Outcomes of Severe ARDS COVID-19 Patients Denied for Venovenous ECMO Support: A Prospective Observational Comparative Study

Background: Few data are available concerning the outcome of patients denied venovenous extracorporeal membrane oxygenation (VV-ECMO) relative to severe acute respiratory distress syndrome (ARDS) due to COVID-19. Methods: We compared the 90-day survival rate of consecutive adult patients for whom our center was contacted to discuss VV-ECMO indication. Three groups of patients were created: patients for whom VV-ECMO was immediately indicated (ECMO-indicated group), patients for whom VV-ECMO was not indicated at the time of the call (ECMO-not-indicated group), and patients for whom ECMO was definitely contraindicated (ECMO-contraindicated group). Results: In total, 104 patients were referred for VV-ECMO support due to severe COVID-19 ARDS. Among them, 32 patients had immediate VV-ECMO implantation, 28 patients had no VV-ECMO indication, but 1 was assisted thereafter, and 44 patients were denied VV-ECMO for contraindication. Among the 44 patients denied, 30 were denied for advanced age, 24 for excessive prior duration of mechanical ventilation, and 16 for SOFA score >8. The 90-day survival rate was similar for the ECMO-indicated group and the ECMO-not-indicated group at 62.1 and 61.9%, respectively, whereas it was significantly lower (20.5%) for the ECMO-contraindicated group. Conclusions: Despite a low survival rate, 50% of patients were at home 3 months after being denied for VV-ECMO for severe ARDS due to COVID-19.

Response to Prone Position in COVID-19 and Non-COVID-19 Patients with Severe ARDS Supported by vvECMO

BACKGROUND

For moderate to severe acute respiratory distress syndrome (ARDS), lung-protective ventilation combined with prolonged and repeated prone position (PP) is recommended. For the most severe patients for whom this strategy failed, venovenous extracorporeal membrane oxygenation (vv-ECMO) allows a reduction in ventilation-induced lung injury and improves survival. Some aggregated data have suggested a benefit regarding survival in pursuing PP during vv-ECMO. The combination of PP and vv-ECMO has been also documented in COVID-19 studies, although there is scarce evidence concerning respiratory mechanics and gas exchange response. The main objective was to compare the physiological response of the first PP during vv-ECMO in two cohorts of patients (COVID-19-related ARDS and non-COVID-19 ARDS) regarding respiratory system compliance (C_RS) and oxygenation changes.

METHODS

This was a single-center, retrospective, and ambispective cohort study in the ECMO center of Marseille, France. ECMO was indicated according to the EOLIA trial criteria.

RESULTS

A total of 85 patients were included, 60 in the non-COVID-19 ARDS group and 25 in the COVID-19-related ARDS group. Lung injuries of the COVID-19 cohort exhibited significantly higher severity with a lower C_RS at baseline. Concerning the main objective, the first PP during vv-ECMO was not associated with a change in C_RS or other variation in respiratory mechanic variables in both cohorts. By contrast, oxygenation was improved only in the non-COVID-19 ARDS group after a return to the supine position. Mean arterial pressure was higher during PP as compared with a return to the supine position in the COVID-19 group.

CONCLUSION

We found distinct physiological responses to the first PP in vv-ECMO-supported ARDS patients according to the COVID-19 etiology. This could be due to higher severity at baseline or specificity of the disease. Further investigations are warranted.

Timing of Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

OBJECTIVES

To assess the association of timing to prone positioning (PP) during venovenous extracorporeal membrane oxygenation (V-V ECMO) with the probability of being discharged alive from the ICU at 90 days (primary endpoint) and the improvement of the respiratory system compliance (Cpl,rs).

DESIGN

Pooled individual data analysis from five original observational cohort studies.

SETTING

European extracorporeal membrane oxygenation (ECMO) centers.

