Minimally invasive extracorporeal CO₂ removal in hypercapnic respiratory failure: a prospective observational study

Lung-protective ventilation in acute respiratory distress syndrome (ARDS) can lead to hypercapnia, an independent risk factor for increased mortality. Extracorporeal CO₂ removal (ECCO₂R) enables further reduction of ventilator intensity, but its routine use is limited due to safety concerns. In the current study, we evaluated the feasibility, efficacy, and safety of minimally invasive ECCO₂R (miECCO₂R) implemented via a renal replacement therapy (RRT) platform in patients with mild-to-moderate ARDS and refractory hypercapnia.

In this prospective single-center observational study, 20 ICU patients with persistent hypercapnia despite escalated ventilation received either standalone miECCO₂R (n = 11) or miECCO₂R combined with continuous RRT (n = 9). As a primary outcome, efficacy of miECCO₂R was assessed. Moreover, ventilator parameters, disease severity, renal function, and adverse events were evaluated as secondary outcome parameters over a time-course of five days upon initiation of miECCO₂R.

miECCO₂R led to a rapid and sustained reduction in PaCO₂ levels from 71.4 mm Hg to 51.6 mm Hg within 24 h. This was accompanied by normalization of pH, and the median CO₂ clearance rate was 64.5 mL/min. Driving pressure decreased significantly from 22 cm H₂O to 15 cm H₂O by day 5, while oxygenation remained stable. The standalone miECCO₂R treatment group demonstrated faster CO₂ reduction, probably due to higher blood flow rates. There were no severe adverse events related to either the device or the therapy. Circuit clotting was managed by system exchange, without clinical consequences for the patients. Platelet counts declined moderately, but no major bleeding complications occurred.

miECCO₂R delivered via an RRT platform appears to be a safe and effective method of controlling hypercapnia and facilitating lung-protective ventilation in patients with ARDS. These findings need to be supported by further randomized controlled trials that can more definitely demonstrate the impact of miECCO₂R on clinical outcomes.