ECCO2-R in protective ventilation: volume distributionanalysis in ARDS patients

Aim. 30% of ARDS patients ventilated according to NIH protocol presents hyperinflation at CT scan even with Pplat < 30 cmH2O. Pplat values < 26 cmH2O are associated with a more protective ventilation.(1,2) Risk of hyperinflation could be reduced using alternative techniques as ECCO2-R that allow a lower VT and Pplat ventilation. Aim of the study was to quantify and analyze in ARDS patients the regional distribution of ventilatory volumes before and after treatment with ECCO2-R. Materials and methods. After diagnosis of ARDS, patients were divided into 2 groups according to Pplat value. Patients with Pplat < 28 cmH2O followed ARDSNet ventilation strategy; patients with Pplat > 28 cmH2O underwent to VT reduction to achieve a Pplat < 25; ECCO2-R combined with mechanical ventilation when pH < 7,3. CT analysis was performed at enrolment and after 72h of ECCO2-R treatment. Discussion. CT regional volume distribution analysis showed in stress population the maximum hyperinflation of 36.8%±9.5 in the medium-sternal region; use of ECCO2-R significantly reduced hyperinflation to 3.3%±2.0, distributed equally from apical to caudal regions. Normally aerated regions become larger from vertebrae to sternum and more distributed in apical and medium regions close to sternum. Conclusion. The use of ECCO2-R protect lungs reducing hyperinflated areas diverting VT to normally aerated areas. Bibliografia 1. Terragni PP, Rosboch G.,Tealdi A et al. Tidal Hyperinflation durino Low Tidal Volume Ventilation in Acute Respiratory Distress Sindrome. Am J Respir Crit Care Med, 2007;175:160-6. 2. Nieszkowska.,Quin L.,Vieira S.,Elman M.,Fetita C.,Rouby JJ. Incidence and regional distribution of lung overinflation during mechanical ventilation with positive end-expiratory pressure. Crit Care Med 2004;32-7:1496-503