Arterio venous carbon dioxide removal (AVCO{sub}2R) for severe respiratory failure

摘要

Arteriovenous carbon dioxide removal (AVCO{sub}2R) by a low-resistance gas exchanger in a simple arteriovenous shunt is capable of achieving near total CO{sub}2 removal and lung rest during ARDS. We evaluated AVCO{sub}2R effect on a LD{sub}50 smoke/burn (36 breath, 40% III° TBSA) ARDS model in a prospective, randomized, controlled, unblinded 7-day outcomes study of ventilator free days and survival. All AVCO{sub}2R sheep survived, while only 2 SHAM animals survived the 7-day study. AVCO{sub}2R had 2.4 ventilator dependent days versus 6.5 days with SHAM. For our initial patient experience, 5 adults in unresponsive, severe ARDS were successfully cannulated for AVCO{sub}2R at bedside and completed the 72-h trial and 3/5 patients were discharged. AVCO{sub}2R removed approximately 70% of CO{sub}2. Changes in ventilator parameters from baseline to 48 h included a decrease in tidal volume, peak inspiratory pressure, minute ventilation, and respiratory rate. Next, a before-after study of AVCO{sub}2R was performed on 8 subjects with ARDS. PaCO{sub}2 decreased significantly despite a decrease in minute ventilation from baseline and normalization of pH. We propose the normalization of CO{sub}2 and decreased minute ventilation allows amelioration of the pathophysiology of ARDS.