Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study

ECMO is associated with decreased hospital mortality in COVID-19 ARDS

This study determined whether compared to conventional mechanical ventilation (MV), extracorporeal membrane oxygenation (ECMO) is associated with decreased hospital mortality or fibrotic changes in patients with COVID-19 acute respiratory distress syndrome. A cohort of 72 patients treated with ECMO and 390 with conventional MV were analyzed (February 2020-December 2021). A target trial was emulated comparing the treatment strategies of initiating ECMO vs no ECMO within 7 days of MV in patients with a PaO2/FiO2 < 80 or a PaCO2 ≥ 60 mmHg. A total of 222 patients met the eligibility criteria for the emulated trial, among whom 42 initiated ECMO. ECMO was associated with a lower risk of hospital mortality (hazard ratio [HR], 0.56; 95% confidence interval [CI] 0.36-0.96). The risk was lower in patients who were younger (age < 70 years), had less comorbidities (Charlson comorbidity index < 2), underwent prone positioning before ECMO, and had driving pressures ≥ 15 cmH2O at inclusion. Furthermore, ECMO was associated with a lower risk of fibrotic changes (HR, 0.30; 95% CI 0.11-0.70). However, the finding was limited due to relatively small number of patients and differences in observability between the ECMO and conventional MV groups.

Extracorporeal Membrane Oxygenation in Immunocompromised Patients With Acute Respiratory Distress Syndrome-A Retrospective Cohort Study

Objective: Although the negative impact of immunosuppression on survival in patients with acute respiratory distress syndrome (ARDS) treated by extracorporeal membrane oxygenation (ECMO) is well known, short-term outcomes such as successful weaning rate from ECMO and subgroups benefit most from ECMO remain to be determined. The aims of this study were (1) to identify the association between immunocompromised status and weaning from ECMO in patients of ARDS, and (2) to identify subgroups of immunocompromised patients who may benefit from ECMO.

Methods: This retrospective cohort study enrolled patients who received ECMO for ARDS from 2010 to 2020. Immunocompromised status was defined as having a hematological malignancy, active solid tumor, solid organ transplant, or autoimmune disease.

Results: This study enrolled 256 ARDS patients who received ECMO, of whom 68 were immunocompromised. The multivariable analysis showed that immunocompromised status was not independently associated with failure to wean from ECMO. In addition, the patients with an autoimmune disease (14/24, 58.3%) and organ transplantation (3/3, 100%) had a numerically higher weaning rate from ECMO than other immunocompromised patients. For causes of ARDS, most patients with pulmonary hemorrhage (6/8, 75%) and aspiration (5/9, 55.6%) could be weaned from ECMO, compared to only a few of the patients with interstitial lung disease (2/9, 22.2%) and sepsis (1/4, 25%).

Conclusions: Immunocompromised status was not an independent risk factor of failure to wean from ECMO in patients with ARDS. For patients with pulmonary hemorrhage and aspiration-related ARDS, ECMO may be beneficial as bridge therapy.

Comparison of prone positioning and extracorporeal membrane oxygenation in acute respiratory distress syndrome: A multicenter cohort study and propensity-matched analysis

Background/Purpose

Both prone positioning and extracorporeal membrane oxygenation (ECMO) are used as rescue therapies for severe hypoxemia in patients with acute respiratory distress syndrome (ARDS). This study compared outcomes between patients with severe influenza pneumonia-related ARDS who received prone positioning and those who received ECMO.

Methods

This retrospective cohort study included eight tertiary referral centers in Taiwan. All patients who were diagnosed as having influenza pneumonia-related severe ARDS were enrolled between January and March 2016. We collected their demographic data and prone positioning and ECMO outcomes from medical records.

Results

In total, 263 patients diagnosed as having ARDS were included, and 65 and 53 of them received prone positioning and ECMO, respectively. The baseline PaO₂/FiO₂ ratio, Acute Physiology and Chronic Health Evaluation II score and Sequential Organ Failure Assessment score did not significantly differ between the two groups. The 60-day mortality rate was significantly higher in the ECMO group than in the prone positioning group (60% vs. 28%, p = 0.001). A significantly higher mortality rate was still observed in the ECMO group after propensity score matching (59% vs. 36%, p = 0.033). In the multivariate Cox regression analysis, usage of prone positioning or ECMO was the single independent predictor for 60-day mortality (hazard ratio: 2.177, p = 0.034).

Conclusion

While the patients receiving prone positioning had better outcome, the causality between prone positioning and the prognosis is unknown. However, the current data suggested that patients with influenza-related ARDS may receive prone positioning before ECMO support.

Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis

BACKGROUND

Prone positioning (PP) improves oxygenation and respiratory mechanics and is associated with lower mortality in patients with moderate to severe acute respiratory distress syndrome (ARDS). Despite this, some patients develop refractory hypoxemia and hypercapnia requiring venovenous extracorporeal membrane oxygenation (VV ECMO) support and are usually cared for in supine position. The physiologic and outcome benefits of routine PP of patients during VV ECMO remains unclear. Hence, we conducted the systematic review and meta-analysis to evaluate the outcome benefits of PP for patients with ARDS being treated with VV ECMO.

