Updike P A, Accurso F J, Jones R H
Nurs Res. 1985 May-Jun;34(3):160-3.
This study investigated evidence of a circadian rhythm in the physiologic variables of transcutaneous oxygen (tcPO2) level, pulse rate, respiratory rate, frequency of respiratory pauses, and skin temperature in six 34- to 37-week-preterm infants. A value for each variable was noted every 30 minutes for 24 hours, providing 245 observations for each infant. An adaptation of cosinor analysis, a least squares procedure that determines the cosine curve for a 24-hour period that best fits the observed pattern of values, was applied to the data. Statistically significant circadian rhythmicity was found for five of the six subjects with regard to skin temperature. Significant circadian rhythm was also demonstrated in two or three patients for all other variables. No significant consistent synchrony for individual variables across subjects was found. Actual peak values of respiratory pause frequency and trough values of tcPO2, however, occurred between midnight and 4:30 A.M. for every infant. Preterm infants exhibited evidence of a circadian rhythm in skin temperature, and tcPO2 and respiratory pause frequency exhibited day/night pattern characteristics.
本研究调查了6名34至37周早产婴儿经皮氧分压（tcPO2）水平、脉搏率、呼吸频率、呼吸暂停频率和皮肤温度等生理变量中的昼夜节律证据。在24小时内，每隔30分钟记录每个变量的值，每个婴儿共获得245次观察数据。对这些数据应用了一种改进的余弦分析方法，这是一种最小二乘法程序，用于确定最适合观察到的值模式的24小时余弦曲线。在6名受试者中，有5名受试者的皮肤温度存在统计学上显著的昼夜节律。对于所有其他变量，也在两三名患者中显示出显著的昼夜节律。未发现各受试者个体变量之间存在显著一致的同步性。然而，每个婴儿的呼吸暂停频率实际峰值和tcPO2谷值均出现在午夜至凌晨4:30之间。早产婴儿表现出皮肤温度的昼夜节律证据，并且tcPO2和呼吸暂停频率呈现出昼夜模式特征。
