# Extracorporeal Carbon Dioxide Removal (ECCO₂R) as a Bridge to Extracorporeal Membrane Oxygenation (ECMO) in Severe H1N1-Associated Acute Respiratory Distress Syndrome (ARDS) in Morbid Obesity: A Case From a Resource-Limited Hospital

## TL;DR

A young woman with severe H1N1-related ARDS and morbid obesity was managed with ECCO₂R as a bridge to ECMO in a resource-limited hospital.

## Contribution

This case highlights ECCO₂R as a viable bridge to ECMO in severe ARDS with morbid obesity when ECMO is unavailable.

## Key findings

- ECCO₂R was used to support protective ventilation in a patient with refractory hypoxemia and permissive hypercapnia.
- Prone positioning and ECCO₂R were used together while awaiting ECMO in a resource-limited setting.
- H1N1-induced ARDS in morbid obesity presents unique ventilatory challenges requiring alternative support strategies.

## Abstract

We present the case of a young woman with morbid obesity who developed severe acute respiratory distress syndrome (ARDS) associated with influenza A H1N1 infection, who, despite providing volume-controlled ventilation strategies, with a positive end-expiratory pressure (PEEP) of 12 cmH₂O, tidal volume of 8 mL/kg of predicted body weight and sedation for Richmond Agitation-Sedation Scale (RASS) score of -3, persisted with refractory hypoxemia and permissive hypercapnia off targets. As stabilization therapy, the initiated veno-venous hemodiafiltration continued with ECCO₂R and cycles of at least 24 hours of prone positioning while awaiting referral to extracorporeal membrane oxygenation (ECMO). Influenza virus A subtype H1N1 has single-stranded RNA and displays on its surface two essential glycoproteins, hemagglutinin (cell adhesion) and neuraminidase (release of new virions), that, due to a dysregulated response of cytokines and proinflammatory factors coupled with increased viral replication, induce greater lung injury and risk of progression to severe ARDS. This medical condition continues to be a challenge for health personnel, with special difficulty in patients with conditions such as morbid obesity, where physiological parameters and ventilatory strategies may have significant variations. Given the severity of the cases and the lack of immediate ECMO availability, ECCO₂R may be an alternative for supporting and maintaining protective ventilatory measures, as mentioned in the case below.