The hemodynamic effects of standardized pressure controlled ventilation (SMV) were compared with the algorithm directed decreased ventilation of extracorporeal percutaneous AVCO2R in adult sheep with smoke/burn induced ARDS. Adult Suffolk ewes (n = 16) received smoke inhalation (36 breaths) + 40% TBSA III0 flame burn, followed by mechanical ventilation. With development of RDS (PaO2/FiO2<200 at 40-48 hrs) animals randomized to AVCO2R (n = 8) or SHAM (n = 8). In the AVCO2R group, the carotid artery (10F) and jugular vein (14F) were cannulated under general anesthesia. SHAM received identical surgical and medical management, sparing the vessels. Ventilator management for both groups entailed algorithm directed reductions in tidal volume (TV) for peak inspiratory pressure (PIP) < 30 cm H2O, then respiratory rate (RR) for PaCO2 < 40mm Hg. PaO2 was > 60mm Hg by adjusting FiO2 at PEEP 5cm H2O. Hemodynamic data (heart rate, cardiac output, mean arterial pressure, pulmonary arterial pressure, and central venous pressure) were recorded every 6 hours following injury. AVCO2R shunt flow (Qb) ranged from 820 to 968 mL/min (mean 870 mL/min) (11% to 14% CO). At 96 hours no significant differences were seen in any hemodynamic parameters (p > 0.05, all values AVCO2R vs. SHAM) for heart rate (122 +/- 8.2 vs. 114.7 +/- 6.9), mean arterial pressure (123 +/- 6.5 vs. 115.7 +/- 3.1), cardiac output (6.6 +/- 0.7 vs. 7.1 +/- 0.6), pulmonary arterial pressure (25 +/- 1.9 vs. 26 +/- 3.0), pulmonary arterial wedge pressure (15 +/- 1.0 vs. 18 +/- 4.0), and central venous pressure (6 +/- 1.4 vs. 7 +/- 1.4). Despite the 11% to 14% shunt flow, AVCO2R maintained stable hemodynamics comparable to SHAM throughout the study and at 96 hours. AVCO2R as an alternative to SMV for severe respiratory failure is a simple and effective method of CO2 removal that is well tolerated without adverse hemodynamic effects.
ASJC Scopus subject areas
- Biomedical Engineering