Additive treatment considerations in COVID-19-The clinician's perspective on extracorporeal adjunctive purification techniques

Mechanical ventilation during extracorporeal membrane oxygenation support - New trends and continuing challenges

BACKGROUND

The impact of mechanical ventilation on the survival of patients supported with veno-venous extracorporeal membrane oxygenation (V-V ECMO) due to severe acute respiratory distress syndrome (ARDS) remains still a focus of research.

METHODS

Recent guidelines, randomized trials, and registry data underscore the importance of lung-protective ventilation during respiratory and cardiac support on ECMO.

RESULTS

This approach includes decreasing mechanical power delivery by reducing tidal volume and driving pressure as much as possible, using low or very low respiratory rate, and a personalized approach to positive-end expiratory pressure (PEEP) setting. Notably, the use of ECMO in awake and spontaneously breathing patients is increasing, especially as a bridging strategy to lung transplantation. During respiratory support in V-V ECMO, native lung function is of highest importance and adjustments of blood flow on ECMO, or ventilator settings significantly impact the gas exchange. These interactions are more complex in veno-arterial (V-A) ECMO configuration and cardiac support. The fraction on delivered oxygen in the sweep gas and sweep gas flow rate, blood flow per minute, and oxygenator efficiency have an impact on gas exchange on device side. On the patient side, native cardiac output, native lung function, carbon dioxide production (VCO2), and oxygen consumption (VO2) play a role. Avoiding pulmonary oedema includes left ventricle (LV) distension monitoring and prevention, pulse pressure >10 mm Hg and aortic valve opening assessment, higher PEEP adjustment, use of vasodilators, ECMO flow adjustment according to the ejection fraction, moderate use of inotropes, diuretics, or venting strategies as indicated and according to local expertise and resources.

CONCLUSION

Understanding the physiological principles of gas exchange during cardiac support on femoro-femoral V-A ECMO configuration and the interactions with native gas exchange and haemodynamics are essential for the safe applications of these techniques in clinical practice. Proning during ECMO remains to be discussed until further data is available from prospective, randomized trials implementing individualized PEEP titration during proning.

Microbead-based extracorporeal immuno-affinity virus capture: a feasibility study to address the SARS-CoV-2 pandemic

In this paper, we report on the utilization of micro-technology based tools to fight viral infections. Inspired by various hemoperfusion and immune-affinity capture systems, a blood virus depletion device has been developed that offers highly efficient capture and removal of the targeted virus from the circulation, thus decreasing virus load. Single-domain antibodies against the Wuhan (VHH-72) virus strain produced by recombinant DNA technology were immobilized on the surface of glass micro-beads, which were then utilized as stationary phase. For feasibility testing, the virus suspension was flown through the prototype immune-affinity device that captured the viruses and the filtered media left the column. The feasibility test of the proposed technology was performed in a Biosafety Level 4 classified laboratory using the Wuhan SARS-CoV-2 strain. The laboratory scale device actually captured 120,000 virus particles from the culture media circulation proving the feasibility of the suggested technology. This performance has an estimated capture ability of 15 million virus particles by using the therapeutic size column design, representing three times over-engineering with the assumption of 5 million genomic virus copies in an average viremic patient. Our results suggested that this new therapeutic virus capture device could significantly lower virus load thus preventing the development of more severe COVID-19 cases and consequently reducing mortality rate.

Additive effectiveness of acrylonitrile-co-methallyl sulfonate surface-treated membranes in the treatment of pneumonia: A propensity score-matched retrospective cohort study

BACKGROUND

The acrylonitrile-co-methallyl sulfonate surface-treated (AN69ST) membrane has cytokine adsorption capacity and is used for treating sepsis. This study aimed to compare the effects of continuous renal replacement therapy (CRRT) using the AN69ST membrane with those of CRRT using other membranes for patients with pneumonia-associated sepsis.

METHODS

This retrospective, propensity score-matched, cohort study was based on a nationwide Japanese inpatient database. We included data from adults hospitalized with a primary diagnosis of pneumonia, who received CRRT using either the AN69ST membrane or another membrane within 2 days of admission, and who were discharged from the hospitals between September 2014, and March 2017. Propensity score matching was used to compare in-hospital mortality between the two groups.

