Objective: To compare blood pressure measurements in newborn infants using the flush method, pulse oximetry and oscillometry according to Doppler findings.
Methods: Noninvasive blood pressure measurements were made using three techniques (flush method, pulse oximetry and oscillometry) in three groups of newborns: 15 normal term infants, 16 stable preterm infants, and 14 critically ill infants. All measurements were video recorded, edited separately, coded and analyzed independently by three neonatologists.
Results: Fifty-seven measurements were made using each method. The flush method and pulse oximetry had a better correlation with Doppler findings than oscillometry (correlation coefficients: 0.89, 0.85, 0.71; p < 0.01). The difference between measurement means, their standard deviations and the 95% confidence intervals when compared with Doppler findings were: -5.2 ± 7.9 (-21.1:10.7) mmHg for the flush method; 0.4 ± 8.9 (-17.5:18.2) mmHg for pulse oximetry; and 6.4 ± 16.1 (-25.8:8.6) mmHg for oscillometry. The flush method had a better agreement with Doppler findings for the diagnosis of hypotension than oximetry and oscillometry.
Conclusions: The flush method and pulse oximetry seem to be useful techniques to measure systolic blood pressure in newborn infants; oscillometry had the poorest agreement with Doppler findings to detect hypotension.