Extrapulmonary ventilation for unresponsive severe acute respiratory distress syndrome after pulmonary resection

Abstract

Background: The purpose of this study was to evaluate the feasibility of integrating an artificial, pumpless extracorporeal membrane ventilator (Novalung) to near static mechanical ventilation and its efficacy in patients with severe postresectional acute respiratory distress syndrome (ARDS) unresponsive to optimal conventional treatment.

Methods: Indications were severe postresectional and unresponsive acute respiratory distress syndrome, hemodynamic stability, and no significant peripheral arterial occlusive disease or heparin-induced thrombocytopenia. Management included placement of the arteriovenous femoral transcutaneous interventional lung-assist membrane ventilator, lung rest at minimal mechanical ventilator settings, and optimization of systemic oxygen consumption and delivery.

Results: Among 239 pulmonary resections performed between 2005 and 2006, 7 patients (2.9%) experienced, 4 +/- 0.8 days after 5 pneumonectomies and 2 lobectomies, a severe (Murray score, 2.9 +/- 0.3) acute respiratory distress syndrome unresponsive to 4 +/- 2 days of conventional therapy. The interventional lung-assist membrane ventilator was left in place 4.3 +/- 2.5 days, and replaced only once for massive clotting. During this time, 29% +/- 0.3% or 1.4 +/- 0.36 L/min of the cardiac output perfused the device, without hemodynamic impairment. Using a sweep gas flow of 10.7 +/- 3.8 L/min, the device allowed an extracorporeal carbon dioxide removal of 255 +/- 31 mL/min, lung(s) rest (tidal volume, 2.7 +/- 0.8 mL/kg; respiratory rate, 6 +/- 2 beats/min; fraction of inspired oxygen, 0.5 +/- 0.1), early (<24 hours) significant improvement of respiratory function, and reduction of plasmatic interleukin-6 levels (p < 0.001) and Murray score (1.25 +/- 0.1; p < 0.003). All but 1 patient (14%) who died of multiorgan failure were weaned from mechanical ventilation 8 +/- 3 days after removal of the interventional lung-assist membrane ventilator, and all of them were discharged from the hospital.

Conclusions: The integration of this device to near static mechanical ventilation of the residual native lung(s) is feasible and highly effective in patients with severe and unresponsive acute respiratory distress syndrome after pulmonary resection.