The following is a summary of “Identification of novel sub-phenotypes of severe ARDS requiring ECMO using latent class analysis,” published in the October 2024 issue of Critical Care by Nishikimi et al.  

Breaking ARDS down into different subtypes could help assess its severity or predict how well patients will respond to treatments. However, limited research exists on the diversity among patients with severe ARDS needing veno-venous extracorporeal membrane oxygenation (V-V ECMO).  

Researchers conducted a retrospective study exploring the varied characteristics of severe patients with ARDS who require V-V ECMO, aiming to provide insights for better treatment evaluation and responsiveness predictions.   

They included patients with severe ARDS receiving V-V ECMO using latent class analysis (LCA) based on initial radiological and clinical data, and researchers identified ARDS sub-phenotypes. Mortality differences and associations with positive end-expiratory pressure (PEEP) settings (≥10 cm H₂O) were analyzed via multivariate Cox regression.   

The results showed that 544 patients with severe ARDS were treated with V-V ECMO, and 3 sub-phenotypes emerged: Dry type (185, 34%), Wet type (169,31%), and Fibrotic type (190, 35%). Patients with the Fibrotic type had a higher 90-day in-hospital mortality risk compared to those with the Dry type (aHR 1.75 [95% CI: 1.10-2.79], P =0.019) and Wet type (1.50 [1.02-2.23], P=0.042). The PEEP was observed ≥10 cm H₂O during the first 3 days, with reduced mortality only in Wet type patients. A significant interaction was noted between Wet type and PEEP ≥10 cm H₂O on 90-day mortality (P_interaction=0.036).   

Investigators concluded that the three ARDS sub-phenotypes had varying mortality rates and responses to early high PEEP settings during V-V ECMO. This suggests that severe ARDS management may benefit from adjustments based on each patient’s specific sub-phenotype.  

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-05143-3