Role of age as eligibility criterion for ECMO in patients with ARDS: meta-regression analysis.

BACKGROUND: Age as an eligibility criterion for V-V ECMO is widely debated and varies among healthcare institutions. We examined how age relates to mortality in patients undergoing V-V ECMO for ARDS. METHODS: Systematic review and meta-regression of clinical studies published between 2015 and June 2024. Studies involving at least 6 ARDS patients treated with V-V ECMO, with specific data on ICU and/or hospital mortality and patient age were included. The search strategy was executed in PubMed, limited to English-language. COVID-19 and non-COVID-19 populations were analyzed separately. Meta-regressions of mortality outcomes on age were performed using gender, BMI, SAPS II, APACHE II, Charlson comorbidity index or SOFA as covariates. RESULTS: In non-COVID ARDS, the meta-regression of 173 studies with 56,257 participants showed a significant positive association between mean age and ICU/hospital mortality. In COVID-19 ARDS, a significant relationship between mean age and ICU mortality, but not hospital mortality, was found in 103 studies with 21,255 participants. Sensitivity analyses confirmed these findings, highlighting a linear relationship between age and mortality in both groups. For each additional year of mean age, ICU mortality increased by 1.2% in non-COVID ARDS and 1.9% in COVID ARDS. CONCLUSIONS: The relationship between age and ICU mortality is linear and shows no inflection point. Consequently, no age cut-off can be recommended for determining patient eligibility for V-V ECMO.

Arterial oxygen pressure during veno-venous extracorporeal membrane oxygenation may be increased by advancing the tip of the drainage cannula into the superior vena cava: a case report.

A simple and robust method for veno-venous extracorporeal membrane oxygenation (V-V ECMO) involves a drainage cannula into the inferior vena cava via the femoral vein (FV) and a reinfusion cannula into the right atrium (RA) via the internal jugular vein (IJV) (F-J configuration). However, with this method, the arterial oxygen (PaO2) is said to remain below 100 mmHg.Since recently, in our ICU, to prevent drainage failure, we apply a modification from the commonly practiced F-J configuration by advancing the tip of the drainage cannula inserted via the FV into the superior vena cava (SVC) and crossing the reinfusion cannula inserted via the IJV in the RA (F(SVC)-J(RA) configuration). We experienced that this modification can be associated with unexpectedly high PaO2 values, which here we investigated in detail.Veno-arteriovenous ECMO was induced in a 65-year-old male patient who suffered from repeated cardiac arrest due to acute respiratory distress syndrome. His chest X-ray images showed white-out after lung rest setting, consistent with near-absence of self-lung ventilation. Cardiac function recovered and the system was converted to F(SVC)-J(RA) configuration, after which both PaO2 and partial pressure of pulmonary arterial oxygen values remained high above 200 mmHg. Transesophageal echocardiography could not detect right-to-left shunt, and more efficient drainage of the native venous return flow compared to common F-J configuration may explain the increased PaO2.Although the F(SVC)-J(RA) configuration is a small modification of the F-J configuration, it seems to provide a revolutionary improvement in the ECMO field by combining robustness/simplicity with high PaO2 values.

New Insights into Hepatic and Intestinal Microcirculation and Pulmonary Inflammation in a Model of Septic Shock and Venovenous Extracorporeal Membrane Oxygenation in the Rat.

Treatment of critically ill patients with venovenous (V-V) extracorporeal membrane oxygenation (ECMO) has gained wide acceptance in the last few decades. However, the use of V-V ECMO in septic shock remains controversial. The effect of ECMO-induced inflammation on the microcirculation of the intestine, liver, and critically damaged lungs is unknown. Therefore, the aim of this study was to measure the hepatic and intestinal microcirculation and pulmonary inflammatory response in a model of V-V ECMO and septic shock in the rat. Twenty male Lewis rats were randomly assigned to receive V-V ECMO therapy or a sham procedure. Hemodynamic data were measured by a pressure-volume catheter in the left ventricle and a catheter in the lateral tail artery. Septic shock was induced by the intravenous infusion of lipopolysaccharide (1 mg/kg). During V-V ECMO therapy, rats received lung-protective ventilation. The hepatic and intestinal microcirculation was assessed by micro-lightguide spectrophotometry after median laparotomy for 2 h. Systemic and pulmonary inflammation was measured by enzyme-linked immunosorbent assays of plasma and bronchoalveolar lavage (BAL), respectively, which included tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), IL-10, C-X-C motif ligand 2 (CXCL2), and CXCL5. Reduced oxygen saturation and relative hemoglobin concentration were measured in the hepatic and intestinal microcirculation during treatment with V-V ECMO. These animals also showed increased systolic, mean, and diastolic blood pressures. While no differences in left ventricular ejection fraction were observed, animals in the V-V ECMO group presented an increased heart rate, stroke volume, and cardiac output. Blood gas analysis showed dilutional anemia during V-V ECMO, whereas plasma analysis revealed a decreased concentration of IL-10 during V-V ECMO therapy, and BAL measurements showed increased concentrations of TNF-α, CXCL2, and CXCL5. Rats treated with V-V ECMO showed impaired microcirculation of the intestine and liver during septic shock despite increased blood pressure and cardiac output. Despite lung-protective ventilation, increased pulmonary inflammation was recognized during V-V ECMO therapy in septic shock.