RESULTS

Eligible patients (N = 2393) were categorized into an AN69ST group (N = 631) and a non-AN69ST group (N = 1762). The overall in-hospital mortality rate was 38.9%. Among the 545 propensity-matched patient pairs, the in-hospital mortality rate was significantly lower in the AN69ST group than in the non-AN69ST group (35.8 vs. 41.8%, p = 0.046).

CONCLUSIONS

Among patients with pneumonia-associated sepsis treated with CRRT, CRRT with the AN69ST membrane was associated with a significantly lower in-hospital mortality than CRRT with standard membranes.

Extracorporeal life support provision in COVID-19 patients - An international EuroELSO 2022 update survey

INTRODUCTION

An analysis on the ECLS use for patients with respiratory or cardiac support in COVID-19 based on an international response to EuroELSO survey, aims to generate a more comprehensive understanding of ECLS role during the recent viral pandemic.

METHODS

EuroELSO announced the survey at the 10th annual congress in London, May 2022. The survey covered 26 multiple-choice questions.

RESULTS

The survey returned 69 questionnaires from 62 centers across 22 European countries and seven centers across five non-European countries. Most of the centers providing ECLS for COVID-19 patients had more than 30 runs for respiratory support since December 2019. In the same period, at least 31 runs in adult COVID-19 patients have been performed in 48 of 69 centers (69.6%). The reported pediatric data from 18 centers is limited to less than the patients per center.

CONCLUSION

Majority of the COVID-19 patients received respiratory ECLS support and adult patients dominated. The indications and contraindications are broadly aligned with available guidelines. Most of the centers considered age >65 or biological age as a relative or absolute contraindication for ECLS in COVID-19. ECLS withdrawal criteria in COVID-19 are controversial because the long-term outcomes after ECLS in COVID-19 and the impact of critical illness and the impact of long-COVID are still not known.

Mechanisms of SARS-CoV-2 Infection-Induced Kidney Injury: A Literature Review

The severe acute respiratory coronavirus 2 (SARS-CoV-2) has become a life-threatening pandemic. Clinical evidence suggests that kidney involvement is common and might lead to mild proteinuria and even advanced acute kidney injury (AKI). Moreover, AKI caused by coronavirus disease 2019 (COVID-19) has been reported in several countries and regions, resulting in high patient mortality. COVID-19-induced kidney injury is affected by several factors including direct kidney injury mediated by the combination of virus and angiotensin-converting enzyme 2, immune response dysregulation, cytokine storm driven by SARS-CoV-2 infection, organ interactions, hypercoagulable state, and endothelial dysfunction. In this review, we summarized the mechanism of AKI caused by SARS-CoV-2 infection through literature search and analysis.

Influence of extracorporeal cytokine adsorption on hemodynamics in severe acute pancreatitis: Results of the matched cohort pancreatitis cytosorbents inflammatory cytokine removal (PACIFIC) study

BACKGROUND

Outcome of severe acute pancreatitis (SAP) highly depends on the degree of systemic inflammation and organ failure. Although treatment approaches targeting the inflammatory cascade have failed in pancreatitis, recent studies suggest that extracorporeal cytokine adsorption effectively reduces concentrations of pro-inflammatory cytokines and potentially improves the outcome of sepsis.

METHODS

Sixteen patients with SAP, presenting within 7 days upon onset of pain, an APACHE-II score of ≥10 and ≥1 marker of poor prognosis, received 2 consecutive 24-h treatments with CytoSorb® extracorporeal cytokine adsorption (intervention group). Hemodynamics, organ failure, and mortality were compared with an APACHE-II score-matched retrospective control group of 32 patients.

RESULTS

The primary objective (20% decrease in the vasopressor dependency index or 20% increase in the cardiac index) was reached in 68.8% of the intervention and 28.1% of the control patients (p = 0.007), respectively. The cytokine adsorption significantly reduced IL-6 (-1998 pg/ml, p = 0.005) serum levels and resulted in stable CRP (p = 0.101) and decreased PCT (p = 0.003) levels in contrast to increased CRP (p = 0.014) and stable PCT levels (p = 0.695) in the control group. While mortality and improvement of respiratory failure were similar in both groups, renal failure significantly improved (change of KDIGO classification 72 h postcytokine adsorption [-1 vs. 0, p = 0.005]) and the SOFA score significantly decreased (day 5: -1.8 ± 2.0 vs. 1 ± 3.8, p = 0.013) in the intervention group.

CONCLUSION

Cytokine adsorption might be an effective treatment option to stabilize hemodynamics in SAP. It decreases levels of the pro-inflammatory marker IL-6 and stabilizes organ function according to serial SOFA score assessments.

