[Artificial respiration with extracorporeal membrane oxygenator in arteriovenous position without pump. Experimental study].
OBJECTIVE
To test the hypothesis of respiratory support and to study the consequent hemodynamic alterations, we performed pumpless A-V ECMO using a 1.2m2 polipropylene hollow fiber membrane oxygenator, specially adapted from conventional model utilized in routine cardiac surgery.


METHODS
Two canine groups of six dogs each were studied. Group 1 had normal lungs and group 2 acute respiratory failure induced by 0.035ml/kg intravenous oleic acid. The dogs were anesthetized and maintained in apnea with curare. Heparin was given in a single dose of 400U/kg. Gasimetric and hemodynamic parameters were monitored each 30 minutes during a 3 hour period. Then the oxygenator was discontinued and after 15 minutes a final arterial blood gas sample was taken for analysis.


RESULTS
Blood samples at 3 hours have shown a mean PaO2 of 260.6mmHg in group 1 and 114.4mmHg in group 2 and PaCO2 of 54.3 and 56.2mmHg, respectively. After the oxygenator was discontinued PaCO2 levels increased to 161.6 and 193.7mmHg, respectively. The hemodynamic parameters shown few alterations.


CONCLUSIONS
In both groups pumpless A-V ECMO was able to maintain gasimetric parameters within acceptable patterns and compatible with life, with few hemodynamic alterations. However, an adequate mean arterial blood pressure is needed to provide flow through membrane oxygenator.
Gomes
W J
WJ
Escola Paulista de Medicina, São Paulo.
Beppu
O S
OS
Palma
J H
JH
Perfeito
J A
JA
Biscegli
J F
JF
Buffolo
E
E
D000818:Animals; D004285:Dogs; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D009829:Oleic Acids; D010313:Partial Pressure; D012121:Respiration, Artificial / Q000379:methods*; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000628:therapy*
D009829:Oleic Acids
Respiração artificial com oxigenador de membrana extracorpóreo em posição artério-venosa sem bomba. Estudo experimental.