Dual lumen cannulation and mobilization of patients with venovenous extracorporeal membrane oxygenation.

BACKGROUND: Mobilization is important in longer courses in intensive care unit (ICU), typical for patients requiring venovenous extracorporeal membrane oxygenation (V-V ECMO). For patients supported with ECMO, especially out-of-bed mobilizations improve outcome. We hypothesized that utilization of a dual lumen cannula (DLC) for V-V ECMO would facilitate out-of-bed mobilization compared to single lumen cannulas (SLC). METHODS: Retrospective single center registry study including all V-V ECMO patients cannulated between 10/2010 and 05/2021 for respiratory failure. RESULTS: The registry included 355 V-V ECMO patients (median age 55.6 years, 31.8% female, 27.3% with preexisting pulmonary disease), 289/355 (81.4%) primary cannulated with DLC, and 66/355 (18.6%) using SLC. Both groups had similar pre-ECMO characteristics. The runtime of the first ECMO cannula was significantly longer in DLC compared to SLC (169 vs. 115 h, p = 0.015). The frequency of prone positioning during V-V ECMO was similar in both groups (38.4 vs. 34.8%, p = 0.673). There was no difference in in-bed mobilization (41.2 vs. 36.4%, for DLC and SLC, respectively, p = 0.491). Patients with DLC were more often mobilized out-of-bed (25.6 vs. 12.1%, OR 2.495 [95% CI 1.150 to 5.268], for DLC and SLC, respectively, p = 0.023). Hospital survival was similar in both groups (46.4 vs. 39.4%, for DLC and SLC, respectively, p = 0.339). CONCLUSION: Patients cannulated with a dual lumen cannula for V-V ECMO support were significantly more often mobilized out-of-bed. Since mobilization is important in prolonged ICU courses typical for ECMO patients, this might be an important benefit. Other benefits of DLC were the longer runtime of the initial cannula set and fewer suction events.

Oncostatin M for characterizing the inflammatory burden and outcome of V-V ECMO in ARDS patients.

BACKGROUND: Assessing the outcome of Veno-Venous Extracorporeal Membrane Oxygenation (V-V ECMO) support remains challenging as plasma lactate (pLA), the widely used tool for this purpose, has been shown unreliable. We hypothesized that plasma oncostatin M (pOSM), a sensitive marker of leukocyte activation in infection and inflammation, could address this deficiency. METHODS: Plasma OSM levels were measured by ELISA in 30 Acute Respiratory Distress Syndrome (ARDS) patients, prior to cannulation (baseline) and decannulation. RESULTS: Based on the absolute pOSM levels at presentation, patients were separated into two groups, A and B. Patients in group A had low pOSM levels (Mean ± SD; Median, 1.1 ± 3.8; 0 pg/mL), whereas group B had high pOSM levels (1548 ± 1999; 767 pg/mL) [t-test: p < 0.01]. The percentage of pOSM levels at decannulation relative to baseline OSM levels was significantly higher in those who died (116.8 ± 68.0; 85.3%) than those who survived (47.6 ± 25.5; 48.9%) [t-test: p = 0.02; Mann-Whitney U Test: p = 0.01]. Conversely, no significant difference was observed in the percentage of pLA levels between those who died (142.9 ± 179.9; 89.8%) and those who survived (79.3 ± 34.3; 81.8%) [t-test: p = 0.31; Mann-Whitney U Test: p = 0.63]. CONCLUSION: These early findings suggested critical value of absolute and relative pOSM to characterize the inflammatory burden of ARDS patients and the outcome of their V-V ECMO support.