COVID-19 and Sepsis

The COVID-19 pandemic has created a major alteration in the medical literature including the sepsis discussion. From the outset of the pandemic, various reports have indicated that although there are some unique features pertinent to COVID-19, many of its acute manifestations are similar to sepsis caused by other pathogens. As a consequence, the old definitions now require consideration of this new etiologic agent, namely SARS-CoV-2. Although the pathogenesis of COVID-19 has not been fully explained, the data obtained so far in hospitalized patients has revealed that serum cytokine and chemokine levels are high in severe COVID-19 patients, similar to those found with sepsis. COVID-19 may involve multiple organ systems. In addition to the lungs, the virus has been isolated from blood, urine, faeces, liver, and gallbladder. Results from autopsy series in COVID-19 patients have demonstrated a wide range of findings, including vascular involvement, congestion, consolidation, and hemorrhage as well as diffuse alveolar damage in lung tissue consistent with acute respiratory distress syndrome (ARDS). The presence of viral cytopathic-like changes, infiltration of inflammatory cells (mononuclear cells and macrophages), and viral particles in histopathological samples are considered a consequence of both direct viral infection and immune hyperactivation. Thromboembolism and hyper-coagulopathy are other components in the pathogenesis of severe COVID-19. Although the pathogenesis of hypercoagulability is not fully understood, it has been pointed out that all three components of Virchow’s triad (endothelial injury, stasis, and hypercoagulable state) play a major role in contributing to clot formation in severe COVID-19 infection. In severe COVID-19 cases, laboratory parameters such as hematological findings, coagulation tests, liver function tests, D-dimer, ferritin, and acute phase reactants such as CRP show marked alterations, which are suggestive of a cytokine storm. Another key element of COVID-19 pathogenesis in severe cases is its similarity or association with hemophagocytic lymphohistiocytosis (HLH). SARS-CoV-2 induced cytokine storm has significant clinical and laboratory findings overlapping with HLH. Viral sepsis has some similarities but also some differences when compared to bacterial sepsis. In bacterial sepsis, systemic inflammation affecting multiple organs is more dominant than in COVID-19 sepsis. While bacterial sepsis causes an early and sudden onset clinical deterioration, viral diseases may exhibit a relatively late onset and chronic course. Consideration of severe COVID-19 disease as a sepsis syndrome has relevance and may assist in terms of determining treatments that will modulate the immune response, limit intrinsic damage to tissue and organs, and potentially improve outcome.

Hemoperfusion and blood purification strategies in patients with COVID-19: A systematic review

BACKGROUND

Coronavirus disease-19 (COVID-19) ranges from asymptomatic infection to severe cases requiring admission to the intensive care unit. Together with supportive therapies (ventilation in particular), the suppression of the pro-inflammatory state has been a hypothesized target. Pharmacological therapies with corticosteroids and interleukin-6 (IL-6) receptor antagonists have reduced mortality. The use of extracorporeal cytokine removal, also known as hemoperfusion (HP), could be a promising non-pharmacological approach to decrease the pro-inflammatory state in COVID-19.

METHODS

We conducted a systematic review of PubMed and EMBASE databases in order to summarize the evidence regarding HP therapy in COVID-19. We included original studies and case series enrolling at least five patients.

RESULTS

We included 11 articles and describe the characteristics of the populations studied from both clinical and biological perspectives. The methodological quality of the included studies was generally low. Only two studies had a control group, one of which included 101 patients in total. The remaining studies had a range between 10 and 50 patients included. There was large variability in the HP techniques implemented and in clinical and biological outcomes reported. Most studies described decreasing levels of IL-6 after HP treatment.

CONCLUSION

Our review does not support strong conclusions regarding the role of HP in COVID-19. Considering the very low level of clinical evidence detected, starting HP therapies in COVID-19 patients does not seem supported outside of clinical trials. Prospective randomized data are needed.

Human factors in ECLS - A keystone for safety and quality - A narrative review for ECLS providers

INTRODUCTION

Although the technology used for extracorporeal life support (ECLS) has improved greatly in recent years, the application of these devices to the patient is quite complex and requires extensive training of team members both individually and together. Human factors is an area that addresses the activities, contexts, environments, and tools which interact with human behavior in determining overall system performance.

