Related Experiment Video
Updated: Feb 5, 2026

Measurement of the Pressure-volume Curve in Mouse Lungs
Published on: January 27, 2015
Analysis of peak inflating pressure and inflating pressure limit during neonatal volume guaranteed ventilation
Eniko Szakmar1,2, Colin J Morley1, Gusztav Belteki3
1Neonatal Intensive Care Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK.
Objectives:
To report how peak inflating pressure (PIP), tidal volume (VT) and low-tidal volume alarms are affected by maximum allowed inflating pressure (Pmax) during volume guarantee (VG) ventilation.
Study Design:
Ventilation data were analysed with 1 Hz sampling rate from 25 neonates receiving synchronised intermittent positive pressure ventilation with VG for >12 h.
Results:
The difference between Pmax and PIP (Pdiff) ranged between 5 and 20 mbar (median = 11 mbar) despite a protocol to keep Pmax 5 mbar above the "working PIP". Pmax was reached in 5.2% of inflations. Computational modelling demonstrated that had Pdiff been kept at 5 mbar more consistently, >10% of inflations would have reached Pmax. The frequency of low-tidal volume alarms showed inverse correlation with Pdiff.
Conclusions:
It is difficult to implement a simple Pmax strategy due to variability of PIP. Setting Pmax close to the "working PIP" limits VT delivery and triggers frequent alarms.
Related Concept Videos
Le Chatelier's Principle: Changing Volume (Pressure)
Pressure and Volume in an Adiabatic Process
Definition and Measurement of Pressure: Atmospheric Pressure, Barometer, and Manometer
Vapor Pressure
Constant Pressure Calorimetry
Vapor Pressure Lowering

