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Related Experiment Video

Updated: Jun 9, 2026

Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs

Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs

Published on: December 22, 2023

Pressure drop vs flow relationship in isolated preterm lamb tracheae.

M L Costantino¹, P Bagnoli, G Dini

¹Department of Bioengineering, Politecnico di Milano, Milano - Italy.

Journal of Applied Biomaterials & Biomechanics : JABB

|August 31, 2010

Summary

Immature tracheae can collapse under negative expiratory pressure, a critical issue for preterm infants. This study modeled this collapse using lamb tracheae, revealing a Starling resistor-like behavior during liquid ventilation.

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Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs

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Published on: December 22, 2023

The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation

The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation

Published on: August 15, 2018

Area of Science:

Biomedical Engineering
Pediatric Respiratory Physiology
Comparative Anatomy

Background:

Understanding immature airway mechanics is crucial for tidal liquid ventilation (TLV) in preterm infants.
Negative pressure during expiration can cause airway collapse and flow limitation in less stiff neonatal airways.

Purpose of the Study:

To investigate the expiratory pressure-flow relationship in isolated preterm lamb tracheae.
To determine hydraulic resistance, collapse pressure, and collapse flow rate of immature airways.

Main Methods:

Isolated preterm lamb tracheal samples were subjected to negative pressure at the outlet to induce liquid flow.
Expiratory pressure drop versus flow rate was measured.
Histological analyses examined tracheal wall morphology post-testing.

Main Results:

Flow resistance tests showed progressive lumen narrowing with increasing pressure drop.
Flow rate increased with pressure drop until a plateau, then decreased, indicating collapse onset.
Tracheal samples exhibited Starling resistor-like behavior, with collapse initiating at the outlet.

Conclusions:

Immature tracheae demonstrate collapse under negative pressure, similar to Starling resistors.
This behavior is critical for understanding airflow dynamics and potential interventions in preterm infants undergoing TLV.