Non-Invasive Blood Pressure Measurement in Extremely Preterm Neonates: Comparative Analysis of Different Methods.

OBJECTIVES

To compare non-invasive (Doppler and Oscillometric) and invasive (indwelling umbilical arterial catheter, UAC) methods for measuring blood pressure in extremely preterm neonates.

METHODS

Neonates < 28 weeks gestation were recruited if UAC was inserted as part of their clinical care. Blood pressure measured 4-6 hourly by Oscillometric and Doppler methods was compared with invasive method (10-15 readings/baby).

RESULTS

438 blood pressure recordings were taken from 11 neonates. Compared to invasive method, non-invasive methods underestimated (P = 0.630) and overestimated (P = 0.431 for > 10% overestimation, P = 0.960 for > 20% overestimation) blood pressure. The frequency of blood pressure being within 10% of UAC reading was higher with the Oscillometric method compared to Doppler (41% vs 17%).

CONCLUSIONS

Compared to invasive arterial recording, non-invasive methods underestimated as well as overestimated blood pressure in extremely preterm neonates. Oscillometric methods are more reliable compared to Doppler methods.