Pulmonary and Ventilatory Effects of Trigger Modulation in Intubated ICU (Trigger)

Pulmonary and Ventilatory Effects of Trigger Modulation in Intubated ICU Patients Spontaneously Breathing With Pressure Support Ventilation. A Physiopathology Exploratory Study.

Pressure support ventilation allows intubated ICU patients to breathe spontaneously. Among specific settings, the adjustment of the trigger value (or threshold for triggering the ventilator) has not been explored to date. The trigger threshold corresponds to the sensitivity of the ventilator to detect patient's inspiratory effort and then deliver the predefined pressure support to inflate the lungs and deliver a tidal volume. The purpose of this study is to explore the influence of trigger level on pulmonary and ventilatory physio (-patho)logical parameters in spontaneously breathing ICU patients.

Study Overview

• Status: Completed
• Conditions: ICU Patients; Intubation; Pulmonary Function; Tracheotomy; Spontaneously Breathing
• Intervention / Treatment: Other: Trigger setting of pressure support ventilation

Detailed Description

The use of invasive mechanical ventilation is one of the most frequent therapies in intensive care units (ICUs). There are several types of indications, depending on the failure: essentially neurological, hemodynamic or respiratory.

In recent years, the notion of lung damage induced by mechanical ventilation (VILI) has led to major changes in ventilator settings in both ICUs and operative rooms (Ors). The reduction of the tidal volume (TV) to 6-8 mL/kg of ideal body weight, the use of an individualized positive end-of-expiratory pressure (PEEP) and the possible use of pulmonary aeration optimization therapies (alveolar recruitment manoeuvres, prone positioning sessions...) have become essential to increase patient's survival.

Withdrawal of invasive mechanical ventilation remains a daily issue and traditionally requires the transition from fully controlled ventilation to pressure support ventilation. Among specific settings of the latter, the adjustment of the trigger value (or threshold for triggering the ventilator) has not been explored to date. The trigger threshold corresponds to the sensitivity of the ventilator to detect patient's inspiratory effort and then deliver the predefined pressure support to inflate the lungs and deliver a tidal volume. The lower (or more sensitive) the trigger threshold, the smallest patient's effort will be rewarded. On the other hand, the higher the threshold, the greater the inspiratory effort required from the patient. Usually, this value is set by default to the minimum level to avoid self-triggering of the ventilator. With the objective to optimize pulmonary aeration, the use of higher trigger levels could increase diaphragmatic work (with a potential re-training and reinforcement effect) and contribute to better alveolar recruitment in the postero-inferior territories that are traditionally the most impacted, following a higher diaphragmatic motion. The authors propose to explore the impact of different trigger levels on pulmonary aeration (evaluated by electrical impedance tomography) and ventilatory parameters, in order to validate our hypotheses and before considering a trial with the objective of defining individualized trigger levels, according to patient's respiratory mechanics and pulmonary parenchyma morphology, with potential benefits on ventilator weaning.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Clermont-Ferrand, France, 63000
    • Service de Réanimation Adultes et Soins Continus

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age ≥18 years
• Patient hospitalized in the Intensive Care Unit of Clermont-Ferrand's Hospital
• Patients with mechanical invasive ventilation in spontaneous ventilation with inspiratory support (intubation or tracheostomy)
• Trigger level set to minimum
• Patient under sedation compatible with spontaneous ventilation (SV) with inspiratory support (AI) and positive end-expiratory pressure (PEP) Patient calm (RASS between -2 and 0) Consent for participation or consent from patient's next of kin or inclusion according to an emergency procedure Patient benefiting from the French social security scheme

Exclusion Criteria:

• Refusal to participate in the proposed study

• Contraindication to the installation of a nasogastric tube:

  • Severe disorder of uncorrected blood clotting
  • Known nasosinus lesion
  • Oesophageal varices recently ligated (<48h)

• Contraindication to the use of the electro-impedancemetry technique by tomography

  • Thoracic lesions
  • Chest dressings
  • Pace-maker / Implantable Defibrillator
• Known lesion of central respiratory centers, including patients with neurological injury
• Patients with Acute Respiratory Distress Syndrome (according to Berlin criteria)
• Patients with restrictive or obstructive pulmonary pathology
• Patients admitted post-operatively for surgery that may affect the diaphragmatic function ( thoracic or abdominal supra-mesocolic)
• Patients with abdominal distention (ileus, intra-abdominal hyperpressure)
• Patient whose BMI is greater than 35 kg.m-2
• Pregnant patient
• Patient under guardianship,

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Trigger increasing steps; Trigger variations will be performed following increasing steps of 2 L/min every 15 minutes. End expiratory lung volume and lung aeration will be conducted using elecrical impedance tomography. Diaphragmatic motion and thickening will be analyzed by ultrasonography. Work of breathing will be evaluated using gastric and oesophageal pressure measurements. Measurements will be conducted during the last minute of each step.

