Related Experiment Video
Updated: May 8, 2025

Transcutaneous Microcirculatory Imaging in Preterm Neonates
Published on: December 31, 2015
Non-Invasive Blood Pressure Measurement in Extremely Preterm Neonates: Comparative Analysis of Different Methods
Shalabh Garg1,2, Adnan Zafar3
1Department of Neonatology, The James Cook University Hospital, Middlesbrough, UK. s.garg@nhs.net.
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.
Related Concept Videos
Equipments Used To Measure Blood Pressure
This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
Sites for measruring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
Assessment of blood pressure in brachial artery(two-step method)
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Measurement of Blood Pressure
Assessment of blood pressure in brachial artery(one-step method)
Prepare for the Procedure:

