[Comparison of the models of acute hypoxia and hypoxic-ischemia in newborn piglets].

Objective: To compare the newborn piglet models of hypoxic ischemic brain damage in hypoxia and hypoxia combined with occlusion of both carotid arteries.

Methods: Twenty four 7-day-old piglets were divided into two groups. Group H: mechanical ventilation with low concentration of oxygen, Group HI: mechanical ventilation with low concentration of oxygen combined with occlusion of both carotid arteries. The piglets were inhaled with 10%, 8%, and 6% low-concentration oxygen for 30 min, and grouped into mild, moderate, and severe hypoxia ones. The changes of physiological parameter, cerebral blood flow and cerebral oxygen perfusion were detected.

Results: There were no significant differences in blood gas analysis of oxygen saturation, blood lactic acid and pH between the two groups(P>0.05).The mean arterial pressure of severe hypoxia in HI was significantly lower than in H (P<0.05). The cerebral blood flow in H and HI was relatively stable after different degrees of hypoxia. As compared with the cerebral blood flow perfusion in group H and HI, there were no significant differences between them(P>0.05). The cerebral oxygen perfusion in H and HI was significantly descent after different degrees of hypoxia(P<0.05). As compared with the cerebral oxygen perfusion in groups H and HI, there were no significant differences between them.

Conclusion: H and HI have the same effect on physiological parameter, cerebral volume and cerebral oxygen perfusion of newborn piglets. The mechanical ventilation with low concentration of oxygen to newborn piglets can develop the HIBD model, it is not necessary to occlude carotid arteries.