中枢神经系统急性低氧反应的个体差异及其评定

为了观察急性低氧条件下中枢神经系统机能状态的改变,用改进了的方法测定了健康人乘车抵达海拔4700m高原现场前后,和在实验室内吸入低氧混合气体(相当于海拔4500～4700m)前后的“光单纯反应时”。在两种条件下,所得结果基本相同:人体中枢神经系统对急性低氧的反应有明显个体差异,可区别出稳定型、兴奋型和抑制型三类。其中抑制型现场和实验室分别有83％及75％的人出现急性低氧反应,其他两型合并统计,分别有79％及80％的人基本无反应。反应时抑制型的人急性低氧反应的发生率高。反应时测定方法用来评定急性低氧反应出现程度,其结果与症状学评定法相比,在两种条件下,吻合率分别为81％及78％,不吻合率分别为19％及22％,其中假阳性率分别为6％及10％,假阴性率分别为14％及12％。

THE INDIVIDUAL DIFFERENCE OF THE ACUTE HYPOXIC RESPONSE OF CNS AND ITS EVALUATION

In order to study the changes of CNS functional status under acute hy-poxic circumstance, light simple reaction time measurement was performed with improved method on a group of healthy people before they started to go to an altitude of 4,700m above sea level by bus and again after they arrived, and on a group of healthy people before and after they inhaled hypoxic oxgen-nitrogen gas mixture (Po2 91.8-89.2mmHg, corresponding to 4500-4700m hight ) in laboratory.At the same time, acute hypoxic symptoms appeared in each individual were ascertained by questionaries. The results of the two groups were almost the same. But it showed that the responses of CNS to acute hypoxia were significantly different from individual to individual. Acording to the results, the subjects can be classified into three groups named steady, excitatory and inhibitory.83% of the inhibitory type subjects at high altitude and 75% in the laboratory showed various kinds of acute hypoxic symptoms but there were almost no symptoms found in 79% of the other two types at high altitude and 80% in laboratory, The rate of the appearance of acute hypoxic symptom of the inhibitory type was much higher than that of the other two types. The coincidental rate of the results of evaluating the extent of the appearance of acute hypoxic symptoms by measuring reaction time on those by observing symptoms was 81% at high altitude and 78% in laboratory respectively. The incongruous rate was 19% and 22% with a false positive rate of 6 % and 10%, and a false negative rate of 14% and 12% respectively.