Other: Trigger setting of pressure support ventilation; Trigger variations will be performed following increasing steps of 3 L/min every 15 minutes, from 0.2 to 15 L/min (0.2 - 3 - 6 - 9 - 12 - 15).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T0 (before the first trigger step)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T15 minutes (last minute of the trigger step n°1)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T30 minutes (last minute of the trigger step n°2)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T45 minutes (last minute of the trigger step n°3)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T60 minutes (last minute of the trigger step n°4)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T75 minutes (last minute of the trigger step n°5)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T90 minutes (last minute of the trigger step n°6)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T105 minutes (last minute of the trigger step n°7)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T120 minutes (last minute of the trigger step n°8)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T135 minutes (last minute of the trigger step n°9)
Lung volume (end expiratory lung volume, EELV) at each trigger level	The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol	T150 minutes (last minute of the trigger step n°10)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Homogeneity of pulmonary aeration	Evaluation of homogeneity of pulmonary aeration with Center Of Ventilation by EIT	Through study completion, 150 minutes
Homogeneity of pulmonary aeration	Evaluation of homogeneity of pulmonary aeration with Global Inhomogeneity index by EIT	Through study completion, 150 minutes
Regional impedance variation	Evaluation of regional impedance variation (TIV: Tidal Impedance Variation) by EIT	Through study completion, 150 minutes
Atelectrauma	Assessement of atelectrauma (RVD: Regional Ventilation Delay) by EIT	Through study completion, 150 minutes
Lung volume variations	Evaluation of lung volume variations by EIT (EELI : End Expiratory Lung Impedance)	Through study completion, 150 minutes
Transpulmonary pressure	Evaluation of maximum transpulmonary pressure (alveolar stress)	Through study completion, 150 minutes
Alveolar strain defined as the ratio between tidal volume and Functional Residual Capacity	Alveolar strain defined as the ratio between tidal volume and Functional Residual Capacity	Through study completion, 150 minutes
Transpulmonary driving pressure	Evaluation of transpulmonary driving pressure	Through study completion, 150 minutes
Work of breathing	Evaluation of work of breathing (WOB) value (P01)	Through study completion, 150 minutes
Work of breathing	Evaluation of inspiratory occlusion pressure values (P01)	Through study completion, 150 minutes
Energy delivered	Evaluation of energy delivered to lungs patient	Measurement during the last minute of each trigger step
Diaphragm thickening	Evaluation of the diaphragmatic thickening by ultrasound	Through study completion, 150 minutes
Diaphragm motion	Evaluation of the diaphragmatic motion by ultrasound	Through study completion, 150 minutes
Patient's weight	Study of the impact of patient's weight	Through study completion, 150 minutes

Collaborators and Investigators

• Sponsor: University Hospital, Clermont-Ferrand

Study record dates

Study Major Dates

• Study Start (Actual): April 3, 2019
• Primary Completion (Actual): January 31, 2023
• Study Completion (Actual): January 31, 2023

Study Registration Dates

• First Submitted: July 25, 2019
• First Submitted That Met QC Criteria: July 30, 2019
• First Posted (Actual): August 1, 2019

Study Record Updates

• Last Update Posted (Actual): February 17, 2023
• Last Update Submitted That Met QC Criteria: February 16, 2023
• Last Verified: February 1, 2023

More Information

Terms related to this study

• Keywords: ICU; Pressure support ventilation; Trigger; Spontaneous breathing; Weaning of mechanical ventilation
• Additional Relevant MeSH Terms: Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Respiratory Aspiration
• Other Study ID Numbers: Trigger - RBHP 2018 GODET; 2018-A03307-48 (Other Identifier: ANSM)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No