HYPOTHESIS

Analyses of the cognitive behavior of ECLS teams and individual members of these teams with respect to the occurrence of human errors may identify additional opportunities to enhance safety in delivery of ECLS.

RESULTS

The aim of this article is to support health-care practitioners who perform ECLS, or who are starting an ECLS program, by establishing standards for the safe and efficient use of ECLS with a focus on human factor issues. Other key concepts include the importance of ECLS team leadership and management, as well as controlling the environment and the system to optimize patient care.

CONCLUSION

Expertise from other industries is extrapolated to improve patient safety through the application of simulation training to reduce error propagation and improve outcomes.

Evaluation of cytokine response to extracorporeal membrane oxygenation

RATIONALE

Increased cytokine response is common in patients receiving extracorporeal life support and is often a poor prognostic indicator. There is interest in using adjunctive cytokine adsorption technologies to reduce inflammatory burden, However, it is debated whether extracorporeal membrane oxygenation (ECMO) itself provides therapeutic benefit beyond gas exchange. Thus, we sought to characterize the inflammatory profile of ECMO in the first 72-96 h of and quantify its effect on cytokine levels in a case series of patients undergoing ECMO.

METHODS

Eight patients initiating ECMO were studied. Of these, we measured cytokines pre- and post-oxygenator over 96 h. Comparisons of cytokine levels were made across the oxygenator and over time.

RESULTS

The average age of patients was 64.3 years with 62% being male. Centrally cannulated patients had higher IL-6 levels (820.43 vs. 6907.53 pg/ml, p < 0.03), whereas peripherally cannulated patients had higher IL-12p70 levels (7.73 vs. 2.59 pg/ml, p < 0.05). Cytokine levels on day one included IL-12p70 (4.17 ± 2.56), IL-6 (4971.23 ± 8569.88), TNF (undetected), IL-8 (346.68 ± 670.18), IL-1B (undetected), and IL-10 (72.27 ± 87.9). Cytokine levels increased over 96 h; however, no significant differences were appreciated despite blood product transfusion. On day 3, IL-12p70 levels were significantly lower post-oxygenator (p < 0.05).

CONCLUSION

The inflammatory profile of ECMO does not change significantly over the early course of illness when accounting for transfusion. However, the decrease in IL-12p70 specifically at day 3 of ECMO may indicate adsorption of specific inflammatory markers by the oxygenator although the clinical significance of this is still unknown. Further investigation of the oxygenator on cytokine response is warranted.

Hemoadsorption for management of patients on veno-venous ECMO support for severe COVID-19 acute respiratory distress syndrome

Background and Aim

Patients with severe coronavirus disease 2019 (COVID‐19) develop a profound cytokine‐mediated pro‐inflammatory response. This study reports outcomes in 10 patients with COVID‐19 supported on veno‐venous extracorporeal membrane oxygenation (VV‐ECMO) who were selected for the emergency use of a hemoadsorption column integrated in the ECMO circuit.

Materials and Methods

Pre and posttreatment, clinical data, and inflammatory markers were assessed to determine the safety and feasibility of using this system and to evaluate the clinical effect.

Results

During hemoadsorption, median levels of interleukin (IL)−2R, IL‐6, and IL‐10 decreased by 54%, 86%, and 64%, respectively. Reductions in other markers were observed for lactate dehydrogenase (−49%), ferritin (−46%), d‐dimer (−7%), C‐reactive protein (−55%), procalcitonin (−76%), and lactate (−44%). Vasoactive‐inotrope scores decreased significantly over the treatment interval (−80%). The median hospital length of stay was 53 days (36–85) and at 90‐days post cannulation, survival was 90% which was similar to a group of patients without the use of hemoadsorption.

Conclusions

Addition of hemoadsorption to VV‐ECMO in patients with severe COVID‐19 is feasible and reduces measured cytokine levels. However, in this small series, the precise impact on the overall clinical course and survival benefit still remains unknown.

