Related Experiment Video

Updated: Aug 12, 2026

Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow

Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow

Published on: April 29, 2011

Physiological effects of flow and pressure triggering during non-invasive mechanical ventilation in patients with

S Nava¹, N Ambrosino, C Bruschi

¹Respiratory Intensive Care Unit, Fondazione S. Maugeri, Montescano, Italy.

|March 1, 1997

Abstract

Background:

The effect of the type of trigger system on inspiratory effort has been studied in intubated patients, but no data are available in non-invasive mechanical ventilation where the "trigger variable" may be even more important since assisted modes of ventilation are often employed from the beginning of mechanical ventilation.

Methods:

The effect of flow triggering (1 and 5 1/min) and pressure triggering (-1 cm H2O) on inspiratory effort during pressure support ventilation (PSV) and assisted controlled mode (A/C) delivered non-invasively with a full face mask were compared in patients with chronic obstructive pulmonary disease (COPD) recovering from an acute exacerbation. The patients were studied during randomised 15 minute runs at zero positive end expiratory pressure (ZEEP). The oesophageal pressure time product (PTPoes), dynamic intrinsic PEEP (PEEPi,dyn), fall in maximal airway pressure (delta Paw) during inspiration, and ventilatory variables were measured.

Results:

Minute ventilation, respiratory pattern, dynamic lung compliance and resistances, and changes in end expiratory lung volume (delta EELV) were the same with the two triggering systems. The total PTPoes and its pre-triggering phase (PTP due to PEEPi and PTP due to valve opening) were significantly higher during both PSV and A/C with pressure triggering than with flow triggering at both levels of sensitivity. delta Paw was larger during pressure triggering, and PEEPi,dyn was significantly reduced during flow triggering in the A/C mode only.

Conclusions:

In patients with COPD flow triggering reduces the inspiratory effort during both PSV and A/C modes compared with pressure triggering. These findings are likely to be due to a reduction in PEEPi,dyn and in the time of valve opening with a flow trigger.

More Related Videos

Increasing Pulmonary Artery Pulsatile Flow Improves Hypoxic Pulmonary Hypertension in Piglets

Increasing Pulmonary Artery Pulsatile Flow Improves Hypoxic Pulmonary Hypertension in Piglets

Published on: May 11, 2015

Preoxygenation Techniques for Tracheal Intubation in Critically Ill Adults Utilizing Oxygen Mask and Noninvasive Ventilation

Preoxygenation Techniques for Tracheal Intubation in Critically Ill Adults Utilizing Oxygen Mask and Noninvasive Ventilation

Published on: December 5, 2025

Related Concept Videos

Pressure Relationships in Thoracic Cavity

Pressure Relationships in Thoracic Cavity

Breathing, otherwise known as pulmonary ventilation, is the process of air movement into and out of the lungs. The main mechanisms propelling pulmonary ventilation are atmospheric pressure (Patm), intra-pulmonary (Ppul ) or intra-alveolar pressure (Palv) within the alveoli, and intrapleural pressure (Pip) within the pleural cavity.
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...

Factors Affecting Pulmonary Ventilation

Factors Affecting Pulmonary Ventilation

Besides the pressure difference between the external environment and the lungs, the airflow rate and ease of pulmonary ventilation are also influenced by three other factors: surface tension of the fluid in the alveoli, compliance of the lungs, and airway resistance.
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...

Mechanical Ventilation I: Indication and Settings

Mechanical Ventilation I: Indication and Settings

Mechanical ventilation is a life-saving technique for managing acute respiratory failure and other respiratory complications. The process involves using a machine known as a ventilator to supply oxygen to the lungs and assist in removing carbon dioxide. It serves as a bridge to long-term mechanical ventilation or a temporary measure until ventilatory support is discontinued. The ventilator can maintain this function for a prolonged period, providing critical support for patients until they can...

Mechanical Ventilation II: Invasive Ventilation

Mechanical Ventilation II: Invasive Ventilation

Ventilators are essential medical equipment used to aid patients with respiratory difficulties. Their primary function is to assist or replace spontaneous breathing by providing mechanical ventilation. There are two general classes of mechanical ventilators: negative-pressure and positive-pressure ventilators.
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...

Mechanical Ventilation III: Noninvasive Ventilation

Mechanical Ventilation III: Noninvasive Ventilation

Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy.
Noninvasive Positive-Pressure Ventilation (NIPPV)

Ventilatory Modes

Ventilatory Modes

Mechanical ventilators are life-saving devices that support or replace spontaneous breathing. They deliver breaths to patients through varying methods known as ventilator modes. Understanding these modes is critical for healthcare providers managing patients with respiratory failure.
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...

Articles linked to this work by shared authors, journal, and citation graph.

Drug management of TB in the intensive care setting: an international multicentre study.

The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease·2025

Polyploidization-driven transcriptomic dynamics in Medicago sativa neotetraploids: mRNA, smRNA and allele-specific gene expression.

BMC plant biology·2025

A tailored machine learning approach for mortality prediction in severe COVID-19 treated with glucocorticoids.

The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease·2024

Clusters of individuals recovering from an exacerbation of chronic obstructive pulmonary disease and response to in-hospital pulmonary rehabilitation.

Pulmonology·2023

Pulmonary tuberculosis in intensive care setting, with a focus on the use of severity scores, a multinational collaborative systematic review.

Pulmonology·2022

Clinical standards for the assessment, management and rehabilitation of post-TB lung disease.

The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease·2021

See all related articles