METHODS

After registration with PROSPERO (CRD42020199723), MEDLINE, EMBASE, Scopus and Cochrane databases were searched for relevant studies that reported PP in more than 10 adult patients supported with VV ECMO from origin to 1 March 2021. Studies were reviewed for quality using appropriate Joanna Briggs Institute (JBI) checklists, and certainty of evidence was assessed using the GRADE approach. The random-effects model (DerSimonian and Laird) was used. The primary outcome of interest was cumulative survival. Secondary outcomes were intensive care unit length of stay (ICU LOS) and ECMO duration. Changes in arterial blood gas (ABG) values, ventilator mechanics and complication rates were also studied.

RESULTS

Of 812 potentially relevant publications, 12 studies (640 patients) met our inclusion criteria. Due to overlapping study populations, 11 studies were included in the final meta-analysis. Cumulative survival in patients that underwent PP was 57% (95% CI 41.9-71.4, high certainty). Patients that underwent PP had longer ICU LOS (+ 14.5 days, 95% CI 3.4-25.7, p = 0.01) and ECMO duration (+ 9.6 days, 95% CI 5.5-13.7, p < 0.0001). After PP, patients had significantly higher PaO2/FiO2 ratio, lower PaCO2 and reduced ventilator driving pressure, and no major complications were reported.

CONCLUSIONS

PP during VV ECMO appears safe with a cumulative survival of 57% and may result in longer ECMO runs and ICU LOS. However, evidence from appropriately designed randomized trials is needed prior to widespread adoption of PP on VV ECMO.

Application of Hybrid Extracorporeal Membrane Oxygenation for the Treatment of Subsequent Shock following Acute Respiratory Distress Syndrome Developing after Firearm Injury

The use of extracorporeal membrane oxygenation (ECMO) in acute respiratory distress syndrome (ARDS) and cardio-circulatory shock has been widely accepted. In recent years, a variety of novel and exceptional indications for ECMO have been proposed; however, experience with ECMO use in the presence of multiple penetrating injuries is limited. In this report, we present successful ECMO application in a patient with multiple firearm injuries. Veno-venous ECMO was applied for ARDS and converted to the venoarterial mode when the patient developed septic cardiomyopathy. The clinical status of the patient gradually improved, and the patient was discharged from the hospital after 24 days, successfully.

Improvement in the survival rates of extracorporeal membrane oxygenation-supported respiratory failure patients: a multicenter retrospective study in Korean patients

Background

Although the utilization of extracorporeal membrane oxygenation (ECMO) is increasing and its technology is evolving, only a few epidemiologic reports have described the uses and outcomes of ECMO. The aim of this study was to investigate the changes in utilization and survival rate in patients supported with ECMO for severe respiratory failure in Korea.

Methods

This was a multicenter study on consecutive patients who underwent ECMO across 16 hospitals in Korea. The records of all patients who required ECMO for acute respiratory failure between 2012 and 2015 were retrospectively reviewed, and the utilization of ECMO was analyzed over time.

Results

During the study period, 5552 patients received ECMO in Korea as a whole, and a total of 2472 patients received ECMO at the participating 16 hospitals. We analyzed 487 (19.7%) patients who received ECMO for respiratory failure. The number of ECMO procedures provided for respiratory failure increased from 104 to 153 during the study period. The in-hospital survival rate increased from 30.8% to 35.9%. The use of prone positioning increased from 6.8% to 49.0% (p < 0.001), and the use of neuromuscular blockers also increased from 28.2% to 58.2% (p < 0.001). Multiple regression analysis showed that old age (OR 1.038 (95% CI 1.022, 1.054)), use of corticosteroid (OR 2.251 (95% CI 1.153, 4.397)), continuous renal replacement therapy (OR 2.196 (95% CI 1.135, 4.247)), driving pressure (OR 1.072 (95% CI 1.031, 1.114)), and prolonged ECMO duration (OR 1.020 (95% CI 1.003, 1.038)) were associated with increased odds of mortality.

Conclusions

Utilization of ECMO and survival rates of patients who received ECMO for respiratory failure increased over time in Korea. The use of pre-ECMO prone positioning and neuromuscular blockers also increased during the same period.

Extracellular histones indicate the prognosis in patients undergoing extracorporeal membrane oxygenation therapy

Introduction:

Extracellular histones have been recently identified as damage-associated molecular-pattern (DAMP) molecules involved with the pathogenesis of various inflammatory diseases. This study intended to investigate whether extracellular histones can indicate the prognosis in critically ill patients supported by extracorporeal membrane oxygenation (ECMO) therapy.

Methods:

A total of 56 patients undergoing ECMO were analysed retrospectively. Median concentrations of extracellular histones in patients before ECMO were assessed and used to divide the patients into two groups (Group 1 <48 µg/ml and Group 2 ⩾48 µg/ml). Mortality rate, Sequential Organ Failure Assessment (SOFA) scores and systemic inflammation were compared between the groups.

Results:

There were relatively higher concentrations of extracellular histones in Group 2 patients (57.78 µg/ml [48.4, 71.3]) than in Group 1 patients (36.76 µg/ml [28.5, 39.3], p<0.0001). The hospital mortality rate was 55.4% for the entire study subjects, with significantly worsened mortality in Group 2 in contrast to Group 1 (58.8% vs. 50%, p=0.031). Moreover, Group 2 patients had significantly higher SOFA scores and more pronounced systemic inflammation than Group 1 patients prior to ECMO initialization.

Conclusions:

Extracellular histones are known contributors to cell damage and organ injury. Our study showed that extracellular histones have a predictive value in the assessment of outcome of patients undergoing ECMO therapy and may be helpful for risk stratification in clinical settings.