Validation of extracorporeal membrane oxygenation mortality prediction and severity of illness scores in an international COVID-19 cohort.

BACKGROUND: Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a lifesaving support modality for severe respiratory failure, but its resource-intensive nature led to significant controversy surrounding its use during the COVID-19 pandemic. We report the performance of several ECMO mortality prediction and severity of illness scores at discriminating survival in a large COVID-19 V-V ECMO cohort. METHODS: We validated ECMOnet, PRESET (PREdiction of Survival on ECMO Therapy-Score), Roch, SOFA (Sequential Organ Failure Assessment), APACHE II (acute physiology and chronic health evaluation), 4C (Coronavirus Clinical Characterisation Consortium), and CURB-65 (Confusion, Urea nitrogen, Respiratory Rate, Blood Pressure, age >65 years) scores on the ISARIC (International Severe Acute Respiratory and emerging Infection Consortium) database. We report discrimination via Area Under the Receiver Operative Curve (AUROC) and Area under the Precision Recall Curve (AURPC) and calibration via Brier score. RESULTS: We included 1147 patients and scores were calculated on patients with sufficient variables. ECMO mortality scores had AUROC (0.58-0.62), AUPRC (0.62-0.74), and Brier score (0.286-0.303). Roch score had the highest accuracy (AUROC 0.62), precision (AUPRC 0.74) yet worst calibration (Brier score of 0.3) despite being calculated on the fewest patients (144). Severity of illness scores had AUROC (0.52-0.57), AURPC (0.59-0.64), and Brier Score (0.265-0.471). APACHE II had the highest accuracy (AUROC 0.58), precision (AUPRC 0.64), and best calibration (Brier score 0.26). CONCLUSION: Within a large international multicenter COVID-19 cohort, the evaluated ECMO mortality prediction and severity of illness scores demonstrated inconsistent discrimination and calibration highlighting the need for better clinically applicable decision support tools.

Risk factors for bleeding complications during venovenous extracorporeal membrane oxygenation as a bridge to recovery.

BACKGROUND: Bleeding complications during venovenous extracorporeal membrane oxygenation (V-V ECMO) can be critical. However, there is limited information on the associated risk factors. This study investigated the risk factors for bleeding complications during V-V ECMO as a bridge to recovery. METHODS: This single-center retrospective study enrolled 59 patients (bleeding and non-bleeding groups) who received V-V ECMO from 2012 to 2020, to evaluate whether peak activated partial thromboplastin time (APTT) value, lowest platelet count, and mobilization to sitting on the edge of the bed during V-V ECMO were risk factors for bleeding complications, defined according to the Extracorporeal Life Support Organization guidelines. Age, sex, body mass index, Sequential Organ Failure Assessment score, and ECMO duration before bleeding complications were covariates in the multivariate logistic regression analysis. RESULTS: Thirty-one (53%) participants experienced 36 bleeding complications; the ECMO cannulation site, gastrointestinal tract, and nasopharyngeal region were the most common bleeding sites. The use of transfusion products and length of ECMO and intensive care unit stay were significantly and medical costs were non-significantly increased in the bleeding group. Peak APTT (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05, p < 0.01) was significantly associated whereas the lowest platelet count (OR 0.96, 95% CI 0.82-1.13, p = 0.66) was unassociated with bleeding complications during ECMO. Achieving mobilization (OR 0.14, 95% CI 0.02-1.17, p = 0.07) decreased the trend of risk for bleeding complications. CONCLUSIONS: Peak APTT might be an independent modifiable factor for bleeding complications during V-V ECMO. The protective effect of mobilization during V-V ECMO requires further investigation.

Outcomes after extracorporeal membrane oxygenation support in COVID-19 and non-COVID-19 patients.

