Hemodynamic stability during arteriovenous carbon dioxide removal for adult respiratory distress syndrome: a prospective randomized outcomes study in adult sheep.

To evaluate the ability of arteriovenous carbon dioxide removal (AVCO2R) to maintain hemodynamic stability during treatment of adult respiratory distress syndrome (ARDS), we used our smoke/burn, LD40 sheep model of ARDS. With onset of ARDS (PaO2/FiO2 < 200) animals were randomized to AVCO2R (n = 20) or SHAM (n = 8). With AVCO2R, the carotid artery (10-14 F) and jugular vein (14-16 F) were cannulated; SHAM received identical management, sparing the vessels. AVCO2R maintained stable hemodynamics compared to SHAM at 48 hours; heart rate (114.8+/-6.1 vs. 110.1+/-11.0 beats/min.), mean arterial pressure (112+/-5.1 vs. 107.0+/-8.5 mm Hg), cardiac output (7.4+/-0.5 vs. 7.5+/-0.9 L/min.), pulmonary arterial pressure (26+/-2.4 vs. 21+/-1.3 mm Hg), pulmonary arterial wedge pressure (14.1+/-1.8 vs. 14.0+/-1.2 mm Hg), and central venous pressure (7+/-1.6 vs. 8+/-0.9 mm Hg). At 48 hours, AVCO2R allowed significant reductions (p<0.05) in minute ventilation (13.6+/-2.5 to 7.6+/-0.8 L/min); tidal volume (TV) (389.4+/-24.1 to 295.0+/-10.1 ml); peak inspiratory pressure (PIP) (25.4+/-9.2 to 18.8+/-2.5 cm H2O); RR (27.5+/-0.7 to 21.6+/-1.8 breaths/min); and FiO2 (0.96+/-0.00 to 0.48+/-0.2) while normocapnia was maintained. AVCO2R is an effective method of CO2 removal during severe respiratory failure that is hemodynamically well tolerated.