Prolonged hemodynamic stability during arteriovenous carbon dioxide removal for severe respiratory failure.
OBJECTIVE
The effects of prolonged arteriovenous carbon dioxide removal on hemodynamics during severe respiratory failure were evaluated in adult sheep with severe smoke inhalation injury.


METHODS
Adult female sheep (n = 6,33.8 +/- 5.2 kg) were subjected to intratracheal cotton severe smoke insufflation to a mean carboxyhemoglobin level of 83% +/- 3%. Twenty-four hours after injury, a low-resistance 2.5 m2 membrane oxygenator was placed in a carotid-to-jugular pumpless arteriovenous shunt at unrestricted flow to allow complete carbon dioxide removal and reductions in ventilator support. Animals remained conscious, and heart rate, cardiac output, mean arterial pressure, and pulmonary arterial pressure were measured at baseline, after injury, and daily during support with the arteriovenous carbon dioxide removal circuit for 7 days.


RESULTS
All animals survived the study period. Carbon dioxide removal ranged from 99.7 +/- 13.7 to 152.2 +/- 16.2 ml/min, and five (83%) of the six animals were successfully weaned from the ventilator before day 7. During full support with the arteriovenous carbon dioxide removal circuit, shunt flow ranged from 1.24 +/- 0.06 to 1.43 +/- 0.08 L/min and accounted for 20.1% +/- 1.4% to 25.9% +/- 2.4% of cardiac output. No statistically significant changes in heart rate, cardiac output, mean arterial pressure, or pulmonary artery pressure were demonstrated over the study course despite the extracorporeal shunt flow.


CONCLUSIONS
Arteriovenous carbon dioxide removal as a simplified means of extracorporeal gas exchange support is relatively safe without adverse hemodynamic effects or complications.
Brunston
R L
RL
Department of Surgery, University of Texas Medical Branch, Galveston 77550-0528, USA.
Tao
W
W
Bidani
A
A
Alpard
S K
SK
Traber
D L
DL
Zwischenberger
J B
JB
D000818:Animals; D002245:Carbon Dioxide / Q000097:blood*; D004195:Disease Models, Animal; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D010107:Oxygenators, Membrane; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*; D015208:Smoke Inhalation Injury / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors
D002245:Carbon Dioxide