PATIENTS

Acute respiratory distress syndrome (ARDS) patients who underwent PP during ECMO.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Time to PP during V-V ECMO was explored both as a continuous and a categorical variable with Cox proportional hazard models. Three hundred patients were included in the analysis. The longer the time to PP during V-V ECMO, the lower the adjusted probability of alive ICU discharge (adjusted hazard ratio [HR] 0.90 for each day increase; 95% CI, 0.87-0.93). Two hundred twenty-three and 77 patients were included in the early PP (≤ 5 d) and late PP (> 5 d) groups, respectively. The cumulative 90-day probability of being discharged alive from the ICU was 61% in the early PP group vs 36% in the late PP group (log-rank test, p <0.001). This benefit was maintained after adjustment for confounders (adjusted HR, 2.52; 95% CI, 1.66-3.81; p <0.001). In the early PP group, PP was associated with a significant improvement of Cpl,rs (4 ± 9 mL/cm H2O vs 0 ± 12 in the late PP group, p=0.038).

CONCLUSIONS

In a large cohort of ARDS patients on ECMO, early PP during ECMO was associated with a higher probability of being discharged alive from the ICU at 90 days and a greater improvement of Cpl,rs.

Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a pooled individual patient data analysis

BACKGROUND

Prone positioning (PP) reduces mortality of patients with acute respiratory distress syndrome (ARDS). The potential benefit of prone positioning maneuvers during venovenous extracorporeal membrane oxygenation (ECMO) is unknown. The aim of this study was to evaluate the association between the use of prone positioning during extracorporeal support and ICU mortality in a pooled population of patients from previous European cohort studies.

METHODS

We performed a pooled individual patient data analysis of European cohort studies which compared patients treated with prone positioning during ECMO (Prone group) to "conventional" ECMO management (Supine group) in patients with severe ARDS.

RESULTS

889 patients from five studies were included. Unadjusted ICU mortality was 52.8% in the Supine Group and 40.8% in the Prone group. At a Cox multiple regression analysis PP during ECMO was not significantly associated with a reduction of ICU mortality (HR 0.67 95% CI: 0.42-1.06). Propensity score matching identified 227 patients in each group. ICU mortality of the matched samples was 48.0% and 39.6% for patients in the Supine and Prone group, respectively (p = 0.072).

CONCLUSIONS

In a large population of ARDS patients receiving venovenous extracorporeal support, the use of prone positioning during ECMO was not significantly associated with reduced ICU mortality. The impact of this procedure will have to be definitively assessed by prospective randomized controlled trials.

Outcomes of patients with decreased arterial oxyhaemoglobin saturation on pulmonary arterial hypertension drugs

RATIONALE

Drugs approved for the treatment of pulmonary arterial hypertension (PAH) improve long-term outcomes. These drugs have pulmonary vasodilator properties which may potentially cause a decrease in arterial oxyhaemoglobin saturation (SaO₂) in some patients.

OBJECTIVES

The present retrospective study of the French PAH Registry aimed to describe clinical characteristics and outcomes of patients showing a ≥3% decrease in SaO₂ while treated with PAH drugs.

METHODS

We reviewed 719 PAH patients. The exclusion criteria were PAH associated with congenital heart disease and PAH with overt features of venous/capillaries involvement.

MAIN RESULTS

One hundred and seventy-three (24%) patients had a ≥3% decrease in SaO₂. At diagnosis, they were older, with a lower diffusion capacity for carbon monoxide and a shorter 6-minute walk distance, when compared to those who did not display a ≥3% decrease in SaO₂. The percentage of patients meeting the ESC/ERS low risk criteria at re-evaluation was significantly lower in those with a ≥3% decrease in SaO₂ and more patients started long-term oxygen therapy in this group (16% versus 5%, p<0.001). A≥3% decrease in SaO₂ was associated with a poorer survival (Hazard Ratio 1.81:95% confidence interval 1.43-2.34; p<0.0001). In a multivariate Cox analysis, a ≥3% decrease in SaO₂ was a prognostic factor independent of age at diagnosis and ESC/ERS risk stratification at follow-up.

CONCLUSIONS

When treated with PAH drugs, a large subset of patients experience a≥3% decrease in SaO₂, which is associated with worst long-term outcomes and reduced survival.