부산대학교 도서관

Attempting to identify predictive antecedents to bradycardia in preterm infants, we analyzed 6500 minutes of heart rate and transcutaneous oxygen patterns of 9 infants who had bradycardic episodes during continuous computerized observations. Sixteen measures of heart rate and TcPO2recorded 5 minutes before a bradycardic episode were compared with baseline values of these variables for the day when each bradycardia occurred. There were 50 episodes of bradycardia isolated by more than 5 minutes from any prior episode. Infants were handled 5 minutes before bradycardia in 29 of the 50 instances. Over the 5 minutes before bradycardia, the mean of the minimum TcPO2's, the absolute minimum TcPO2and the mean of the TcPO2's were all lower than baseline 24 of 29 times when touch preceded bradycardia (p <.01). However, when no caregiver touch occurred prior to bradycardia, these same 3 TcPO2variables were recorded higher than baseline for the 5-minute pre-bradycardic period. In the absence of touch, the mean heart rate as well as the maximum variability in high - low heart rates were lower than baseline 14 of 21 times during the pre-bradycardic period. These results generate the hypothesis that preterm infants who are handled when TcPO2is low are very prone to subsequent bradycardia. Bradycardia following handling appears to have a different and potentially more preventable causative mechanism from spontaneously occurring episodes.