A Comparison of Non-Invasive Methods of Blood Pressure Measurement in Healthy Term Neonates

Invasive Blood Pressure (BP) monitoring in neonates is fraught with many complications and is rarely practical for routine monitoring, hence the need for alternative methods of BP measurements, especially in well neonates. This study aimed to compare BP measurements in neonates using Oscillometric and Doppler Ultrasound methods.

One hundred and eighty-five neonates were consecutively recruited. Blood pressure measurements were taken at 12, 24, 36, and 48 hours of life using Doppler ultrasound with Aneroid Sphygmomanometer (DAM) (gold standard), Doppler ultrasound with Hybrid Sphygmomanometer (DHM), and oscillometric methods. Data was analysed using the IBM statistical package for the social sciences (SPSS) version 23. Comparison between the mean BP values obtained from different instrumentswas done using the paired Student t-test, and the degree of agreement between values was tested using the intra-class correlation coefficient scores. Bland-Altman analyses were also done. P-value was set at <0.05.

Blood pressure increased gradually from 12 to 48 hours of life. The blood pressure values using the automated oscillometric method were significantly higher when compared to the values obtained using the gold standard (p < 0.001), and the level of absolute agreement between the two methods was poor (intra-class coefficient < 0.5). Values from the DHM were not significantly different from those from thegold standard method (p > 0.05), and the level of absolute agreement between the two methods was excellent (Intra-class correlation coefficient >0.9).

There was poor agreement between BP values using oscillometry when compared with DAM. However, the use of DAM or DHM demonstrated no difference in BP values. Caution should be exercised when interpreting values from oscillometric BP measurements in the newborn. On the other hand, either of the Doppler ultrasound methods may be used interchangeably.