Effect of artificial liver blood purification treatment on the survival of critical ill COVID-19 patients

Our aim was to investigate the effect of artificial liver blood purification treatment on the survival of severe/critical patients with coronavirus disease 2019 (COVID-19). A total of 101 severe and critical patients with coronavirus SARS-CoV-2 infection were enrolled in this open, case-control, multicenter, prospective study. According to the patients' and their families' willingness, they were divided into two groups. One was named the treatment group, in which the patients received artificial liver therapy plus comprehensive treatment (n = 50), while the other was named the control group, in which the patients received only comprehensive treatment (n = 51). Clinical data and laboratory examinations, as well as the 28-day mortality rate, were collected and analyzed. Baseline data comparisons on average age, sex, pre-treatment morbidity, initial symptoms, vital signs, pneumonia severity index score, blood routine examination and biochemistry indices etc. showed no difference between the two groups. Cytokine storm was detected, with a significant increase of serum interleukin-6 (IL-6) level. The serum IL-6 level decreased from 119.94 to 20.49 pg/mL in the treatment group and increased from 40.42 to 50.81 pg/mL in the control group (P < .05), indicating that artificial liver therapy significantly decreased serum IL-6. The median duration of viral nucleic acid persistence was 19 days in the treatment group (ranging from 6 to 67 days) and 17 days in the control group (ranging from 3 to 68 days), no significant difference was observed (P = .36). As of 28-day follow-up,17 patients in the treatment group experienced a median weaning time of 24 days, while 11 patients in the control group experienced a median weaning time of 35 days, with no significant difference between the two groups (P = .33). The 28-day mortality rates were 16% (8/50) in the treatment group and 50.98% (26/51) in the control group, with a significant difference (z = 3.70, P < .001). Cytokine storm is a key factor in the intensification of COVID-19 pneumonia. The artificial liver therapy blocks the cytokine storm by clearing inflammatory mediators, thus preventing severe cases from progressing to critically ill stages and markedly reducing short-term mortality.

Blood purification with CytoSorb in critically ill COVID-19 patients: A case series of 26 patients

Severe forms of the coronavirus disease 2019 (COVID‐19) can progress to sepsis‐like complications accompanied by “cytokine storm” for which the most effective treatment has not yet been established. Our study describes the results of CytoSorb hemoadsorption in COVID‐19 patients treated on the intensive care unit (ICU). In this retrospective study, 26 patients with COVID‐19 and acute respiratory distress syndrome (ARDS) were treated with hemoadsorption therapy. Pre‐, and post‐treatment values (clinical and laboratory) were compared. Data are expressed as mean (confidence intervals, CI), or median [interquartile ranges, IQR], as appropriate. Patients received 2 hemoadsorption treatments. This resulted in a significant decrease in norepinephrine requirements, and inflammatory marker plasma concentrations (procalcitonin, C‐reactive protein, ferritin) when comparing pre versus post treatment levels. The PaO₂/FiO₂ and overall organ function (ie, Sequential Organ Failure Assessment—SOFA score) also improved significantly. Patients stayed on the ICU for 9 days and 21 of them survived. To the best of our knowledge, this is one of the largest case series to date reporting early experiences on extracorporeal hemoadsorption therapy in SARS‐CoV‐2 positive patients with hyperinflammation and moderate ARDS. Treatment proved to be effective, technically feasible and well‐tolerated.

Opportunities, controversies, and challenges of extracorporeal hemoadsorption with CytoSorb during ECMO

Extracorporeal membrane oxygenation (ECMO) is frequently used in many centers around the globe for various indications. However, prognosis is often poor even with all supportive therapies, and in many cases, clinical deterioration is associated with inflammation. Hemoadsorption with CytoSorb is a novel approach to limit the inflammatory response, and the device can be safely and easily installed into ECMO circuits. CytoSorb has been used more than 130.000 times to date, but because randomized controlled trials are largely lacking, there is substantial debate on its use. Here, experts from critical care medicine, cardiology, cardiac surgery, and perfusion technology discuss the pros and cons of this novel therapy and outline the future aspects for its clinical application and research.

The use of therapeutic plasma exchange as adjunctive therapy in the treatment of coronavirus disease 2019: A critical appraisal of the current evidence

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a major pandemic. While vaccine development moves forward, optimal treatment continues to be explored. Efforts include an ever-expanding number of clinical trials along with newly proposed experimental and off-label investigational therapies; one of which is therapeutic plasma exchange (TPE). There have been a number of publications on TPE use as adjunctive therapy for coronavirus disease 2019 (COVID-19), but no prospective randomized controlled trials (RCTs) have been completed. This article critically appraises the current available evidence on TPE as a treatment modality for SARS-CoV-2 infection.