BACKGROUND: Veno-venous extracorporeal membrane oxygenation (V-V ECMO) support is increasingly used in the management of COVID-19-related acute respiratory distress syndrome (ARDS). However, the clinical decision-making to initiate V-V ECMO for severe COVID-19 still remains unclear. In order to determine the optimal timing and patient selection, we investigated the outcomes of both COVID-19 and non-COVID-19 patients undergoing V-V ECMO support. METHODS: Overall, 138 patients were included in this study. Patients were stratified into two cohorts: those with COVID-19 and non-COVID-19 ARDS. RESULTS: The survival in patients with COVID-19 was statistically similar to non-COVID-19 patients (p = .16). However, the COVID-19 group demonstrated higher rates of bleeding (p = .03) and thrombotic complications (p < .001). The duration of V-V ECMO support was longer in COVID-19 patients compared to non-COVID-19 patients (29.0 ± 27.5 vs 15.9 ± 19.6 days, p < .01). Most notably, in contrast to the non-COVID-19 group, we found that COVID-19 patients who had been on a ventilator for longer than 7 days prior to ECMO had 100% mortality without a lung transplant. CONCLUSIONS: These findings suggest that COVID-19-associated ARDS was not associated with a higher post-ECMO mortality than non-COVID-19-associated ARDS patients, despite longer duration of extracorporeal support. Early initiation of V-V ECMO is important for improved ECMO outcomes in COVID-19 ARDS patients. Since late initiation of ECMO was associated with extremely high mortality related to lack of pulmonary recovery, it should be used judiciously or as a bridge to lung transplantation.

Veno-venous extracorporeal membrane oxygenation during COVID-19 pandemic: case series.

The course of COVID-19 with an incidence of 15-42% can be complicated by the development of acute respiratory distress syndrome (ARDS). The mortality rate with severe forms exceeds 60%, which sometimes requires extracorporeal methods of life support. AIM: The aim of this study was to analyse the therapeutic efficacy of V-V ECMO in patients with ARDS caused by SARS-CoV-2. MATERIALS AND METHODS: A retrospective analysis was performed in patients with acute lung injury caused by COVID-19 and treated with V-V ECMO within a period from February 2020 to May 2021 at the ECMO Center of the Heart Institute Ministry of Health of Ukraine. All patients had PCR testing for viral RNA particles using RT-PCR ELITe analyser. RESULTS: During this period, 7 cases reported of V-V ECMO for ARDS caused by COVID-19. Five of seven patients were urgently transferred to our ECMO Center from other medical institutions, while 2 patients were transferred to the hospital being already connected to ECMO, and one patient was connected to ECMO immediately after hospitalization. The most common ECMO complication was circuit thrombosis - 42.9% (3/7), which required oxygenator replacement - in 2 cases and circuit replacement - in 1 case. Three patients had bleeding at the cannulation site. ECMO mortality rate was 57.1% (4/ 7), while the 30-day mortality rate - 71.4% (5/7). CONCLUSIONS: In our case series, out of seven critically ill COVID-19 patients who required ECMO to maintain adequate oxygenation, inpatient mortality was observed in 71.4%.

Neurological complications during veno-venous extracorporeal membrane oxygenation: Does the configuration matter? A retrospective analysis of the ELSO database.

BACKGROUND: Single- (SL) and double-lumen (DL) catheters are used in clinical practice for veno-venous extracorporeal membrane oxygenation (V-V ECMO) therapy. However, information is lacking regarding the effects of the cannulation on neurological complications. METHODS: A retrospective observational study based on data from the Extracorporeal Life Support Organization (ELSO) registry. All adult patients included in the ELSO registry from 2011 to 2018 submitted to a single run of V-V ECMO were analyzed. Propensity score (PS) inverse probability of treatment weighting estimation for multiple treatments was used. The average treatment effect (ATE) was chosen as the causal effect estimate of outcome. The aim of the study was to evaluate differences in the occurrence and the type of neurological complications in adult patients undergoing V-V ECMO when treated with SL or DL cannulas. RESULTS: From a population of 6834 patients, the weighted propensity score matching included 6245 patients (i.e., 91% of the total cohort; 4175 with SL and 20,270 with DL cannulation). The proportion of patients with at least one neurological complication was similar in the SL (306, 7.2%) and DL (189, 7.7%; odds ratio 1.10 [95% confidence intervals 0.91-1.32]; p = 0.33). After weighted propensity score, the ATE for the occurrence of least one neurological complication was 0.005 (95% CI - 0.009 to 0.018; p = 0.50). Also, the occurrence of specific neurological complications, including intracerebral hemorrhage, acute ischemic stroke, seizures or brain death, was similar between groups. Overall mortality was similar between patients with neurological complications in the two groups. CONCLUSIONS: In this large registry, the occurrence of neurological complications was not related to the type of cannulation in patients undergoing V-V ECMO.

