conducted after the year 2000 if no significant shifts in technology or treatment occur. Until these new results become available, data on use of ECMO in patients with acute respiratory failure remain inconclusive. For patients with acute cardiac failure or arrest, outcomes of ongoing RCTs will assist clinicians in determining what role ECMO and ECPR can play in patient care.

Extubation during pediatric extracorporeal membrane oxygenation: a single-center experience

OBJECTIVES

Describe aspects of one center's experience extubating infants and children during extracorporeal membrane oxygenation.

DESIGN

Retrospective review of medical records.

SETTING

Seventy-one-bed critical care service (PICU and cardiovascular ICU) in a large urban tertiary children's hospital.

PATIENTS

Pediatric and neonatal patients supported on extracorporeal membrane oxygenation between 1996 and 2013 who were either not intubated or extubated greater than 24 hours during their extracorporeal membrane oxygenation course.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixteen of 511 patients on extracorporeal membrane oxygenation were extubated for at least 24 hours during their extracorporeal membrane oxygenation courses. Fourteen had respiratory failure and two had cardiac disease. Five patients died while on extracorporeal membrane oxygenation, but the cause of death was not related to complications associated with extubation. Extubated patients were supported a median of 19.7 days on extracorporeal membrane oxygenation, with a median extubation latency (time between cannulation and first extubation) of 6.2 days and a median extubation duration of 5.5 days. Mean time extubated was 43% of the total time on extracorporeal membrane oxygenation. Two patients were reintubated briefly or had a laryngeal mask airway placed for decannulation (n = 1). The remaining patients were extubated within 5 days of decannulation, weeks afterward (n = 2), transferred to outside facilities (n = 2), or died during extracorporeal membrane oxygenation support (n = 5). We also observed no complications directly attributable to extubation and spontaneous reaeration of consolidated lungs in acute respiratory distress syndrome in extubated patients on extracorporeal membrane oxygenation.

CONCLUSION

Extubation and discontinuation of mechanical ventilation appear feasible in patients requiring long-term extracorporeal membrane oxygenation. Emergency procedure planning may need to be modified in extubated patients on extracorporeal membrane oxygenation.

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.

Transferring Patients With Refractory Hypoxemia to a Regional Extracorporeal Membrane Oxygenation Center

Because of technological advancements and encouraging experiences during the 2009 influenza A (H1N1) epidemic, many critical care clinicians consider extracorporeal membrane oxygenation (ECMO) a reasonable strategy for managing patients with refractory hypoxemia when standardized therapies have failed. Although the literature remains unclear as to whether it should be considered a routine or a rescue strategy in the management of patients with severe acute respiratory distress syndrome, experts agree that ECMO therapy is most likely to result in positive outcomes and fewer complications when provided at regional ECMO centers. Some institutions have developed the expertise and resources required to provide this sophisticated therapy, but significantly more facilities may choose to send their patients to a tertiary ECMO center when they do not respond to usual care. This article provides information essential for health care teams who refer their patients to such centers. The clinical indications for, and the use of, ECMO therapy in the management of refractory hypoxemia is briefly reviewed, followed by a description of how ECMO works to provide gas exchange and tissue perfusion. The primary considerations for circuit management, hemodynamic support, and pulmonary care are described, and significant complications of the therapy are identified. The remainder of the article focuses on the patient care and preparatory activities that occur before and during ECMO initiation, so that health care teams, patients, and their families can be confident of an efficient, safe, and highly skilled transfer of care between institutions.

Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is an advanced form of life support technology whereby venous blood is oxygenated outside of the body and returned to the patient. ECMO was initially used as last-resort rescue therapy for patients with severe respiratory failure. Over the last four decades, it has developed into a safe, standard therapy for newborns with progressive cardiorespiratory failure, as a resuscitation therapy after cardiac arrest, and in combination with other treatments such as hypothermia and various blood filtration therapies. ECMO has also become routine for children and adults with all forms of cardiogenic shock and is also routine in early graft failure after transplantation. The one area of ongoing debate is the role of ECMO in adults with hypoxemic respiratory failure. As ECMO equipment becomes safer, earlier use improves patient outcomes. Several modifications of the two basic venovenous and venoarterial ECMO systems are now occurring, as are many minor variations in cannulation strategies and systems of care for patients receiving ECMO. The indications and situations in which ECMO have been tried continue to change, and ECMO for sub-acute and chronic illnesses is now commonplace, as is the use of ECMO in patients with clinical problems previously regarded as contraindications, such as sepsis, malignancy, and immunosuppression.

Psychiatric outcome after severe cardio-respiratory failure treated with extracorporeal membrane oxygenation: a case-series

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used to save patients with severe cardiopulmonary failure at high risk of dying, but the long-term psychiatric outcome of the treatment has not been studied.

METHODS

Twenty-eight adults who survived ECMO were subjected to psychiatric assessment 5 years after ECMO by means of interviews (MINI-Neuropsychiatric Interview and Montgomery-Åsberg Depression Rating Scale) and psychometrics [Neuroticism and social conformity (EPQ-N+L); General Health Questionnaire (GHQ), Hospital Anxiety Depression Scale; Aggression Questionnaire, Toronto Alexithymia Scale, and Giessener somatic symptom checklist (GBB)].

RESULTS

Fifteen patients (54%) suffered lifetime psychiatric disorders prior to ECMO. After ECMO, 11 subjects (39%) developed new psychiatric disorders, mostly organic mental (18%), obsessive-compulsive disorders (OCD) 15%, and/or post-traumatic stress disorders (PTSD) 11%. These 11 patients reported higher scores on Montgomery-Åsberg Depression Rating Scale (MADRS), GHQ, EPQ-N, and GBB. Disregarding the presence of psychiatric disorders at follow-up, ECMO patients reported high levels of distress, physical aggression, anger, and alexithymic traits.

CONCLUSIONS

Severe life-threatening cardiovascular or pulmonary failure with subsequent ECMO is associated with an increased prevalence of long-term psychiatric disorders and distress. Studies addressing the etiology and prevalence of psychiatric consequences after ECMO are needed.

[Interhospital transport with extracorporeal life support: results and perspectives after 5 years experience]

OBJECTIVE

Describing the experience of a referral center for interhospital patients transport treated with extracorporeal circulatory or respiratory support (ECLS), the difficulties encountered and the results obtained.

STUDY DESIGN

Retrospective and observational study.

PATIENTS AND METHODS

All patients with respiratory or circulatory failure accepted for extracorporeal assistance for which routine medical transport was life threatening.

STATISTICAL ANALYSIS

A descriptive analysis was performed (median and interquartile deviation). Comparison of biological data was performed using a non-parametric Wilcoxon test and 5 years overall survival was determined by a Kaplan-Meier analysis.

RESULTS

Over a 55-month period, 29 patients were selected for transportation under ECMO or ECLS. Indication was respiratory failure in 38 % of cases, hemodynamic instability in 52 % of cases and combined symptoms in 10 % of cases. Average duration of transportation was 40 km (9-64 km). No complication related to transport was observed. Incidence of intrahospital death was 57 %. There was no correlation between death and indication of ECLS. Five-year survival was 55 % and 39 % for venovenous and arteriovenous ECLS, respectively.

CONCLUSION

In our experience, interhospital transport of patients under ECMO is feasible in satisfactory conditions of safety with trained team and standard procedures.