Related Experiment Video
Updated: Mar 24, 2026

Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
The accuracy of delivery of target pressures using self-inflating bag manometers in a benchtop study
Anthony R Rafferty1,2, Lucy Johnson1,3, Dominic Maxfield1
1Newborn Research Centre, The Royal Women's Hospital, Melbourne, Vic., Australia.
Aim:
We tested whether operators using manometers attached to self-inflating bags could accurately deliver set targeted peak inspiratory pressures (PIPs) compared to the Neopuff(™) T-piece resuscitator (TPR).
Methods:
Participants provided positive pressure ventilation to a leak-free neonatal test lung at a rate of 60 inflations/min and a flow of 8 L/min. Participants used three manometers attached to self-inflating bags and a Neopuff(™) TPR to target PIPs of 20, 30 and 40 cmH2 O on each device. Mean PIPs delivered with each manometer were compared to the 'gold standard' Neopuff(™) TPR.
Results:
In total, 13 991 inflations delivered by 20 participants were analysed. At all target PIPs, the mean PIP delivered using the Mercury Medical manometer attached to a Laerdal self-inflating bag was significantly higher by 5 cmH2 O (p < 0.01) than the Neopuff(™) TPR. The PIP delivered using both the Ambu(™) and Parker Healthcare manometers attached to their respective devices was similar to that delivered by the Neopuff(™) TPR at all targeted PIPs.
Conclusion:
Accurately targeted PIPs can be achieved when a manometer specifically designed for use on a self-inflating bag is used during manual ventilation. This may be useful in settings where access to a Neopuff(™) TPR or a gas flow source is limited.
Related Concept Videos
Sites for measuring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
Assessment of blood pressure in brachial artery(two-step method)
Errors occurring during blood pressure monitoring
Several factors...
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...
Measurement of Fluid Pressure
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
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.

