Abstract
Background: Protective ventilation (PV) with low tidal volumes is recommended in acute respiratory distress syndrome (ARDS). However, hypercapnic acidosis resulting from PV enhances pulmonary hypertension.
Aim: We investigated if extracorporeal veno-venous CO2 removal therapy could have beneficial effects on pulmonary circulation.
Methods: This study was performed on an experimental model of ARDS obtained in 8 anaesthetized pigs connected to a volume-cycled ventilator. A micromanometer-tipped catheter was inserted into the main pulmonary artery and an admittance micromanometer-tipped catheter was inserted into the right ventricle. ARDS was obtained by repeated bronchoalveolar lavage. PV was then achieved and the pigs were connected to a pump-driven extracorporeal membrane oxygenator (PALP, Maquet, Germany) in order to achieve CO2 removal.
Results: ARDS induced severe hypercapnic acidosis. Systolic pulmonary artery pressure significantly increased from 29.6±1.8 to 43.9±2.0 mm Hg (p<0.001). After the PALP was started, acidosis was corrected and normocarbia was maintained despite protective ventilation. Pulmonary artery pressure significantly decreased to 31.6±3.2 mm Hg (p<0.001).
Conclusions: Veno-venous CO2 removal therapy enabled PV while maintaining normocarbia during ARDS. CO2 removal therapy decreased pulmonary hypertension and may be an effective lung- and RV- protective adjunct to mechanical ventilation.
- Copyright ©ERS 2015
