Physiologic effect and safety of the pumpless extracorporeal interventional lung assist system in patients with acute respiratory failure--a pilot study

Interventional lung assist (iLA) effectively reduces CO(2) tension and permits protective lung ventilation in patients with acute respiratory distress syndrome. However, there is little experience in using iLA in acute respiratory failure from various causes and no experience for small body sizes such as Asian patients. We evaluated the physiologic effect and safety of the iLA device in patients with acute respiratory failure from various causes. We enrolled 11 consecutive patients with severe respiratory failure from various causes. Wire-enforced cannulae (13-15 Fr) were inserted under ultrasound guidance and connected to iLA. Arterial blood gas analysis, ventilator parameters, hemodynamic parameter, and adverse events were recorded serially. During the first 24h of iLA use, mean blood flow was 1.08±0.15L/min, PaCO(2) decreased from 83.9±23.4mmHg to 40.7±10.2mmHg, and PaO(2) /FiO(2) ratio increased from 110±37 to 141±74. Minute ventilation decreased from 9.4±2.5 to 6.3±1.5L/min, and peak inspiratory pressure decreased from 30.3±7.1cm H(2) O to 28.8±9.4cm H(2) O. No serious adverse events were observed during iLA use. iLA showed effective CO(2) removal, allowed for reducing the invasiveness of mechanical ventilation in patients with severe respiratory failure from various causes even using a small-sized catheter and was safe in small body-sized patients.