Objectives: Mechanical ventilation
is injurious to the lung. Use of lung-protective strategies may complicate patient management, motivating a search for better lung-replacement approaches. We investigated the ability of a novel extracorporeal venovenous 2 removal">CO2 removal
device to reduce minute ventilation while maintaining normocarbia.
Prospective animal study.
Government laboratory animal intensive care unit.
Seven sedated swine
Tracheostomy, volume-controlled mechanical ventilation
, and 72 hrs of round-the-clock intensive care unit care. A 15-F dual-lumen catheter was inserted in the external jugular vein and connected to the Hemolung, an extracorporeal pump-driven venovenous 2 removal">CO2 removal
device. Minute ventilation was reduced, and normocarbia (Paco2
35–45 mm Hg) maintained. Heparinization was maintained at an activated clotting time of 150–180 secs.
Measurements and Main Results:
Minute ventilation (L/min), 2 removal">CO2 removal
by Hemolung (mL/min), Hemolung blood flow, O2
consumption (mL/min), CO2
production by the lung (mL/min), Paco2
, and plasma-free hemoglobin (g/dL) were measured at baseline (where applicable), 2 hrs after device insertion, and every 6 hrs thereafter. Minute ventilation was reduced from 5.6 L/min at baseline to 2.6 L/min 2 hrs after device insertion and was maintained at 3 L/min until the end of the study. 2 removal">CO2 removal
by Hemolung remained steady over 72 hrs, averaging 72 ± 1.2 mL/min at blood flows of 447 ± 5 mL/min. After insertion, O2
consumption did not change; CO2
production by the lung decreased by 50% and stayed at that level (p
< .001). As the arterial PCO2
rose or fell, so did 2 removal">CO2 removal
by Hemolung. Plasma-free hemoglobin did not change.
Venovenous 2 removal">CO2 removal
enabled a 50% reduction in minute ventilation while maintaining normocarbia and may be an effective lung-protective adjunct to mechanical ventilation