Role of extracorporeal membrane oxygenation in critically Ill COVID-19 patients and predictors of mortality

The role of extracorporeal membrane oxygenation (ECMO) in the management of critically ill COVID‐19 patients remains unclear. Our study aims to analyze the outcomes and risk factors from patients treated with ECMO. This retrospective, single‐center study includes 17 COVID‐19 patients treated with ECMO. Univariate and multivariate parametric survival regression identified predictors of survival. Nine patients (53%) were successfully weaned from ECMO and discharged. The incidence of in‐hospital mortality was 47%. In a univariate analysis, only four out of 83 pre‐ECMO variables were significantly different; IL‐6, PCT, and NT‐proBNP were significantly higher in non‐survivors than in survivors. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score was significantly higher in survivors. After a multivariate parametric survival regression, IL‐6, NT‐proBNP and RESP scores remained significant independent predictors, with hazard ratios (HR) of 1.069 [95%‐CI: 0.986‐1.160], P = .016 1.001 [95%‐CI: 1.000‐1.001], P = .012; and .843 [95%‐CI: 0.564‐1.260], P = .040, respectively. A prediction model comprising IL‐6, NT‐proBNP, and RESP score showed an area under the curve (AUC) of 0.87, with a sensitivity of 87.5% and 77.8% specificity compared to an AUC of 0.79 for the RESP score alone. The present study suggests that ECMO is a potentially lifesaving treatment for selected critically ill COVID‐19 patients. Considering IL‐6 and NT‐pro‐BNP, in addition to the RESP score, may enhance outcome predictions.

Coronavirus-associated kidney outcomes in COVID-19, SARS, and MERS: a meta-analysis and systematic review

OBJECTIVES

A meta-analysis and systematic review was conducted on kidney-related outcomes of three recent pandemics: SARS, MERS, and COVID-19, which were associated with potentially fatal acute respiratory distress syndrome (ARDS).

METHODS

A search of all published studies until 16 June 2020 was performed. The incidence/prevalence and mortality risk of acute and chronic renal events were evaluated, virus prevalence, and mortality in preexisting hemodialysis patients was investigated.

RESULTS

A total of 58 eligible studies involving 13452 hospitalized patients with three types of coronavirus infection were included. The reported incidence of new-onset acute kidney injury (AKI) was 12.5% (95% CI: 7.6%-18.3%). AKI significantly increased the mortality risk (OR = 5.75, 95% CI 3.75-8.77, p < 0.00001) in patients with coronavirus infection. The overall rate of urgent-start kidney replacement therapy (urgent-start KRT) use was 8.9% (95% CI: 5.0%-13.8%) and those who received urgent-start KRT had a higher risk of mortality (OR = 3.43, 95% CI 2.02-5.85, p < 0.00001). Patients with known chronic kidney disease (CKD) had a higher mortality than those without CKD (OR = 1.97, 95% CI 1.56-2.49, p < 0.00001). The incidence of coronavirus infection was 7.7% (95% CI: 4.9%-11.1%) in prevalent hemodialysis patients with an overall mortality rate of 26.2% (95% CI: 20.6%-32.6%).

CONCLUSIONS

Primary kidney involvement is common with coronavirus infection and is associated with significantly increased mortality. The recognition of AKI, CKD, and urgent-start KRT as major risk factors for mortality in coronavirus-infected patients are important steps in reducing future mortality and long-term morbidity in hospitalized patients with coronavirus infection.

Artificial lungs--Where are we going with the lung replacement therapy?

Lung transplantation may be a final destination therapy in lung failure, but limited donor organ availability creates a need for alternative management, including artificial lung technology. This invited review discusses ongoing developments and future research pathways for respiratory assist devices and tissue engineering to treat advanced and refractory lung disease. An overview is also given on the aftermath of the coronavirus disease 2019 pandemic and lessons learned as the world comes out of this situation. The first order of business in the future of lung support is solving the problems with existing mechanical devices. Interestingly, challenges identified during the early days of development persist today. These challenges include device-related infection, bleeding, thrombosis, cost, and patient quality of life. The main approaches of the future directions are to repair, restore, replace, or regenerate the lungs. Engineering improvements to hollow fiber membrane gas exchangers are enabling longer term wearable systems and can be used to bridge lung failure patients to transplantation. Progress in the development of microchannel-based devices has provided the concept of biomimetic devices that may even enable intracorporeal implantation. Tissue engineering and cell-based technologies have provided the concept of bioartificial lungs with properties similar to the native organ. Recent progress in artificial lung technologies includes continued advances in both engineering and biology. The final goal is to achieve a truly implantable and durable artificial lung that is applicable to destination therapy.