Abstract
BACKGROUND: Low-flow extracorporeal CO (2) removal (ECCO (2) R), managed using a renal replacement platform, is useful in achieving lung-protective ventilation with low tidal volume. However, its capacity for CO (2) elimination is limited. Whether this system is valuable in reducing strong inspiratory efforts in respiratory failure is unclear. The combined use of alkaline agents with low-flow ECCO (2) R might be useful in hypercapnic subjects preserving inspiratory efforts. METHODS: This study examined the effects of low-flow ECCO (2) R on respiratory status and investigated the effects of NaHCO (3) , trometamol, and saline on respiratory status during low-flow ECCO (2) R in CO (2) inhalation models. RESULTS: Although low-flow ECCO (2) R did not significantly change the respiratory rate (92.2% ± 24.3% [mean ± standard deviation] of that before ECCO (2) R), it reduced minute ventilation (MV) (78.9% ± 13.5% of that before ECCO (2) R). The addition of NaHCO (3) improved acidemia but did not change MV compared with that of the saline group (0.451 ± 0.026 L/min/kg body weight [BW] vs. 0.556 ± 0.138 L/min/kg BW, respectively). The addition of trometamol improved acidemia and reduced MV compared with that of the saline group (0.381 ± 0.050 L/min/kg BW vs. 0.556 ± 0.138 L/min/kg BW, respectively). The total amounts of CO (2) removed during ECCO (2) R in the NaHCO (3) group were lower than those in the saline and trometamol groups. CONCLUSION: The low-flow ECCO (2) R reduced MV in subjects preserving spontaneous breathing efforts with CO (2) overload. The addition of NaHCO (3) improved acidemia but did not change MV, whereas the addition of trometamol improved acidemia and reduced MV.