Effect of oxygenation of transperitoneal ventilation on the death time after asphyxiation in rabbits

To observe the effects of transperitoneal ventilation on death time in asphyxiated rabbits.

Twenty-four adult rabbits were randomly divided in three groups (N=8, each): control group (no transperitoneal ventilation), air group (transperitoneal ventilation with air) and oxygen group (transperitoneal ventilation with oxygen). All animals were anesthetized with pentobarbital (3%, 30 mg/kg) given via intramuscular injection. Autonomous breathing was maintained. Each rabbit's peritoneal cavity was punctured with two catheters, one of which was placed in the left lower abdomen and served as the inlet for gas; the other was placed in the right upper abdomen and served as the outlet for gas. Asphyxia was induced by clamping the rabbit's trachea; transperitoneal ventilation was then administered in the air group and the oxygen group. Rabbits' death times were recorded and their heart rate, blood pressure, PaO2, and PaCO2 were monitored and analyzed before asphyxia and every minute after asphyxia.

All animals died successively after asphyxia. The death time in the oxygen group was significantly longer than in the control group and the air group, with no significant difference between the control group and the air group. PaO2 of all three groups declined significantly and the levels of PaO2 within 1-4 minutes after asphyxia in the oxygen group were higher than in the other two groups. PaCO2 increased significantly in all groups with no significant difference among three groups within 1-3 minutes after asphyxia. The increase of PaCO2 at the fourth minute in the oxygen group was reduced in comparison to that observed in other groups.

These results suggest that transperitoneal ventilation can markedly prolong the death time of asphyxiated rabbits.