Thrombotic circuit complications during venovenous extracorporeal membrane oxygenation in COVID-19.

The novel coronavirus SARS-CoV-2 and the resulting disease COVID-19 causes pulmonary failure including severe courses requiring venovenous extracorporeal membrane oxygenation (V-V ECMO). Coagulopathy is a known complication of COVID-19 leading to thrombotic events including pulmonary embolism. It is unclear if the coagulopathy also increases thrombotic circuit complications of the ECMO. Aim of the present study therefor was to investigate the rate of V-V ECMO complications in COVID-19. We conducted a retrospective registry study including all patients on V-V ECMO treated at our centre between 01/2018 and 04/2020. COVID-19 cases were compared non- COVID-19 cases. All circuit related complications resulting in partial or complete exchange of the extracorporeal system were registered. In total, 66 patients were analysed of which 11 (16.7%) were SARS-CoV-2 positive. The two groups did not differ in clinical parameters including age (COVID-19 59.4 vs. non-COVID-19 58.1 years), gender (36.4% vs. 40%), BMI (27.8 vs. 24.2) and severity of illness as quantified by the RESP Score (1pt. vs 1pt.). 28 days survival was similar in both groups (72.7% vs. 58.2%). While anticoagulation was similar in both groups (p = 0.09), centrifugal pump head thrombosis was more frequent in COVID-19 (9/11 versus 16/55 p < 0.01). Neither the time to first exchange (p = 0.61) nor blood flow at exchange (p = 0.68) did differ in both groups. D-dimer levels prior to the thrombotic events were significantly higher in COVID-19 (mean 15.48 vs 26.59, p = 0.01). The SARS-CoV-2 induced infection is associated with higher rates of thrombotic events of the extracorporeal system during V-V ECMO therapy.

A case of massive hemoptysis caused by lung cancer saved by V-V ECMO and hemostasis achieved by radiotherapy.

Massive hemoptysis is one of the fatal complications of lung cancer. There is no established standard treatment method for it, and it often causes sudden suffocation, and some cases may be difficult to save. A 63-year-old man was admitted to the hospital with dyspnea, and developed massive hemoptysis from lung cancer shortly after admission. The tumor had obstructed the right main bronchus and had invaded the right pulmonary artery. Surgery and interventional radiology were judged impossible. The patient was successfully saved by the introduction of Veno-Venous Extra Corporeal Membrane Oxygenation (V-V ECMO), and hemostasis was obtained by radiotherapy. Two months after completion of radiotherapy, he was weaned off the ventilator and discharged on his own. He died of increased peritoneal dissemination and other complications 1 year and 1 month later, but no recurrence of hemoptysis was noted until his death. We experienced a case of massive hemoptysis in which V-V ECMO and radiation therapy succeeded in saving life and stopping bleeding. The use of V-V ECMO by emergency care teams and multimodality therapy, including radiotherapy, were effective for massive hemoptysis from lung cancer.

Safety of Supraclavicular Approach for Dual-Lumen Catheter Placement in Veno-Venous Extracorporeal Membrane Oxygenation: A Case Report.

In veno-venous extracorporeal membrane oxygenation (V-V ECMO), the dual-lumen catheter (DLC) facilitates mobility, reduces recirculation, and mitigates the risk of infection. The right internal jugular vein (IJV) is the most common site for DLC insertion. Still, it is often unavailable for various reasons, including local infection, hematoma, or thrombus. A 64-year-old male patient with mantle lymphoma, which was in remission after autogenous blood transplantation, suffered lung damage and refractory pneumothorax from coronavirus disease 2019 (COVID-19) and required V-V ECMO treatment initiated on day 39. The patient was unable to be weaned off V-V ECMO due to uncontrolled high serum carbon dioxide (CO2) concentration and required long-term V-V ECMO treatment for more than 80 days. DLC placement was necessary to implement aggressive rehabilitation, reduce puncture site-induced infections, and reduce recirculation. On day 119, a supraclavicular approach was used for DLC placement under fluoroscopic guidance using ultrasound guidance because a thrombus in the right IJV prevented the DLC insertion at a usual puncture site. Rehabilitation was safely performed at a higher intensity than preoperatively of DLC insertion. Overall, the DLC catheter was maintained for more than 30 days until the patient died due to septic shock by an unknown focus on day 150, with no complications such as bleeding or infection. This case report highlights the significance of using the supraclavicular approach for DLC placement in V-V ECMO in cases where IJV is not possible due to thrombus presence. In conclusion, the supraclavicular approach is safe and feasible for V-V ECMO insertion as an alternative to the IJV.

Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome With COVID-19: A Meta-Analysis.

The available literature has furnished substantial evidence indicating the favorable outcomes of prone positioning (PP) on oxygenation parameters among patients afflicted with coronavirus disease 2019 (COVID-19). However, there is a notable disparity in the reported influence of PP on the overall outcomes of COVID-19 patients undergoing venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS) across studies. This article has been prepared in adherence with Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. MEDLINE, Embase, and Cochrane databases were utilized for data retrieval. The primary endpoint was to evaluate the cumulative survival rate among COVID-19 patients receiving V-V ECMO, comparing those who received PP to those who did not. Secondary endpoints included the duration of intensive care unit (ICU) stay, ECMO duration, and mechanical ventilation duration. A total of 15 studies involving 2286 patients were analyzed in the meta-analysis. PP significantly improved the cumulative survival rate (0.48, 95% CI: 0.40-0.55); risk ratio (RR) of 1.24 (95% CI: 1.11-1.38).PP during ECMO for COVID-19 patients yielded favorable outcomes in terms of 60-day survival, 90-day survival, ICU survival, and hospital survival. In contrast, patients who underwent PP had longer ECMO duration (8.1 days, 95% CI: 6.2-9.9, p<0.001) and mechanical ventilation duration (9.6 days, 95% CI: 8.0-11.2, p<0.001). PP demonstrated improved survival in COVID-19 patients with ARDS receiving V-V ECMO. However, additional well-designed prospective trials are warranted to further explore the effects of this combination on survival outcomes in COVID-19 patients.

Current knowledge gaps in extracorporeal respiratory support.

Extracorporeal life support (ECLS) for acute respiratory failure encompasses veno-venous extracorporeal membrane oxygenation (V-V ECMO) and extracorporeal carbon dioxide removal (ECCO2R). V-V ECMO is primarily used to treat severe acute respiratory distress syndrome (ARDS), characterized by life-threatening hypoxemia or ventilatory insufficiency with conventional protective settings. It employs an artificial lung with high blood flows, and allows improvement in gas exchange, correction of hypoxemia, and reduction of the workload on the native lung. On the other hand, ECCO2R focuses on carbon dioxide removal and ventilatory load reduction ("ultra-protective ventilation") in moderate ARDS, or in avoiding pump failure in acute exacerbated chronic obstructive pulmonary disease. Clinical indications for V-V ECLS are tailored to individual patients, as there are no absolute contraindications. However, determining the ideal timing for initiating extracorporeal respiratory support remains uncertain. Current ECLS equipment faces issues like size and durability. Innovations include intravascular lung assist devices (ILADs) and pumpless devices, though they come with their own challenges. Efficient gas exchange relies on modern oxygenators using hollow fiber designs, but research is exploring microfluidic technology to improve oxygenator size, thrombogenicity, and blood flow capacity. Coagulation management during V-V ECLS is crucial due to common bleeding and thrombosis complications; indeed, anticoagulation strategies and monitoring systems require improvement, while surface coatings and new materials show promise. Moreover, pharmacokinetics during ECLS significantly impact antibiotic therapy, necessitating therapeutic drug monitoring for precise dosing. Managing native lung ventilation during V-V ECMO remains complex, requiring a careful balance between benefits and potential risks for spontaneously breathing patients. Moreover, weaning from V-V ECMO is recognized as an area of relevant uncertainty, requiring further research. In the last decade, the concept of Extracorporeal Organ Support (ECOS) for patients with multiple organ dysfunction has emerged, combining ECLS with other organ support therapies to provide a more holistic approach for critically ill patients. In this review, we aim at providing an in-depth overview of V-V ECMO and ECCO2R, addressing various aspects of their use, challenges, and potential future directions in research and development.

Mechanisms of limitation of oxygen delivery during veno-venous extracorporal membrane oxygenation.

