Research on effect of oxygen-reuptake on cardiac functions of anoxic dogs by self-reflection method

Objective To study the intervention effect of oxygen-reuptake on cardiac functions of anoxic dogs by self-reflection method.Methods Six male hybrid dogs were used in the present study.The dogs were anaesthetized with pentobarbital sodium and were fixed on the operating tables.The catheterizations of trachea,left ventricle and femoral artery were performed.The dogs first inhaled normal air followed by mixture of oxygen and nitrogen and then inhaled normal air again.Records were taken at 60min,30min,10min before hypoxia and 10 min,30 min,60min at hypoxia and 10 min,30 min,60min at oxygen-reuptake.The bio-signals of heart rate(HR),left ventricle systolic pressure(LVSP) and +dp/dtmax were recorded.Arterial partial pressure of oxygen(PaO2) and arterial partial pressure of carbon dioxide(PaCO2) were analyzed by automatic blood gas system.Results Heart rates of dogs were increased gradually by inhaling the mixture of oxygen and nitrogen.LVSP,however,experienced a process of increase at 10 min and 30min and decrease at 60min.Decreased PaO2 and increased PaCO2 were observed during the inhalation of anoxic air.Conclusion Anoxic air inhalation could affect the cardiac functions of the dogs and oxygen-reuptake could ameliorate these changes.