Delivery of oxygen to the mitochondrium is a process involving multiple steps. We here present the integration of the mechanisms of oxygen delivery (DO2) during veno-venous (V-V) extracorporal membrane oxygenation (ECMO) into a holistic physiological model. The final steps of oxygen transport in this model are the convective transport of oxygen bound to hemoglobin in the arterial blood and the diffusion to the mitochondrium from the microcirculation. Limitation of DO2 may occur on both steps. In cases of severe respiratory failure without lung function, ECMO may provide the entire oxygen supply for the patients. If the cardiac output (CO) is significantly higher than the maximal ECMO flow, the addition of deoxygenated venous blood will lead to a low arterial oxygen saturation (SaO2). In this situation the convective transport of oxygen is mostly limited by the maximal ECMO flow. If a bi-caval dual lumen cannula is used, the recirculation may be very low. Lowering the CO in this situation will increase the arterial SaO2. An increased arterial SaO2 may increase the oxygen transport to the mitochondrium by diffusion. The hypothesis derived from this model is that lowering the CO during V-V ECMO support in the situation described above might increase DO2 to the tissues by improving oxygen diffusion.

Impact of prone positioning duration on the outcome of patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: A meta-analysis.

Purpose: Research has shown that prone positioning (PP) improves the survival of patients receiving venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS). However, the reported impact of PP duration on the outcome of V-V ECMO patients with ARDS varies across studies. Methods: A meta-analysis approach was used to identify studies that investigated the impact of PP duration on the outcome of ARDS patients who were treated with V-V ECMO; the following databases were used: MEDLINE, Embase, Wanfang, and the China National Knowledge Infrastructure. The primary outcome was cumulative survival. Secondary outcomes were length of stay in an intensive care unit, exchange of arterial blood gases, and adverse events. Results: A total of 8 studies were included in the final meta-analysis. Patients with longer duration of PP (≥12 h) had a longer survival period (risk ratio: 1.24; 95% confidence interval: 1.00, 1.54]) than those with PP < 12 h. There was no evidence of publication bias across the studies. Conclusion: Our results imply that a longer duration of PP ≥ 12 h might improve the outcome of patients with ARDS who receive V-V ECMO therapy.

Vasoactive Inotropic Score as a Prognostic Factor during (Cardio-) Respiratory ECMO.

The vasoactive inotropic score (VIS) is calculated as a weighted sum of all administered vasopressor and inotropic medications and quantifies the amount of pharmacological cardiovascular support in patients with the most severe combined cardiopulmonary failure supported with extracorporeal membrane oxygenation (ECMO). This study evaluated (1) whether VIS prior to the initiation of ECMO is an independent predictor of survival in these patients and (2) whether VIS might guide the selection of the appropriate extracorporeal cannulation modality (Veno-Venous 'V-V' or Veno-VenoArterial 'V-VA'). In this study, 39 V-VA and 182 V-V ECMO runs were retrospectively analyzed. VIS immediately prior to ECMO initiation (pre-ECMO) was 40 (10/113) in all patients, 30 (10/80) in patients with V-V ECMO and 207 (60/328) in patients with V-VA ECMO. Pre-ECMO VIS was an independent predictor of survival in univariate (AUC = 0.68, p = 0.001) and multi-variable analyses (p = 0.02). Pre-ECMO VIS was clearly associated with mortality (p = 0.001) in V-V ECMO group; however, V-VA ECMO disrupted this association (p = 0.18). Therefore, in conjunction with echocardiography, VIS might assist in selecting the appropriate ECMO cannulation strategy as patients with a pre-ECMO VIS ≥ 61.4 had significantly lower odds of survival compared to those with lower VIS.

The use of veno-venous extracorporeal membrane oxygenation for massive hemoptysis following a traumatic lung injury: a case report.

BACKGROUND: Published reports regarding the use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) for massive hemoptysis following a thoracic injury are still scarce. CASE PRESENTATION: A 34-year-old man developed massive hemoptysis from the right lung after a 2 m fall and being compressed with an iron pipe weighing 500 kg. He was immediately intubated using a double-lumen tube, and one-lung ventilation was started. Endotracheal hemorrhage was controlled by sealing the right lumen. V-V ECMO was initiated to endure the lethal hypoxemia while waiting for the right lung to heal. He came off of V-V ECMO after 17 days and was discharged on foot on day 46. CONCLUSION: The strategy of using V-V ECMO in combination with one-lung ventilation is useful and should be strongly considered to save lethal massive hemoptysis cases following traumatic lung injury.